THE W T KEENER CO MCOICAL BOOKStlXlKS. -/^ n DISEASES OF THE EYE. BY EDWARD NETTLESHIP, F.R.C.S., OPHTHALMIC SURGEON TO ST. THOMAS'S HOSPITAL ; SXJRGEOX TO THE ROYAL LONDON (MOORFIELDS) ophthalmic HOSPITAL ; LATE OPHTHALMIC SURGEON TO THE HOSPITAL FOR SICK CHILDREN, GREAT ORMOND STREET. FOURTH AMERICAN FROM THE FIFTH ENGLISH EDITION. WITH A CHAPTER ON EXAMINATION FOR COLOR-PERCEPTION. BY WILLIAM THOMSON, M.D., PROFBSSOR or OPHXnALMOLOGY IW THE JEFFEKSON MEDICAL COLLEGE OF PHILADELPHIA. PHILADELPHIA: LEA BROTHERS & CO 1890. \yOLC 2% Entered according to Act of Congress, in the year 1890, by LEA BROTHERS & CO., in the oflSce of the Librarian of Congress. All rights reserved. DORN AN, PRINT BR. TO JONATHAN HUTCHINSON, F.R.S., CONSULTING SURGEON TO THE MOORFIELDS OPHTHA.LMIC HOSPITAL AND TO THE LONDON HOSPITAL, ETC., THIS BOOK IS DEDICATED IN GRATEFUL ADMIRATION OF HIS EMINENT QUALITIES AS A CLINICAL TEACHER AND INVESTIGATOR. AMERICAN PUBLISHERS' PREFACE. In presenting to the medical profession the fourth American edition of Dr. Nettleship's work on " The Diseases of the Eye," the publishers desire to state that no pains have been spared to place it in every particular upon a level with the latest developments of the specialty of which it treats. In addition to a most thorough and careful revision by the author, comprising many important changes and additions, there has been inserted as a supplement the chapter from the previous edition upon the Detection of Color-blindness, from the pen of Dr. William Thomson, whose painstaking investigations upon this subject are widely known, and his methods generally adopted for the examination of railroad employes. Every care has been taken with the typography, and in all respects the publishers feel assured that the work will be found to merit in an increased degree the confidence awarded by the profession to the previous editions. Philadelphia, 1890. PREFACE TO THE FIFTH EDITION. The general work of revision and of correction for the press for the present edition has been carried out with much pains by Mr. Holmes Spicer. The bulk of the volume has been but little increased, though I have taken every care to include such new matter as seemed suitable for a book of this class, and considerable changes will be found, especially in the chapter on Opera- tions. The number of illustrations is the same as in the last edition; but Figures 9, 50, 53, 95, and 131 have been replaced by new cuts ; and for the colored papers of the former editions, there has been substituted, at the suggestion of the Publishers, a copy of Professor Holmgren's well- known plate, executed at Stockholm with the kind permission of the Professor. September, 1890, PREFACE TO THE FIRST EDITION. The aim of this little book is to supply students with the information thev most need on diseases of the eve durinsr their hospital course. It was apparent from the beginning that the task would be a difficult one, all the more as several excellent manuals, covering nearly the same ground, are already before the public. That not one of them singly appeared exactly to cover the ground most important for the first beginner in clinical ophthalmology encouraged me to attempt the present work. The scope of the work has precluded frequent reference to authors, those named being chiefly such as have made recent additions to our knowledge in this country. I am greatly indebted to Dr. Gowers, Dr. Barlow, and other friends for much information, and for many valuable suggestions. My best thanks are due to Mr. A. D. Davidson for his kind assistance in reading the sheets for the press. WiMPOLE Street : October, 1890. CONTENTS, PART I._MEAXS OF DIAGNOSIS. PAGE List of Abbreviations 25 CHAPTER I. Optical Outlines. Lenses and prisms ; Refraction of the eye, and conditions of clear vision ; Numeration of spectacle lenses ; Table showing the equivalent numbers of lenses made bv the inch scale and metrical scale respectively ...... 25-42 CHAPTER IL External Examination of the Eye. Examination of : (1) Surface of cornea ; (2) Tension of eye ; (3) Field of vision ; (4) Color-perception ; (5) Acuteness of sight ; (6) Accommodation ; (7) Pupils : (8) Color of iris ; (9) External bloodvessels of eye; (10) Mobility of eye and field of fixation ; (11) Squint of strabismus, apparent strabis- mus, measurement of strabismus; (12) Diplopia; (13) Ap- parent size of objects ; (14) Protrusion and enlargement of eye 43-62 CHAPTER III. Examination of the Eye by Artificial Light. (1) Focal or "oblique'" illumination. (2) Ophthalmoscopic examination ; Experiments showing indi- rect and direct methods ; Use of the ophthalmoscope. Indirect method ; Appearance of optic disc ; scleral ring, physio- logical pit, lamina cribrosa: of choroid: of retina: vessels, yellow 3pot,/oi-ea centralis. Xll CONTENTS. PAGE Direct method : Examination of vitreous ; Determination of re- fraction ; Table of relation between refraction and length of eye ; Examination of fine details by direct method. Retinoscopy (Keratoscopy) (33-S9 PART II.— CLINICAL DIVISION. CHAPTER IV. Diseases of the Eyelids. Blepharitis ; Stye ; Meibomian cyst ; Horns and warty forma- tions ; MoUuscum contagiosum ; Xanthelasma ; Pediculus pubis. Ulcers : Rodent cancer ; Tertiary syphilis ; Lupus ; Chancre. Congenital ptosis ; Epicauthus . . . 91-98 CHAPTER V. Diseases of the Lachrymal Apparatus. Epiphora, stillicidium lachrymarum, and lachrymation. Epiphora from alterations of punctum and canaliculus ; Dacryo- liths. Diseases of lachrymal sac and nasal duct ; Mucocele and lachry- mal abscess ; Stricture of nasal duct ; Lachrymal abscess in newborn infants ........ 99-104 CHAPTER VI. Diseases of the Coxjunctiva. General diseases : Purulent and gonorrhoeal ophthalmia ; Muco- purulent ophthalmia ; Catarrhal, and other forms of muco- purulent ophthalmia ; Membranous and diphtheritic oph- thalmia ; Atropine and eserine irritation ; Partial diseases: Granular ophthalmia, follicular conjunctivitis : Results of granular ophthalmia ; Pannus, distichiasis, and trichiasis, organic entropion ; Chronic conjunctivitis ; Amyloid dis- ease ; Spring catarrh ; Conjunctivitis from drugs ; Primary shrinkage of conjunctiva ...... 105-125 CONTENTS. Xlll CHAPTER VII. Diseases of the Cornea. PAGE A. Ulcers and non-specific inflammation. Appearances of the cornea in disease: "Steamy" and "ground-glass" cornea; Infiltration; Swelling; Ulcera- tion ; Nebula and leucoma. Symptoms in ulceration : Photophobia ; Congestion ; Pain. Clinical types of ulcer : Central ulcer of children ; Facet- ting ulcer ; Phlyctenular aS'ections ; Phlyctenular, or recur- rent vascular, ulcer. Marginal conjunctivitis. (Spring catarrh) ; Creseentic ulcer of old age ; Infective ulcers ; Ab- scess and suppurating ulcer ; Hypopyon ; Onyx. Treatment of ulcers of cornea. Conical cornea. B. Diffuse keratitis. Syphilitic keratitis. Other forms of keratitis : Keratitis punctata ; Corneal changes in glaucoma ; Buphthalmos (Hydrophthalmos) ; Calcareous film ; Arcus senilis ; Inflam- matory arcus ; Opacity from use of lead lotion ; Staining of conjunctiva or cornea from use of nitrate of silver 126-151 CHAPTER VIII. Diseases of the Iris. Iritis, symptoms : Muddiness and disccloration of iris ; Syn- echiae ; Corneal haze ; Ciliary congestion ; Pain ; Lymph nodules ; Hypopyon. Results of iritis. Causes : Syphilis ; Rheumatism ; Gout ; Sympathetic dis- ease ; Injuries and local causes ; Chronic iritis. Treatment of iritis. Congenital irideremia ; Coloboma ; Persistent pupillary mem- brane 152-163 CHAPTER IX. Diseases of the Ciliary Region. Episcleritis (or Scleritis), Sclero-keratitis, and allied diseases: Cyclitis (Irido-choroiditis, "Serous iritis"); Traumatic cyclitis (or Panophthalmitis). XIV CONTENTS. PAGE Sympathetic affections : Sympathetic irritation ; Sympathetic inflammation ; Treatment 164-177 CHAPTER X. Injuries op the Eyeball. Contusion and concussion injuries: Rupture of eyeball; Intra- ocular hemorrhage ; Detachment of iris ; Dislocation of lens ; Detachment of retina ; Rupture of choroid ; Paralysis of •iris and ciliary muscle ; Iritis ; Commotio retinse ; Trau- matic myopia. — Treatment of blows on eye ; Dislocation of lens ; Use of ice after injuries of eyeball. Surface wounds of eyeball : Abrasion and foreign body on cornea; Foreign body on conjunctiva. Burns and scalds ; Prognosis uncertain for some days : Lime- burn ; Serious results of severe burns. Penetrating wounds of eyeball : Slight cases ; Severe cases ; Traumatic cataract ; Cyclitis ; Foreign body in eye. Treat- ment. Rules as to the excision of wounded eyes. Electro- magnet for removing bits of iron .... 178-188 CHAPTER XI. Cataract. Senile changes in lens . Definition of cataract : General cataract : Nuclear and cortical, each may be hard (senile) or soft (juvenile) ; Con- genital. Partial cataract : Lamellar ; Pyramidal ; Ante- rior and posterior polar. Cataract following wound or con- cussion of eyeball. Dislocation of lens. Primary and secondary cataract. Symptoms and diagnosis of cataract. Prognosis before and after operation. Treatment: Palliative; Atropine. Radical: Extraction, Dis- cission or solution, Suction. Rules as to operating for cataract ; Artificial ripening of cataract ; Causes of failure after extraction ; Hemorrhage ; Suppuration of globe ; Iritis ; Prolapse of iris ; Influence of lachrymal disease. Sight after removal of cataract Treatment of lamellar cataract .... 189-209 CONTENTS. XV CHAPTER Xir. Diseases of the Choroid. PAGE Participation by the retina and the vitreous. Appearances in health ; Appearances in disease. Atrophy, pig- ment in choroid and retina ; Exudations, syphilitic, tuber- cular ; Rupture; ** Colloid" change ; Hemorrhages. Clinical forms of disease : Syphilitic choroiditis disseminata ; Myopic changes ; Central senile choroiditis ; Other forms. Coloboma; Albinism 210-225 CHAPTER Xlir. Diseases of the Retina. Appearances in health: Bloodvessels, yellow spot, and "halo" around it ; " Opaque nerve-fibres." Appearances in disease : Congestion; Retinitis, (1) Diffuse, (2) and (3) Localized, with white spots and hemorrhages, (4) Solitary patch. Hemorrhage; Pigmentation; Atrophy; Disc in Atrophy of retina ; Detachment. Clinical forms of disease : Syphilitic retinitis ; Albuminuric ; Hemorrhagic ; Retinitis apoplectica and large single hemor- rhages ; Embolism and thrombosis ; Retinitis pigmentosa ; Retinitis from intense light ...... 226-247 CHAPTER XIV. Diseases of the Optic Nerve. Relation between changes at the Disc, disease of the Optic Nerve, and affection of Sight. Pathological changes in optic nerve. Appearances of optic disc in disease : Inflammation, optic neuritis, papillitis, or choked disc ; Atrophy after papillitis ; Papillo-retinitis. Etiology of papillitis. Retro-ocular neuritis ; Syphilis causing papillitis. The pupils in neuritis. Atrophy of disc : Appearances and causes ; Clinical aspects ; State of sight, field of vision, and color-perception ; A. Double atrophy ; C. Single atrophy . . . 248-263 XVI CONTENTS. CHAPTER XV. Amblyopia axd Functional Disorders of Sight. PAGB "Amblyopia" and "Amaurosis:" Single amblyopia: From suppression or congenital defect ; from defective images ; from retro-ocular neuritis. Double amblyopia : Central am- blyopia (Tobacco amblyopia). Hemianopia ; Hysterical amblyopia and Hypersesthesia oculi ; Asthenopia. Functional disorders of vision ; Endemic nyctalopia ; Snow and Electric-light blindness. Hemeralopia ; Colored vision ; Micropsia ; Muscse volitantes ; Diplopia ; Malingering ; Color-blindness 264-280 CHAPTER XVI. Diseases of the Vitreous Humor. Usually secondary to other diseases of eye. Examination for opacities : Cholesterine ; Blood ; Blood- vessels in vitreous ; Cysticercus. Conditions causing disease of vitreous : Myopia ; Blows and wounds ; Spontaneous hemorrhage ; Cyclitis, choroiditis, retinitis ; Sympathetic disease ..... 281-285 CHAPTER XVII. Glaucoma. Primary and secondary. Primary glaucoma : Premonitory stage ; Chronic or Simple ; Subacute ; Acute ; Absolute. Ophthalmoscopic changes ; Cupping of disc. Symptoms explained ; Mechanism. General and diathetic causes ; Treatment ; Prognosis. Secondary glaucoma ; Conditions causing it . . . 286-306 CHAPTER XVIII. Tumors and New-growths. A. Of the conjunctiva and front of the eyeball. Cauliflower wart ; Lupus ; Syphilitic tarsitis ; Pinguecula ; Pterygium ; CONTENTS. XVll PAGE Lymphatic cysts ; Dermoid tumor ; Episcleritis simulating tumor ; Fibro-fatty growth ; Cystic tumors ; Fibrous and Bony tumors ; Epithelioma ; Sarcoma. B. Intra-ocular tumors. Glioma of retina ; Pseudo-glioma. Sarcoma of choroid ; Tubercular tumor of choroid. Tumors of iris : Sarcoma ; Sebaceous tumor ; Cysts ; Granuloma. 307-316 CHAPTER XIX. Lnjl'ries, Diseases, and Tumors of the Orbit. Contusion and concussion injuries: Emphysema of orbit; Traumatic ptosis. Abscess and cellulitis of orbit ; Inflammation and abscess of lachrymal gland. Wounds : Of eyelids ; of orbit ; Large foreign bodies in orbit. Tumors of orbit. General symptoms : Distention of frontal sinus ; Ivory exostosis ; Tumors growing from parts around the orbit ; Pulsating exophthalmos ; Cystic tumors ; Solid intra-orbital tumors. Naevus. Dermoid tumor in eye- brow 317-325 CHAPTER XX. Errors of Refraction and Accommodation. Emmetropia ; Ametropia. Myopia. Symptoms : Insufficiency of internal recti. Pos- terior staphyloma and crescent ; Other complications. Tests for. Causes. Measurement of degree. Treatment ; Spec- tacles ; Tenotomy. Hypermetropia. Symptoms : Accommodative asthenopia, Con- vergent strabismus. Tests for hypermetropia ; Treatment ; Spectacles ; Treatment of the strabismus. Astigmatism. Regular and irregular ; Seat ; Focal interval ; Cylindrical lenses ; Forms of regular astigmatism ; Detec- tion and measurement ; Spectacles. Unequal refraction in the two eyes (Anisometropia). Presbyopia : Rate of progress ; Treatment : Range and region of accommodation in E., M., and H. . . . . 326-362 XVin CONTENTS. CHAPTER XXI. Strabismus and Paralysis. PAGE Definition of strabismus ; Diplopia ; True and false image ; Homonymous and crossed diplopia ; Suppression of false image. Causes : Strabismus from Over-action ; from Weakness ; from Disuse ; from Weakness following tenotomy ; from Paraly- sis. Paralysis of Sixth nerve (external rectus) ; of Fourth nerve (superior oblique) ; of Third nerve ; Ophthalmoplegia ex- terna. Primary and secondary strabismus ; Giddiness in paralytic strabismus. Affections of Internal muscles of eye: Physiology and action of drugs on the Internal Muscles ; Affections of Pupil alone ; of Accommodation alone ; of Pupil and Accom- modation ; Ophthalmoplegia interna. Causes of external ocular paralyses : Syphilitic growths ; Meningitis ; Tumors ; Rheumatism. Causes of internal ocular paralyses. Treatment. Nystagmus 3(53-380 CHAPTER XXII. Operations. A. On the eyelids. Epilation ; Eversion of lid ; Meibomian cyst ; Inspection of cornea ; Spasmodic entropion ; Organic entropion and trichiasis ; Ectropion ; Blepharoplasty ; Ptosis ; Cantho- plasty ; Peritomy ; Symblepharon. B. On the lachrymal apparatus. Lachrymal abscess ; Slitting canaliculus ; Stricture of nasal duct, (1) Probing, (2) Incising, (3) Syringing. C. For strabismus. Tenotomy : Graefe's : Critchett's ; Liebreich's. Re- adjustment and Advancement. D. Excision of the eye and alternative operations. Abscission, Optico-ciliary Neurotomy, Evisceration, Stretching Infra-trochlear nerve. E. On the cornea. Foreign body ; Paracentesis ; Corneal section for ulcer ; Conical cornea. CONTENTS. Xix On the ins. Iridectomy : For artificial pupil ; for glaucoma. Irido- desis ; Iridotomj (iritomyj. Sclerotomy. For cataract. Extraction: Linear; (rraefe's -'modified linear;" Short flap ; Corneal section ; Old flap. Complications during extraction. Treatment after extraction. Secondary opera- tions. Discission or Solution ; Suction. Treatment after solution and suction. Anaesthesia in Ophthalmic Surgery .... 381-428 PART III.— DISEASES OF THE EYE IX RELA- TION TO GENERAL DISEASES. CHAPTER XXIII. A. General Diseases. Eye diseases caused by : Syphilis, acquired and inherited, diseases of optic nerve and oculo-motor nerves in relation to syphilis ; - Smallpox ; Scarlet fever, typhus, etc. ; Diphtheria ; Measles ; Mumps ; Chicken-pox and whooping-cough ; Malarial fevers ; Relapsing fever ; Epidemic cerehro-spiual menin- gitis ; Purpura and scurvy ; Pyaemia and septicaemia ; Lead- poisoning ; Alcohol ; Tobacco ; Bisulphide of carbon ; Qui- nine ; Kidney disease : Diabetes ; Leucocyth^mia ; Perni- cious anaemia ; Heart disease ; Tuberculosis ; Rheumatism and gonorrhoea! rheumatism ; Gout, personal and inherited ; Struma ; Entozoa ••...... 447 B. Local Disease at a Distaxce from the Eye. Eye symptoms caused by : Megrim ; >'euralgia and sympathetic disease ; Diseases of brain ; Cerebral tumor ; Syphilitic dis- ease ; Meningitis ; Cerebritis ; Hydrocephalus ; Diseases of spinal cord : Myelitis ; Locomotor ataxy. General paralysis of insane. L.iteral and insular sclerosis. Motor disorders of eyes and affections of the pupils in cerebral and spinal disease. Convulsions in relation to imperfections of teeth and lens. 447-454 XX CONTKNTS. c. The Eye Shaking i>- a Locai, Disease of the Neighboring Parts. PAGE Eye symptoms caused by : Herpes zoster of fifth nerve ; Paralysis of fifth, of facial, and of cervical sympathetic nerves ; Exoph- thalmic goitre ; Erysipelas and orbital cellulitis . . 454-457 The teeth in inherited syphilis ....... 457 [SUPPLEMENT. Examination for Color-perception. Instructions for examination of railway employes as to vision, color-blindness, and hearing : Acuteness of vision ; Range of vision ; Field of vision ; Color-sense ; Hearing ; Expla- nations 461-473] APPENDIX. Formulae ........... 475 Shades. Protective glass ........ 487 Test-types, etc 488 Ophthalmoscopes ......... 488 Perimeters .......... 490 Tests for color-blindness ........ 490 Index 493 PART I. MEANS OF DIAGXOSIS. The following abbreviations wi 1 be used in this work : T. Tension of the eyeball. cm. Centimetre. E. Emmetropia. mm. Millimetre. M. M3-opia. D. Dioptre, the unit in the H. H)-perinetropia. metrical system of meas- m. H. Manifest hypermetropia. uring lenses ; a lens 1. H. Latent hypermetropia. whose focal length is 1 m. Pr. Presbyopia. y. s. Yellow spot of the retina. As. Astigmatism. b. D. Optic disc. Ace. Accommodation. F. Field of vision. P- Piinctum proximum near point. or V. Visus, acuteness of sight, power of distinguishing r. Punctum remotissimum or form. far point. Symboh. + A convex, — a cou- p.l. Perception of light. cave, lens. 'Foot, Inch, P. Pupil. "Line. m. Metre. CHAPTER I OPTICAL OUTLINES. 1. Rays of light are deviated or refracted when they pass from one transparent medium, e. g., air, into another of different density, e. g., water or glass. 2. If the deviation in passing from vacuum into air be represented by the number 1, that for crown-glass, of which ordinarv lenses are made, i? 1.5, and for ror-k crvstal, 26 OPTICAL OUTLINES. "pebble" of opticians, 1.66. Such a number is the "re- fractive index" of the substance. Every ray is refracted except the one which falls perpendicularly to the surface, Fig. 1, a. FiG.l. Tjmm^^m^^^^^^^^m^^^^Bm*. Refraction by a medium ^vith parallel sides. 3. In passing from a less into a more refracting medium the deviation is always toward the perpendicular to the refracting surface ; in passing from a more into a less refracting medium it is always, and to the same extent, away from the perpendicular, Fig. 1, h\ i.e., the angle x in the figure = the angle y. Fig. 2. Refraction by a prism. 4. Hence, if the sides of the medium, Fig. 1, m, be par- allel, the rays on emerging (6') are restored to their original OPTICAL OUTLINES. 2Y direction (b) and, if the medium be thin, very nearly to their original ^ja^/i. 5. But if, as in a prism, the sides of m form an angle, Fig. 2, a, the angles of incidence and emergence, x and y, still being equal, 6' must also form an angle with b. The Fig. 3. Apparent displacement of object by a prism. angle a is the ''refracting angle" or edge of the prism ; the opposite side is the "base." The figure shows that light is always deviated toward the base. The deviation, shown by the angle d, is equal to about half the refracting Fig. 4. Refraction the same for different angles of incidence. angle a if the prism be of crown-glass. The relative direc- tion of the rays is not changed by a prism ; if parallel or divergent before incidence, they are parallel or similarly divergent after emergence. Fig. 3. 28 OPTICAL OUTLINES. 6. An object seems to lie, or is "projected," in the direction which the rays have as they enter the eye; ob, Fig-. 3, seen by an eye at a' or 6', seems to be at o'b, where it would be if the rays a' b' had undergone no deviation. 7. For very thin prisms the deviation, a and j8, Fig. 4, remains the same for varying angles of incidence. For thin lenses this is expressed b}^ saying that the angle d, Fig. 5, is the same for the rays a a', b b', and c c' , inci- FiG. 5. Refraction by a thin lens the same for all rays incident at the same distance from the axis. dent at different angles, but at the soAne distance from, the axis. 8. An ordinary lens is a segment of a sphere, plano- convex or plano-concave, or of two spheres whose centres are joined by the axis of the lens, biconvex or biconcave. 9. A lens is regarded as formed of an infinite number of minute prisms, each with a different refracting angle. Fig. G shows two such elements of a convex lens, the angle (a) of the prism at the edge of the lens being larger, and therefore, in accordance with § 5, refracting more, than j3, the angle of the prism near the axis. If tw^o parallel rays, a and 6, traverse this system, a will be more refracted than b, and the ravs will meet at f. Fiu'. 7 shows the cor- OPTICAL OUTLINES. respouding facts for a concave lens, by which parallel rays are made divergent. Fig. 6. Prismatic elements of a convex lens. Fig. 7. Prismatic elements of a concave lens. 10. The only ray not refracted by a lens is the one passing thronghthe centre of each surface; compare §2, which is the principal axis, ax, Fig. 8. Secondary axes are Fig. 8. Axes of a lens. rays, such as s. ax, entering and emerging at points on the lens parallel to each other, and hence, see § 4, not altered in direction : all rays which pass through the central 30 OPTICAL OUTLINES, point of the lens are secondary axes, except the principal axis. 11. The principal focus, /, Fig. 10, of a lens is the point where the rays, a a, that were parallel before they trav- ersed the lens meet, after they have passed through it ; the deviation of each ray varying directh^ with its distance from the principal axis. Fig. 6. But this is only approximately true. In an ordinary lens the rays, a, Fig. 9, which traverse the margin are refracted Fig. 9. Spherical aberration. more, and meet sooner, than the rays [h) which lie nearer the axis ; and the result is, not one focus, but a number of foci. Fig. 10. Foci of a couvex lens. " Spherical aberration" increases with the size of the lens. In the eye it is, to a great extent, prevented by the iris, which cuts off the light from the margin of the crystalline lens. OPTICAL OUTLINES. 31 If parallel rays are incident from the side toward/, Fig. 10, they will be focussed at f , at the same distance from the lens as /; hence every lens has two principal foci — anterior and posterior. 12. The path of a ray passing from one point to another is the same, whatever its direction ; the path of the ray h h\ Fig. 10, is the same, whether it pass from cf to c'f, or in the contrary direction. 13. From § 7 it follows that in Fig. 10 the angles a and a' are equal, and hence the ray 6, diverging from cf, will not meet the axis at f, but at c'f ; cf and cf are conju- gate points, and each is the conjugate focus of the other. The angle a or a.' remaining the same, then if cf be fur- ther from the lens cf will approach it. A ray, c, directed toward the axis will be focussed at c"f", because the angle a"=za ; no real point conjugate to c'f' exists : but if the ray start from c"f" it will, on taking the direction c, appear to have come from vf, which consequently is the virtual focus of c"f", see § 6. Fig. 11. Foci of a coucave lens. 14. All the foci of concave lenses are virtual. In Fig. 11, a, parallel to the axis, is made divergent, see Fig. 7, its virtual focus being at /; similarly cf is the virtual con- jugate focus of the point emitting the ray h. 15. In equally biconvex or biconcave lenses of crown- glass the principal focus, f, is at the centre of curvature of 32 OPTICAL OUTLINES. cither surface of the lens, ?'. e.,f=:r, the radius; in jdauo- convcx, or concave, lenses /"=2r. 16. Images The image formed by a lens consists of foci, each of which corresponds to a point on the object. Given the foci of the boundary points of an object, we have the position and size of its image. In Fig. 12 the object ah lies beyond the focus/. From the terminal point a take two rays, a and a', the former a secondary axis, and therefore unrefracted ; the latter par- Fia. 12. Real inverted image formed by a convex lens. allel to the princi})al axis, and therefore passing after re- fraction through the principal focus /^ These two rays, and all others which pass through the lens from the point a, will meet at a the conjugate focus of a. Similarly the focus of the point h is found, and the real inverted conju- gate image of a 6 is formed at a b. The relative sizes of a h and a b vary as their distances from the lens. If a b be so far off that its rays are virtually parallel on reaching the lens, its image a b will be at/', and very small. Ifaftbeat/, its rays will become parallel after refraction, §§11 and 12, and form no image. \i a b lies between/, or/^ and the lens, the rays will diverge after refraction, and again will not form an image, see Fig. 10, c"/". OPTICAL OUTLINES. 33 But in the last two cases a virtual image is seen by an eye so placed as to receive the rays. In Fig. 13 two rays from a take after refraction the course shown by a and a', virtually meeting at A, see Fig. 10, vf\ and an observer at X will see at a b a virtual^ magnified, erect image of a b. Fig. 13. Virtual erect image formed by a convex lens. The enlargement in Fig. 13 is greater the nearer a 6 is to /', and greatest when it i< at/'. But as A b has no real existence, its apparent size varies with the known or estimated distance of the surface against which it is pro- jected. A uniform distance of projection of about 12'' (30 cm.) is taken in comparing the magnifying power of different lenses. When a 5 is at /', Fig. 13, we shall find on trial that the image a b can be seen well only by bringing the eye close up to the lens ; at a greater distance only part of the image will be seen, and this part will be less brightly lighted. This is important in direct ophthalmoscopic ex- amination. Thus in Fig. 14 an observer placed anywhere between the lens and .r, receivins- rays from every part of a b, will see the whole image. But if he withdraw to y, his eye will receive rays only from the central part of a b, and will therefore not see the ends of the object. It is easily shown by similar constructions that the 9* 34 O P T 1 C A L U T L 1 N E S . images formed by concave, lenses are always virtual, erect, and diminished, whatever the distance of the object, Fig. 15. Compare Y\g. 11. Fig. U. Virtual image ; result of observer varying distance oi his eye from the lens. 17. The size of the image, w^hether real or virtual, varies with (1) the focal length of the lens, and (2) the distance of the object from the principal focus. (1) The shorter the focus of the lens, the greater is its effect, or the " stronger" it is ; the refractive power of a lens varies inversely as its focal length. Fig. 15. Image formed by a concave lens. (2) For a confer lens, the image, whether real or virtual, is larger, i. e., the effect greater, the nearer the object is to the principal focus, whether within or beyond it. For a concave lens, the image is smaller, i. e., the effect greater, the further the object is from the lens, w^hether within or beyond the focus. OPTICAL OUTLINES. 35 18. Prisms. — Any object viewed through a prism seems dis^placed towards the edge of the prism, and the amount of the displacement varies directly as the size of the refracting angle, §§ 5 and 6. The eye is directed towards the position which the object now seems to take; and this Fig. Fig. 17. Effect of prisms in lessening: convergence. Lenses acting as prisms. effect may be variously utilized: 1. To lessen the conver- gence of the visual lines without removing the object further from the eyes. In Fig. 16 the eyes, r and l, are looking at the object, ob, wath a convergence of the visual lines represented by the angle a. If prisms be now added with their edges towards the temples, they deflect the light, so that it enters the eyes under the smaller angle jS, as if it had come from o6', and towards this point the eyes will be directed, though the object still remains at ob. The same eff'ect is given by a single prism of twice the strength before one eye, though the actual movement is 36 O P T T C A L i: T L I N E S . then limited to the eve in question. If spectacle lenses be placed so that the visual lines do not pass throuprh their centres, they act as prisms; though the strength of the prismatic action varies with the power of the lens and the amount of this " decentration," ^ee § 9, Figs. 6 and 7. Table shoioing the Prismatic Effect of Decenlering Lenses {Maddox). Amount of Decentration in Millimetres. Lens. .5 mm. 10 mm. 15 mm. 1 D . 17' 35' 52' 2 D . . 35 1° 9 1° 43 3 D . 52 1 43 2 34 4 D . . 1- 10 2 18 3 26 ^^ D . . 1 43 6 26 5 9 8 I) . .... 2 18 4 35 6 50 In Fig. 17 the visual lines pass outside the centres of the convex lenses, a, and inside those of the concave lenses, b. Each pair therefore acts as a prism with its edge outwards. 2. To remove double vision caused In* slight degrees of strabismus. The prism so alters the direction of the rays as to compensate for the abnormal direction of the visual line. In Fig. 18, r is directed towards j; instead of towards ob, and two images of ob are seen, see Chapter XXI. The prism, p, deflects the rays to y, the yellow spots, and single binocular vision is the result. 3. To test the strength of the ocular muscles. In Fig. 19 the prism at first causes diplopia by displacing the rays from the yellow spot, ?/, of ihe eye k, see Chapter XXI. By a compensating rotation of the eye, cornea, outwards, shown in th^ figure by the change of the tran.sverse axis from 1 to 2, y is brought inwards to the situation of im, the images are fused and single vision restored ; the effect of the prism is overcome b}- the action OPTICAL OUTLINES. 37 of the external rectus. This " fusion power " of the several pairs of muscles may be expressed by the strongest prism that each pair can overcome. The fusion power of the two external recti is represented by a prism of about 8° ; that of the two internals bv 25° to 50° or more ; that of the Fig. 18. Fig. 19. Diplopia removed by prism. Prism used for testing strength of muscle. superior and inferior recti, acting against each other, by only about 3°. 4. Feigned hlindneas of one eye may often be exposed by means of the diplopia, unexpected by the patient, produced by a prism. The prism should be stronger than can be overcome by any effort, e. g., 8° or 10°, base upwards or downwards. The patient is best thrown off his guard if the prism be held before the sound eye. If he now exclaims that he sees double, he must of course be seeing with both eyes. 38 OPTICAL OUTLINES, 19. Refraction of the eye The eye presents three re- fracting surfaces — the front of the cornea/ the front of the lens, and the front of the vitreous ; and in the normally formed or emmetropic eye (E.), with the accommodation relaxed, the principal focus, § 11, of these combined diop- tric media falls exactly upon the layer of rods and cones of the retina ; i. e., the eye in a state of accommodative rest is adapted for parallel rays The point at which the secondary axial rays, see § 10, Fi;^. 8, cross, the " porterior nodal point," v, Fiir. 20, lies, in the normally formed eye, at 15 mm. in front of the yellow spot of the retina, and Fig. 20. Visual angle and retinal image. 06, object ; y, visual angle ; «, nodal point where the axial rays cross ; d, distance from n to the retina. The position of the retina in different states of refraction is shown by the three curved lines to the right, H. being represented by the line nearest to, and N. by the one furthest from, w, whilst the middle thin line shows the retina in E. very nearly coincides with the posterior pole of the crys- talline lens. The angle included between the lines joining n with the extremities of the object, o6, is the visual angle, v. If the distance, d, from n to the retina remain the same, the size of any image, Ini, on the retina will depend on the ' The posterior surface of the cornea being parallel with the anterior causes no deviation, and the aqueous has the same refractive power as the cornea. Hence the refractive effect of the cornea and aqueous to- gether is the same as if the corneal tissue extended from the front of the cornea to the front of the lens. O P T I C A L O U T L I N E S . 39 size of the angle u, and this again on the size and distance of 06. But if the distance, d, alters, the size of the image, Im, is altered without any change in v. Now the length of d varies with the length of the posterior segment of the eye ; it is greater in myopia (M.) and less in hypermetropia (H.) ; and hence the retinal image of an object at a given distance is, as the figure shows, larger in myopia and smaller in hypermetropia than in the normally formed eye. The length of d also varies with the position of n, and this is influenced by the positions and curvatures of the several refractive surfaces, n is slightly advanced by the increased convexity of the lens during accommodation, and much more so if the same change of refraction be induced by a convex lens held in front of the cornea : hence convex lenses, by lengthening c/, enlarge the retinal image. Concave lenses put n further back, and, by thus shortening d, lessen the image. If the lens w^ich corrects any optical error of the eye be placed at the " anterior focus" of the eye,' 13 mm., or half an inch, in front of the cornea, n moves to' its normal distance (15 mm.) from the retina, whatever the length of the eye, and the images are therefore reduced or enlarged to the same size as in the emmetropic eye. For definition of astigmatism see Chapter XX. The length of the visual axis, a line drawn from the yellow spot to the cornea in the direction of the object looked at, is about 23 mm. The centre of rotation of the eye is rather behind the centre of this axis, and 6 mm. behind the back of the lens. The focal length of the cornea is 31 mm., and that of the crystalline lens varies from 43 mm. with accommodation relaxed, to 33 mm. during strong accommodation. The optical conditions of clear sight are as follows : (1) The image must be clearly focussed on the retina, i e., the retina must lie exactly at the focus of the rays 1 The anterior focus is the point where rays which were parallel in the vitreous are focussed in front of the cornea. 40 OPTICAL OUTLINES. whicli proceed from the object looked at: (2) it must he formed at the centre of the yellow spot, Chapter II,, § 11: (3) it must have a certain size, and this is expressed by the size of the corresponding visual angle, v, Fig. 20 ; with good iudoor light v must be equal to at least 5 minutes, j^^th of a degree, in order that the form of the image may be perceived ; an object subtending any smaller angle, down to about 1 minute, is still visible, though only as a point of light:^ (4) the cornea, lens, and vitreous must be clear: (5) the illumination must be sufficient. Influence of the piqnl : Other things being equal, the larger the pupil the worse is the sight, definition being lessened by the spherical aberration caused by the marginal part of the lens. Fig. 9. See Artificial Pupil. The smaller the pupil, the less the spherical aberration (p. 30), and, ccet. par., the better the V. Also, the smaller the pupil tlie less is the accommodation needed for near vision. If the pupil be so small as to subtend an angle, "angle of diver- gence," of not more than 5 minutes with any point on the object, the object will be clearly seen without accommodation. By calculation it appears that if the pupil had a diameter = 0.66 mm., it would subtend an angle of divergence of 5 minutes at about 0.5 m. (18"); i. e., with a pupil of 0.66 mm. print should, in a good light, be clearly seen at 18'' without any accommodation. That this is true may be proved by looking at fine print through a hole of the above size in a thin card held as close as possible to the eye. Numeration of spectacle lenses. — Some system of num- bering is required w^hich shall indicate the refractive power of the lenses used for spectacles. Two systems are current. In the first system, which was till lately universal, the unit of strength is a strong lens of f focal length. As all the lenses used are weaker than this, their relative strengths can be expressed only by using fractions. Thus, a lens of 1 In bright light, as in the open air, the minimum visual angle is coiisiderahlv less than 5 minutes. OPTICAL OUTLINES. 41 2'' focus, being half as strong as the unit (§17, 1), is ex- pressed as -^ ; a lens of 10^' focus is J^ ; of 20^' focus ^V 5 and so on. The objections are, that fractions are incon- venient in practice ; that the intervals between the succes- sive numbers are very unequal ; and that the length of the inch is not the same in all countries, so that a glass of the same number has not quite the same focal length when made by the Paris, English, and German inches respect- ively.^ In the second system, which has almost displaced the old one, the metrical scale is used, the unit is a weak lens of 1 metre (100 cm.) focal length, known as a dioptre (D), and the lenses differ by equal refractive intervals. A lens twice as strong as the unit, with a focal length of half a metre, 50 cm., is 2 dioptres (2 D), a lens of ten times the strength, or one-tenth of a metre focus, 10 cm., is 10 D, and so on. The weakest lenses are 0.25, 0.5, and 0.T5 D, and numbers differing by 0.5 or 0.25 D are also introduced between the whole numbers. A slight inconvenience of the metrical dioptric system is that the number of the lens does not express its focal length. This, however, is ob- tained by dividing 100 by the number of the lens in D ; thus the focal length of 4 D = ^l'= 25 cm. If it be desired to convert one system into the other, this can be done, pro- vided that we know what inch was used in making the lens whose equivalent is required in D. The metre is equal to about 37^' French and 39'' English or German ; a lens of :i6'' French (No. 36 or Jg old scale), or of 40'' English or German (No. 40 or J^), is very nearly the equivalent of 1 D. A lens of 6" French {^=z^%) will therefore be equal to 6 D; alensof 18"French(Jg=r32e) = 2 D, etc.; a lens of 4 = 3%=^, i. e., a lens of 9" French, etc. The following lenses are used for spectacles, and are, therefore, necessary in a complete set of trial glasses. The ^ 1" English = 25.3 mm., 1'' Frenc]i=2T mm., 1" Austrian =26.3 mm.. 1" Prussian = 26.1 mm. 42 OPTICAL OUTLINES first column gives the number in D, the second the focal length in centimetres, the third the approximate numbers on the French inch scale, the denominator of each fraction showing the focal length in French inches. It will be seen that some metrical lenses have no exact equivalents on the inch system. In this table, and throughout the book, con- vex lenses are indicated, according to custom, by the -f sign ; concave lenses by the — sign. Prisms are numbered by their angle of refraction, which is (p. 27) about double the angle of deviation; another method is to name the prism by the number of degrees of deviation which it produces ; to indicate that degrees of deviation are meant the letter d should be used ; thus prism 2° d indicates that the prism produces a deviation of 2° (Maddox). Prisms cannot be used as spectacles of a greater strength than about 4° d in each eye on account of the dispersi3n of light which they produce. 1. 2. 3. 1. 1 2. 3. D. Focal No. and D. Focal No. and (Dioptres.) Length in Focal Length : (Dioptres.) Length in Focal Length cm. in Paris inches. ! cm. in Paris inches. 0.25 400 5 20 1 T 0.5 200 tV 5.5 18 0.75 133 sV 6 16 i 1 100 3V 7 14 hi 1.25 80 sV 1 8 12.5 1.5 66 ^v i 9 11 i 1.75 57 ] 22 10 10 sX 2 50 tV i il 9 2.25 44 tV i 12 8.3 JL 3 2.5 40 A 13 7.7 2.75 36 t'3 14 7 hi 3 33 tV 15 6.7 2% 3.5 28 tV 16 6.2 hA 4 25 i 18 5.5 4.5 22 I 20 5 CHAPTER II. EXTERNAL EXAMINATION OF THE EYE. (1) To detect irregularity of the corneal surface, the patient faces the window and follows with his eyes an object, e. g., the uplifted finger, held about 18'^ from him and moved slowly in different directions. The image of the window reflected from the cornea will become distorted or broken as it passes over any irregularity, such as an abrasion or ulcer. (2) To estimate the tension of the eyeball (T.) : The patient looks steadily down and gently closes the eyelids ; the observer then makes light pressure on the globe through the upper lid, alternately with a finger of each hand as in trying for fluctuation, but much more deli- cately. The finger-tips are placed very near together, and as far back over the sclerotic as possible, not over the cornea. The pressure must be gentle, and be directed vertically doicnicards, not backwards. It is best for each observer to keep to one pair of fingers, not to use the index at one time and the middle finger at another. Patient and observer should always be in the same relative position, and it is best for both to stand and face one another. Alwayscompare the tension of the two eyes. Be sure that the eye does not roll upwards during examination, for if this occur a wrong estimate of the tension may be formed Some test both eyes at once with two fingers of each hand. Normal tension is expressed by T. n. Recognizable in- crease and decrease are indicated by the -|- or — sign, followed by the figure 1, 2, or 3. Thus T.-fl means de- cided increase ; T.-|-2, greater increase, but eye can still be indented ; T.-|-3, eye very hard, cannot be indented by 44 EXTERNAL EXAMINATION OF THE EYE. moderate pressure ; T. — 1 — 2 — 3 indieate suceessivo de- grees of lowered tension. A note of interrogation (T.?-|- or ? — ) for doubtful eases, and T. n. for normal, give nine degrees which may be usefulh^ distinguished. Even good observers sometimes differ as to the minor changes of ten- sion. Apart from variations in delicacy of touch, it is to be remembered that eyes deeply set in the orbits are more difficult to test, and that T. in a few cases really does change at short intervals, e. g., within half an hour. In- crease in the rigidity of the sclerotic, which often occurs in old age ; or in its thickness, as the result of disease, may increase the apparent tension, though the internal pressure may be normal or even too low. When an eye contains bone it feels like wood covered with w^ash-leather.^ (3) The field of vision (F.), properly, of indirect vision, is the entire surface from which, at a given distance, light reaches the retina,^ the eye being stationary. Fig. 21. If each part of the field be equidistant from the part of the retina to which it corresponds, the field will be hemispher- ical, with its inner or concave surface towards the eye ; it may, however, be projected on to a flat surface, and for many clinical purposes this is sufficient. For roughly test- ing the field, e. g., in a case of chronic glaucoma, or of atrophy of optic nerve, or of hemianopsia, the following is generally enough. Place the patient with his back to the window ; let him cover one eye, and look steadily at your eye or nose, as a centre, from a distance of 18'^ or 2'. Then hold up your hands with your fingers spread out in a plane with your face, and ascertain the greatest distance from the central point at which they remain visible vrhen moved ^ Plates of bone, sometimes joined so as to form a cup, are not uncom- monly found on the inner (retinal) surface of the choroid in eyes which have been long blind from irido-choroiditis. ■^ Strictly " the percipient part of the retina." It now seems estab- lished that the most peripheral zone of the retina is not sensitive to light. (Landolt.) EXTERNAL EXAMIXATION OF THE EYE. 45 in various directions — up, down, in, out, and diagonally. The patient must look steadily at the face, and not allow his eye to wander after the moving fingers. Fig. 21. Field of vision with radius of 12", projected up to 45° on to a flat surface two feet square, f, fixation spot. A more exact method is to make the patient gaze, with one eye covered, at a white mark, the " fixation spot," on a large blackboard at a distance of \2" or 18^', and to move a piece of white chalk set in a long black handle, from various parts of the periphery towards the fixation spot, until the patient exclaims that he sees something white. If a mark be made on the board at about eight such peri- pheral points, a line joining them will give, with fair accu- racy, the boundary of the visual field if this be not larger than 45^ in any direction; but beyond that angle the object, if on a flat surface, will be much too far from the eye to make the test accurate, see Fig. 21. A true map, unless the field be much contracted, can be made only by means of an instrument, the perimeter, which consists essentiallv of an arc marked in degrees, and movable 46 EXTERNAL EXAMINATION OF THE EYE. around a central pivot on which the patient fixes his gaze. Thus measured the field covers a somewhat oval portion of the hemisphere, the smaller end being upwards and in- wards, Fig. 22. From the fixation point it extends 90° or Fig. 22. Field of vision of right eye as projected b}' the patient on the inner surface of a hemisphere, the pole of which forms the object of regard (half-diagrammatic). T. temporal, N, nasal side, w, boundary for white B, for blue ; r, for red ; g, for green. (Landolt.) more in the outward direction, but only about 65° or rather less inwards, upwards, and downwards. The visual fields of the two eyes overlap only at their inner and central parts, so that binocular vision is impossible in the outer part of the field, Fig. 23. (4j Color-perception is best expressed by the power EXTERNAL EXAMINATION OF THE EYE. 47 of discriminating between various colors without naming them. The best test-objects are a series of skeins of colored wool, or, for pocket use, smaller strips of colored paper, or colored stuffs A color-blind person will expose his defect by placing together, or "confusing" as similar, certain colors, usually mixed tints, which to the normal eye appear quite different. The set of wools now in com- mon use was introduced by Professor Holmgren, of Upsala.^ Fig. 23. Binocular field of vision. The white part is the portion common to the two eyes, i. e , possessing binocular vision ; the shaded (temporal) part shows the portion in which binocular vision is wanting. F, fixa- tion point. The two blind spots are marked by round spots. (Simpli- fied, after FiJrster.) See Appendix. Acquired color-blindness (from atrophy of the optic nerves) may often be detected quite well by asking the names, if the patient has been well trained in colors. But for the congenitally color-blind the " confu- sion test," without names, is far better : first, because such persons can often distinguish ordinary colored objects from one another by differences of shade, i. e., by differences in the quantity of white light which they reflect, and hence they escape detection unless tested with a large series of different colors in many shades, some of which shades, con- taining equal quantities of white, will look, to them, exactly 1 De la Cecite des Couleurs, etc., 1877. 48 EXTERNAL EXAMINATION OF THE EYE. alike; and secondly, though such persons often use the names for colors freely, the words do not convey the same meaning' to them as to those with normal color-sense, and hopeless confusion results from an examination so made. For details see Chapter XY. and Supplement. (5) Testing- the acuteness of sight By acuteness of sight (Y. or S.) is meant the power of distinguishing/orm, and, as commonly used, the term refers only to the centre of the visual field, the peripheral part of the retina having a very imperfect power of distinguishing form and size. Y. varies considerably in different persons whose eyes are normal. It is said to diminish some w'' at in old age, with- out disease of the eye (Donders) The standard taken as normal is the power of distinguishing square letters that subtend a visual angle of 5 minutes, Fig. 20 and p. 40, the limbs of which are of uniform thickness, each limb subtending an angle of 1 minute (Snellen's Test-types). Rays forming so small an angle are very nearly parallel, and may be considered as coming from an object at an infinite distance. The types are made of various sizes, each being numbered according to the distance, in feet or metres, at which it subtends a visual angle of 5 minutes. Thus, No. 6 subtends this angle at 6 m., No. 3 at 3 m.. No. 1 at 1 m., etc. Nnmerically, acuteness of vision is ex- pressed by a fraction, of which the denominator is the numl:)er of the type D, and the numerator the greatest dis- tance (d) at which it can be read, Y=-: if No. G is read at 6 m. -= [; or 1, i. e., Y is normal ; if onlv No. 18 can be read at 6 m. ^-=r% ; if only 60, then | = (fo- ^^J dis- tance greater than about 3 m. may be selected for this test ; i. e., No. 3 read at 3 m., or No. 5 at 5 m., g iierally shows the same acuteness as No. 6 read at 6 m. But at distances less than 3 m. the accommodation comes into play, and the illumination is often brighter ; hence No 1 at 1 m. (|) does EXTERNAL EXAMINATION OP THE EYE. 49 not necessarily show the same state of sight as Xo. 6 at G m. (^). It is therefore best, by recording the fractions unre- duced, to indicate the distance at which the test was used. For testing near vision, Snellen's types are thought by some to be practically inferior to those of Jaeger and others, in which the letters have the form and proportions found in ordinar}' type. See Appendix. If Y. be very bad, less than -g% or j\, it may be expressed accurately enough by noting the distance at which the outspread fingers can be counted when exposed to a good light and against a dark background. Below this point we can still distin- guish good from bad, or uncertain, perception of light and shade (p. /.), by alternately exposing and shading the eye ■w'lth the hand, without touching the face. (6) Accommodation (Ace.) is tested clinically by meas- uring the nearest point (punctum proximum, p.) at which the smallest readable type (Snellen's 0.5 or Jaeger's 1) can be clearly seen. The region of accommodation is the space Fig. 24. Accommodation represented b\' a convex lens. in which it is available (see Presbyopia). The amplitude, ptoicer, or range of Ace. is expressed in terms of the convex lens whose focal length = the distance from the cornea^ to p., this being the lens which adapts Y. in an eye with- * Strictly, from a point about "i^'' in front of the cornea, sines the glass cannot be placed upon the eyeball. 3 50 EXTERNAL EXAMINATION OF THE EYE. out Acc. from tho farthest point of distinct vision (jiunctum remotiHsimum, r.) to p. Tlius in Fife. 24 let 73 be at 10 cm. : if Acc. be then rehixed, i. e., the eye be adapted for parallel rays, the rays from p will be focussed at c. f., behind the retina ; but Y. will again be clear at 10 cm. if a lens, I, of 10 cm. focus (=10 D., see p. 41) be held close to the cornea ; because rays from p will be made parallel by I before entering the eye (Chapter I., §§ 11 and 12) and will therefore be focussed on the retina. Convergence of the visual axes upon a point at any given distance is usually associated with accommodation for the same distance. The t^vo functions can, however, be somewhat dissociated to an extent that varies with age and in different persons; i. e., Acc. can be either relaxed a little or increased a little, without changing any given degree of convergence ; this independent portion is know^n as the 7'eJative accommodation. (7) The pupils are to be examined as to their equality, size in ordinary light, mobility, and form. The pupils are often large and inactive, and sometimes oval, in amaurotic patients, in glaucoma, and in paralysis of the circular fibres of the iris, supplied by the third nerve. They may be too large, though active, in myopia and in conditions of defective nerve tone. Wide, recent dilatation of one pupil or both, wdth dimness of sight but without ophthalmoscopic signs of disease, is usually traceable to atropine or bella- donna, used by accident or design. When very small the pupil is seldom quite round. The centre of the pupil usually lies a little to the nasal side of the corneal centre.* The pupils should be round and, w^hen equally lighted, equal in size. When one eye is shaded its pupil should dilate considerably, and on ' This eccentricity varies in degree and exact position in different persons. Coinpare Irregular Astigmatism. EXTERNAL EXAMINATION OF THE EYE. 51 exposure contract quickly to its former size, ''direct reflex action ;" during this trial the other pupil will act, but to a much less extent," indirect reflex action^ The pupils con- tract when the gaze is directed to a near object, say G" distant, i. e., during accommodation and convergence, and dilate in looking at a distant object ; but the range of this '' associated action '* is much less than that of the reflex action. The pupil dilates when painful impressions are made on the sensory nerves of the skin, e. g., by the fara- daic brush or by pricking with a pin. The pupils may be motionless to light and shade from iritic adhesions (Chap- ter YIII.) or from atrophy of the iris in glaucoma or other local disease ; such conditions should be carefully noted or excluded. Reflex action is lost when the eyes are blind from disease of the optic nerves or retinae ; if only one eye be blind, the direct action of the pupil is lost in that eye, but (unless there l>e disease of the third nerve) its indirect action is much increased. When one eye is blind the pupil is often rather larger than that of the other. Reflex action may also l)e lost without any affection of sight, and icithout loss of associated action. Chapters XXI. and XXIII. Permanent inequality of the pupils without disease, either of eyes or of nervous system, is rare, but temporary dilata- tion of one pupil is not uncommon. When very active pupils are suddenly exposed after being shaded they often oscillate for a few seconds before settling, and finally re- main a little larger than at the first moment of exposure. Considerable differences in the action of the pupils, both in 9'ange and rapidity, are compatible with health ; in general, however, the pupils become smaller and lose both in range and rapidity of action with advancing years: atropine also often causes only partial dilatation in old people. Marked inactivity, with small size, should excite suspicion of spinal or cerebral disease (Chapter XXIII.). The pupils are smaller whenever the iris is consrested, whether this be a 52 EXTERNAL EXAMINATION OF THE EYE. merely local condition, e. g., in abrasion of cornea, or form part of a more general congestion, as in typhus fever 'and in plethoric states, or be caused by venous obstruction, as in mitral regurgitation and bronchitis. They are large in anaemia, in conditions, such as aortic insufficiency,'' where the systemic arteries are badly filled, and during rigors ; irritation of the sympathetic nerve in the neck is an occa- sional cause of m3^driasis.^ Chapter XXI. (8) Note the color of the iris, and compare it with that of the fellow-eye. Occasionally the two irides, although healthy, differ in color, one being blue or gray, the other brown or greenish ; more frequently a large sector-shaped patch of dark color occupies part of the iris of one eye. Small pigmented spots are often seen on the iris. If the iris of an inflamed eye look greenish, that of its fellow being blue, we should suspect iritis; and if the iris of a defective eye be different from its fellow, some morbid change should be suspected. Chapter YIII. (9) Information derived from the bloodvessels visible on the surface of the eyeball Three systems of vessels have to be considered in disease ; but most of them are too small to be easily seen in health. (1) The vessels proper to thecon^unci'iva,, posterior conjinictival vessels, in which it is not important to distinguish between arteries and veins, Fig. 25, Post. Conj., and Fig. 26. (2) The anterior ciliary vessels, lying in the subconjunctival tissue ; their perforating arterial branches supply the sclerotic, iris, and ciliary body, their veins receive blood from Schlemm's canal and the ciliary body. The perforating branches of the arteries, 1 The small pupil of typhus and the frequently large pupil of typhoid are ascribed by Murchison to the diflFerences in the vascularity of the iris in these diseases. Continued Fevers, p. S-tl. ^ Medical Examiner, March 2, 1879. 3 This condition seems to be rare ; I can hear but little of it in the experience of my medical friends. EXTERNAL EXAMINATION OP THE EYE. 53 Fig. 25, A, are seen in health as several comparatively large tortuons vessels which stop short about -^^" or \" from the corneal margin, Fig. 27 ; their very numerous, small, non- FiG. 25. strr^ Vessels of the front of the eyeball, cm. Ciliary muscle. Ch. Choroid. iicl. Sclerotic. F. V. Vena vorticosa. I. Marginal loop-plexus of cornea. Ant. and Post. Conj. Anterior and posterior conjunctival vessels. Ant. Cil. A. and V. Anterior ciliary arteries and veins. (Simplified and altered from Leber.) perforating (episcleral) branches are invisible in health, but form, when distended, a pink zone of fine, nearly 64 EXTERNAL EXAMINATION OF THE EYE. straight, very closely-set vessels round the cornea, Fig. 25, A, and Fig. 28, "ciliary congestion," "circumcorneal zone," see Iritis and Diseases of Cornea ; the perforating veiiis are very small, but more numerous than the perforating arte- FiG. 26. Conjunctival congestion, engorgement of the posterior conjunctival arteries and veins, (After Guthrie.) Fig. 27. Congestion of the perforating branches of the anterior ciliary arteries. (Dalrymple.) The dusky spots at the seats of perforation are often seen in dark-complexioned persons. ries, Fig. 25, v, and their episcleral twigs form a closely- meshed network, Fig. 29. (3) The vessels proper to the margin of the cornea and immediately adjacent zone of conjunctiva, anteinor conjunctival vessels, and their loop plexus on the corneal border, Fig. 25, /, and Fig. 53 ; by EXTERNAL EXAMINATION OF THE EYE 55 these numerous minute branches, which are offshoots of the anterior ciliary vessels, Systems 1 and 2 anastomose. Speaking generally, congestion composed of ( 1 ) tortuous, bright-red (brick-red) vessels (System I) moving with the Fig. 28. Fig. 29. *' Ciliary congestion," engorge- ment of episcleral twigs of ante- rior ciliary arteries. (After Dai- ry mple.) Congestion of anterior ciliary veins, episcleral venous plexus. (After Dalrymple.) conjunctiva when it is slid over the globe, and least intense just around the cornea. Fig. 26, indicates a pure conjuncti- vitis (ophthalmia), and is usually accompanied by muco- purulent or purulent discharge. (2) A zone of pink con- gestion surrounding the cornea, and formed by small, straight, parallel vessels, closely set, radiating from the cornea, and not moving with the conjunctiva, anterior ciliary arterial twigs, Fig. 28, points to irritation or in- flammation of the cornea, or iris. A more scanty zone of dark or dusky color, Fig. 29, which, when severe, is finely reticulated, episcleral venous plexus, often points to glau- coma, but may accompany other diseases, especially in old people. Congestion in the same region, more deeply seated, and of a peculiar lilac tint, especially if unequal in different parts of the zone, shows cyclitis or deep scleritis. (3) Con- gestion in the same zone, and also composed of small vessels, but superficially placed, bright red, and often en- 56 EXTERNAL EXAMTNATTON OF THE EYE. croaching a little on the cornea, anterior conjunctival ves- sels and loop plexus of cornea, Fig. 53, shows a tendency to irritable but often superficial corneal inflammation. Localized or fasciculated congestion generally points to phlyctenular disease, Figs. 45 and 46. Although in the severe forms of all acute diseases of the front of the eye these types of congestion are usually mixed and but im- perfectly distinguishable, much information may often be derived from attention to the leading forms described. (10) The mobility of the eyeball may be impaired in any or every direction, and in any degree. Commonly only one eye is affected. First, to test the lateral and vertical movements, direct the patient with both eyes open to look successively towards, or follow a pencil or finger moved in, each of the four directions, up, down, right, and left; next, to test the convergence power, he looks at the object held vertically in the middle line, rather below the horizontal, and gradually approached from 2' to about 6^^ In each position we must notice both eyes ; thus, when the patient looks to his right we have to note the outward movement of his right and the inward movement of his left. The fixed marks for the inward and outward movements are the inner and outer canthi, and as the apparent range of movement judged in this way varies a little in different people, the corresponding movements of the two eyes should always be compared. In lookingstrongly outwards the corneal margin does not in all persons quite reach the outer canthus, but it should always reach the inner canthus during inward rota- tion. In children and stupid people the movements are often defective from inattention. In very myopic eyes the move- ments are somewhat defective in all directions. The vertical movements are best shown by noting the position of the cor- nea in relation to the border of the lower lid; the border of the upper lid is less trustworthy, since there may be some ptosis or other cause of inequality between the two sides. EXTERNAL EXAMINATION OP THE EYE. 5Y The range of movement of the eye, "field of fixation," or "field of direct vision," can be measured on the perimeter in the same way as the ordinary field of " indirect vision." The test-object, e. y.,a word of small print, moved along the various meridians from the centre towards the peripher}-, is followed by the eye under examination until it can no longer be read, i, e., until the visual axis can no longer be directed to it. A coarse test-object would be recognized by parts of the retina away from the yellow spot, and must, therefore, not be used. In this way it is found that the normal range of movement of the eye ex- tends through about 45^ in each direction from the centre. The state of mobility of the eye, and the progress, in cases of ocular paralysis, may be accurately recorded in this way.^ (11) Squint or strabismus exists if the visual axes are not both directed to the same object. A squint may be the result either of over-action, or of weakness or paralysis, of a muscle. The internal recti, by excessive contraction, often cause convergent squint ; but most other forms of strabismus result from actual defect of nervous or muscu- lar power. When a squint is well marked there is no difiBculty in identifying the squinting eye as the one which is mis- directed when an object is held up to the patient's atten- tion ; in most cases the patient always squints with the same eye, but a few persons can squint with either indiffer- ently, alternating squint. Nor is there often any doubt as to whether the squint is internal, convergent, or external, divergent, i. e., whether the axis of the squinting eye crosses that of its fellow between the patient and the object he looks at, or crosses it beyond this object, or even posi- tively diverges from it ; upward or downward squint, though less common, is almost as evident. But to prove beyond doubt which is the squinting eye, direct the patient 1 For further details consult a paper by Landolt in Trans. luteruat. Med. Congress, 1881, vol. iii. p. 25 (London), 3* 58 EXTERNAL EXAMINATION OF THE EYE. to look at a pencil held up in the middle line at about 18'' from his face, and with a card or piece of ground-glass cover the apparently sound, or " working" eye, the squint- ing e3^e will at once move so as to look at, or "fix" the pencil, proving that it had previously been misdirected. If the sound eye be watched behind the screen, it will be seen to squint as soon as the affected eye " fixes" the object ; this is known as the secondary squint, and its direction is the same as that of the original or primary squint. Thus, if the primary squint be convergent, the secondary will also be convergent. In squint from over-action, or from mere disuse, of one muscle, the secondary and primary deviations are equal, but in paralytic squint the secondary often exceeds the primary. If the squinting eye retain full range of movement, i. e., move in companionship with its fellow in all directions, the squint is termed concomitant, in contradistinction to paralytic; hence in every case of squint it is necessary to test the mobility of the eyes. It is also important to note whether the squint is constant or only occasional (periodic).^ It was, until lately, usual to measure the squint (when necessary) by means of a scale placed on the lower lid and graduated in such a way as to indicate in lines (or mm.) the amount of deviation. The centre of this scale, marked zero, is placed over the centre of the lid, and therefore cor- 1 We sometimes meet with an apnare^it squint, either external or in- ternal. The optic axis of the eye passes from a point rather to the inner side of the y. s. through the centre of the cornea, and forms a small angle (" angle a") with the visual axis, the line Avhich joins the y. s. to the objectlooked at and which commonly cuts the cornea rather within its centre. As we judge of the apparent direction of a person's eyes by the centres of his corneae, i. e., by the ojJtic axes, a slight apparent out- ward squint will be produced if the angle, a, be, as in many hyper- metropic eyes, larger than usual, and an apparent convergent squint if, as in myopia, it be smaller. Apparent squint is always slight, and the screen test described in the text gives a negative result. EXTERNAL EXAMINATION OF THE EYE 59 responding to the centre of the pupil if there be no squint ; the number which corresponds to the centre of the pupil of the squinting eye gives the linear measurement of the devi- ation. A more accurate and more rational method, intro- duced by Landolt, gives the deviation in terms of the angle, d, Fig. 30, formed by the visual axis of the squint- ing eye where it cuts that of the working eye. In Fig. 30, L is the squinting left eye of the patient placed at the Fig. 80. Angular measurement of squint. (After Landolt.) centre of a perimeter ; L x , the direction of its visual axis ; L Ob, the direction its visual a.xis should have ; Ob, an object, as far off as possible, at which the patient is to look ; X a small candle-flame which the observer, stationed close behind the perimeter, moves along the arc until he sees its 00 EXTERNAL EXAMINATION OF THE EYE. image reflected from the centre of the squinting cornea ; the size of the angle x L Ob, read off on the perimeter, is nearly' the same as that of the angle of deviation d. (12) Diplopia (double sight) is almost always a result of sciuint, and is usually most troublesome when the devi- ation is so slight as to be hardly perceptible. Diplopia caused by squint is, of course, binocular, and disappears when one eye is covered. Uniocular diplopia (double sight with one eye), however, often occurs in commencing cataract, and sometimes in healthy but astigmatic eyes; it has also been met with in some cases of cerebral tumor. In the former cases it has a physical cause in the crystal- line lens (sec Cataract) ; in the latter it must depend upon some psychical change. To find out what defect of movement is causing binocular diplopia, darken the room, and ask the patient to follow with his eyes a lighted candle, held about 6' from him, moved successively into different positions, and to describe the relative places of the double images in each position. Ascertain which of the two images belongs to each eye by placing before one eye a strongly-colored glass, or by covering one eye and asking which image disappears. In many cases the image formed in the squinting eye (the " false" image) is less bright or distinct, and this difference gives a valuable means of distinguishing the sound from the affected eye ; but the patient does not always notice a difference between the two images, and there may then be difficulty in proving which eye is at fault. The patient's replies may be recorded on such a diagram as Fig. 123 ; other radii may of course be added for intermediate posi- tions ; the false image is marked by the dotted line, the true one by the unbroken line. With this graphic repre- sentation of the candle as it appears to the patient, we can 1 The ansrles X L Ob and cZ would be exactly equal if Ob were far eiiuus^li away to make L Ob and R Ob parallel. EXTERNAL EXAMINATION OF THE EYE. 61 deduce from the apparent position of the false image what movements of the corresponding eye are at fault, and con- sequently which muscle or muscles are defective. It is essentialthat the patient shouldr\ot move his head during the examination, and that he remain throughout at the same distance from the candle. Remember that, in the extreme lateral movements, the nose eclipses one image. When the double images are very wide apart, i e., when there is much squint, the patient often fails to notice the false image. For the diagnosis of a case of diplopia it is often suffi- cient to ask in which directions the double sight is most troublesome, and how the images appear in respect to height, lateral separation, and apparent distance from the patient. Chapter XXI. (13) The apparent size of an object depends, in the first place, on the size of its retinal image, and this, as already shown, § 19, p. 38, depends upon {a) the size of the visual angle, and (6) the distance of the retina from the nodal point. It is clear that in Fig. 20 a smaller object placed nearer to the eye or a larger one placed further off might subtend the same angle as Ob, and therefore have a retinal image of the same size. There are, however, other factors contributing to our estimate of the size of objects, especially contrast of size and shade, estimation of distance, and effort of accommodation. A white object on a black ground looks larger than a black object of the same size on a white ground. The fur- ther off an object is judged to be, the larger does it look. The greater the accommodative effort used, whatever may be the distance of the object, the smaller does it appear ; thus patients whose eyes are partly under the influence of 1 Apparent distance is also influenced by the color of the object. The chromatic aberration of the eye is said to aflford the explanation, rays of different refrangibilities being focussed on slightly difi'erent parts of the retina. G2 EXTERNAL EXAMINATION OF THE EYE. atropine, and presbyopic persons whose g-lasses are too weak conijilain that near objects, if looked at intently for a short time, become much smaller ; whilst when one eye is under the action of eserine, causing spasm of the accom- modation, objects appear larger than if held at the same distance from the other eye. Prisms with their bases towards the temples seem to diminish objects seen through them by necessitating excessive convergence of the eyes, the converse of Fig. 16. (14) Protrusion (proptosis) and enlarg^ement of the eye. — Unequal prominence of the two eyes is best ascer- tained by seating the patient in a chair, standing behind him, and comparing the summits of the two corneae with each other, and with the bridge of the nose, or the line of the eyebrows. The appearance of prominence or recession, as seen from the front, depends very much on the quantity of sclerotic exposed ; thus, slight ptosis gives a sunken ap- pearance to the eyes, and in slight cases of Graves's disease the proptosis seems to increase when the upper lids are spasmodically raised. It is to be remembered that real prominence of the eye may depend on enlargement of the eyeball, myopia, staphyloma, or intra-ocular tumor, as well as on its protrusion, and that if only one eye be m3'opic, the appearance will be uns3^mmetrical. Decided proptosis may follow tenotomy or paralysis of one or more ocular muscles. In hypermetropia, in which the eyeball is too short, and in the rare cases of paralysis of the cervical sympathetic, the eye often looks sunken. (15) The uses of prisms have been explained at p. 35. (IG) Examination by focal illumination is described in Chapter III. CHAPTER III. EXAMINATION OF THE EYE BY ARTIFICIAL LIGHT. This includes (1) examination by focal or oblique light ; (2) examination by the ophthalmoscope. 1. Examination by Focal or Oblique Light. In using focal, oblique, or lateral illumination the anterior parts of the eye are examined with the light of a lamp concentrated by a convex lens. The method is used to detect or examine opacities of the cornea, changes in the appearance of the iris, alterations in the outline and area of the pupil from iritis, and opacities of the lens. Such an examination is to be made by routine in every case before using the ophthalmoscope. We require a somewhat dark- ened room, a convex lens of two or three inches focal length, one of the large ophthalmoscopic lenses, and a bright, naked lamp-flame. The patient is seated with his face towards the light, which is about 2' distance. The lens, held between the finger and thumb, is used like a burning-glass, being placed at about its own focal length from the patient's cornea, and in the line of the light, so as to throw a bright pencil of light on the front of the eye at an angle with the observer's line of sight. Thus all the superficial media and structures of the eye can be successively examined under strong illu- mination, the distance of the lens being varied a little according as its focus is required to fall on the cornea, the iris, or the anterior or posterior surface of the crystalline lens. Fig. 31. By varying the position of the light and 64 EXAMINATION BY ARTIFICIAL GUT. Fig. 31. of tlie patient's eye, making him look up, down, and to each side, we can examine all parts of the corneal surface, of the iris, of the pupillary area, i. e., the anterior capsule of the lens, and of the lens-substance. If the light be thrown at a very acute angle on the cornea or lens, opaci- ties are much more visible than if it fall almost perpendicularly. By habitually magnifying the illuminated parts by a second lens held in the other hand, much additional information can be gained. For complete exploration of all parts of the crystalline lens the pupil must be dilated with atropine, but careful exami- nation without atropine will generally enable us to detect opacities lying in or near the axis of the lens even if deeply seated. In examining the posterior pole of the lens the light must be thrown almost perpendicularly into the pupil, and the ob- server must place his eye as nearly in the same direction as is possible without inter- cepting the incident ^ , .,, . ,. light. Opacities of the Focal illumination. ^ ^ cornea and anterior layers of the lens appear whitish, deep opacities in the lens, especially in old people, look yellowish, by focal light. Tumors, large opacities in the vitreous, and retinal detach- ments may be seen by this method if they lie close behind the lens. Minute foreign bodies in the cornea will often be seen by focal light when invisible, because covered by hazy epithelium, in daylight. ophthalmoscopic examination. g5 2. Ophthalmoscopic Examination. The ophthalmoscope enables us to see the parts of the eye behind the crystalline lens, by making the observer's eye virtually the source of illumination for the observed eye. Rays of light entering the pupil in a given direction are partly reflected back by the choroid and retina, and on emerging from the pupil take the same or very nearly the same course that they had on entering (§12, p. 31). Hence the eye of the observer, if so placed as to receive these returning rays, must also be so placed as to cut off the entering rays : as, therefore, no light can enter in the necessary direction, none can return to the observer's eye. This is why the pupil is usually black. Although with a large pupil, especially in a hypermetropic or myopic eye, the observer receives some of the returning rays, because he does not intercept all the entering light, and in this way sees the pupil of a fiery red instead of black, still for any useful examination the observer's eye must, as already stated, be in the central path of the entering, and emerging, rays. This end is gained by looking through a small hole in a mirror, by which light is reflected into the patient's pupil, and this perforated mirror is the ophthalmoscope. There are two ways of seeing the deep parts of the eyeball by this means. A. The indirect method of examination, by which a clear, real, inverted image of the fundus, somewhat magnified, is formed in the air between the patient and the observer. The following simple experiment will show how this is effected : Take two convex lenses of about '^" focal length each ; hold one in the left hand, at about ^" from this print ; take the other in the right hand, and, moving your head a few inches back, hold the second lens at about its focal length in front of the first ; you will then see an in- verted image of the print slightly magnified, a. Observe 66 EXAMINATION BY ARTIFICIAL LIGHT. that in order to see this image clearly you have to make aa eftbrt, and that you cannot see both the image of the print and the print itself, clearly, at the same moment; this is because the eye of the observer (obs, Fig. 82) cannot be adjusted for the image (im) and the more distant object (06) at the same time. The fundus of the eye seen on this prin- ciple is magnified about five diameters, if the eye be normal. Fig. 32. ob. The object, a. The first lens. I. The second lens. iui. The mag- nified inverted image of ob viewed by the observer, oba. The image is larger in h and smaller in m. b. Notice that if the observer's head be moved slightly from side to side, the image will appear to move in the opposite direction. B. The direct method of examination, by which, except when the eye is myopic, a virtual, ere3t image is seen, more magnified than in the former method and situated behind the patient's eye. The conditions are the same as those under which a mag- nified image of any object is seen through a convex lens, Fig. 13, as in the following experiment : Hold a convex lens of, say 3'' focal length, at any distance from this page not greater than 3'', and place your eye close to the lens. OPHTnALMOSCOPIC EXAMINATION. 67 The print will be magnified, and seen in its true position, i. e., " erect." a. The enlargement will be more the greater the distance of the lens from the page up to 3'' (§§ 16 and 1*7, p. 34). If the distance be further increased, the print will not be seen clearly. The image is a. " virtual" one, because it is the image which would be formed if the rays which enter the eye in a diverging direction could be pro- longed backwards until they met behind the lens. Figs. 13 and 35. b. If the lens be placed just at its focal length from the paper, the image will be seen clearly only if the accommodation be completely relaxed, c. If it be nearer to the page, more or less accommodation must be used, or else the observer must withdraw his head further from the lens. d. If, keeping the lens quite still, the observer with- draw his head, the field of view will be lessened. Fig. 14, whilst the image will appear to increase in size without really doing so, and these changes will be greater the nearer the lens is to its focal distance from the paper ; if it be almost exactly at its principal focal distance, only a very small part of the print will be seen when the head is withdrawn, e. If the head be moved a little from side to side, the image will appear to move in the same direction. The emmetropic eye, with the accommodation fully re- laxed, is adjusted for distant objects, i. e., parallel rays, and receives a clear image of such objects on the layer of rods and cones of the retina, p. 38. A clear image of the fundus of the eye, i. e., the retina, optic disc, and choroid, can be obtained in such an eye, as in the experiment just described, where the distance of the lens from the paper was equal to or less than its focal length, on condition that the eyes, both of patient and observer, be adjusted for in- finite distance, i. e., for parallel rays; in other words, that the accommodation of both be relaxed. The fundus so seen is magnified about 20 diameters. 08 EXAMINATION BY ARTIFICIAL LIGHT. In order to use the ophthalmoscope^ it is first necessary to learn to manage the mirror and light. (1) Seat the patient in a darkened room and place a lamp with a large steady, naked flame on a level with his eyes, a few inches from his head, and about in a line with his ear. The lamp may be on either side, but is usually placed on his left, and it is better to keep to the same side until practice has given steadiness to the various combined movements which are necessary. (2) Sit down in front of the patient with his face fronting your own, feature to feature. It is most con- venient for the observer's face to be a little higher than that of the patient. (3) Take the mirror of the ophthal- moscope, without any lens behind, and without the large lens, in your left hand for examining the patient's left eye, and vice vei'sd for his right eye, hold it, mirror toward the patient, close to your own eye, and with the sight-hole placed so that, with your other eye closed, you see the pa- tient through it. Xow rotate the mirror slightly toward the lamp until the light reflected from the flame is thrown into the patient's pupil, and open your other eye. (4) You will so far have seen nothing except the front of the pa- tient's eye, unless atropine have been used, for he will have looked at the centre of the mirror, and his pupil, strongly contracted, will look either black or very dull red. (5) Now tell him to look steadily a little to one side, into va- cancy, or at an object on the other side of the room. The pupil will now become red — bright fiery red if it be rather large, a duller red if it be small or the patient's complex- ion be dark. In one position, when the eye under exami- nation looks a little inward, the red will change to a yellowish or whitish color, and this indicates the position of the optic disc. (6) Learn to keep the light steadily on the pupil, during slow movements backward and forward 1 For choice of instruments see Appendix. OPHTHALMOSCOPIC EXAMINATION. 69 and from side to side, taking care that the patient keeps his eye all the time in the same position, and does not fol- low the movements of the mirror; the test of steadiness will be that the pupil remains of a good red color in all positions. Up to this point the examination may be made without atropine ; and so far only a uniform red glare will have been seen, no details of the fundus being visible, un- less the patient be either myopic or considerably hyperme- tropic. In order to see the details of the fundus it is best to begin by learning the Indirect Method, Fig. 33, for, though rather less easy, it is more generally useful than the direct. Take the mirror without any lens behind it in one hand,^ and one of the large convex " objective" lenses correspond- ing to / in Fig. 32 in the other. Always, if possible, have the pupil dilated with atropine, for by this means you learn to see the fundus much more quickly and easily. In ex- amining the patient's right eye apply the mirror with your right hand to your right eye, holding the lens in your left hand ; it is best to reverse everything for his left eye, but the position of the light need not be changed. The hand which carries the lens should be steadied by resting the little or ring-finger against the patient's brow or temple. We usually begin by looking for the optic disc, which is one of the most important and easily seen parts. As the disc lies to the nasal side of the posterior pole of the eye, the cornea must be rotated a little inward, i. e., the back of the eye outward, in order to bring the disc opposite the pupil, when the observer is immediately in front ; the right eye, e. g., must be directed to the observer's right ear, or to the uplifted little finger of his mirror hand. The patient 1 But many learn to see the iraasfe more quickly and easily by placing a convex lens of 4 D. behind the mirror. If the observer wears glasses for reading, he should wear them, or put a lens of the same strength behind the mirror, for the indirect examination. EXAMINATION BY ARTIFICIAL LIGHT. o t« C =: 3 «, 2 -2 - H ^ ,=i- x: ^ .O i. *^ +J -r- *^ 9 z 5 - ^ •i I S J 1 "^ i I o i o I H 5 2 fcfl 55C o ^• ^ -s w O 5 M .S 2 .- s 5 o ^ c: o 5 OPHTHALMOSCOPIC EXAMINATION, 71 must turn his eye, not bis head, in the required direction. The lens should be held about 'i"-?>", and the observer's eye be about 15'', from the patient's eye ; the image of the fundus being formed in the air 2'' or ?>" in front of the lens, will thus be situated about 10'' from the observer. The bright-red glare, from the choroid, will be obvious enough ; but most beginners find some difficulty in avoid- ing the reflection of the mirror from the patient's cornea, and in adjusting the accommodation and the distance of the head, so as to see the image clearly. The head must be slowly moved a little further from or nearer to the patient, and at the same time an attempt made to adjust the eyes, both being kept open, for a point between the observer and the lens. As a rule, the disc and retinal ves- sels are seen clearly at the first sitting. The optic disc — the ending of the optic nerve in the eye above the lamina cribrosa, optic papilla, Figs. 34 and 36 — is round, well defined, much lighter in color than the fiery red of the surrounding fundus, and numerous blood- vessels are seen to radiate from its centre, chiefly upward and downw^ard. As soon as the disc can be easily seen the student must pass on to the study of the most important details of this part itself, and of the other parts of the fundus. Some of these will l)e described here, and others in the chapters on the Diseases of the Choroid and Retina, and on the Errors of Refraction. The disc, as a whole, is grayish-pink in color with an admixture of yellow. It is nearly circular, but seldom perfectly so, being often apparently oval or slightly irreg- ular. Two differently colored parts are noticeable — a cen- tral patch, whiter than the rest, and into which most of the bloodvessels dip'; and a surrounding part of pink or grayish-pink. In many eyes, especially in old persons, we distinguish a third part, a narrow boundary line of lighter color, which represents the border of the sclerotic, scleral 72 EXAMINATION BY ARTIFICIAL LIGHT. ring,'^ Fig. 34. The bloodvessels consist of several large trunks and a varying number of small twigs ; the large trunks emerge from the central white part of the disc, and often bifurcate once or twice on its area ; the small twigs may emerge separately from various parts of the disc, or form branches of the large trunks. Variations — The color of the disc appears paler or darker according to the color of the surrounding choroid, the brightness of the light used, and the patient's age and state of health. A curved line of dark pigment often bounds a part of the circumference of the disc, Fig. 36, and has no pathological meaning. The central white patch varies greatly in size, position, and distinctness ; it may be so small as hardly to be perceptible, or very large ; may shade off gradually or be abruptly defined ; may be central or eccentric ; when large it generally shows a gray- ish stippling or mottling, Fig. 36. This central white patch represents a hollow, the physiological cup or jnt, compare Figs. 36 and 37, left by the nerve fibres as they radiate out from the centres of the disc toward the retina, like the tentacles of an open sea-anemone ; and through it the chief bloodvessels pass on their way between the nerve and the retina. This depression is generally shaped like a funnel or a dimple, with gradually sloping sides. Fig. 37 ; but sometimes the sides are steep, or even overhanging ; in other eyes it is wide, shallowed, and enlarged toward the outer side of the discs. The physiological pit is whiter than the rest of the disc, because the grayish-pink nerve fibres are absent at this part, and we can, therefore, see down to the opaque, white, fibrous tissue, which, under the name of lamina cribrosa, forms the floor of the whole disc, Fig. 37. The stippled appearance often noticed in the pit 1 I fail to see the force of the objection to this term raised by Jaeger and Loring^, Loring's Text-book, i. p. 57, since the inner sheath of the nerve and the fibres of the sclera are blended into one at this part. OPHTHALMOSCOPIC EXAMINATION 73 is caused by the holes in this lamina, through which the bundles of ner^e-fibres pass on their wa}' to the retina ; the holes appear darker because filled by non-medullated nerve- tibres, which reflect but little light. The other parts of the fandus.-^The groundwork is of a bright fiery red — the choroid, not the retina ; in many eyes this color is nearly uniform, but in persons of very light or very dark complexion we see a pattern of closely- set, tortuous, red bands (vessels of the choroid), separated by spaces either of darker or of lighter color, Fig. 34. For details see Chapter XII. Fig. 34. Ophthalmoscopic appearances of healthy fundus in a person of ver}' fair complexion. Scleral ring well marked. Left eye, inverted image. ( Wecker and Jaeger. ) Upon this red ground the vessels of the retina divide and subdivide dichotomously. It will be noticed that the chief trunks pass almost vertically upward and downward, and that no large branches go to the part apparently inward 4 74 EXAMINATION BY ARTIFICIAL LIGHT. from the disc (to the left in the figure) ; that the visible retinal vessels are comparativeh' few and are widely spread ; that they become prof;ressively smaller as they recede from the optic disc ; and that they never anastomose with each other. Special attention must be given to the part — appar- ently to the inner, nasal, side of the optic disc, really to its outer temporal side — which is the region of most accurate vision, the yellow spot, 3^ s., macula lidea, or, shortly, "macula." In this region, which comes into view when the patient looks straight at the ophthalmoscope, the cho- roidal red is duller and darker than elsewhere. It is skirted by large retinal vessels which give off numerous twigs towards its centre, though none of them can be seen quite to reach that point. Compare Fig. 78, Chapter XIII. In many eyes nothing but these indefinite characters mark the y. s. ; but in some, especially in dark eyes and young patients, a minute bright dot occupies its centre, and is encircled by an ill-bounded dark area, round which again a peculiar shifting, white halo is seen. The minute dot is the fovea centralis, the thinnest part of the retina. The neighborhood of the disc and y. s. forms the central region of the fundus. The perijjheral parts are explored by tell- ing the patient to look successively up, down, and to each side, without moving his head. To see the extreme peri- phery the observer must move his head as well as the patient his eye. Toward the periphery the choroidal trunk-vessels are often plainly visible even when none were distinguishable at the more central parts. The vessels of the retina are easily distinguished from those of the choroid by their course and mode of branching ; by the small size of all except the main trunks ; by their sharper outline and clearer tint ; but especially by the presence of a light streak along the centre of each, Fig. 34, which gives them an appearance of roundness, very different from the flat, band-like look of the choroidal ves- OPHTHALMOSCOPIC EXAMINATION. 75 sels. They are divisible into two sets — a darker, larger, somewhat tortuous set — the veins ; and a lighter, brighter red, smaller, and usually straighter set — the arteries ; the diameter of corresponding branches being about as 3 to 2. The arteries and veins run pretty accurately in pairs. Pressure on the eyeball, through the upper lid, causes visible pulsation of the arteries on the disc. The indirect method of examination is most generally useful, because it gives a larger field of view under a low magnifying power, about five diameters, and thus allows us to appreciate the general character and distribution of any morbid changes better than if we begin with the direct method, in which the field of view is smaller and the mag- nifying power much greater. It has also the great advan- tage of being equally applicable in all states of refraction ; whereas, if the patient be myopic, his fundus cannot be examined by the direct method without the aid of a suit- able concave lens, found experimentally, placed behind the mirror, p. 81. The inversion of the image seen by the in- direct method is such that what appears to be the upper is lower, and what appears to be R. is L. In the Direct MeUiod the examination is made by the mirror alone, or with the addition of a lens in the clip or disc behind it, but without the intervention of the objec- tive lens. By this method the parts, unless the eye«be myopic, are seen in their true position. Fig. 35, the upper part of the image corresponding to the upper part of the fundus, the right to the right, etc. ; it is, therefore, often called the method of the "erect" or "upright" image, though, as will be seen below, these terms are not strictly convertible with "direct examination." It is used: (1) to detect opacities in the vitreous humor and detachments of the retina ; (2) to ascertain the condition of the patient's re- fraction, i. e., the relation of his retina to the focus of his 16 EXAMINATION BY ARTIFICIAL LIGHT. •= 5 cu 2 « ::2 H 5 > 1 i k3 "^i bJD = t5 ^ 2 -5 fcii W « c o >^ ^ '^ S 2 o <" O JS cu o dj « c o -j; — OPHTHAIiMOSCOPIC EXAMINATION. 7*7 lens system ; (3) for the minute examination of the fundus by the highly-magnified, virtual, erect image (Fig. 36) ; (4) for examining the cornea, iris, and lens with magnify- ing power. (1) To examine the vitreous humor. The patient is to move his eye freely in different directions, whilst the light is reflected into it from a distance of a foot or more — for details see Diseases of Vitreous ; detachments of the retina are seen in the same way. Opacities in the vitreous and folds of detached retina, being situated far within the focal length of the refractive media, are seen in the erect posi- tion under the conditions mentioned at p. 6*7, c, the observer being at a considerable distance from the eye. If the ob- server be close to the patient. Ace. must be used or a con- vex lens be placed behind the mirror, as in high degrees of H. See next page. (2) To ascertain the refraction. If when using the mirror alone at a distance of 12''-18'', or more, from the patient's eye, we see some of the retinal vessels clearly and easily, the eye is either myopic or hypermetropic. If, when the observer's head is moved slightly from side to side, the vessels seem to move in the same direction, the image seen is a virtual one, and the eye is hypermetropic. The eye is myopic if the vessels seem to move in the con- trary direction ; the image in M. is, indeed, formed and seen in the same way as the inverted image seen by the "indirect" method of examination, compare Figs. 33 and 105, but except in the highest degrees of M. it is too large and too far from the patient to be useful for detailed exam- ination. In low degrees of M. this image is formed so far in front of the patient's eye as to be visible only when the observer is distant perhaps 3' or 4' ; whilst in E. and in the lower degrees of H. the erect image will not be easily seen at a greater distance than 12'' or 18'', p. 67, d, and Fig. 14. If, therefore, in order to get a clear image by the 78 EXAMINATION BY ARTIFICIAL LIGHT. direct method, the observer has to go either very near to, or a long way from, the patient, no great error of refrac- tion can be present. The above tests only reveal qualitatively the presence of either M. or H., but by a modification of the method, the quantity of any error of refraction, e. g., H., can be deter- mined with great accuracy. {Determination of the refrac- tion by the ophthalmoscope.) In E., as already stated at p. 67, the erect image can be seen only if the observer be near to the patient, and also completely relax his accom- modation ; for, in experiment d there described, when the head was withdrawn from the lens the field of view and illumination rapidly diminished. The same occurs with the eye, but in a much greater degree, and hence in E. no useful view can be gained by the direct method without going very near to the eye. In H., where the retina is within the focus of the lens system, the erect image is seen when close to the patient's eye only by an effort of accommodation in the observer, just as in the same experiment when the lens was within its focal length from the page, p. 67, c. And as in that experiment the print was alse seen easily, even when the head was withdrawn, so in H. the erect image is seen at a distance, as well as close to the patient. If now the observer, instead of increasing the convexity of his crystalline, place a convex lens of equivalent power behind his ophthalmoscope mirror, this lens will be a measure of the patient's H, i. e., it will be the lens which, when the patient's accommodation is in abeyance, will be needed to bring parallel rays to a focus on his retina. If a higher lens be used, the result will be the same as when in the experiment the convex lens was removed beyond its focal length from the print ; the fundus will be more or less blurred. Hence, to measure H.: (1) Ace. both in patient and OPHTHALMOSCOPIC EXAMINATION. 7 i) observ^er must be fully relaxed, usually by atropine in the patient and by voluntary effort in the observer; (2) the observer must go as close as possible to the patient ; ( 3) he must then place convex lenses behind his mirror, beginning at the weakest and increasing the strength, till the highest is reached which still permits the details of the o. d., or, better, of the y. s., to be seen with perfect clearness. By practice the distance between the corneae of patient and observer may be reduced to about T'. The light must be on the same side as the eye under examination. The right eye must examine the right, and vice versa. In the same way, though with less accuracy in the high degrees, M. can be measured by means of concave lenses ; the lowest lens with which a clear erect image is obtained being slightly more than the measure of the M. It is sometimes useful to know how much lengthening or shortening of the eye corresponds to a given neutralizing lens. The following numbers, slightly altered from Kuapp, are suffi- ciently near the truth. The distance between the eye of the observer and that of the patient is supposed to be not more than 1 inch. H. of 1 D. represents shortening of 0.3 mm. u 2 " 3 u 5 u u g u u 9 " 12 18 " 2 3 5 6 9 12 18 0.5 (. 1 1.5 2 3 4 6 thei ling of 0.3 0.5 0.9 1.3 1.75 2.6 3.5 5 80 EXAMINATION BY ARTIFICIAI. LIGHT. Astigmatism (As.) may also be measured by this method, the refraction being estimated successively in the two chief meridians by means of appropriate retinal vessels. See Astigmatism. Any line, e.g., a horizontally running vessel, is seen by means of rays which pass through the meridian of the cornea at a right angle to its course; hence, if a vertical vessel be clearly seen through a -|- 2 D. lens there is H. 2 D. in the horizontal meridian, etc. This application of the direct method needs much prac- tice. The lenses, of which there are twenty or more, are placed in a thin metal disc, which can be revolved behind the mirror so as to bring each lens in succession opposite the sight-hole. There are many forms of these " refraction ophthalmoscopes," varying in the details of their construc- tion. See Appendix. (3) The erect image is very valuable, on account of the high magnifying power, about 20 diameters in the E. eye, Fig. 36. Ophthalmoscopic appearance ol licalthy disc, as seen in the erect image. Dark vessels, veins. Physiological pit stippled. X 1.5 diam- eters. (After Jaeger.) for the examination of the finer details of the fundus. The disc looks less sharply defined, because more magni- fied, than when seen by the indirect method ; both the disc OPHTHALMOSCOPIC EXAMINATION 81 and the retina often show a faint radiating striation, the nerve-fibres ; the lamina cribi^osa is often more brilliantly white ; and the pigment epithelium of the choroid can be recognized as a fine uniform dark stippling. If the refraction be E. or H., no lens is needed behind the mirror ; if M., a concave lens must be placed in the clip behind the mirror, of sufficient strength to give a good, clear, erect image. The observer must come as near as possible to the patient. Fig. 37. Vertical section of healthy optic disc, etc. X about 1.5. R. Retina, outer layers shaded vertically, nerve-fibre layer shaded longitudinally. Ch, Choroid. Scl. Sclerotic. L. Cr, Lamina cribrosa. S. V. Sub- vaginal space between inner and outer sheath of optic nerve. The central vein and one of the divisions of the central artery are seen in the nerve and disc. By reference to Fig. 35 it will be seen that only those rays are useful which strike near the centre of the mirror, none others entering the patient's pupil ; hence, if the aperture in the mirror be too large, the fundus will not be well lighted. It should not be larger than 3 mm., nor smaller than 2 mm. (4) Minute changes in the cornea, iris, and lens can often be better studied by direct ophthalmoscopic examina- 4* 82 EXAMINATION BY ARTIFICIAL LIGHT. tion with a high -|- lens behind the mirror than focal illu- mination (p. 64). All opacities seen in this way, however, look black against the red background, whilst by focal light they are seen in their true colors. Retinoscopy (Keratoscopy, Pupilloscopy, or the Shadow Test). By this method the refraction is determined by noticing the direction of movement of the light thrown on to the retina by the mirror when the latter is rotated. The de- gree of error of refraction is measuredby the lens, which, placed close to the patient's eye in a case of ametropia, renders the movement and other characters of the illumi- nation the same as in emmetropia. The test is most accurate when used at a great distance from the patient . in practice a distance of about 1 m. — 100-120 cm., or 3'-4' — is chosen. The observer, seated in front of his patient, throws the light from an ophthalmo- scope mirror into the patient's pupil. He will then see the area of the pupil illuminated, and on slightly rotating the mirror will notice a movement in this lighted area, which movement will have a direction either the same as, or opposite to, that in which the mirror is turned, " with" or " against " the mirror. The lighted area is bordered by a dark shadow, and it is to the edge of this shadow that the attention must be directed. The edge is parallel to the axis on which the mirror is turned, but moves in, and shows the refraction of, the meridian at right angles to it, e. g., the shadow whose edge passes vertically across the pupil moves across the horizontal meridian, the refraction of which it indicates, and vice versa. Retinoscopy may be practised with a concave or a plane mirror. With the for- mer the shadow moves " against " the mirror in E. H. and low M. ; and " with " the mirror in M. of more than 1 D. OPHTHALMOSCOPIC EXAMINATION. 83 Fig. 38. Retinoscopy (irith c^7iravf mirror). 84 EXAMINATION BY ARTIFICIAL LIGHT. With the latter these movements are exactly reversed. The light should be thrown as nearly as possible in the direction of the visual axis and the lamp be placed imme- diately over the patient's head rather than to one side, (1) With a concave mirror (of about 22 cm, focus), Pig. 38. In Fig. 38, 1, the mirror, M, forms an inverted image, I, of the light, L, at its principal focus, and i becomes the source of light for the eye, e. A second image of i, again inverted, is formed at i' on the retina of e If the far point of E be at i, this retinal image, i', Avill be clear and distinct, but in ever}* other case it will be more or less out of focus and indistinct. On rotating M to m', i will move to i'' andi^ to i^^ and these movements (of i and i') will occur no matter what the refraction of E may be. The observer placed behind him, M, sees an image of i' formed in the same way as the image of the fundus seen by the direct method, p. 67, and therefore either inverted and real, or erect and virtual, according as the refraction of the eye is M. or H., p. 77. If the observer's eye be accurately adapted for this image of i', he will indeed see not only the light and shadow, but the retinal vessels; he neglects these, however, in attending to the movements of the shadow. In the following description, l, t, and i^ are disregarded, i' or i'"^ being considered as the source of light. If E he myopic, Fig. 38, 2, the image of i' is real and in- verted and formed at i'\ the far point of e, compare Fig. 105. On rotating the mirror, as in Fig. 38, 1, i' will move to l'^ and i" will move to l''^ i. e., the image seen by the observer moves in the same dir^ection as {or " ivitJi^^) the mirror. If E be hypermetropic, Fig. 38, 3, or emmetropic, rays reflected from its retina leave the eye divergent or parallel and are not brought to a focus after emerging; the observer therefore sees a virtual image erect at l'', the virtual focus OPHTHALMOSCOPTC EXAMINATION. 85 of i', compare Fig. 13, and see its movemeDts actually as they occur, i. e., in the same direction as the movements of the real image i^ or i'^ and therefore " against'' the move- ments of the mirror. Hence in H. and Em. the shadow moves '' against^^ the mirror. The above statement for myopia is true only if the ob- server be beyond the far point of the observed eye. (See Myopia.) In M. of 1 D. the rays returning from the pa- tient's eye are focussed at a distance of 1 m., and if the observer intercept these rays before they meet, Pig. 38, 4, he will refer them toward i" and i"'^ and obtain an erect virtual but unfocussed image of i', the movements of which will be the same as those in H. or E., Fig. 38, 3, i. e., '' against^^ the mirror. Hence, at a distance of about 1 m., movement " against" the mirror may indicate M., of about 1 D., or E. or H. The lowest M. which can give the char- acteristic movement at this distance is slightly more than 1 D., say 1.25 D. (2) With a plane mirror, Fig. 39. Here the source of light for the observed eye is an erect and virtual image of the flame formed at the same distance behind the mirror as the lamp is in front of it. In Fig. 39, 1, this image is at I, the virtual focus of L. A second and inverted image of I is formed on the retina of e at i. The movements of these images, on rotation of the mirror, are the reverse of those of the image i (and its retinal image i') Fig. 38, 1, obtained when the concave mirror is used. When the mirror m is rotated to m', / will move in the opposite direc- tion to V, bat its retinal image i will move to i'; i, e., in the same direction as, or ''with'^ the mirror. These movements of I and i occur in every eye, whatever its re- fraction. In E. and H., however, the movement of the retinal image is seen as it occurs, and therefore "m//i" the mirror ; but in m. Fig. 39, 2, the observer sees an inverted image of i formed at the far point of e, and its 86 EXAMINATION BY ARTIFICIAL LIGHT. OPHTHALMOSCOPIC EXAMINATION. 87 movements are exactly the reverse of those of the retinal image. Therefore, when, on rotating m to m^, i moves to i ^ the image i' seen by the observer moves to i'\ i. e., " against " the mirror. If the plane mirror be used at a distance of rather more than 1 m., 3'-4', from the patient, a movement of the shadow ''with " the mirror will occur in M. of 1 D. or less, for the reasons given previously, Fig. 38, 4 ; but if the observer be about 2 m. (say 1') away, the characteristic movement "agamst^^ the mirror will be ob. tained, unless the M. be less than 0.5 D., since the far point of an eye with M. 5 D., and, therefore, the image seen, is at 2 m. As a plane mirror gives at a long distance a better illumination than a concave one, it can, if necessary, be used at a greater distance from the patient, and by this means low degrees of ametropia be very accurately meas- ured. Generally, however, the distance given, 3'-4', will be found most convenient. In employing retinoscopy the patient is armed with a trial frame, into which lenses are successively put until one is reached which just reverses the movement of the shadow. This lens indicates nearlj^, but not quite, the refraction of the eye under observation. In H. we must subtract (about) 1 D. from the lowest -\- lens which reverses the shadow, because w^e know that this movement would not occur until a myopia of at least 1 D. had been produced. In M., for the same reason, 1 D. must be added to the lowest — lens which reverses the shadow. Astigmatism is easily detected, and its amount measured by observing, on rotating the mirror, first from side to side, then from above downward, whether the shadow has the same movement and characters in each direction ; or by noting that when the shadow in one meridian is "cor- rected" by a lens, the meridian at right angles to it still shows decided ametropia. The lens is then found which 88 EXAMINATION BY ARTIFICIAL LIGHT. corrects the latter meridian, and the As. equals the differ- ence between the two lenses. Apart from the direction in which the image (and wshadow) moves, something may be learned from variations in (1) its brightness; (2) its rate of movement ; (S) the form, straight or crescentic, of its border. The image is brightest, its movement quickest and most extensive, in very low M. and in Em. The higher the ametropia, whether M. or H., the duller the illumination, the slower and less extensive its movement, and the more crescentic and ill-defined its shadow border. The brightness of the image depends on how clearly i, Fig. 38, 1, is focussed on the retina ; the more accurately i' is an image of i, the brighter and larger will i'\ Fig. 38, 2 or 3, be ; and as the flame is rectangular, the borders of the image will be nearly straight. These conditions occur when the eye is exactly adapted for the distance of i, i. e., in M. of 1 D. or less. If the M. be higher than 1 D., i will be out of focus, and, therefore, be spread over a larger retinal area, and being formed by the same number of rays as before, it will be less bright. The image i''. Fig. 38, 2, will be correspond- ingly diffused and dull, and being formed nearer to the patient's eye, as, for example, at x, it will move only from X to x' in the same time as i^' takes in moving to i'^^, and hence its movement is slower and less extensive. The same is true in H., Fig. 38, 3, because the higher the H., the more diffused is i' and the nearer is l'' to the patient's eye. In both cases, high M. and high H., the border of the shadow is crescentic, because the diffused image forms a nearly round area on the retina. Retinoscopy is a valuable means of objectively deter- mining the quantity of any error of refraction, and as it is more easily learned, and, on the whole, more accurate in its results, than estimation by the direct method, p. 79, it OPHTHALMOSCOPIC EXAMINATION. 89 has, in the hands of many of our students and assistants, almost displaced the latter method during the last four or five years as a preliminary to testing the patient with trial lenses. For the quick discovery of very slight astigmatism, and of the direction of the chief meridians in astigmatism of all degrees, retinoscopy probably excels all other methods. Retinoscopy, however, carries with it none of the col- lateral advantages afforded by a thorough training in the more difficult "direct method;" for in retinoscopy w^e see nothing and think nothing of the condition of the fundus of the eye. Accurate retinoscopy is not quicker than measurement by the direct method ; indeed, with a good instrument, the latter method certainly has the advantage in rapidity. I think there is reason to fear that the free use of retinoscopy by students, before they have mastered the more difficult "direct method," may tend to lower the present high quality of English ophthalmoscopic work. 1 cannot help thinking, therefore, that the importance of retinoscopy has been somewhat overrated, and that though in some difficult cases it will remain our best objective test, we shall do well generally to use it as an auxiliary rather than as a substitute for other methods. PART II. CLINICAL DIVISION. CHAPTER IV. DISEASES OF THE EYELIDS. The border of the lid, which contains the Meibomian glands, the follicles of the eyelashes, and certain modified sweat-glands and sebaceous glands, is often the seat of troublesome disease. Being half skin and half mucous membrane, it is moist and more susceptible than the skin itself to irritation by external causes ; being a free border, its circulation is terminal, and therefore especially liable to stagnation. Its numerous and deeply-reaching glandu- lar structures, therefore, furnish an apt seat for chronic inflammatory changes. Blepharitis (ophthalmia tarsi, tinea tarsi, sycosis tarsi) includes all cases in which the border of the eyelid is the seat of subacute or chronic inflammation. There are sev- eral types. The skin is not much altered, but chronic thickening of the conjunctiva near the border of the lid is generally observed. The disease may affect both lids or only one, and the whole length or only a part. In the commonest and worst form the glands and eye- lash-follicles are the principal seats of the disease. The symptoms are, firm thickening and dusky congestion of the border region, with exudation of sticky secretion from its edge, glueing the lashes together into little pencils. 92 DISEASES OF THE EYELIDS. Very mild cases present merely overgrowth of lashes and excess of Meibomian secretion. But generally the disease progresses ; little excoriations, and ulcers covered by scab, form along the free border, and often minute pustules ap- pear ; the thickening and vascularity increase; the lashes are loosened, and free bleeding occurs if they are pulled out After months or years of varying activity some or all of the hair-follicles become altered in size and direction, or quite obliterated ; and the lashes stunted, misplaced, or entirely lost. As the thickening gradually disappears, little lines, or thin seams, of scar form just within the edge of the lid, and often cause slight eversion. The resulting ex- posure of the marginal conjunctiva, added to the scanti- ness of the cilia, causes the disagreeably raw and bald appearance termed lippitudo; and epiphora, from eversion, tumefaction, or narrowing of the puncta, often results. Often, however, the disease leads to nothing worse than the permanent loss of a certain number of the lashes. In another type the changes are quite superficial — mar- ginal eczema ; the patient is liable, perhaps through life, to soreness and redness of the borders of the lids, and little crusts, scales, or pustules form at the roots of the lashes, the growth of the lashes not being much interfered with. In such people the eyes look weak or tender ; the condition is made worse by exposure to heat, dust, and wind, and by long spells of work. See Chronic Lachrymal Conjunctivitis, Chapter YI. Ophthalmia tarsi generally begins in childhood, and an attack of measles is a common exciting cause. It seldom becomes severe or persistent except from neglect of cleanli- ness in a child with sluggish circulation ; the patients are generally anaemic, often scrofulous, and the condition is then often the result of a previous more acute ophthalmia. In adults severe sycosis of the eyelids may accompany DISEASES OF THE EYELIDS. 93 sycosis of the beard, but, as a rule, no tendency to such disease of the skin is observed. Treatment. — When the inflammatory symptoms are severe nothing has such a marked effect as pulling out all the lashes. Cases of a few weeks' standing may be cured and recurrence in older cases very much relieved by one or two such epilations, together with local remedies. Local applications are always needed (1) for the removal of the scabs, (2) to subdue the inflammatory symptoms. A warm alkaline and tar lotion, with which the lids are to be care- fully soaked for a quarter of an hour night and morning, followed by a weak mercurial ointment applied along the edges of the lids after each bathing, is an efficient plan if the mother will take the pains. In bad cases painting, or pencilling, the border of the lid with nitrate of silver, either in strong solution, or the diluted stick, or the use of weak copper drops, is very useful in addition to the oint- ment. In old cases with much epiphora the canaliculus is to be slit up. The patients generally need a long course of iron. (F. 1, 2, 3, 6; 15, 16; 24, 25, 26.) A stye is the result of suppurative inflammation of the connective tissue, or of one of the glands, in the margin of the lid. Owing to the close texture of the tarsus and the vascularity of the parts, the pain and swelling are often severe, and even alarming to the patient. The matter gen- erally points around an eyelash ; but if seated in a Meibomian gland, it may point either to the border of the lid or to the conjunctiva, rarely to the skin. Styes almost always show some derangement of health especially of the stomach or reproductive organs. Over- use of the eyes, especially if ametropic, is the exciting cause in some cases ; exposure to cold wind in others. Styes are very apt to recur, singly or in crops, for several weeks or months. 94 DISEASES OF THE EYELIDS. Treatment. — A stye may sometimes be cut short if seen quite early, by the vigorous use of an antiphlogistic lotion ; but an incision followed by hot fomentations or a poultice is usually more eflBcacious ; the puncture must be made parallel to the free border and extend rather deeply ; a Beer's knife or broad needle, Figs. 160 and 145, may be used. The health always needs attending to, and a purga- tive iron mixture often suits better than anything else. Some persons are subject to very small postules or styes, much more superficial than the above, and less closely asso- ciated with derangement of health. A Meibomian gland is often the scene of chronic over- growth, a little tumor in the substance of the lid being the result — Meibomian cysts, chalazion. In a few weeks or months the growth becomes as large as a pea, forming a firm, hemispherical, painless swelling, over which the skin is freely movable. A dusky spot where the tarsal tissues are thinned marks the conjunctival aspect, and when spon- taneous rupture has occurred a flattened mass of granula- tion is found there. The deeper part of the gland is the common seat of disease; if, as sometimes happens, the part near the edge of the lid is affected, the tumor usually remains very small. Occasionally the growth pushes for- ward and adhesion to the skin occurs; even then it is easily distinguished from a sebaceous cyst by the firmness of its deep attachment. During its course the cyst may inflame and even suppurate, and in the latter case it forms one variety of "stye." The same tumor may inflame several times, and finally suppurate and shrink. Like styes, these tumors are apt to continue forming one after another. They are much commoner in young adults than earlier or later in life, but they are now and then seen in infants. Patients as often apply for the disfigurement as for any discomfort which these little growths occasion. DISEASES OF THE EYELIDS. 95 Treatment. — The cyst is to be removed from the loiver surface of the lid ; but if it point forward the iDcision may be in the skin. The tumor generally consists of a soft, pinkish, gelatinous mass, or of a gruelly or puriform fluid, without a cyst wall. Sometimes the contents are very firm and adherent. See Operations. Small yellow dots are sometimes seen on the inner sur- face of the lids, due to little cheesy collections in the Mei- bomian glands, and causing irritation by their hardness. They should be picked out with the point of a knife. Warty formations are not very common on the border of the lid, and are of little consequence, except in elderly people, in whom they should be looked upon with suspicion as possible starting-points of rodent cancer. A small fleshy, yellowish-red, flattened growth is sometimes met w^ith just upon the tarsal border, and apparently seated at the mouth of a Meibomian gland. It causes some irrita- tion, and should be pared off. Small pellucid cysts are also not uncommon on the lid border. Cutaneous horns are occasionally seen on the skin of the eyelids. Molluscum contagiosum is partly an ophthalmic disease, because so often seated on the eyelids. One or more little funded prominences, showing a small dimpled orifice at the top, plugged by dry sebaceous matter, are seen in the skin, varying from the size of a mustard-seed to a cherry, but usually not larger than a sweet pea ; at first they are hemispherical, but afterwards become constricted at the base. The skin is tightly stretched, thinned, and adherent. The larger specimens sometimes inflame, and their true nature may then, without due care, be mistaken. Each molluscum must be removed, the white, lobulated, gland- like mass which forms the growth being squeezed out through the incision made by a knife or scissors. Xanthelasma palpebrarum appears as one or more yellow patches like pieces of washleather in the ?ikin, varying 96 DISEASES OF THE EYELIDS. from mere dots to the size of a kidney bean, quite soft in texture, and very little raised. The disease is commonest near the inner canthus, and, unless symmetrical, is usually on the left side. It occurs chiefly in elderly persons who have previously been subject to become very dark around the eyes when out of health. The patches are due to infil- tration of the deeper parts of the skin by groups of cells loaded with yellow fat. The frequency of xanthelasma in the eyelids is perhaps related to the normal presence of certain peculiar granular cells, some of which contain pig- ment, in the skin of these parts. The pediculus pubis (crab-louse) in very rare cases will reach the eyelashes and flourish there. The lice cling close to the border of the lid, and look like little dirty scabs; the eggs are darker, and may also be mistaken for bits of dirt. The absence of inflammation and the rather peculiar appearances will lead, in doubtful cases, to the use of a magnifying glass, by which the question will be at once settled. Ulcers on the eyelids may be malignant, or lupous, or syphilitic; and in the last case the sore may be either a chancre or a tertiary ulcer. Rodent cancer, rodent ulcer, flat epithelial cancer, is by ^ far the commonest form of carcinoma affecting the eyelids ; although cases of eyelid cancer occasionally present both the clinical and pathological characters of ordinary epithe- lioma. The peculiarities of rodent cancer are that it is very slow, that ulceration almost keeps pace with the new growth, and that it does not cause infection of lymphatics. It seldom begins before, generally not until considerably after, middle life, and in its course often extends over many years. Beginning as a "pimple" or "wart," it slowly spreads, but years may pass before the ulcer is as large as a sixpence. When first seen we generally find a shallow ulcer, covered by a thin scab, most often involving the DISEASES OP THE EYELIDS. 97 skin at the inner end of the lower lid. Its edge is raised, sinuous, nodular, and very hard, but neither inflamed nor tender. Slowly extending both in area and depth, it at- tacks all tissues alike, finally destroying the eyeball and opening into the nose. In a few very chronic cases the disease remains quite superficial, and cicatrization may occur at some parts of the ulcerated surface. Xow and then a considerable nodule of growth forms in the skin before ulceration begins. The diagnosis is generally easy. A long-standing ulcer of the eyelids in an adult is nearly certain to be rodent cancer. Tertiary syphilitic ulcers are much less chronic, more inflamed and punched out, and devoid of the very peculiar, hard edge of rodent ulcer; moreover, they are very rare. Lupus seldom occurs so late in life as rodent cancer, presents more inflammation and much less hard- ness, and is often accompanied by lupus elsewhere on the cutaneous or mucous surfaces. Lupus is seldom difficult to distinguish on the eyelids from tertiary syphilis, the latter being more acute, more dusky, and showing more loss of substance, with none of the little, ill-defined, soft tubercles seen in lupus. When a chancre occurs on the eyelid ' the induration and swelling are usually very marked, the surface abraded and moist, but not much ulcerated ; the glands in front of the ear and behind the jaw become enlarged. The same glands enlarge, either with or without suppuration, in lupus and in many inflammatory conditions of the lid. Several cases are on record in which a hard chancre formed on the palpebral conjunctiva so far from the border of the lid as to be quite concealed. I have seen two such, and Mr, James Adams and Mr. Wherry have each recorded one. In all of these cases the swelling bore considerable 1 An interesting monograph on this subject was read by Dr. De Beck at the American Ophth. Soc, July, 1886. 5 98 DISEASES OF THE EYELIDS. resemblance to a large Meibomian cyst. In all there were enlarged glands and well-marked constitutional symptoms. Treatment of Rodent Cancer — Early removal is of great importance, and probably the more so in proportion to the youth of the patient. Chloride of zinc paste or the actual cautery is necessary in addition to the knife in bad cases ; scraping may also be employed. The disease is very apt to return locally. Even in very advanced cases, where complete removal is impossible, the patient may be made much more comfortable, and life probably prolonged, by vigorous and repeated treatment. Congenital ptosis is not a very rare affection. It may be double or unilateral, is present from birth, and its causa- tion is unknown. I believe it is never complete. It some- times seems to diminish in the first few years of life, but probably never disappears. Although the lid droops, the skin is often scanty, the lid being tight and deficient in the natural folds. Operations have been devised for producing deep cicatricial bands, by means of subcutaneous sutures passed from the brow to the tarsus (Bowman, Pagenstecher, Wecker).' These rather tedious procedures avoid the risk of further shortening of the lid which attends the simpler operation of removing an elliptical fold of skin. I have obtained considerable improvement from Pagenstecher's operation. (See also Ocular Paralysis, Chapter XXI.) Epicanthus is a rare condition, in which a fold of skin stretches across from the inner end of the brow to the side of the nose, hiding the inner canthus. If it does not dis- appear as the child's nose develops, an operation — removal of a piece of skin from the bridge of the nose, sometimes combined with canthoplasty — is indicated. 1 Panas has devised a new operation more recently. Arch. d'Oph- talmologie, T. 6, p. 1, 1S86. CHAPTER y. DISEASES OF THE LACHRYMAL APPARATUS. These may be divided into the affections of the secret- ing parts — the lachrymal gland and its ducts ; and those of the drainage apparatus — the puncta, canaliculi, lachry- mal sac, and nasal duct. In the great majority of cases the fault lies entirely in the drainage system. The flow of tears over the edge of the lid, " watery eye, " is called epiphora or stillicidium lacrimarum. No useful pur- pose is served by keeping the two names, and only the former will be here used. Lachrymation indicates the increased flow which often accompanies inflammation of the eyeball. The drainage system may be at fault in any part from the puncta to the lower end of the nasal duct. The slightest change in the position of the lower punctum causes epiphora. In health the punctum is directed back- ward against the eye ; if it look upward or forward, the tears do not all reach it, and some will then flow over a lower part of the lid. Thus in paralysis of the facial nerve the patient sometimes comes to us for epiphora before he notices the other symptoms ; the watering is caused partly by loss of the compressing and sucking action of the punctum that is effected in winking, by those fibres of the orbicularis which lie in relation with the lachrymal sac, partly by a slight falling of the lid away from the eye and a consequent displacement of the punctum. The various chronic dis- eases of the border of the lids, ophthalmia tarsi, and also ^ For Diseases of Lachrymal Gland, see Diseases of Orbit. Chap. XIX. 100 DISEASES OF LACHRYMAL APPARATUS. granular disease of the conjunctiva, granular lids, are com- mon sources of (1) tumefaction, with narrowing, of the puncta and canaliculi ; (2) cicatricial stricture of the same parts ; and in both cases the puncta are displaced as well as constricted. Narrowing, even to complete obliteration, of the puncta is sometimes seen as the result of former inflammation, of which all traces have long since passed away. Wounds by which the canaliculi are cut across cause their obliteration, and epiphora is the result. In all the above cases epiphora is accompanied by a visi- ble change in the size or position of the punctum, none of the signs of inflammation in the lachrymal sac or stricture in the nasal duct being present ; and simple division of the canaliculus will cure, or much relieve, the watering. (See Operations.) This is, however, seldom necessary in the epiphora of facial paralysis. The canaliculus is occasionally plugged by the growth in it of a mycelial fungus, which, mingled with pus-cells and mucus, forms a yellowish, or greenish, putty-like concre- tion. These masses sometimes calcify, and are then called dacryoliths.^ Epiphora not explained by the above causes is usually due to obstruction in the nasal duct, and accompanied by distention and disease of the lachrymal sac from the same cause. Primary disease of the lachrj^mal sac is rare. Obstruction of the nasal duct is usually caused by chronic thickening of the mucous and submucous tissues lining the canal. Dense, hard thickening causes a stric- ture, often very tight and unyielding ; but obstruction is often present, though the canal be of full size or perhaps even dilated,^ excess of mucus being apparently the chief 1 The same term is applied to concretions, still more rare, in the ducts of the lachrymal gland. 2 There can be little doubt that the healthy nasal duct varies much in size in different persons (Noyes). DISEASES OF LACHRYMAL APPARATUS. 101 cause. Disease of the duct occurs at all ages, and is much commoner in females than in males.^ In some cases the change evidently forms a part of a chronic disease of the naso-pharyngeal mucous membrane, but in many no cause can be assigned. Sometimes stricture is the result of periostitis or of necrosis, and of these conditions syphilis, either acquired or inherited, scarlet fever, and smallpox are the commonest causes. Injuries to and growths in the nose, or invading it, account for a few cases. A stricture may be seated at any part of the duct ; but the upper end, where there is often a natural narrowing, is the commonest spot. Obstruction of the nasal duct, by preventing the escape of tears, leads to distention of the lachrymal sac, to chronic thickening of its lining membrane, and increased secretion of mucus. The mucus may be clear or turbid. At length a point is reached at which the distention can be seen as a little swelling under the skin at the inner canthus, mucocele or chronic dacryo-cystitis. This swelling can generally be dispersed by pressure with the finger, the mucus and tears either regurgitating through the canaliculi or being forced through the duct into the nose. In cases of old standing the sac is often much thickened, and may contain polypi, and the swelling cannot then be entirely dispersed by pres- sure. A mucocele is always very apt to inflame and suppurate, the result being a lachrymal abscess. Most cases of lachry- mal abscess, indeed, have been preceded by mucocele. Its formation gives rise to great pain, and to tense, brawny, dusky swelling, which, extending for a considerable dis- tance around the sac, is sometimes mistaken for erysipelas. The matter always points a little below the tendo-palpe- brarum ; the pus often burrows in front of the sac, forming ^ In a group of 113 cousecutive cases I find 89 females and ^ males. 102 DISEASES OF LACHRYMAL APPARATUS. little pouches in the cellular tissue, and if allowed to open spontaneously, a fistuja, very troublesome to cure, is likely to follow. If seen early, before there is decided pointing, it is best to open the abscess by slitting the lower canaliculus freely into the sac, and passing a knife down the nasal duct ; anaesthesia is usually necessary. If interference be delayed, the skin over the sac soon becomes thinned, and the abscess is then best opened through the skin, by a free puncture inclined downward and a little outward ; no an- aesthetic is necessary, and the resulting scar is insignificant. When the thickening has subsided, under the use of warm lead lotion dressing, the stricture of the duct is to be treated ; but the mucocele will form again, and another abscess may occur at any time, unless a free passage can be restored down the nasal duct. Obstinate chronic conjunctivitis is often set up by unre- lieved lachrymal obstruction (Chap. VI.). It has long been known that severe suppurative inflammation was very likely to occur after any operation performed on the cornea when there was pus in the lachrymal sac. (See Cataract.) These evidences of local irritation and infection are now believed often to depend upon septic organisms which, owing to the obstruction, collect in the lachrymal sac. Treatment of Mucocele and Lachrymal Stric- ture. — The object aimed at is the permanent dilatation of the stricture ; but, whether this can be gained or not, a free opening from the canaliculus into the sac should be maintained, so that the secretions may be often and easily squeezed out. Dilatation by probing (Chap. XXII.) is the ordinary and best treatment for all strictures, whether there be mucocele or not, the rule being to use the largest probe that will pass readily. The probing is repeated every few days or less often, according to the duration of its effect, and often needs to be continued for weeks or months. The DISEASES OF LACHRYMAL APPARATUS. 103 patient may sometimes learn to use the probe himself. When the stricture is tough and tight, it is best at once to divide it by thrusting a strong-backed, narrow knife down the duct, and afterward to use probes. In cases where the stricture is quite soft, and the obstruction due rather to general thickening of the mucous membrane and over- secretion of mucus than to dense fibrous thickening, fre- quent washing out of the duct with water or weak astrin- gents by means of a lachrymal syringe is quite as beneficial as, and less painful than, probing. The diligent use of astringent lotions to the conjunctiva is also useful, particu- larly in soft strictures, some of the lotion reaching the sac and duct. In cases of long standing, where other treat- ment has failed and the sac is much thickened, its complete obliteration by the actual cautery gives great relief; extir- pation of the lachrymal gland is also occasionally practised. For refractory children and for patients who cannot be seen often, a style of silver or lead, passed in exactly the same way as a probe, but worn constantly for many weeks, is very useful; but it may slip into the sac out of reach unless furnished with a bend or head so large as to be somewhat unsightly. As a rule, probing should not be begun until the inflammatory thickening and tenderness following a lachrymal abscess have subsided. If the probe be used too often, or with much violence, or if false pas- sages be made, the case may easily be made worse instead of better. It must be confessed, indeed, that in many lachrymal cases, whether the stricture be soft or firm, treatment, however skilful, gives only partial relief to the epiphora. Suppuration of the lachrymal sac, on one or both sides, sometimes takes place in newborn infants without appa- rent cause ; if there be much redness, the abscess should be opened, but the suppuration is sometimes chronic, and 104 DISEASES OF LACHRYMAL APPARATUS. will cease under the use of astringent lotions. The cases of epiphora with contracted punctum, which are sometimes met with in older children, may perhaps be the conse- quences of this infantile suppuration. Cases in which the sac or duct is obliterated by injury can seldom be relieved. CHAPTER YI. DISEASES OF THE CONJUNCTIVA. It is convenient to distinguish those which, from the outset, are general and affect the whole membrane, ocular and palpebral alike, and of which the various forms of conta- gious ophthalmia are examples, from others which primarily affect either the ocular or the palpebral part alone. The ter^m " ophthalmia'''' includes all inflammations of the con- junctiva, and should not be applied to other diseases. General Diseases. The conjunctiva, like the urethra, is subject to purulent inflammation, and, like the respiratory mucous membrane, is liable to the muco-purulent and to the membranous or diphtheritic forms of disease. All cases in which there is yellow discharge are in greater or less degree contagious. The congestion which forms a part of conjunctivitis is much influenced by age , the younger the patient the less is the congestion in proportion to the discharge — a fact to be borne in mind in examining patients at both ends of the scale. Purulent ophthalmia (0. neonatorum, Gonorrhceal 0., Blenorrhoea of the conjunctiva) is generally due to con- tagion from the same disease, or from an acute or chronic discharge from the urethra or vagina, which may or may not be gonorrhceal. It is commonest in newborn infants whose eyes have been inoculated from the mother during birth ; next in adults with gonorrhoea ; it is also seen some- times in young girls who have non-venereal discharges from the genitals. Muco-purulent ophthalmia, when quickly 5* 106 DISEASES OP THE CONJUNCTIVA. passed on from one to another, under conditions of health favorable to suppuration, e. g., weakness after acute ex- anthenis, may be intensified into the purulent form. The presence of a special form of micrococcus in the pus-cells of gonorrhoea and of purulent ophthalmia, described by Neisser in 1879, has been confirmed by Sattler, Widmark, and many others. The coccus is said (1) to be absent in some of the milder forms of infantile ophthalmia ; (2) when cultivated, to be capable of producing purulent oph- thalmia by inoculation ; (3) to be usually present in the vaginal discharge of women whose babies have purulent ophthalmia. Gonorrhoea was experimentally produced by inoculation with pus from purulent ophthalmia long before the days of bacterial pathology. Like gonorrhoea, puru- lent ophthalmia may occur more than once. It varies greatly in severity, but is, on the whole, much worse in adults than in infants, perhaps because there is much more adenoid tissue in the conjunctiva of adults than of babies (Widmark). The quality of the infecting discharge, no doubt, has much influence, severe forms being generally caused by inoculation from a recent or severe case ; but chronic discharge may also give rise to a severe attack. The health of the recipient and the previous condition of the eyelids exert an important influence, and if the lids be granular, various slight causes sometimes bring on severe purulent ophthalmia. The disease sets in from twelve to about forty-eight hours after inoculation ; in infants the third day after birth is almost invariably given as the date when discharge was first noticed. Itchiness and slight redness of conjunctiva soon pass on to intense congestion of conjunctiva, with chemosis, tense inflammatory swelling of the lids, great pain, and discharge. The discharge at first is serous, or like turbid whey, but soon becomes more profuse, creamy (purulent), and yellow, or even slightly greenish. Dark, GENERAL DISEASES. 107 abrupt ecchymoses are often present. The lids, always swollen, hot, and red, in bad cases become very tense and dusky. The upper lid hangs down over the lower, and is often so stiff that it cannot be completely everted. The conjunctiva is succulent and easily bleeds. The disease if untreated declines spontaneously, and the discharge almost ceases in about six weeks, the palpebral conjunctiva being left thick, relaxed, and more or less granular. Cicatricial changes, identical with, but less severe than, those resulting from chronic granular lids, and analogous to what occurs in stricture of the urethra, some- times follow^ ; considerable permanent thickening of the ocular conjunctiva may also occur. There is a risk to the cornea in this disease, partly from strangulation of the vessels, partly from the local influence of the discharge. If within the first two or three days the cornea becomes hazy and dull, like that of a dead fish, there is great risk that total or extensive sloughing will occur. In many of the milder cases ulcers form a little below the centre, and rapidly cause perforation. In other cases clear deep ulcers form close to the edge of the cornea. There is less risk of ulceration of the cornea in the purulent ophthalmia of infants than in that of adults, but a form of corneal affection appears in infants which seems to be pecu- liar to them. This variety is generally seen when the dis- charge is getting scanty, or perhaps when too much nitrate of silver has been used; it sometimes occurs w^hen the attack is of a diphtheritic type. The cornea becomes quickly and almost entirely opaque throughout, with the exception of a narrow zone at its edge ; the surface is dull, and the epi- thelium irregular, but there is little, if any, loss of sub- stance. In many cases the opacity clears up to a great extent, even entirely, and eserine seems to help the recov- ery ; it remains longest and densest at the centre. Either one or both eyes may be attacked ; in adults one eye often 108 DISEASES OF THE CONJUNCTIVA. escapes ; in infants, where the inoculation occurs during birth, both eyes almost always suffer. Treatment. — If only one eye be affected, and the patient be old enough to obey orders, the sound eye must be covered up w4th the shield introduced by Dr. Buller : Take two pieces of india-rubber plaster, one 4J'^, the other A" square, cut a round w indow in the middle of each, and stick them together, with a small watch-glass inserted into the window. The plaster is fixed by its free border, and by other strips, to the nose, forehead, and cheek, and the patient looks through the glass; the lower outer angle is left open for ventilation ; particular attention is to be paid to the fastening on the nose. All concerned are to be warned as to the risk of contagion and the means of con- veying it. The essential curative measures are : (1) Fre- quent removal of the discharge by the free use of weak antiseptic or astringent lotions (F. 3, 19, 20, 23, 28, 29). Every hour, day and night, the lids are gently opened, and the discharge removed with soft bits of moistened rag or cotton-wool ; or a syringe or irrigation apparatus, such as the hollow speculum or retractor described by Mr. Edgar Browne and Mr Collins, may be used.^ In adults, where the swelling is often extreme and very brawny, the cleans- ing must be done very gently lest the congestion and irri- tability be increased. (2) Iodoform, at first extensively tried, has, I believe, not given satisfaction in this disease. Many surgeons greatly prefer weak nitrate of silver (F. 3) to all other remedies. (3) Strong solutions of nitrate of silver or the mitigated solid nitrate (F. 1 and 2) are of great service in shortening the attack and lessening the risks, and, whatever other treatment be adopted, they should be used in all severe cases, unless specially contra- indicated. A ten- or twenty-grain solution is brushed ' British Medical Journal, 188.5, vol. i. GENERAL DISEASES. 109 freely over the conjiiiictiva of the lids, everted as well as possible and freed from discharge. If the mitigated stick is used, more care is needed ; and to prevent too great an effect it is to be washed off with water, after waiting about fifteen seconds. These strong applications must be made by the surgeon. The pain caused by them is lessened, and the benefit increased, by free bathing with cold or iced water afterward. The application is not to be repeated until the discharge, which will be markedly lessened lor some hours, has begun to increase again; once a day is enough in many cases. (4) Between the cleansings either warm or cold applications ; warmth is often preferred by the patient. (5) In the early stage, in adults, several leeches to the temple will give relief, or, if the swelling be very tense, we may divide the outer canthus with scissors or knife, and thus both bleed and relax the parts at the same time. Removal of the ring of conjunctiva which overlaps the cornea is valuable when the chemosis is severe. The late Mr. Critchett, in a very bad case, divided the upper lid vertically across, and kept its two halves turned upward by sutures fastened to the forehead, at once relieving the tension of the lids and rendering the conjunctiva acces- sible. (6) The'lids should be often anointed with a simple oiDtraent. The following additional precautions are important: Strong nitrate of silver applications are unsafe in the earliest stage, before free discharge has set in, and also in cases where, even later in the disease, there is much hard, brawny swelling of the ocular conjunctiva and compara- tively little discharge ; cases, in fact, approaching the con- dition known as diphtheritic ophthalmia. In these either verv cold or very hot applications, leeches, cleanliness, and weak lotions should be chiefly relied upon. Ice and leeches are seldom advisable for infants. It is of extreme import- ance to begin treatment very early, for the cornea is often 110 DISEASES OF THE CONJUNCTIVA. irreparably damaged within two or three days. The patients, if adults, are often in feeble health, and need sup- porting treatment. Ulceration of the cornea does not con- tra-indicate the use of strong nitrate of silver if the discharge is abundant. Treatment must be continued so long as there is any discharge, for a relapse of purulent discharge often takes place if remedies are discontinued too soon. Over-use of nitrate of silver sometimes seems to cause the diffuse opacity of the cornea referred to at p. 107 ; I have seen it clear quickly and entirely when eserine was used. I once saw hemorrhage continuing for some time, without apparent cause, from the conjunctiva of the lid, in a child recovering from purulent ophthalmia. Serious conjunc- tival hemorrhage has been noted by Pomeroy and Schmidt- Rimpler. The systematic prevention of ophthalmia neonatorumhj the cleansing and disinfection of the eyes of every infant immediately after birth, sometimes preceded by disinfec- tion of the maternal passages, has been introduced by Crede during the last three or four j^ears, and largely carried out in many lying-in hospitals, especially on the Continent. Crede applies a few drops of a 2 per cent solution of nitrate of silver (about 8 gr. to ^j) to the conjunctival sac once. Various other agents or weaker solutions of silver have been used. The general result of such measures has been to reduce the number of cases in an astonishing degree ; and as it is calculated that about a third of all the blind in Europe have become so by the ravages of this dis- ease, considerable importance is to be attached to the general adoption of Crede's principle by medical men and midwives.^ Muco-purulent ophthalinia The commonest and best characterized of the acute ophthalmia is the so-called 1 Particulars and statistics may be found in " Edinburgh Medical Journal," April, 1888 (Dr. A. R. Simpson), and in more recent papers. GENERA li DISEASES. Ill catarrhal ophthalmia. The name is a bad one, for neither does the disease form part of a general catarrh of the respiratory tract, nor does it show the tendency to relapse so characteristic of catarrh, nor does it seem to be caused by cold. The disease attains its height very quickly, almost always attacks both eyes, and gets well spontaneously in about a fortnight. There is great congestion, much gritty pain, which often prevents sleep, spasm of the lids, free muco-purulent discharge, and, in many cases, ecchy- motic patches in the conjunctiva. The lids are somewhat swollen and red, but never tense, and the cornea seldom suffers. This disease seems to be much oftener communicated from person to person than purulent ophthalmia, for which it is sometimes mistaken. It varies much in severity, even in different members of the same household, who catch it almost at the same time, but attacks all ages indiscrimi- nately. It is, I believe, commonest in warm weather, or perhaps at the change from cold to warm. It is rare to find that the patient has suffered from the disease before. Any mild antiseptic lotion Avill cut it short, nitrate of silver (F. 3) being the best. Troublesome ophthalmia, with muco-purulent discharge, is common in chWdren after exanthemata, especially measles. It runs a less definite course than the preceding disease, shows but little tendency to spontaneous cure, and is very often complicated with phlyctenular ulcers of the cornea, blepharitis, and eruptions on the face ; the patients are frequently strumous. The discharge is seldom so abundant as in the disease just considered. The treatment is often troublesome, and many changes have to be tried ; weak nitrate of silver lotions (F. 3), with the use of the yellow ointment (F. 12 to 14), or boracic acid ointment, both to the skin and conjunctiva, or calomel dusted into the eye, are the best local means ; atropine alone often increases 112 DISEASES OF THE CONJUNCTIVA. the irritation. Careful attention to health is necessary. The patients should not be confined to the house, but with a large shade over both e^^es should take plenty of exercise in fine weather. The eyes should not be bandaged in any form of ophthalmia, and ^^oidtices are very seldom suitable. Some forms of acute conjunctivitis, with little or no discharge, are seen both in children and adults, which do not conform to the above types, and are of comparatively slight importance. Many such appear to depend on changes of weather or exposure to cold, and are compli- cated with phlyctenulge. A few are distinctly rheumatic. The conjunctiva is involved more or less in herpes zoster of the ophthalmic division of the fifth nerve, in erysipelas of the face, in the early stage of measles, and slightly in eczema of the face. Slight degrees of chronic conjunc- tivitis are set up by various local irritants, dust, smoke, cold wind, etc., and by the strain attending the use of the eyes without glasses in cases of hypermetropia. Mention must be made of the cases sometimes seen in children, where an ophthalmia appears to form part of an impeti- ginous or herpetic eruption on the face, with which it is simultaneous. These again differ from the commoner cases in which the lids, cheek, and lining membrane of the nose are irritated into an eruption by tears and discharge from a pre-existing conjunctivitis. Muco-purulent ophthalmia of any kind becomes a very important affair if it breaks out in schools or armies, etc., where granular disease of the eyelids is prevalent. Membranous and diphtheritic ophthalmia. — In a few cases of ophthalmia, either purulent or muco-purulent, the discharge adheres to the conjunctiva in the form of a mem- brane, membranous or croupous ojjhthalmia. Still more rarely, in addition to membrane on the surface, the whole depth of the conjunctiva is stiffened by solid exudation, which much impairs the mobility both of the lids and eye- GENERAL DISEASES. 113 balls, and, by compressing the vessels, prevents the forma- tion of free discharge, and places the nutrition of the cornea in great peril. It is to the latter cases that the term diph- theritic has been limited by most authors ; but we find many connecting links between the two types, and between each of them and the ordinary purulent and muco-purulent cases. It is of much consequence in practice, both for prognosis and treatment, to recognize the presence of membranous discharge and of solid infiltration in any case of ophthal- mia ; for the liability to severe corneal damage is much increased l)y either of these conditions, especially by the latter. The membrane may cover the whole inside of the lids, or it may occur in separate or in confluent patches ; it often begins at the border of the lid, and is seldom found on the ocular conjunctiva. It can be peeled off, the con- junctiva beneath bleeding freely unless infiltrated and solid ; in the latter case the membrane is more adherent, the con- junctiva is of a palish color, and scarcely bleeds when exposed, and there is little or no purulent discharge. In most cases the solid products, whether membrane or deep infiltration, pass after some days into a stage of liquefac- tion, with free purulent secretion. In rare cases the mem- brane forms and reforms for months. As regards cause: (1) very rarely the process creeps up to the conjunctiva from the nose in cases of primary diphtheria, or is caused by inoculation of the conjunctiva with membrane; whilst in a few the ophthalmia forms the first symptom of general diphtheria, or of masked or anomalous scarlet fever. (2) more commonly it is part of a diphtheritic type of inflam- mation following some acute illness ; (3) it may be caused by the over-use of caustics in ordinary purulent ophthalmia ; (4) it may be due to contagion, either from a similar case or from a purulent ophthalmia, or a gonorrhoea, the diph- theritic type depending on some peculiarity in the health 114 DISEASES OP THE CONJUNCTIVA. or tissues of the recipient. Membranous and diphtheritic ophthalmia are seen most often in children from two to eight years old, less commonly in adults and infants. It is commoner in North Germany than in other parts of Europe, but severe and even fatal cases are well known in our own country. In two cases I have seen the same con- dition attack the skin of the eyelids and cause sloughing patches. In treatment the cardinal point is not to use nitrate of silver in any form when there are scanty discharge and much solid infiltration of the conjunctiva. The agents to be relied on are : (1) either ice or hot fomentations ; ice, if it can be used continuously and well ; fomentations, to en- courage liquid exudation and determination to the skin if the cold treatment cannot be carried out, or fails to make any impression on the case ; (2) leeches, if the patient's state will bear them ; (3) great cleanliness. The presence of membrane is no bar to the use of caustics, provided that the conjunctiva is succulent, red, and bleeds easily. Mr. Tweedy strongly advises quinine lotion used very fre- quently (F. 27). Partial Diseases. Granular ophthalmia (trachoma) is a very important malad}^, characterized by slowly progressive changes in the conjunctiva of the eyelids, in consequence of which this membrane becomes thickened, vascular, and roughened by firm hemispherical elevations, instead of being pale, thin, and smooth. The change usually begins in the conjunc- tiva of the lower lid, extending to the submucous tissue of both lids at a later period, and giving rise to the growth of much organized new tissue in the deep parts of the conjunctiva. The tissue is afterward partly absorbed and partly converted into dense, tendinous scar, which by very PARTIAL DISEASES. 115 close shrinking often gives rise to mnch trouble. It is stated by Reid and others that trachoma follicles come to the surface, open, discharge their contents, and leave minute ulcers ; but it cannot be said clinically that trachoma is an ulcerative disease, and the prominences are not " granula- tions" in the pathological sense. ^ There have been, and still are, extraordinary differences of opinion as to the origin and nature of the " granulations" or ''trachoma bodies" in this disease. The latest researches favor the view that they are derived either from natural lymphatic follicles or from tubular glands. The question is very difficult, whether from the histological or the clinical point of view, though we may hope that it will be simplified if Sattler's view that trachoma is due to a specific coccus be confirmed, 18S1 and 1882. Fig. 40 shows a section through some recent trachoma bodies. Fig. 40. X14 Microscopical section through four recent trachoma bodies (" sago- grain granulations") , from the lower lid of a young Irish soldier whose eyes became affected in the late Egyptian campaigns. The epithelial cells became almost indistinguishable from those of the growth where they cover the largest nodule. No reticulum can be made out between the cells of which the growths are composed. The disease is first shown by the presence, on the lower lid, of a number of rounded, pale, semitransparent bodies like little grains of boiled sago, or sometimes looking like vesicles; the so-called "vesicular," or "sago-grain," or "follicular" granulations, Fig. 41. Judging clinically, ^ I am aware that Raehlmann makes a contrary statement. lie DISEASES OF THE CONJUNCTIVA. they are, to a certain degree, normal, and are seen, espe- cially on the lower lids, in many young persons with slight ophthalmia, who never afterwards suffer from true granu- lar lids. Such mild cases, in which no parts deeper than the normal lymphatic follicles and papillae are affected, and in which recovery takes place without cicatricial Fig. 41. Granular lower lid. (After Eble.) changes, are by Saemisch and some other authors placed, under the name of conjunctivitis follicular is, in a separate category from the granular disease ; the two conditions being supposed due to radically different causes. But the frequent coincidence of transitional forms in the same case, the fact that both " follicular conjunctivitis-' and well- marked granular disease admittedly occur under the same general conditions, and that in a given case the distinctions between " follicles" and " granulations'' often cannot be made until it is known whether or no cicatricial changes will occur, certainly much lessen the clinical value of the asserted pathological difference. Granular disease is very important because it greatly increases the susceptibility of the conjunctiva to take on acute inflammation and to produce contagious discharge; makes it less amenable to treatment, and very liable to relapses of ophthalmia for many years; and often gives rise to deformities of the lid and to serious damage of the cornea. In crowded poor-law schools we see many cases of granular lids in which there is no history of an acute PARTIAL DISEASES. 117 attack having ever occurred, but in ordinary practice it is rare to see such. Chronic granular disease is the result (I) of prolonged overcrowding, or rather of long residence in badlv-venti- lated and damp rooms; it used to be very abundant in the army and navy, and is still seen in great perfection in workhouse schools ; (2) a generally low state of health, no doubt, increases the susceptibility to it ; (3) it is, cseteris paribus, commonest and most quickly produced in children ; (4) certain races are peculiarly liable to suffer, e. g., the Irish, the Jews, and some other Eastern races, and some of the German and French races. The Irish and Jews carry it with them all over the world, and transmit the liability to their descendants wherever they live. Negroes in Amer- ica are said to be almost exempt; (5) damp and low-lying climates are more productive of it than others ; thus it is rare in Switzerland. Possibly w^hat are now race tenden- cies may be the expression of climatal conditions acting on the same race through many generations. It is difficult clinically to decide whether the trachoma growths, apart from the discharge, are caused by contagion, or by the in- fluence of non-vital causes, such as damp and impure air ; many high authorities held for a long time that the chronic disease was contagious, and even communicable at a dis- tance through the air, without the presence of any appre- ciable discharge. When accompanied by discharge, the disease is contagious : and it is generally held that the dis- charge from a case of trachoma is specific, i. e., that it will give rise by contagion, not only to muco-purulent or puru- lent ophthalmia, but to the true granular disease. Sattler in 1881-2 believed that he had discovered a spe- cific microbe for trachoma ; bis results have been substan- tially confirmed by Michel and others, and it is held by Koch and other recent investigators that in mixed cases ot catarrhal and granular disease two specific microbes exist. 118 DISEASES OF THE CONJUNCTIVA. Should this prove true, it will at once simplify and explain the varying characters of contagious ophthalmia compli- cated by granular lids. Those who practise in the army, or who have charge of such institutions as pauper schools, will find that in prac- tice the causes of the chronic granular condition are in- extricably mixed up with all kinds of facilities for con- tagion, and that it will be necessary to fight against two enemies — the cause of spontaneous chronic granular dis- ease, and the sources of contagious discharge. The former is to be combated by improved hygienic conditions, espe- cially by free ventilation, dry air, abundant open-air exer- cise, and improvement of the general vigor. The sources of contagion are endless, especially since, as has been stated, granular patients are liable to relapses of muco- purulent discharge from almost any slight irritation. Fre- quent inspection of all the eyes, rigid separation of all who show any discharge or are known as especially subject to relapses, arrangements for washing such as will prevent the use of towels and water in common, extreme care against the introduction of contagious cases from without — such are the chief preventive measures. Extra precautions will be needed in time of war or famine, or when measles or scarlet fever is prevalent, or during marches through hot, sandy, or windy districts. The curative treatment, when discharge is present, does not differ from that of the acute ophthalmiae already given. The use of strong astringents (solid sulphate of copper) or caustics (nitrate of silver in strong solution, or in the miti- gated solid pencil), however, is generally needed in order to make much impression on the granular state of the lids. The lids being thoroughly everted, are touched all over with one or other application, and this is repeated daily, or less often ; some experience being required before we can decide how often to touch the evelids in each case. PARTIAL DISEASES. 119 B}" careful treatment on this principle most patients may be kept comfortably free from active symptoms, many relapses may be prevented, the duration of the disease shortened, and the risks of secondary damage to the cornea much lessened. Do what we will, however, granular dis- ease when well established is most tedious, and fastens many risks and disabilities on its subjects for 5^ears to come. For routine treatment on a large scale nothing is so effectual as nitrate of silver, either a ten- or twenty-grain solution or the mitigated solid point (F. 1 and 2). But silver has the disadvantage of sometimes permanently staining the conjunctiva after long use, and in very chronic cases I think either sulphate of copper or the lapus divi- nus (F. 5) is to be preferred, especially as the patient may sometimes be taught to evert his own lids and use it him- self. The solid mitigated nitrate of silver needs washing off with w^ater at first, but in old cases it is often better not to do so. Results of granular disease Friction by the granula- tions of the upper lid, a, Fig. 42, especially in cases of long standing where some scarring is present, 6, often causes Fig. 42. a'' Granular upper lid. a. Granulations, h. Line of scar in t3'pical position, parallel with border of lid. cloudiness of the cornea, partly from ulceration, but mainly from the growth of a layer of new and very vascular tis- 120 DISEASES OP THE CONJUNCTIVA. sue, in the superficial layers of the cornea — pannus,^ Fig. 43. In later periods the conjunctiva and deeper tissues are shortened and puckered by the scar following absorp- tion of the "granulations," Fig. 42, b. These changes, when severe, often lead to inversion of the border of the lid, entropion ; when slighter, some or all of the lashes may be distorted so as to rub against the cornea, without actually turning inward, ^is^zc/iiasis,^?'zc/iiasis; and these conditions Fig. 43. Section showing layer of new and vascular tissue (pannus) between epithelium {Ept.) and cornea ( C) . *SW. Sclerotic. C. J/. Ciliary mus- cle. Sch. C. Schlemm's canal. /. Iris. X about 10 diameters. are often combined with pannus. Pan nus begins beneath the upper lid, its vessels are superficial and continuous with those of the conjunctiva, and are distributed in rela- tion to the parts covered by the lid, not in reference to the structure of the cornea. Fig. 44. The proper corneal tis- sue suffers but little except where ulcers occur ; but when the vascularity is extreme it may soften and bulge, even without ulcerating. 1 It is doubtful how far the development of pannus is due to friction, or to extension of the trachoma over the sclerotic to the cornea. Tra- choma bodies may certainly be sometimes seen on the ocular conjunc- tiva. Raehlmann states that the first sign of pannus consists in a col- lection of lymph-cells in the cornea beneath Bowman's membrane ; subsequently a layer resembling adenoid tissue is found there containing blood and lymphatic vessels. That friction may alter the epithelium is proved by certain cases in which the upper half of the cornea loses its polish during a temporary papillary roughening of the upper lid. PARTIAL DISEASES. 121 Pannus disappears when the granular lid or the displace- ment of lashes is cured. Yery severe and universal pannus is sometimes best treated by artificial inoculation with puru- lent ophthalmia, the inflammation being- followed by oblit- eration of vessels and clearing of the cornea ; but this Fig. 44. Pannus affecting upper half of cornea. treatment needs great judgment and caution. More re- cently an infusion of the seeds known in commerce as "jequirity" (F. 40) has been introduced into Europe by de Wecker. It acts in much the same way as pus from purulent ophthalmia, but less severely ; a very acute attack of diphtheritic or purulent ophthalmia with much swelling comes on a few hours after the infusion has been used, lasts a few days, and is followed by more or less shrinking of the trachoma bodies and of the vessels. It occasionally causes glandular swellings in the neck and considerable general disturbance. Repeated attacks may be induced with safety at intervals of a few weeks. Jequirity proba- bly depends for its action upon a non-organized ferment such as is found in some other seeds. Sattler believed, from experiment, that a specific bacillus was the active agent, 1883, but his results have been negatived by Wid- mark, Klein, and several others ; whilst an albuminous ex- tract free from organisms, but possessing the peculiar prop- 6 122 DISEASES OF THE CONJUNCTIVA. erties of the infusion of the seed, has been separated by Warden and Waddell, Salomonsen, and others.^ Much dif- ference of opinion exists as to the clinical value of jequirity, owing to its having been often employed too strong and in unsuitable cases; it is not safe unless there are vessels on the cornea, and, safety apart, it is of little or no use if the conjunctiva be succulent and producing pus. It should be reserved for old, dry, granular lids with more or less pan- nus, and in such I have repeatedly had excellent results from it. Removal of a zone of conjunctiva and subcon- junctival tissue, syndectomy ,peritomy , from around the cor- nea is free from risk and sometimes very beneficial in old eases which, though severe, are not bad enough for inocu- lation. In old cases of granular disease, even where no complications have arisen, the upper lids often droop from relaxation of the loose conjunctiva above the tarsal carti- lage, and the patient acquires a sleepy look. For the cure of the displaced lashes and incurved eye- lids we may: (1) repeatedly pull out the lashes with for- ceps ; (2) extirpate all the lashes by cutting out a narrow strip of the marginal tissues of the lid ; (3) attempt by operation to restore the lashes to their proper direction, Chap. XXII. ; (4) employ electrolysis ; for a few^ lashes I now use sewing needles, inserting several at a time into the hair follicles, and passing the current through all at once, by means of a broad eyelid forceps ; such operations well selected and carefully performed give very good results ; but as the inner surface of the lid continues to shorten, and this shortening tends to reproduce the original state of things, some of these procedures give only temporary relief. Chronic conjunctivitis, chiefly of the lower lid, is a common disease, especially in elderly people. There is 1 Mr. Martindale last year went to considerable trouble in trying to prepare such an active principle for me, but unfortunately the substance he separated was almost inert. PARTIAL DISEASES. 123 more or less soreness and smarting, redness and papillary roughness of the inner surface of the lid or of both lids, but very little discharge and no trachoma granulations. The caruncle is red and fleshy, as it is in all forms of pal- pebral conjunctivitis, and there is often soreness of the lids at the canthi. Lapis di vinus is one of the best applications, and yellow ointment is sometimes useful (F. 5 and 12.) Lachrymal conjunctivitis. — Troublesome chronic con- junctivitis, often complicated by small pustules at the roots of the lashes, or by chronic blepharitis, is a common result of lachrymal obstruction. Recently microorganisms of several kinds associated with pus-formation have been found in these little abscesses as well as in pus from the lachrymal sac (Widmark). Palpebral conjunctivitis of long standing with watering, gummy discharge, and more or less blephar- itis, should, especially if confined to one eye, always lead to the suspicion of mucocele or chronic lachrymal abscess. The rare disease described as Amyloid of the Conjunctiva seems scarcely to have been noticed in this country. De- tailed accounts of its clinical and pathological characters may be found in Knapp's Archives of Ophthalmology, vols. X. and xi., and an excellent abstract of one of these papers appeared in the Ophthalmic Review for August, 1882. Spring catarrh. — A peculiar and apparently specific chronic disease, affecting the conjunctiva of the globe and upper lid. In the former situation it takes the form of confluent broad patches of fleshy-looking thickening of a light brown-pink color, slightly overlapping the edge of the cornea for a considerable part of its circumference. In the latter situation it occurs as large, pale, flat-topped granulations, which are sometimes made to assume poly- gonal outlines by their pressure upon one another. They begin, like trachoma, at the inner and outer end of the lid : either variety may occur separately. The disease is worst in the warm part of the year, but it lasts in some cases 124 DISEASES OF THE CONJUNCTIVA. many years, and gives but little ti'ouble ; the growths on the upper lid do not produce pannus. The thickening is said to consist chiefly of epithelium, and not to affect the deep tissues. Treatment by nitrate of silver is unnecessary ; occasional touching of the larger granulations by the galvano-cautery is the best treatment. Unlike trachoma, it occurs com- monly in all classes of society, and is probably not con- tagious ; hence its differential diagnosis in children at school is very important. Hitherto it has not been noticed much in this country, but probably it is not so rare as has been thought. Conjunctivitis from drugs. — The local use of atropine sometimes gives rise to a peculiar inflammation of the con- junctiva and skin of the lid — atropine irritation. The conjunctiva of the lids becomes vascular, thickened, and even granular, and usually the skin is reddened, slightly excoriated, and somewhat shining. This effect of atropine is commonest in old people. Some persons are very sus- ceptible, and cannot bear even a drop or two without suf- fering in some degree. Daturine and duboisin cause less irritation and may be used instead ; but it is better, if pos- .sible, not to use mydriatics at all for a few days. An ointment containing lead and zinc should be applied to the lids, and zinc or silver lotion to the conjunctiva ; some- times glycerine suits better than ointment. In susceptible persons I have not found this peculiar inflammation pre- vented, either by the use of solutions made with antiseptics, or of solutions quite freshly made. Eserine sometimes causes identical symptoms. Congestion of the conjunctiva has been seen among those employed in aniline dye-works ; conjunctivitis was seen by Trousseau in 4 to 5 per cent, of patients treated for psoriasis by chrysophanic acid. If con- tinued long enough, arsenic will in some persons produce PARTIAL DISEASES. 125 redness and congestion of the conjunctiva. The action of jequiritj is described on p. 121. Primary shrinking of the conjunctiva (Pemphigus of Conjunctiva). — A very peculiar and rather rare disease, in which, with the phenomena of chronic inflammation, the whole conjunctiva slowly atrophies and contracts, owing to the formation in it of cicatricial tissue. During the earlier stages, the thickening of the tarsus and the congestion, with scarring of the palpheral conjunctiva, have sometimes led to the disease being mistaken for trachoma ; the two mala- dies are, however, quite distinct. Finally, the whole con- junctival sac disappears, and the free borders of the lids, fixed closely to the globe, are directly continuous with the cornea, which , irritated and dried by exposure and want of secretion, becomes opaque and covered with crusts — "xerosis." No treatment seems of any use. In some of the cases there has been a history of general pemphigus, and reason to believe that the disease of the conjunctiva resulted from a modified form of pemphigus eruption. CHAPTER YII. DISEASES OF THE CORNEA. A Ulcers and Non-specific Inflammatory Diseases. Inflammation of the cornea may be circumscribed or diffuse, and, though usually affecting the proper corneal tissue, may be limited to the epithelium on either of its surfaces. It may be a local process leading to formation of pus or to ulceration ; or the expression of a constitu- tional disease, such as inherited syphilis ; or it may form part, and perhaps only a minor part, of disease involving also the deeper parts of the eyeball — the iris (kerato-iritis) or sclerotic (sclero-keratitis), for example. The different varieties of corneal ulceration and suppu- rative inflammation form a very large and important con- tingent of ophthalmic cases. The cornea, although a fibrous structure, is further removed from the bloodvessels than almost any other tissue, and its delicate surface is much exposed; it is, therefore, extremely susceptible both to external irritants and to disturbances of nutrition from defective supply, or bad quality, of blood ; ulceration of the cornea always means deficient vitality. Lastly, its sur- face is so delicate, and its perfect transparency and regu- larity so important, that slight injuries and irritations are of more moment here than in any other part of the body. When inflamed, the cornea always loses its transparency. If only the anterior epithelium be involved, the surface loses its polish, and looks like clear glass which has been breathed upon — "steamy," or finely pitted^-a condition NON-SPECIFIC INFLAMMATORY DISEASES. 127 occurring- in many states of disease. Thickening of the epithelium, and, still more, exudation into the corneal tissue, is shown by a white, grayish, or yellowish tint. If the corneal tissue be opalescent, while the surface is at the same time "steamy, "the term "ground-glass" gives a good idea of the appearance, though, to make the simile correct, the glass ought to be milky throughout, as well as ground on the surface. Rapid suppurative inflammation is preceded by a stage of diffused opalescence ; hence rapid opalescence is a sign of imminent danger in such diseases as purulent ophthalmia, severe burns, or paralysis of the fifth nerve. Fluorescence of the cornea has been seen as the result of the use of quinine lotions to the eye, and appears to be due to the deposit of crystals of quinine in the cornea. Before describing the most important types of corneal ulcer, it is convenient to mention the principal changes at- tendant on ulceration of the cornea in general. An ulcer of the cornea is preceded by a stage of infiltration, and the inflamed spot is generally a little raised. After the centre of the spot has broken down into an ulcer, the extent, density, and color of the infiltration at its base and edges are important guides to its future course. The ulcer, when healed, leaves a hazy or opaque spot, leucoma if dense, nebula if faint, which is slight, and may disappear entirely if superficial, but will in part be permanent if the ulcer have been deep. These opacities are likely to clear, cseteris paribus, in proportion to the youth of the patient; time, also, is a very important element, nebulae often continuing to clear slowly for years ; local stimulation aids in the re- moval of the opacities, one of the best applications being the ointment of yellow oxide of mercury (F. 12, 13). Other modes of local stimulation have been recommended, such as tattooing, massage, electrolysis, and the use of various powders. Several successful attempts have been made to transplant circular portions of the clear cornea 128 DISEASES OF THE CORNEA removed from the rabbit by a trephine, to replace portions of the hnman cornea rendered opaque by disease. To do this successfully it is necessary to leave behind Descemet's membrane in the diseased cornea (v. Hippel). Ulcers which have little or no infiltration often heal slowly, but leave a permanent facet or flattening; such facets destroy the regular curvature of the cornea, and thus often cause more damage to vision than a considerable degree of mere clouding. During repair bloodvessels often form and pass from the nearest part of the corneal edge to the ulcer, to disappear when healing is complete ; phlyctenular ulcers, however, are vascular from the beginning. Corneal im- perfections are, of course, most damaging to vision when placed over the pupil. The chief sywjjtoms of corneal ulceration are : (l)p/?o- tophobia, with its consequence, spasm of the orbicularis, blepharospasm ; (2) congestion ; (3) pain. All three symp- toms vary extremely in degree in different cases. As a broad rule with many exceptions, we may say that toler- ance of light is worse in children than in adults, worse with superficial than with deep ulcers, and worse in persons who are strumous and irritable than in those with healthy tissues and good tone. Photophobia should always lead to a careful inspection of the cornea, and we shall then some- times be surprised to find how slight a change gives rise to this symptom in its severest form. The degree of conges- tion varies with the seat and cause of the ulcer, and with the patient's age, being usually greatest in adults. The visible congestion is, as in iritis, due especially to disten- tion of the subconjunctival twigs of the ciliary zone, Fig. 25, Ant. Cil., and Fig. 28, bat there is often congestion of the conjunctival vessels as well. In some forms of mar- ginal ulcer, only those vessels which feed the diseased part are congested. Great pain in and around the eye often at- tends the earlier stages of corneal abscess, and is common NON-SPECIFIC INFLAMMATORY DISEASES. 129 in Diany acute ulcers ; as a symptom, it, of course, always needs careful attention ; it is generally relieved by those local measures which are best for the disease itself. Types of Corneal Ulceration. (1) One of the simplest forms is the small ceritral ulcer often seen in young children. A little grayish-white spot forms in the central part of the cornea, at first elevated and bluntly conical, afterward showing a minute shallow crater ; the congestion and photophobia vary, but are often slight. The ulcer is usually single, but it is apt to recur in the same or the other eye. The infiltration often extends into the corneal tissue, and the residual opacity remains for a long time, if not permanently. The patients are always •badly nourished. In most cases the ulcer Cjuickly heals, but now and then the infiltration passes into an abscess, or a spreading, suppurating ulcer. (2) Less commonly we meet with a central ulcer, or a succession of ulcers, of a much more chronic character, and attended with little or no infiltration. After lasting for months the loss of tissue is only partly repaired, and a shallow depression or a flat facet is left with but little loss of transparency. Some of the best examples are seen in anaemic or strumous patients with granular lids of long standing. (3) Phlyctenular ophthalmia andphlycienular ulcers of cornea (phlyctenulae, herpes corneje, pustular ophthalmia, marginal keratitis, " strumous ophthalmia "). — The forma- tion of little papules, or pustules, on or near the corneal margin is exceedingly common, either independently or as a complication of some existing ophthalmia. Although there are many varieties and degrees of phlyctenular in- flammation in respect to the seat, extent, and course of the disease, the following features are common to all : They 6* 130 disp:ases of the cornea. show a strong tendency to recur during several years ; they are seldom seen in very young children, and comparatively seldom after middle life ; they occur so often in strumous subjects, that we are justified in suspecting scrofulous ten- dencies in all who suffer much from them ; ophthalmia tarsi is often seen in the same patients ; the first attack often follows closely after an acute exanthem, and especi- ally after measles ; the cases are much influenced by climate and weather, and their condition often varies extremely from day to day without making either progress or re- gress. An elevated spot, like a papule, commonly about the size of a small mustard-seed, is seen either on the white of the eye near the cornea, or upon, or just within, the corneal border. It is preceded and accompanied by localized con- gestion. Its top sometimes becomes as yellow as that of an acne pustule, but more often when seen it has become abraded and aphthous-looking. Pustules at a little dis- tance from the cornea, Fig. 45, although generally larger than those seated on the corneal border, occasion less pho- tophobia and are more easily cured. Pustules at the cor- neal border, though often very small, cause troublesome, and even very severe, photophobia ; they are troublesome in proportion rather to their number than their size, and if so numerous as to form a ring around the cornea, their cure is often very tedious. A pustule is always liable, even when it has begun on the conjunctiva, to advance as a superficial ulcer on to the cornea, though it never extends in the opposite direction over the sclerotic. Such a phlyctenular ulcer, if it do not stop near the corneal border, will make, in an almost radial direction, for the centre, carrying with it a leash of vessels which lie upon the track of opacity left in the wake of the ulcer. Fig. 46. Finally, the ulceration stops, the vessels dwindle and disappear, but the path of opacity seldom NON-SPEGIFIO INFLAMMATORY DISEASES. 131 clears up entirely. The term recurrent vascular ulcer is used when such ulcers are solitary ; but they are often multiple as well as recurrent, and then, in the end, we find the cornea covered by a thin, irregular network of super- ficial vessels on a patchy, uneven, hazy surface, the so- called "phlyctenular pannus.''^ Fig. 45. Fig 46. ^^ Phlyctenular ophthalmia, conjunc- tival form. (Dabymple.) Phlyctenular ulcer. (Travers.) A common variety of phlyctenular inflammation, aptly called marginal conjunctivitis, perhaps allied to the "spring catarrh''^ of Continental authors, occurs in the form of a slight, granular-looking, often vascular, swelling, begin- ning crescentially above or below, but often extending all around the edge of the cornea. If the process continue, the cornea is invaded by a densely vascular, superficially ulcerated, and yet thickened zone. It is to be distinguished from a deeper variety of marginal keratitis alluded to at p. 140. In another variety a single pustule just within the border of the cornea ulcerates deeply, becomes surrounded by swollen, softened, suppurating tissue, and may perforate : such cases are seen in weakly women and strumous chil- dren. In very rare cases, what appears to be an ordinary conjunctival pustule, persists, grows deeply, and may even 132 DISEASES OF THE CORNEA. perforate the sclerotic in the form of an ulcer ; or it may- infiltrate the sclerotic and ciliary body beneath, forming a soft, semi-suppurating tumor, whence the inflammation is likely to spread to the vitreous and destroy the eye. Stop- ping short of these extreme results, such a case forms one type of episcleritis. Chapter IX. Occasionally a large, sometimes solitary blister forms under the anterior corneal epithelium ; it rises quickly, is attended by severe neuralgic pain, which is often relieved when the vesicle bursts, about a day after the onset. The condition is liable to relapse in the same cornea, and seems often, though not ahva3'S, to have its origin in a superficial injury. See Abrasion. The corneal changes produced by the friction of granular lids have been considered under that subject. The pannus of granular lids usually differs from the "phlyctenular pannus '' just mentioned in being more uniform and worse beneath the upper lid, Fig. 44 ; any doubt is dispelled by everting the lid. But it must be borne in mind that ulcer- ation of the cornea often occurs as a complication of tracho- matous pannus. (4) In old persons a crescentic ulcer sometimes forms in the situation of, or actually upon, an arcus senilis. Though these cases generally do well, they should be watched, for at first they may be indistinguishable from more serious forms about to be described. (5) Infective corneal ulcers. — Several varieties of dan- gerous corneal ulcer may be grouped together as probably depending upon local infection, and there seems to be no doubt that destructive inflammation of the cornea may occur in utero. Differing widely in rapidity and depth, they agree in being often the result of slight injuries by chips of metal, beards of corn, etc., in tending to spread at one border, whilst healing at another, in the absence of " vessels of repair," such as are usually formed during the NON-SPECIFIC INFLAMMATORY DISEASES. 133 healing of other ulcers, and in being often complicated with hypopyon. Fig. 48. The most important variety is the acute serpiginous ulcer, which begins as a gray spot showing slight ulceration, and having a sharply-cut border, one pa7't of which is more Fig. 47. Acute serpig-inous ulcer of cornea with crescentic border of infiltration. (From a sketch by Dr. Herbert Habershon.) densely opaque than the rest, Fig. 47 ; this infiltrated, ad- vancing edge is the distinguishing mark of the ulcer. If the ulcer have lasted for some little time, a portion of its edge, usually that nearest the corneal border, will be more or less filled up ; in such a state the most conspicuous part of the ulcer is crescentic. Fig. 47. Unless quickly checked, the process often spreads widely, eats deeply, becomes com- plicated with iritis and hypopyon, and leads to perforation of the cornea. Probably man}^ cases of corneal abscess and acute sup- purating ulcer of less distinct type than the above are, like it, due to infection. Abscess may occur at any age, but, like serpiginous ulcer, is commonest in those who are old, underfed, or damaged by drink ; but the little gray central ulcers of children may go on to abscess. Abscess usually forms at the centre of the corneal area as a small, round, raised spot, with great pain and congestion; rapidly enlarging,it usually bursts forward, leaving a round ulcer covered with lymph\^ 134 DISEASES OF THE CORNEA. pus, but it may perforate the hinder surface of the cornea; hypopyon often occurs. The purulent infiltration may spread rapidly and destroy almost the whole cornea. Hypopyon signifies a collection of pus or puro-lymph at the lowest part of the anterior chamber ; its upper boundary is usually, but not always, level. Fig. 48. It may occur with any ulcer, whether deep or not, which is accompanied Fig. 48. Fig. 49. Hypopyon, seen from the front, and in section, to show that the pus is behind the cornea. a. Abscess, h. Onyx. by purulent infiltration of the surrounding cornea ; or with corneal abscess. The pus may be derived either from an abscess breaking through the posterior surface of the cornea, or from suppuration of the epithelium covering Descemet's membrane, or from the surface of the iris. Simple iritis now and then gives rise to hypopyon. The diameter of the anterior chamber being rather greater than the apparent diameter of the clear cornea, a very small hy- popyon may be hidden behind the overlapping edge of the sclerotic. In some cases of severe corneal suppuration (a, Fig. 49) the pus sinks down between the lamellae of the cornea (6). To this condition the term onyx is applied and should be limited, though it is sometimes used in other NON-SPECIFIC INFLAMMATORY DISEASES. 135 senses. The term, however, may verv well be discarded. Onyx and hypopyon often co-exist, and then the distinction between them can hardly be made without tapping the ante- rior chamber. Hypopyon, if liquid, will, but onyx will not, change its position if the patient lies down ; as, however, the pus of hypopyon is often gelatinous or fibrinous, this test loses much of its value. The distinction can sometimes be made by means of oblique illumination, if the cornea in front of an hypopyon remain clear. Chronic and subacute serpiginous ulcers are seen from time to time spreading for weeks or even months. They sometimes have the form above described, Fig. 47, but occasionally the ulceration takes the form of a stem with irregular broad buds or branches not unlike a liverwort, the disease being superficial from beginning to end, and showing no tendency to the formation of pus, but spoiling the surface of the cornea — dendritic creeping ulcer. Treatment of ulcers of the cornea. The principles of local treatment for the various types of corneal ulceration are : (1) To favor healing by keeping the surface at rest. (2) To relieve pain, photophobia, and severe congestion. (3) To promote absorption of pus, whether in the corneal layers or in the anterior chamber. (4) To check the spread of local infection by scraping, actual cautery, and antiseptics. (5) By incision to evacu- ate pus between the corneal layers (abscess), or in the anterior chamber (hypopyon), when abundant or increas- ing. (6) To stimulate the surface of ulcers which have begun to heal, or of indolent ones which are stationary. (7) Counter-irritation by a seton in certain chronic cases. (8) When the corneal ulceration is caused by granular lids, or associated with any form of acute ophthalmia, the 13G DISEASES OF THE CORNEA. treatment of the conjunctiva is usually more important than that of the cornea. Often we have no difficulty in deciding upon the treat- ment ; but in some cases, especially the severer ones, much judgment is needed, and it is sometimes impossible to predict with certainty what measures will be best. Ulcers of the cornea are so often a sign of bad health that every care should be bestowed upon the patient's general state. Treating the matter clinically, we shall find that local stimulation (6) is best for a large number of the cases as the}^ first come under notice, including phlyctenular cases, chronic superficial ulcers of various kinds, and even many recent ulcers if not threatening to suppurate. As a general rule, this plan alone is not suitable when there is much photophobia ; but exceptions occur, especially in old-stand- ing cases. The most convenient remedy is the ointment of amorphous yellow^ oxide of mercury (F. 12 and 13), of w'hich a piece about as large as a hemp-seed is to be put inside the eyelids once or twice a day. If smarting continue for more than half an hour, the ointment should be washed out with warm water ; and if the irritability increase after a few days' use of the ointment, the preparation must be weakened or discontinued. The same ointment, combined with atropine, gives excellent results in cases of superficial ulcer with much photophobia (F. 14). Calomel flicked into the eye daily or less often is also an admirable remedy. Nitrate of silver in the form of solid mitigated stick (F. 1) is useful if carefully applied to large conjunctival pustules, and occasionally to indolent corneal ulcers ; its use, how- ever, needs some skill, and is seldom really necessary : solutions of from 5 to 10 grains to the ounce may be cau- tiously used by the surgeon instead of the yellow ointment, and are particularly valuable in old vascular ulcers and in ulcers with conjunctivitis. When in doubt it is best to NON-SPECIFIC INFLAMMATORY DISEASES. 187 depend for a few days on atropine alone, used once or twice a day. Division of the outer canthus by scissors is sometimes employed for children with severe photophobia, but is only of temporary use ; free douching of the head and face, by putting the child's head under a tap of cold water, is some- times successful. In all cases of corneal disease attended with intolerance of light, the patient is to wear a large shade over both eyes, or, better, a pair of "goggles;" a little patch over one eye does not relieve photophobia. Many a child is kept within doors, to the injury of its health, who, with suitable protection, can go out daily without the least detriment to its e3'es. In chronic and relapsing cases, with photophobia and irritability, where other methods have had a fair trial, a seton gives the best results, whether the eye be much con- gested or not. The silk must be very thick ; the punctures should be at least an inch apart, and be so placed that the scars may be hidden by the hair on the temple or behind the ear. The seton is to be moved daily, and if acting badly may be dressed with savin ointment ; it should be worn at least six weeks. Severe inflammation, and even abscess, sometimes sets in a few days after the insertion of the thread, and in very rare cases secondary bleeding has occurred from a branch of the'temporal artery. To avoid w^ounding this artery the skin is to be held well away from the head. Yery severe, recent phlyctenular cases are occasionally difficult to influence, and remain practically "blind'' with spasm of the lids for weeks. There is seldom any risk, provided that the cornea be examined at intervals of a few days, and in the end such cases do well. Calomel dusted on the cornea sometimes helps more than any other local measure, and change of air, especially to the seaside, fre- quently effects a more rapid cure than any local treatment. 138 DISEASES OF THE CORNEA. Cases for which the stimulating treatment is suitable seldom need the eye to be banda<2^ed, though, as mentioned, they often need a shade or goggles. The remaining methods are applicable to the severer forms of ulceration — the serpiginous ulcer, deep suppurat- ing ulcers, abscess, and generally all ulcers with hypopyon, and all acute ulcers in elderly persons. In many cases of severe type, at an early stage, the pain may be relieved and the ulceration stopped by very hot fomentations (of water, poppy-head, or belladonna) to the eyelids for twenty minutes every two hours, the eye being tied up in the in- tervals with a large pad of cotton-wool and bandage, and atropine used two or three times a day ; the patient must rest, have good food, often with alcohol, and take quinine, or bark and ammonia. If, nevertheless, the ulceration spread, or an hypopyon form or increase, incision of the cornea and the use of topical remedies are called for. Of such remedies the best seems to be the actual cautery, pre- ceded by scraping with a sharp spoon, and followed by iodoform or boracic acid. The actual cautery may be either the fine galvano-cautery, or a very small Paquelin ; the edge of the ulcer is to be well burnt before the heat is applied to the floor, and I like to burn a little beyond the opaque edge. Iodoform, which is probably the most useful corneal anti- septic, may be used in powder or strong ointment (20 or 30 gr. to ^j ; F. 19), freely three times a day or more ; it gives no pain. Boracic acid may be used in the same way ; perchloride of mercury, of the strength of 1 in 1000, has also been used in cases of dendritic creeping ulcer. Hypopyon, if large, Fig. 48, or increasing, must be let out, and, on the whole, for most cases, Saemisch's plan of cutting through the cornea quite across the ulcer is the best for this purpose, because if there be pent-up pus in the cornea this section will allow its removal at the same time; NON-SPECIFIC INFLAMMATORY DISEASES. 139 the section should be made with a Graefe's cataract knife, Fig. 154, entered with its back toward the lens at one bor- der of the ulcer, carried across the anterior chamber, and brought out at the other side of the ulcer. It is sometimes an advantage to keep up leakage by reopening the wound with a probe for a few days. Corneal section also often instantly relieves the severe pain of these cases, and it has been strongly advocated for this purpose by Mr. Teale and others. The section may sometimes be made with equally good effect in the lower part of the cornea away from the ulcer. If the ulcer have already perforated and the eye be worth saving, iridectomy should be done, either by draw- ing the prolapsed iris freely through the perforation and cutting it off, or by making an incision in a sound part of the cornea. I believe that careful scraping and burning will do much to reduce the severity of infective corneal ulcers. Some of these ulcers are accompanied by a good deal of muco-purulent conjunctivitis, for which a ten-grain so- lution of nitrate of silver, painted inside the lower lid with a brush about once a day, may generally be used ; its effect must be watched, and its employment discontinued if it increase irritability. Use of atropine and eserine in severe ulcers of the cornea. Formerly either atropine or belladonna lotion was used for nearly every case of severe corneal ulcer. Atropine often relieves pain, prevents or lessens iritis, and probably lessens engorgement of the vessels of the iris and ciliary region ; it may generally be used, sparingly, as an auxiliary in suppurating and serpiginous cases. But atro- pine tends to increase any existing conjunctival inflam- mation, and by narrowing the area and contracting the vessels of the iris, it probably retards, rather than hastens, the absorption of pus in the anterior chamber. During the last few years eserine has come into use for certain 140 DISEASES OF THE CORNEA. cases which would formerly have been treated chiefly by atropine. The deep, funnel-shaped, suppurating ulcer which sometimes develops from a marginal pustule (p. 131) is the most suitable for treatment by eserine, whether complicated with hypopyon or not. Although in a bad case of this sort, hot fomentations and the compress are necessary, I have seen a certain number of less severe ones recover quickly under eserine alone, used about six times a day (F. 35). Eserine probably acts partly by enlarging the surface of the iris and dilating the ciliary arteries, and thus favoring absorption ; possibly, also, it acts locally on the ulcerated surface. There is no clinical proof that eserine lowers tension unless this were previously in- creased, as it seldom is in corneal ulcers. Eserine causes congestion of the deep vessels of the ciliary region, and after a time increases the photophobia and irritability of the eye: these symptoms usually coincide with disappear- ance of the corneal infiltration and the commencement of vascularization of the ulcer, and when this stage is reached the eserine should be discontinued The alternate use of heat and cold for short periods is recommended in some obstinate cases of corneal ulcer- ation, the object being to improve nutrition by causing frequent changes in the quantity and rate of the blood- supply. Rapidly destructive ulceration of the cornea is common in children dying of meningitis, and is probably due to the exposure and drying associated with the patients' semi- comatose state, but its occasional limitation to one eye sug- gests the thought that it may be in part directly due to trophic influence. Dr. Barlow tells me that very similar ulceration may occur in the severe exhaustion following infantile diarrhoea. Ulceration from exposure may also occur in severe cases of exophthalmic goitre. In all the above cases the ulceration usuall}' takes place between NON-SPECIFIC INFLAMMATORY DISEASES. 141 the centre and the lower edge, the part of the cornea which is last covered when the lids are closed and first exposed when they- are opened. General dense opacity of the cornea occasionally»comes on with extreme quickness in infants who are recovering from purulent ophthalmia. If it lead to destructive ulcera- tion, the term kerato-malacia hnot inappropriate; the opac-' ity sometimes, however, clears up in a remarkable and very unexpected manner. I have seen two such recoveries under the use of eserine. Conical cornea In this condition the central part of the cornea verv slowly bulges forward, forming a bluntly conical curve. The focal length of the affected part of the cornea is thereby shortened, and the eye becomes myopic. The curvature, however, is not uniform, and hence irregular astigmatism complicates the myopia. Chapter XX. The disease, which is rare, occurs chiefly in young adults, especially women, and is often associated with chronic dyspepsia ; its onset is sometimes dated from a severe, exhausting illness ; it appears to be due to defective nutrition of that part of the cornea which is furthest from the bloodvessels. In advanced cases the protrusion of the cornea is very evident, whether viewed from the front or from the side, but slight degrees are less easily distinguished from ordinary myopic astigmatism. In high degrees the apex of the cone, which is situated rather below the centre of the cornea, often becomes nebulous. The disease may progress to a high degree, or stop before great damage has been done. Concave glasses alone are of little use ; but they are sometimes useful in combination with a screen perforated by a narrow slit or small central hole, which allows the light to pass only through the centre, or through some one meridian of the cornea. In advanced 142 DISEASES OF THE CORNEA. cases an operation must be performed which, by substi- tuting a contracting cicatrix for the corneal tissue at or near the apex of the cone, shall lead to a diminution of the cuiivature. Chapter XXII. B. Diffuse Keratitis. Syphilitic, interstitial, parenchymatous, or " strumous^^ keratitis. In this disease the cornea in its whole thickness under- goes a chronic inflammation, which shows no tendency either to the formation of pus or to ulceration. After several months the inflammatory products are either wholly or in great part absorbed, and the transparency of the cornea restored in proportion. The changes in the cornea are usually preceded for a few days by some ciliary congestion and watering. Then a faint cloudiness is seen in one or more large patches, and the surface, if carefully looked at, is found to be " steamy " (p. 126). These nebulous areas may lie in any part of the Fig. 50. Interstitial keratitis. cornea. In from two to about four weeks the whole cornea has usually passed into a condition of white haziness with steamy surface, of which the term "ground-glass" gives the best idea. Even now, however, careful inspection, especially by focal light, will show that the opacity is by DIFFUSE KERATITIS 143 no means uniform, that it shows many whiter spots, or larger denser clouds, scattered among the general mist ; in very severe cases the whole cornea is quite opaque and the iris hidden ; but, as a rule, the iris and pupil can be seen, though very imperfectly. Fig. 50. In many cases iritis occurs and posterior synechiae are formed. Bloodvessels derived from branches of the ciliary vessels, Fig. 25, are often formed in the layers of the cornea, Fig. 51 ; they are small but set thickly, and in patches ; as they are covered by a certain thickness of hazy cornea, their bright scarlet is toned down to a dull reddish-pink color ("salmon patch" of Hutchinson). The separate vessels are visible only if magnified, when we see that the trunks, passing from the border, divide at acute angles into very numerous twigs, lying close to each other, and taking a nearly straight course toward the centre. Fig. 52. These salmon patches when small are often crescentic, but if large tend to assume Fig. 51. Thickening of cornea and formation of vessels in its layers in syphilitic keratitis. Subconjunctival tissue thickened. X about 10 diameters. Compare with Fig. 36. a sector-shape. In another type the vascularity begins as a narrow fringe of looped vessels which are continuous with the loop-plexus of the corneal margin, Fig. 53, com- pare Fig. 25, /, and gradually extend from above and below 144 DISEASES OF THE CORNEA. toward the centre. The vessels in these cases are some- what more superficial, and the cornealtissue in which they lie is always swollen by infiltration. This type, which forms a variety of ''marginal keratitis,^'' compare p. 131, usually Fig. 52. Fig. 53. Vessels in interstitial Marginal vascular keratitis, keratitis. occurs in syphilitic subjects, but I believe that some of the patients are at the same time strumous. A similar condi- tion, sometimes leading to secondary glaucoma, occurs now and then in elderly people. In extreme cases of either type of vascular keratitis the vessels cover the whole cornea, except a small central island. The degree of congestion and the subjective symptoms in syphilitic keratitis vary very much ; as a general rule, there is but moderate photophobia and pain, but when the ciliary congestion is great these symptoms are sometimes very severe and protracted. The attack can be shortened and its severity lessened by treatment ; but the disease is always slow, and from six to twelve months may be taken as a fair average for its dura- tion from beginning to end. Yery bad cases, with exces- sively dense opacity, sometimes continue to improve for several years, and may recover an unexpected degree of DIFFUSE KERATITIS. 145 sight. Perfect recovery of transparency is less common, even in moderate cases, than is sometimes supposed, but the slight degree of haziness which so often remains does not much affect the sight. The epithelium usually becomes smooth before the cornea becomes transparent ; but in severe cases irregularities of surface may remain, and render the diagnosis difficult. Yery minute vessels (as in Fig. 52) seen by direct ophthalmoscopic examination with a high 4- lens (p. 81), nearly straight, and branching at acute angles with short abrupt rectangular bends here and there, are often left, and when found are good evidence of pre- vious interstitial keratitis. Syphilitic keratitis is almost always symmetrical, though an interval of a few weeks commonly separates its onset in the two eyes : rarely the interval is several months, a year, or even more. It generally occurs between about the ages of six and fifteen ; sometimes as early as two and a half or three years ; in rare instances it may set in after forty ; many of the very late cases are severe and complicated. If it occur very early the attack is generally mild. Re- lapses of greater or less severity are common. Not only does iritis occur with tolerable frequency, but we occasion- ally meet with deep-seated inflammation, in the ciliary region, giving rise either to secondary glaucoma, or to stretching and elongation of the globe in the ciliary zone, or to softening and shrinking of the eyeball.^ Dots of opacity may sometimes be seen on the back of the cornea at its lower part, before the cornea itself is much altered : sometimes, too, the interstitial exudation is much more dense at the lower part of the cornea than elsewhere. 1 "When the cornea has cleared, ophthalmoscopic eigms of past choroid* itis (Chap. XII.) are often found at the fundus. The choroiditis often dates much further back than the keratitis, but there is little doubt that it may relapse, or occur as an accompaniment of the corneal dis* ease. (Chap. XXIII.) 7 146 DISEASES OP THE CORNEA. Syphilitic keratitis in strumous children often shows more irritability, photophobia, and conjunctival congestion, than in others ; but it is very seldom that ulceration occurs, and although in the worst cases the cornea becomes softened and yellowish, and for a time seems likely to give way, actual perforation is one of the rarest events. Pannus from granular disease may coexist with syphilitic keratitis. Treatment. — A long but mild course of mercury is certainly of use. It is customary to give iodide of potassium also, and it probably has some influence. If the patients be very anaemic, and they often are so, iron, or the syrup of its iodide, is more advisable than iodide of potassium as an adjunct to the mercury. Locally it is well to use atropine by routine until the disease has reached its height, on the ground that iritis may be present. Setons in my experi- ence are seldom of use; but in cases attended by severe and prolonged photophobia and ciliary congestion iridec- tomy is occasionally followed by rapid improvement ; this operation, however, is seldom needed or justifia])le unless there be decided glaucomatous symptoms. When all inflammatory symptoms have subsided, the local use of yellow ointment of calomel (F 11 and 12) appears to aid the absorption of the residual opacity. The form of keratitis above described is caused by inherited syphilis. In rare cases it has been seen as the result of secondary acquired syphilis. Other cases of diffuse keratitis occur in w^hich syphilis has no share, but they are seldom symmetrical, nor do they occur early in life. That diffuse, chronic keratitis, affecting both eyes of children and adolescents, is, when well characterized, almost invari- ably the result of hereditary syphilis, is proved by abundant evidence. A large proportion of its subjects show some of the other signs of hereditary syphilis in the teeth, skin, ears (deafness), physiognomy, mouth, or bones. When the patients themselves show no such signs, a history of infantile DIFFUSE KERATITIS. 147 syphilis in the patient or in some brothers and sisters, or of acquired syphilis in one or other parent, may often be obtained.' That this keratitis stands in no causal relation to struma, is clear, because the ordinary signs of struma are not found oftener in its victims than in other children, because persons who are decidedly strumous do not suffer from this keratitis more often than others, and because the forms of eye disease which are universally recognized as "strumous" (ophthalmia tarsi, phlyctenular disease, and relapsing ulcers of cornea) very seldom accompany this diffuse keratitis. Illustrations of the teeth in inherited syphilis are given in Fig. 164, Chap. XXIII. Other Forms of Keratitis. Inflammation of the cornea forms a more or less con- spicuous feature in several diseases where the primary, or the principal, seat of mischief lies in another part of the eye. It is important for purposes of diagnosis to compare these secondary or complicating forms of keratitis with the primary diseases of the cornea already described. In iritis the lower half of the cornea often becomes steamy, and more or less hazy. In some cases a number of small, separate, opaque dots are seen on the posterior elastic lamina (Descemet's membrane), often so minute as to need magnifying. These dots are sharply defined, large ones looking very like minute drops of cold gravy-fat, the smallest like grains of gray sand ; in cases of long standing they may be either very white or highly pigmented. They are generally arranged in a triangle, with its apex toward the centre and its base at the lower margin of the cornea, ^ I have found other personal evidence of inherited syphilis in oi per cent, of my cases of interstitial keratitis, and evidence from the family history in li per cent, more ; total 68 per cent. ; and in most of the remaining 32 per cent, there have been strong reasons to suspect it. 148 DISEASES OF THE CORNEA. the smallest dots being near the centre, Fig. 54 ; but in some eases, sympathetic ophthalmitis, especially, the dots are scattered over the whole cornea. They are, of course. Fig. 54, Keratitis punctata. (From a sketch by Dr. Herringham.) difficult to detect in proportion as the corneal tissue itself is hazy. The term heratitis punctata is used to express this accu- mulation of dots on the back of the cornea, and by some authors is allowed to include also allied cases in which small spots with hazy outlines are seen in the cornea proper. Keratitis punctata is, almost without exception, secondary to some disease of the cornea, iris, or choroid and vitreous. But a few cases are seen, chiefly in young adults, where the corneal dots form the principal, if not the sole, visible change ; the number of such cases diminishes, however, in proportion to the care with which other lesions are sought. It is now and then difficult to say, in a mixed case, whether the iritis or keratitis have been the initial change; but when this doubt arises the cornea has generally been the starting-point ; and with care we are seldom at a loss to decide whether the case be one of syphilitic keratitis with iritis, or sclerotitis with corneal mischief and iritis, or of primary iritis with secondary haze of cornea. See Chaps. YIII. and IX. Slight loss of transparency of the cornea occurs in most cases of glaucoma. The earliest change is a fine, uniform DIFFUSE KERATITIS. 149 feteaminess of the epithelium. In very severe, acute cases, the cornea becomes hazy throughout, though not in a high degree. The same haze occurs in chronic cases of long standing with great increase of tension, but the epithelial " steaminess" often then gives place to a coarser " pitting" with little depressions and elevations (vesicles), especially on the part which is uncovered by the lids. In buphthalmos (hydrophthalmos) the corneal changes are often very conspicuous, although not essential. In this rare and very peculiar malady there is general and slowly progressive enlargement of cornea, anterior part of sclerotic, and iris, together with extreme deepening of the anterior chamber and slight increase of tension. The cornea often becomes hazy and semi-opaque. The disease, w^hich may, perhaps, be looked upon as a congenital or infantile form of glaucoma, is either present at birth or comes on in early infancy, and usually causes blindness. Operative treat- ment generally fails, but eserine is said to be useful. See Glaucoma. A rare but peculiar form of corneal disease, generally seen in elderly persons, is the transverse calcareous film, forming an oval patch of light-gray opacity, w^hich runs almost horizontally across the cornea. It lies beneath the epithelium, and consists of minute crystalline granules chiefly calcareous. Arcus senilis is caused by fatty degeneration of the cor- neal tissue just within its margin, Fig. 55. It first appears beneath the upper lid, next beneath the low^er, thus form- ing tw^o narrow, white or yellowish crescents, the horns of which finally meet at the sides of the cornea ; it always begins, and remains most intense, on a line slightly within the sclero-corneal junction, and the degeneration is most marked in the superficial layers of the cornea beneath the anterior elastic lamina ; in other w^ords, the change is greatest at the part most influenced by the marginal blood- 150 DISEASES OF THE CORNEA. vessels. Arcus, though seldom seen except in senile per- sons, is not found to interfere with the union of a wound carried through it, though the tissue of the arcus is often very tough and hard. Fig. 55. Arcus senilis. (From a sketch by Dr. Herringham.) Less regular forms of arcus are seen as the result of pro- longed or relapsing inflammations near the corneal border, whether ulcerative or not. It is general!}^ easy to distin- guish such an arcus, because the opacity is denser and more patchy, and its outlines are less regular than in the primary form; when arcus is seen unusually early in life it is gen- erally of this inflammatory kind, for simple arcus is rare below forty. Opacity of a very characteristic kind is likely to follow the use ofa lotion containing lead when the surface of the cornea is abraded. An insoluble, densely opaque, very white film of lead salts is precipitated on, and adheres very firmly to, the ulcerated surface ; the spot is sharply defined, and looks like white paint. If precipitated on a deep and much inflamed ulcer, the layer of tissue to which the film adheres is often thrown off, but when there is only a superficial abrasion or ulcer, the lead adheres very firmly, and can only be scraped off imperfectly. But even in the latter cases the film is probably, after a time, thrown off or worn off, if we may judge by the fact that nearly all the lead opacities which come under notice are comparatively DIFFUSE KERATITIS. 151 new. The practical lesson is never to use a lead lotion for the eye when there is any suspicion that the corneal surface is broken. The prolonged use of nitrate of silver, whether in a weak or strong form, is sometimes followed by a dull, brownish- green, permanent discoloration of the conjunctiva, and even the cornea may become slightly stained. CHAPTER VIII. DISEASES OF THE IRTS. Iritis. Inflammation of the iris may be caused by certain specific blood diseases, especially syphilis; or may be the expression of a tendency to relapses of inflammation in certain tissues under the influence largely of climate and weather — rheumatic iritis ; it often occurs in the course of ulcers, and of wounds and other injuries of the cornea; also w^ith diffuse keratitis and sclerotitis. Iritis also forms a very important part of the remarkable and serious dis- ease know^n as sympathetic ophthalmitis. Acute iritis, whatever its cause, is shown by a change in the color of the iris, indistinctness or "muddiness" of its texture, diminution of its mobility and the formation of adhesions {posterior synechise) between its posterior (uveal) surface and the capsule of the lens; there is, besides, in most cases, a dulness of the whole iris and pupil, caused by muddiness of the aqueous humor, and partly, also, by slight corneal changes. The eyeball is congested and sight usually dimmed. There may or may not be pain, photophobia, and lachrymation. The congestion is often almost confined to a zone about one-twelfth or one-eighth of an inch wide, which surrounds the cornea, its color pink (not ra"w red), the vessels small, radiating, nearly straight, and lying beneath the conjunc- tiva, ciliary or circumcorneal congestion, Fig. 28, These are the episcleral branches of the anterior ciliary arteries, IRITIS. 153 Fig. 25. Quite the same congestion is seen in many other conditions, e. g., corneal ulceration; whilst on the other hand, in some cases of iritis, the superficial (conjunctival) vessels are engorged also, especially in their anterior divi- sions, which are chiefly offshoots of the ciliary system. We therefore never diagnose iritis from the character of the congestion alone ; but the disease being proved by the other symptoms, the kind and degree of congestion help us to judge of its severity. The altered color of the iris is due to its congestion, and the effusion of lymph and serum into its substance ; a blue or gray iris becomes greenish, a brown one is but little changed. The inflammatory swelling of the iris also ac- counts both for the blurring (muddiness) of its beautifully reticulated structure, and for the sluggishness of movement noticed in the early period. Lymph is soon thrown out at one or more spots on its posterior surface, and still further hampers its movements by adhering to the lens capsule ; and most cases do not come under notice till such synechise have formed. The quantity of solid exudation, whether on the hinder surface or into the structure of the iris, varies much ; it is usually greatest in syphilitic iritis, when distinct nodules of pink or yellowish color are sometimes seen pro- jecting from the front surface, generally close to the pupil. In rare cases pus thrown off by the iris into the aqueous subsides and forms hypopyon ; a corresponding deposit of blood constitutes hyphasmia. Firm adhesions to the lens capsule may be present without much evidence of exuda- tion into the structure of the iris. Exudative changes are usually most abundant at the inner ring of the iris, w^here its capillary vessels are far the most numerous. Fig. 56. Apparent discoloration of the iris is, however, often due entirely to suspension of blood-corpuscles, or inflammatory products in the aqueous humor ; sometimes this altered fluid coagulates into a slightly turbid gelatinous mass, 154 DISEASES OF THE 1RI8 which almost fills the chamber ("spongy exudation"). The aqueous sometimes becomes yellow without losing transparency. Fig. 56. Vessels of human iris artificially injected ; capillaries most numerous at pupillary border, and next at ciliary border. The tension of the eyeball, usually unaltered in acute iritis, may be a little increased ; rarely it is considerably diminished, and in such cases there are generally other peculiarities. The condition of the pupil alone is diagnostic in all except very mild or incipient cases of iritis. It is sluggish or motionless, and not quite round ; it is also rather smaller than its fellow (supposing the iritis to be one-sided), because the surface of the iris is increased (and the pupil, therefore, encroached on) whenever its vessels are distended. Atro- pine causes it to dilate between the synechiae ; the synechias being fixed, appear as angular projections when the iris on each side of them has retracted. If there be only one IRITIS. 155 adhesion it will merely notch the pupil at one spot ; if the adhesions be numerous the pupil will be crenated or irreg- ular, Fig. 57. If the whole papillary ring, or still more, if the entire posterior surface of the iris be adherent, scarcely any dilatation will be effected ; the former condition is called annular or circular synechia, and its result is ''exclu- sion " of tJie pupil ; the latter is known as total posterior Fig. 57. Fig. 58. # Iritic adhesions (posterior synechife) causing irregularity of pupil. ( Wecker and Jaeger.) Spots of pigment and lymph at seat of former iritic adhesions. synechia. If the synechiae be new and the lymph soft the repeated use of atropine will break them down and the pupil become round ; but even then some of the uveal pig- ment, which is easily separable from the posterior surface of the iris, often remains behind, glued to the lens capsule by a little lymph, Fig. 58. The presence of one or more such spots of brown pigment on the capsule is always con- clusive proof of present or of past iritis. T he pupillary area itself in severe iritis is often filled by grayish or yellowish lymph, which spreads over it from the iris ; if such exuda- tion become organized a dense white membrane or a delicate film (often, however, presenting one or more little clear holes), is formed over the pupil (" occlusion^^ of the pupil). The iris may be inflamed without any lymph being effused from its hinder surface, and then the pupil, though slug- gish, acting imperfectly to atropine, and never dilating widely, wnll present no posterior synechiae nor any adhesion 156 DISEASES OF THE IRIS. of pigment spots to the lens, but it will always be discol- ored (serous iritis) ; iritis of this kind often occurs with ulceration of the cornea, and as a complication of deeper inflammations. Pain referred to the eyeball and to the parts supplied by the first, and sometimes by the second division of the fifth nerve, is common with iritis, especially in the early period. It is, however, a very variable symptom, and gives no clue to the amount of structural change, being sometimes quite insignificant when much lymph is thrown out. The pain is seldom constant, but comes on at intervals, is often worst at night, and is described as shooting, throbbing, or aching. It is commonly referred to the temple or forehead, as well as to the eyeball ; sometimes also to the side of the nose and to the upper teeth. Photophobia and w^atering are generally proportionate to the pain. The duration of acute iritis varies from a few^ days when mild, to many wrecks when severe. The defect of sight is proportionate to the haziness of the cornea, aqueous, and ])upillary space, but in some cases is increased by changes in the vitreous. Iritis sometimes sets in very gradually, caufsing no marked congestion or pain, but slowly giving rise to the formation of tough adhesions, and often to the growth of a thin membrane over the pupillary area; in some of these cases the iris becomes thickened and tough, and its large vessels undergo much dilatation, w^hilst in others keratitis punctata occurs. See Cyclitis, Chap. IX., Diseasesof Cornea, p. 147; and Sympathetic Ophthalmitis, Chap. IX. Permanent results of iritis. — Reference has been made to the adhesions, which are often permanent, and to the spots of uveal pigment on the lens capsule, w^hich are ahvays so ; either condition tells a tale of past iritis, and is thus a valuable aid to diagnosis. A blue iris which has undergone .severe inflammation may remain greenish. RITIS 157 Patches of atrophy may follow severe plastic exudations into the iris, and are recognized by their whitish color and thinness. Large patches of new pigment occasionally form, extending from the pupillary border on the anterior surface. When the pupil is "excluded" or " occluded," the re- mainder of the iris being free, fluid collects in the posterior aqueous chamber, and by bulging the iris forward, and diminishing the depth of the anterior chamber, except at its centre, gives the pupil a funnel-like appearance ; if the bulging be partial, or be divided by bands of tough mem- brane, the iris looks cystic. Secondary glaucoma is likely to follow, and the tension of the globe should, therefore, be carefully noted whenever bulging is present ; in not a Fig. 59. Diagram to show the result, upon the iris, of exclusion of the pupil (p. 15r>). (From a specimen.) few of these cases, however, we find the eye soft and begin- ning to shrink, the sequel, perhaps, of a glaucomatous state. " Total posterior synechia" always shows a severe, though often a chronic, iritis; it is often accompanied by deep-seated disease, and followed by opacity of the lens, secondary cataract, and in some cases ultimately the lens 158 DISEASES or THE IRIS. becomes absorbed. Relapses of iritis are believed to be induced by the presence of synechiae, even where there is no protrusion of the iris by fluid; but their influence in this direction has, I believe, been much overrated. It must, however, be observed that there is still much differ- ence of opinion on the point last referred to. The iritis of syphilis is still held b}- some to be liable to recur, and to be by no means limited to the secondary stage : and we still often he ar it stated that iritic adhesions, by preventing free movement of the iris, operate as sources of irritation, and thus predispose to relapse. I have seldom succeeded in getting a history of recent syphilis in cases of recurring iritis, whilst in a number of cases of old iritis with the history that the attack occurred durin g secondary syphilis years before, I have scarcely found one with well-marked history of relapses. On the other hand, I have several times seen severe relapses in rheumatic cases after iri- dectomy had been performed as a preventive. All the evidence seems to me to favor the view that recurrences of iritis depend, as a rule, upon the constitutional cause of the disease. The following are the most important points as to the causes of iritis, and the chief clinical diflferences between the several forms. Constitutional Causes. Syphilis. — The iritis is acute ; it shows a great tendenc}' to eff'usion of lymph and forma- tion of vascular nodules (plastic iritis), and the nodules, when very large, may even suppurate ; it is symmetrical in a large proportion, probably at least two-thirds, of the cases. But asymmetry and absence of lymph-nodules are common. It occurs only in secondary syphilis, either ac- quired or inherited, and seldom relapses. Its significance is thus entirel}^ diS'erent from that of the iritis which often complicates syphilitic keratitis. Bheamatism is the cause of most cases of relapsing un- symmetrical iritis ; there is but little tendency to eff'usion of lymph, and nodules are never formed, but there is occa- IRITIS. 159 sionally fluid hypopyon ; the congestion and pain are often more severe than in syphilitic iritis. An attack is usually unsymmetrical, though both eyes commonly suffer by turns. It relapses at intervals of months or years. E ven repeated attacks sometimes result in but little damage to sight. Gout is apparently a cause of some cases of both acute and insidious chronic iritis. It is perhaps doubtful whether the gout or the chronic rheumatism from which the same patients sometimes suffer is the cause of the iritis. In its ten- dency to relapse, and to affect only one eye at a time, gouty resembles rheumatic iritis. The children of gouty parents are occasionally liable to a very insidious and destructive form of chronic iritis, with disease of the vitreous, keratitis punctata, and glaucoma. Chaps. IX. and XXIII. Chronic iritis {plastic irido-choroiditis). — In a few cases symmetrical iritis, of a chronic, progressive, and de- structive character, is complicated with choroiditis, disease of vitreous, and secondary cataract. These cases, for which it is at preseni impossible to assign any cause, either gen- eral or local, are chiefly seen in adults below middle life. Sympathetic iritis — See Sympathetic Ophthalmitis. Local Causes. Injuries. — ^Perforating wounds of the eyeball, particularly if irregular, contused, and complicated with wound of the lens, are often followed by iritis, and more often if the patient be old than young. If the cor- neal wound suppurate, or become much infiltrated, the iritis is likely to be suppurative, and the inflammation to spread to the ciliary processes and cause destructive pan- ophthalmitis. Iritis may follow a wound of the lens-cap- sule without wound of the iris, and with only a mere puncture of the cornea. Examples of traumatic iritis from these several causes are seen after the various operations for cataract. The iritis, or more correctly irido-capsulitis, following extraction of senile cataract is often prolonged, attended by chemosis, much congestion, and the formation 160 DISEASES OF THE IRIS. of tough membrane behind the iris. Iritis may also follow superficial wounds and abrasions of the cornea, or direct blows on the eye ; but it is of great importance, whenever the question of injury comes in, to ascertain whether or not there has been a perforating wound. Iritis often ac- companies ulcers and other inflammations of the cornea, especially when deep, or complicated with hypopyon, or occurring in elderly persons. Iritis may accompany deep- seated disease of the eye. Treatment. — (1) In every case where iritis is present atropine is to be used often and continuously, in order to break down adhesions already formed, and to allow any lymph subsequently effused to be deposited outside the ordinary area of the pupil. A strong solution, four grains of sulphate of atropine to one ounce of distilled water, is to be dropped into the conjunctival sac every hour in the early period. Even if the synechias are, when first seen, alread}^ so tough that the atropine has no effect on them, it may prevent the formation of new ones on the same circle. Atropine also greatly relieves pain in iritis, and lessens the congestion, and through these means it no doubt helps ma- terially to arrest exudation. Mild acute iritis may some- times be cured by atropine alone. (2) If there be severe pain with much congestion, three or four leeches should be applied to the temple, to the malar eminence, or to the side of the nose. They may be repeated daily, in the same or smaller numbers, with ad- vantage, for several days, if necessary; or, after one leech- ing, repeated blistering may be substituted. Some surgeons use opiates instead of, or in addition to, leeches. Leeches occasionally increase the pain. Severe pain in iritis can nearly always be quickly relieved by artificial heat, either fomentations or dry heat, as hot as can be borne, to the eyelids. To apply dry heat, take a piece of cotton-wool the size of two fists, hold it to the fire or against a tin pot IRITIS. 161 full of 6o27i>?^ water, till quite hot, and apply it to the lids; have another piece ready, and change as soon as the first gets cool ; continue this for twenty minutes or more, and repeat it several times a day.^ Paracentesis of the anterior chamber should be resorted to in severe iritis if the aque- ous humor remain very turbid after a few days of other treatment ; it may be repeated every day or two unless there is marked improvement. (3) Rest of the eye is very important. Many an attack is lengthened out, and many a relapse after partial cure is brought on, by the patient continuing at, or returning too soon to, work. It is not in most cases necessary to remain in a perfectly dark room ; to wear a shade in the room with the blinds down is generally enough, provided that no at- tempt be made to use the eyes. Work should not be resumed till at least a week after all congestion has gone off. (4) Cold draughts of air on the eye and all causes of " catching cold " are to be very carefully avoided by keep- ing the eye warmly tied up with a large pad of cotton wool. (5) The cause of the disease is to be treated, and into this careful inquiry should always be made. If the iritis be syphilitic, treatment for secondary syphilis is proper, mercury being given just short of salivation for several months, even though all the active eye symptoms quickly pass off. The rheumatic and gouty varieties are less defi- nitely under the influence of internal remedies: iodide of potassium, alkalies, colchicum, salicylate of soda, and tur- pentine, each have their advocates ; when the pain is severe tincture of aconite is sometimes markedly useful ; mercury is seldom needed, but in protracted and severe cases it may be given with advantage. It is sometimes advisable to 1 1 owe my knowledge of the value of dry heat to Mr. Llebreich. 162 DISEASES OP THE IRIS. combine quinine or iron with the mercury in syphilis, or to g-ive them in addition to other remedies in rheumatic cases. (6) As a rule no stimulants are to be allowed, and the bowels should be kept well open. (7) Iridectomy is needed for cases of severe iritis, even when there is no increase of tension, if judicious local and internal treatment have been carefully tried for some weeks without marked relief to the symptoms. It is chiefly in cases of constitutional origin, either syphilitic or rheumatic, and in the iritis accompanying ulcers of the cornea, that iridectomy is useful ; it is not admissible in sympathetic iritis, nor in iritis after cataract extraction. Iridectomy has been largely employed to prevent relapses of iritis, but the operation has much less effect in this way thaa has often been supposed ; it should not, therefore, be employed until the other means of cure have been fairly tried. It must be borne in mind, that unless iridectomy is necessary, it is injurious, by producing an enlarged and irregular pupil through which, for optical reasons, the patient will often not see so well as through the natural pupil, even though this be partially obstructed. In regard to all methods of local treatment we must bear in mind that acute iritis occurs in all degrees of severity, and that the mildest cases often need only atropine and rest. Traumatic iritis, in the earliest stage, is best combated by atropine, continuous cold obtained by laying upon the closed eyelids pieces of lint wetted in iced water and changed every few minutes, and by leeches. Gold is not to be used in any other form of iritis, and is useless even for traumatic cases after the first day or so ; later, warmth is more appropriate. Congenital irideremia (absence of iris) is occasionally seen, and is often associated with other defects of the eye, especially opacities in the lens. IRITIS. 163 Coloboma of the iris (congenital developmental cleft in the iris) giv'es the effect of a very regularly made iridec- tomy. It is always downwards or slightly down-in, and is often, but not always, symmetrical. It occurs in different degrees, and sometimes a mere line or seam in the iris indi- cates the slightest form of the defect. It often occurs without coloboma of the choroid. Pupillary and capsule-pupillary membranes. — In early foetal life, the capsule of the lens is vascular, supplied with blood by the hyaloid artery ; when the iris grows in from the anterior part of the choroid, and comes into contact with the capsule, its vessels anastomose with those of the capsule, and the membrane so formed fills the pupil. Nor- mally this membrane disappears entirely with the vessels of the lens capsule; sometimes the part attached to the capsule only disappears, leaving behind the anterior part of the structure, which is known as the pupillary mem- brane. In this, bands of tissue, resembling that of the iris, run from one part of the anterior surface of the iris to another, springing from near the pupillary edge. Some- times the whole thickness of the membrane remains, in which case bands of tissue pass from the anterior surface of the iris to the capsule ; this forms the capsulo-pupillary membrane. Some of the latter cases have probably been described as the remains of intra-uterine iritis. CHAPTER IX. DISEASES OF THE CILIARY REGION. This chapter is intended to include cases in which the ciliary body itself, or the corresponding part of the sclerotic, or the episcleral tissue, is the sole seat, or at least the headquarters, of disease. From the abundance of vessels and nerves in the ciliary body, and the importance of its nutritive relations to the surrounding- parts, we find that many of the morbid processes of the ciliary region show a strong tendency to spread, according to their precise posi- tion and depth, to the cornea, iris, or vitreous, and, by influencing the nutrition of the lens, to cause secondary cataract. Although alike on pathological and clinical grounds it is necessary to subdivide the class into groups, we may observe that the various diseases of this part show a general agreement in some of their more important characters ; thus all of them are protracted and liable to relapse, and in all there is a marked tendency to patchiness, the morbid process being most intense in certain spots of the ciliary zone, or even occurring in quite discrete areas. It is convenient to make three principal clinical groups, the differences between w^hich are accounted for to a great extent by the depth of the tissue chiefly implicated. The most superficial may be taken first. (1) Episcleritis (more correctly Scleritis) is the name given to one or more large patches of congestion in the ciliary region, with some elevation of the conjunctiva from thickening of the subjacent tissues. The congestion gen- erally affects the conjunctival as well as the deeper vessels, DISEASES OP THE CILIARY REGION. 165 and the yellowish color of the exudation tones the brig-ht blood-red down to a more or less rusty tinge, which is especially striking at the central, thickest part of the patch. The thickening seldom causes more than a low, widely-spread mound of swelling. Episcleritis is a rather rare disease. It occurs chiefly on the exposed parts of the ciliary region, and especially near the outer canthus; but the patches may occur at any part of the circle, and exceptionally the inflammation is difl'used over a much wider area than the ciliary zone, extending far back, out of view. The iris is often a little discolored and the pupil sluggish, but actual iritis is the exception. There is often much aching pain. The disease is subacute, reaching its acme in not less than two or three weeks, and requiring a much longer time before absorption is complete. Fresh patches are apt to spring up while old ones are de- clining, and so the disease may last for months ; indeed, relapses at intervals, and in fresh spots, are the rule. It usually affects only one eye at a time, but both often suffer sooner or later. After the active changes have disappeared, a patch of the underlying sclerotic, of rather small size, is generally seen to be dusky, as if stained ; it is doubtful whether such patches represent thinning of the sclerotic from atrophy, or only staining; it is but seldom that they show any tendency to bulge as if thinned. In rare cases the exudation is much more abundant, and a large swell- ing is formed, which may even contain pus ; such cases pass by gradations into conjunctival phlyctenulge, and are generally seen in children. Episcleritis is seldom seen except in adults, and is com- moner in men than women. Inquiry often shows that the sufferer is, either from occupation or temperament, particu- larly liable to be affected by exposure to cold or by changes of temperature. Some of the patients are rheumatic, some gouty. Similar patches, but of brownish, rather translucent 166 DISEASES OF THE CILIARY REGION. appearance, are occasioually caused by tertiary syphilis, acquired or inherited (gummatous scleritis). In the treatment, protection by a warm bandage, rest, the yellow ointment (F. 12), the use of repeated blisters, and local stimulation of the swelling, are generally the most efficacious. Atropine is very useful in allaying pain. Internal remedies seldom seem to exert much influence, except in syphilitic cases. Salicylate of soda has been highly spoken of by some. Systematic kneading of the eye through the closed lids ("massage"), and scraping away the exudation with a sharp spoon, after turning back the conjunctiva, have also been recommended, and are worth trial. (2 ) Sclero-keratitis and sclero-iritis ("scrofulous sclero- titis," "anterior choroiditis"). A more deeply-seated, very persistent, or relapsing, subacute inflammation, character- ized by congestion of a violet tint (deep scleral congestion, p. 55), abruptly limited to the ciliary zone, and affecting some parts of the zone more than others (tendency to patchiness). Early in the case there is a slight degree of bulging of the affected part, due partly to thickening ; whilst patches of cloudy opacity, which may or may not ulcerate, appear in the cornea close to, and often continuous with, its margin ; iritis generally occurs later ; pain and photophobia are often severe. After a varying interval, always weeks, more often months, the symptoms recede ; at the focus of greatest congestion, or it may be around the entire zone, the sclerotic is left of a dusky color, some- times interspersed with little yellowish patches, and per- manent haziness of the most affected parts of the cornea remains. The disease is almost certain to relapse sooner or later; or a succession of fresh inflammatory foci follow each other without any intervals of real recovery, the whole process extending over months or years. After each attack more haze of cornea and fresh iritic adhesions are DISEASES OF THE CILIARY REGION. 167 left. The sclerotic, in bad cases of some years' standing, is much stained, and may become bulged (ciliary or ante- rior staphyloma), and the cornea becomes more opaque and altered in curve ; the eye is then useless, though seldom liable to further active symptoms. The characteristic appearance of an eye which has been moderately affected is the dusky color of the sclerotic and the irregular, patchy opacities in the cornea (Fig. 60), which Fig. 60. Relapsing sclero-keratitis. (From nature.) are often continuous with the sclerotic. The disease does not occur in children, nor does it begin late in life ; most of the patients are young or middle-aged adults, and, unlike the former variety, most are women. It is not associated with any special diathesis or dyscrasia, but generally goes along with a feeble circulation and liability to "catch cold ;'' in some cases there is a definite family history of scrofula or of phthisis. Predisposed persons are more likely to suffer in cold weather, or after change to a colder or damper climate, or after any cause of exhaustion, such as suckling. Treatment is at best but palliative. Local stimulation by yellow ointment or calomel is very useful in some cases, particularly in those which verge toward the phlyctenular type. In the early stages, especially when the congestion 168 DISEASES OF THE CILIARY REGION. is v^ery violent and altogether subconjunctival, atropine often gives relief, and it is, of course, useful for the iritis. Repeated blistering is also to be tried, though not all cases are benefited by it. I have not seen much benefit from setons. Warm, dry applications to the lids are, as a rule, better than cold. Mercury, in small and long-continued doses, is certainly valuable when the patient is not anaemic and feeble, but it is to be combined with cod-liver oil and iron. Protection from cold and bright light by "goggles" is a very important measure, both during the attacks and in the intervals between them. There is no rule as to sym- metry ; both eyes often suffer sooner or later, but sometimes one escapes whilst the other is attacked repeatedly. Transi- tion forms occur between this disease and episcleritis. (3) Cyclitis with disease of vitreous and keratitis punctata (chronic serous irido-choroiditis, "serous iritis"). A small but important series of cases, in which there is congestion, as in mild iritis, and dulness of sight, but usually no pain or photophobia. Flocculi are found in the anterior part of the vitreous or numerous small dots of deposit are seen on the posterior surface of the cornea, keratitis punctata, Fig. 54 ; the anterior chamber is often too deep, and insidious iritis often follows. Patches of recent choroiditis (Chap. XII.) are sometimes to be seen at the fundus. In bad cases buff-colored masses of deposit form in the lower part of the angle between iris and cornea ; or distinct nodules may be present on the iris near its peri- phery, but not, as in syphilitic iritis, at the pupillary border. Persistence, variability, and liability to relapse are almost as marked here as in other members of the cyclitic group. The tension is often slightly augmented at the beginning, but usually becomes normal again. Sometimes, however, the eye passes into a permanent state of chronic glaucoma,^ I Perhaps from blocking of the ligamentum pectinatum with cells. DISEASES OF THE CILIARY REGION. 169 without the intervention of plastic iritis (see Glaucoma) ; but usually the final condition in bad eases depends on the extent of the iritic adhesions, for when the synechiae are numerous and tough, and the iris is much altered in structure, or the pupil blocked by exudation, secondary glaucoma is likely to arise from imprisonment of fluid behind the iris. Fig. 59. When seen quite early the diag- nosis will probably be "serous iritis" or "ciliary conges- tion," unless the eye be carefully examined; for the pupil is generally free in all parts, or shows, at most, one or two adhesions after atropine has been used. In a few cases the punctate deposits on the back of the cornea constitute almost the only objective change (simple keratitis punc- tata), but these are rare. The refraction sometimes becomes temporarily myopic in serous iritis. The cases occur in adolescents or young adults, and the disease is often sooner or later symmetrical. Many mild cases recover perfectly, and in most others the final result is satisfactory. In respect to cause, there is strong reason to believe that many of these cases are the result of gout in a previous generation, the patient himself never having had the disease. The disease seems often to be excited in predisposed persons by prolonged overwork or anxiety, combined with underfeeding, or defective assimilation ; the patients often describe themselves as delicate ; some are phthisical. On the other hand, in some of the worst cases, leading to secondary cataract, and ultimately to shrinking of the eyes, the patient appears to be, from first to last, in good health, and free from any ascertainable morbid dia- thesis. In the treatment, prolonged rest of the eyes is important. Atropine is usually necessary, but if there be increase of tension its effect must be carefully watched, and in cases where there are no iritic adhesions eserine may have to be substituted. If the increase of tension keeps up, an4 170 DISEASES OF THE CILIARY REGION. Fccnis to be damaging the sight, iridocton^y is nccessory. Small doses of iodide of potassium and mercury appear to he useful in the earlier stages, given with proper precau- tions, and accompanied by iron and cod-liver oil. Change of climate would probably often be very beneficial. In the worst cases, where the changes are like those resulting from sympathetic ophthalmitis, no treatment seems to have any effect. Cases of acute inflammation are occasionally seen in which most of the symptoms resemble those of acute iritis, but with the iris so little affected that it is evidently not the headquarters of the morbid action. The tension may be much reduced, whilst repeated and rapid variations, both in sight and objective symptoms, occur. To some of these the term idiopathic phthisis hiilbi has been applied. Again, some cases of syphilitic inflammation, which are classed as syphilitic " iritis," might more correctly be called " cyclitis." In some cases of heredito-syphilitic keratitis there is much cyclitic complication, and these are always difficult to treat. Plastic inflammation of the ciliary body, following injury, traumatic ileitis or irido-cyclitis, is the usual start- ing-point of the changes which set up sympathetic inflam- mation of the fellow-eye; the tension is often lowered, and the symptoms subacute The onset oi purulent traumatic cyclitis panophthalmitis is signalized by congestion, pain, chemosis, and swelling of the lids, and the appearance of opacity at the w^ound. The inflammation quickly spreads to the iris, ciliary body, and vitreous, and then to the cap- sule of Tenon and the muscles, so that the eye becomes glued to the surrounding parts and fixed. If the lens be transparent a yellow or greenish reflection is, after a few days, sometimes seen behind it, indicating the presence of' pus in the vitreous humor; but usually the cornea and aqueous are too turbid, even should the lens be clear, to SYMPATHETIC IRRITATION. 171 allow deep inspection. Suppurative panophthalmitis occa- sionally sets in acutely and without apparent cause in eyes which have long been blind from corneal disease or from glaucoma. It may also occur in pyaemia (Chap. XXIII). See also Pseudo-glioma. Sympathetic Irritation and Sympathetic Ophthalmitis. Certain morbid changes in one eye may set up either functional disturbance or destructive inflammation in its fellow. The term sympathetic ir^ritation is given to the former, and sympathetic ophthalmitis, or ophthalmia, to the latter. Though these conditions may be combined, they more often occur separately, and it is very important to distinguish between them. Although at present the exact nature of the changes which precede sympathetic inflammation is unknown, and their path has not been fully traced out, we are sure (1) that the changes start from the region most richly supplied with vessels and nerves, viz. : the ciliary body and iris ; (2) that the first changes recognized by the surgeon in the sympathizing eye are generally in the same structures ; (3) that the exciting eye has nearly always been wounded, and in its anterior part, and that plastic inflammation of its uveal tract is always present ; (4) that inflammatory changes have in some cases been found in the ciliary nerves, and in the coverings of the optic nerve, of the exciting eye. Within the last few years the hypothesis of transmission along the ciliary nerves, which had many adherents, has been almost given up in favor of the theory of infection. Deutschmann has shown (1882-84) that the introduction of certain septic organisms into the interior of the eyeball, in rabbits, is followed by acute inflammatory changes in the other eye, and Giff'ord (1886), and others more recently, 172 DISEASES OF THE CILIARY REGION. have obtained results which tend to confirm the infection theory. Most of Deutschmann's subjects died in a few- days, and though in many of them the ocular changes were those of inflammation traceable along the optic nerve- sheaths of the "exciting" eye, byway of the chiasma, and down the optic nerve to the optic disc of the " sympathiser," still in one or two the morbid process had spread to the vitreous and uveal coat. Berlin' had previously suggested that the second eye was infected by a special organism w^hich could flourish only in the eye-tissues, and which was carried by the blood from the first eye ; and Hutchinson' afterwards independently propounded a nearly identical view. Though there are diflBculties to be explained and gaps to be filled in our knowledge before the infection theory in any form can be accepted, yet at the present time it claims more and stronger adherents than any other ; and the difficulties are, perhaps, not greater than for any other theory. In almost every case sympathetic inflammation is set up by a perforating wound, either accidental or operative, in the ciliary region of the other eye, i. e., within a zone, nearly a quarter of an inch wide, surrounding the cornea. The risk attending a wound in this " dangerous zone" is increased if it be lacerated, or heal slowiy, or if the iris or ciliary body be engaged between the lips of the sclerotic, or if the eye contain a foreign body ; under all conditions, indeed, which make the occurrence of plastic or purulent irido-cyclitis probable. Sympathetic inflammation may also be set up by a foreign body lodged in the eye, w^hether the wound be in the ciliary region or not ; by an eye con- taining a tumor, perhaps even if the eye have not been perforated by operation or ulceration ; by a purely corneal wound, or a perforating ulcer, if complicated by adhesion of the iris, with dragging on the ciliary body. 1 Berlin, 1880. 2 Hutchinson, 1885. SYMPATHETIC IRRITATION. 173 Symptoms in the exciting eye The exciting eye, when it is causing sympathetic tmYahow, generally shows ciliaiy congestion and photophobia, and often sufifers neu- ralgic pain. In an eye which is causing sympathetic in- Jiammation, obvious iritis, often with lowered tension, is usually present ; but the iritis is often painless and without noticeable congestion, and thus may easily be overlooked ; it is especially important to remember that the exciting eye, though its sight is always damaged, need not be blind, and that under certain circumstances it may in the end be the better eye of the two. Symptoms in the sympathizing eye. a. Sympathetic irri- tation. — The eye is, in common speech, " weak " or " irrita- ble." It is intolerant of light and easily flushes and waters if exposed to bright light, or if much used ; the accommo- dation is weakened or irritable, so that continued vision for near objects is painful, or even impossible ; and the ciliary muscle seems liable to give way for a short time, the patient complaining that near objects now and then suddenly be- come misty for a while. Neuralgic pains, referred to the eye and side of the head, are also common. Temporary dark- ening of sight, indicating suspension of retinal function, and subjective sensations of colored spots, clouds, etc., occur in certain cases. Such attacks may occur again and again in varying severity, lasting for days or weeks, and finally ceasing without ever passing on to structural change. Sympathetic irritation is always and, as a rule, promptly, cured by removal of the exciting eye ; but occasionally the symptoms persist for some time afterwards. A condition which cannot be distinguished from hysterical blindness is sometimes seen in the "sympathizing" eye, but the term sympathetic irritation does not then seem suitable.^ ^ Mr. Gunn tells me that he has noticed that marked oscillation of the iris often occurs when sympathetic irritation is about to give place to inflammation. 174 DISEASES OF THE CILIARY REGION. b. Sympathetic in Jlammation {Ophthalmitis). — The dis- ease may arise out of an attack of " irritation," but more commonly it sets in without any such warning It may be acute and severe, or so insidious as to escape the notice of the patient until well advanced. It is in nearly all cases a prolonged and a recurring disease ; when once started it is self-maintaining, and its course usually extends over many months, oreven a year or two. In mild casesa good recov- ery eventually takes place, but in a large majority the eye becomes blind. The disease usually takes the form of a plastic irido-cyclitis or irido-choroiditis with exudation from the entire posterior surface of the iris, leading to total posterior synechia. Its chief early peculiarities are great liability to dotted deposits on the back of the cornea, clouding of the vitreous by floating opacities, and often neuro-retinitis; there is a dusky ciliary congestion with marked engorgement of the large vessels which perforate the sclerotic in the ciliary region. In acute and severe cases the congestion is intense, there is severe pain, photophobia, and tenderness on pressure, and the iris, besides being thick, is changed in color to a peculiar buff or yellow^ish brown, and shows numerous enlarged bloodvessels. Attacks of in- tense neuralgia of the fifth nerve characterize some cases. In cases of all degrees the tension is often increased, the eyebecoming decidedly glaucomatous for a longer or shorter time. Many dotted opacities appear in the lens, which afterwards becomes completely cataractous and in some cases is finally quite absorbed. In the worst cases the eye finally shrinks, but in many it remains glaucomatous with total posterior synechia, corneal haze, and more or less ciliary staphyloma. In the mildest cases, the so-called "serous" form, the disease never goes beyond a chronic iritis with punctate keratitis and disease of the vitreous, with which neuro-retinitis often, perhaps always, coexists. Sympathetic ophthalmitis generally begins between six SYMPATHETIC OPHTHALMITIS. 175 weeks and about three months after the injury to the ex- citing eye ; very seldom sooner than three weeks, i^e., not until time has elapsed for well-marked inflammatory changes to occur at the seat of injury. On the other hand, the disease may set in at any length of time, even many years, after the lesion of the exciting eye. It occurs at all ages. Distinct inflammatory changes are probably always present in the exciting eye ; but, as already stated, these may be very slight and difficult of detection. When carefully observed, these changes are found to precede by some days, if not longer, the onset of structural disease in the sympathizing eye, the morbid process apparently taking some time to travel from one eye to the other. Treatment. — By far the most important measure refers to prevention. When once sympathetic inflammation has begun we can do little to modify its course. The clear re- cognition of this fact leads us to advise the excision^ of every eye which is at the same time useless and liable to cause sympathetic mischief, i. e., of all eyes which are blind from injury or destructive corneal disease; and to give this advice most urgently when the blind eye is already tender or irritable, or is liable to become so, when it has been lost by wound, and when it is probable that it may contain a foreign body. Any lost eye in which there are signs of past iritis, even if there be no history of injury, is best removed, especially if shrunken. But much judg- ment is needed if the damaged eye, though irritable and likely to cause mischief, still retains more or less sight. Every attention must then be paid to the exact position of the wound, the evidence as to its depth, the evidence of 1 Feeling doubtful whether either abscission or op tico-ciliary neuro_ tomy confers as great safety from sympathetic disease as does excision, I have not performed those operations. The more newly revived evis- ceration has not yet been performed often enough for trustworthy con- clusions to be drawn on this point. 176 DISEASES OF THE CILIARY REGION. hemorrhage, and especially to the condition of the lens, and to the presence of the yellowish haziness behind the lens which indicates lymph or pus in the vitreous. The date of the injury and the condition of the wound, whether healed by immediate union, or with scarring, puckering, or flattening, are very important points. Irritation of the fellow-eye may set in a few days after the injury ; but since inflammation very seldom begins sooner than two or three weeks, we may, if we see the case early, watch it for a little time. Complete and prolonged rest in a darkened room is a very important element in the prevention of sympathetic irritation and inflammation, and should always be insisted on when we are trying to save an injured eye. In rare cases sympathetic inflammation sets in a/ifer the removal of the exciting eye, even after an interval of several weeks, a contingency which emphasises the importance of excising every condemned eye at the earliest possible moment. When sympathetic ophthalmitis has set in we can do com- paratively little. A. The exciting eye, if quite blind or so seriously dam- aged as to be for practical purposes certainly useless, is to be excised at once, though the evidence of benefit from this course is slender. But it is not to be removed if there is reason to hope for restoration of useful sight in it; if there is simply a moderate degree of subacute iritis, with or with- out traumatic cataract, and with sight proportionate to the state of the lens, the eye is to be carefully treated, since it may very probably in the end be the better of the two. B. The sympathizing eye. — The important measures are : (1) atropine, used very often, as for acute iritis; (2) abso- lute rest and exclusion of light by residence in a dark room and with a black bandage over both eyes; (3) repeated leeching if the symptoms are severe, or counter-irritation by blisters or by a seton in chronic cases. (4) Mercury is believed by some to be beneficial. Quinine is sometimes SYMPATHETIC OPHTHALMITIS. 177 given. (5) As a rule no operation is permissible whilst the disease is still active, since iridectomy, performed whilst there are active symptoms, is followed by closure of the gap with fresh lymph. Operations in severe cases which have become quiet are seldom of use, the eye being gen- erally then past recovery. The prognosis is, as will be gathered, very grave ; even in the mildest cases, when seen quite early, we must be very cautious, for the disease often slowly progresses for many months. 8* CHAPTER X. INJURIES OF THE EYEBALL. A CLEAR distinction is to be made between contusion and concussion injuries, and wounds of the eyeball. (1) Contusion and concussion injuries. — RuxAure of the eyeball is commonly the result of severe direct blows. The rent is nearly always in the sclerotic, either a little behind or close to the corneal margin, with which it is concentric ; the cornea itself is but seldom rent by a blow. The rup- ture is usually large, involves all the tunics, and is followed by immediate hemorrhage between the retinal and choroid and into the vitreous and anterior chambers ; the lens and some of the vitreous often escape ; sight is usually reduced to perception of light or of large objects. The conjunc- tiva, however, often escapes untorn, and in such a case if the lens pass through the rent in the sclerotic, it will be held down by the conjunctiva and form a prominent, rounded, translucent swelling over the rupture. The diag- nosis of rupture is generally easy, even if the rent be more or less concealed. The eyeball often shrinks ; but occa- sionally it recovers with useful vision. Immediate excision is generally best when the wound is " compound ;" but if the conjunctiva be not torn, and occasionally even when it is, we should wait a few days until the disappearance of the blood from the anterior chamber allows the deeper parts to be seen. The treatment is the same as for wounds of the eye. When the lens is lying beneath the conjunctiva it should be removed when the scleral wound has healed, if we decide to save the eve. INJURIES OF THE EYEBALL. 179 It may be here mentioned that copious hemorrhage, ac- companied by severe pain, sometimes occurs between the choroid and sclerotic as the result of sudden diminution of tension, either by an operation, such as extraction of cata- ract or iridectomy, or by a glancing wound of the cornea. Eyes in which this occurs are for most part already unsound and often glaucomatous. Blows oftencsiuseinternaldamagewithout rupture of tfie hard coats of the eye. The iris may be torn from its ciliary attachment {coredialyais), so that two pupils are formed, Fig. 61. Separation of iris following- a blow. Fig. 61, or the lens may be loosened or displaced by partial rupture of its suspensory ligament, so that the iris, having lost its support, will shake about with every movement {tremulous iris). Such lesions are likely to be obscured for a time by bleeding into the anterior chamber and into the vitreous. The lens often becomes opaque afterward. De- tachment of the retina is often found after severe blows, which have caused hemorrhage into the vitreous. Blows on the front of the eye may cause rupture of the chor^oid or hemorrhage from choroidal or retinal vessels. These changes are found at the central part of the fundus, and if the yellow spot is involved visual acuteness is much damaged. The rents in the choroid appear after the blood has cleared up, as lines or narrow bands of atrophy bor- dered by pigment, and often slightly curved toward the 180 INJURIES OF THE EYEBALL. disc, Fig. 74. Hemorrhages from the choroidal vessels without rupture of the choroid usually leave some residual pigment after absorption. In an eye predisposed to detach- ment of retina, a blow will sometimes determine its occur- rence, ParalymHofthe iris and ciliary mvscle, with partial and often irregular dilatation of the pupil, are often the sole results of a blow on the eye ; the defect of sight can be remedied by a convex lens. Complete restitution is moderately common ; the ciliary muscle recovers before the iris. Partial dilatation or imperfection of the pupil after a blow is sometimes dependent on a rupture of the sphincter, one or more notches in the pupillary border of the iris indicating the seat of the lesion or lesions. For Traumatic Iritis see p. 159. Great defect of sight following a blow, and neither rem- edied by glasses nor accounted for by blood in the anterior chamber, will generally mean copious hemorrhage into the vitreous, with one or another of the changes just men- tioned in the retina and choroid. The red blood may some- times be seen by focal light, but often its presence can only be inferred from the opaque state of the vitreous. Proba- bly in most of these cases the blood comes from the large veins of the ciliary body, but sometimes from the vessels of the choroid or retina. There may be no external ecchy- raosis. The tension of the globe is to be noted ; it is not often increased unless inflammation have set in, or the eye were previously glaucomatous, and in some cases it is below par. The prognosis should be very guarded whenever there is reason to think, from the opaque state of the parts behind the lens, that much bleeding has taken place, or that the retina is detached, or when the iris is tremulous or partly detached, or if any rupture of the choroid can be made out. Blood in the anterior chamber is often completely absorbed in a day or two, or even sometimes in a few hours ; but in the vitreous humor absorption, though rapid, INJURIES OF THE EYEBALL. 181 is less complete, and permanent opacities are often left. The use of atropine, the frequent application, during the first twenty-four hours, of iced water, or of an evaporating lotion to the lids, and occasional leeching if there be in- flammatory symptoms, will do all that is possible for the first week or two after a severe blow with internal hemor- rhage. If the lens be loosened it may at any time act as an irritating foreign body, or set up a glaucomatous in- flammation : Dislocation of Lens, p. 208. Now and then optic neuritis occurs in the injured eye as the immediate effect of the blow. Hemorrhage behind the choroid is be- lieved to account for certain well-known cases in which, after a blow, there is defect of sight without a visible change, or with localized temporary haze of retina {''commotio retinse''-). Temporary myopia or astigmatism may also follow a blow on the eye ; they depend on altered curvature of the lens, and are sometimes entirely removed by paralyzing the ciliary muscle with atropine. See also Hysterical Amblyopia, (2) Wounds. — A. Superficial abrasions of the cornea cause much pain, with watering, photophobia, and ciliary congestion. They are frequently due to a scratch by a finger-nail of a baby at the breast. The abraded surface is often very small and shows no opacity ; it is detected by watching the reflection of a window from the cornea, whilst the patient slowly moves the eye. Now and then the symp- toms return after a long interval of cure. Many, if not all of the cases of relapsing bullje of the cornea seem to have originated in a slight superficial injury. Minute fragments of metal or stone flying from tools, etc., often partly imbed themselves in the cornea, /o7'e?'y^i body on the cornea, and give rise to varying degrees of irri- tability and pain. The fragment soon becomes surrounded by a hazy zone of infiltration, but it remains easily visible unless it be very small or covered by mucus or epithelium. 182 INJURIES OF THE EYEBALL. When in douht always examine tlie cornea by focal light with magnifying power. The pupil is often smaller than its fellow, and the color of the iris altered, in cases of superficial injur}^ to the cornea, indicating congestion of the iris. Actual iritis sometimes occurs, but not unless the corneal wound inflame. Treatment. — (For removal of foreign bodies, see Ope- rations.) After surface injuries a drop of castor oil may be applied, and the eye kept closed for the day with a pad of wadding and a bandage. Atropine is required if there be much irritation or threatened iritis. If hypopyon ap- pear the case becomes one of hypopyon ulcer. Foreign bodies often adhere to the inner surface of the upper lid ; whenever a patient states that he has " some- thing in his eye" and nothing can be found on the cornea, the upper lid must be everted and examined. Large bodies sometimes pass far back into the upper or lower conjunctival sulcus and lie hidden for weeks or months, causing only local inflammation and some thickening of the conjunctiva. Search must be made, if needful, with a small scoop or probe whenever the suspicion arises. (See Orbit.) B. Bi(7V2s, scalds, and injuries by caustics, etc. — The conjunctiva and cornea are often damaged by splashes of molten lead, or by strong alkalies or acids, of which lime, either quick or freshly slaked, is the commonest. The eye- ball is not often scalded, the lids closing quickly enough to prevent the entrance of steam or hot water. As in no such cases is the full effect apparent for some daj^s, a cautious opinion should be given in the early stages. The effects of such accidents are manifested by (1) in- flammation of the cornea passing into suppurative keratitis with hypopyon, in bad cases; (2) scarring and shortening of the conjunctiva, and in bad cases adhesion of its palbe- bral and ocular surfaces, symhlepharon. The most superficial burns whiten and dry the surface INJURIES OF THE EYEBALL. 183 and in a few hours the epithelium is shed. This is shown on the cornea by a sharply outlined, slightly depressed area. The surface is clear if the damage be quite super- ficial and recent, but more or less opalescent, or even yel- lowish, if the case be a few days old, and the burn be deep enough to have caused destruction or inflammation of the true corneal tissue. When there is much opacity it does not completely clear, and considerable flattening of the cornea and neighboring sclerotic often occurs at the seat of deep and extensive burns. The conjunctival whitening is followed by mere desquamation and vascular reaction, or by ulceration and scarring, according to the depth of the damage. Treatment. — In recent cases, seen before reaction has begun, a drop of castor oil once or twice a day, a few leeches to the temple, and the use of a cold evaporating lotion, or of iced water, will sometimes prevent inflamma- tion. If seen immediately after the accident, the conjunc- tival sac is to be carefully searched for fragments, or washed with very weak acid or alkaline solution if a liquid caustic of the opposite character have done the damage. If in- flammatory reaction be already present, treatment by com- press, hot fomentations, and the other means recommended for suppurating ulcers, p. 138, is most suitable. There is often much pain and chemosis. (See Operation for Symblepharon.) c. Penetrating wounds and gunshot injuries. — When a patient says that his eye is wounded, the first step is to examine the seat, extent, and character of the wound, ascertain the interval since the injury, and test the sight of the eye ; the next to make out all we can about the wounding body, and especially whether any fragment has been left within the eyeball. Yery large foreign bodies, such as pieces of glass, some- times lie long in the eye without causing much trouble. 184 INJURIES OF THE EYEBALL. the large wound having given exit to the contents of the globe, and been followed by rapid shrinking without in- flammation. Treatment. — Penetrating wounds are least serious when they implicate the cornea alone, or the sclerotic behind the ciliary region, i. e., ^ inch or more behind the cornea. Penetrating wounds of the cornea without injury to the iris or lens, and without any prolapse of iris, are rare ; they generally do very well, and if the case be not seen until one or two days after the injury, the wound will often have healed firmly enough to retain the aqueous, and it may be difficult to decide whether the whole thickness of the cornea have been penetrated or not. Wounds of the sclerotic seldom unite without the interposition of a layer of lymph ; when seen early they should, if gaping, clean, and uncomplicated by evidence of internal injury, be treated by the insertion of fine sutures, which should be passed only through the conjunctiva, followed by the use of ice. But penetrating wounds are usually very serious to the injured eye ; the iris is frequently lacerated and included in the track of the wound ; the lens is punctured and becomes swollen and opaque from absorption of the aqueous humor, traumatic cataract, and liable in its swollen state to press on the ciliary processes and cause grave symptoms; exten- sive bleeding perhaps takes place in the vitreous ; within the first few days purulent inflammation may destroy the eye. The fellow-eye is, of course, often in danger of sym- pathetic inflammation. Every case has therefore to be judged from two points of view, the damage to the injured eye and the risk to the sound one; and the question whether to sacrifice or attempt to save the former, is some- times very difficult to decide. ( I. ) In the two following cases the eye should be sacrificed at once: (1) If the wound, lying wholly or partly in the INJURIES OF THE EYEBALL. 185 "dangerous region" be so large and so complicated with injury to deeper parts that no hope of useful sight remains. (2) If, even though the wound be small, it lie in the dan- gerous region, and have already set up severe iritis (pp. 159 and 170). (II.) There is a large class of cases in which it is certain or very probable that the eye contains a foreign body, al- though the injury is not of itself fatal to sight and has not as yet led to inflammation or to shrinking of the eye. The first question then is whether the foreign body can be seen, the second, whether or not it is steel or iron, and therefore possibly removable by a magnet. A foreign body, if lying on or embedded in the iris, the lens being intact, should be removed, usually with the portion of iris to which it is attached ; if loose in the anterior chamber its removal may be difficult. If it can be seen embedded in the lens and the condition of the eye be otherwise favorable, a scoop extraction may be done in the hope of removing the fragment with the lens ; or the lens may be allowed, or by a needle operation induced, to undergo partial absorption and shrinking so as to enclose the foreign body more firmly, and when subsequently extracted bring it away. If we are certain that the foreign body has passed into the vit- reous, whether through the lens or not, and whether by gunshot or not, we can seldom save the eye. The foreign body can in such a case seldom be seen, but a track of opacity through the lens, with blood in the vitreous, or even the latter alone, with conclusive history that the wound was made by a fragment or a shot, and not by an instrument or large body, will generally decide us in favor of excision. These rules need some modification when the foreign body is of iron or steel, since it is possible in certain cases, by means of a strong electro-magnet, to remove such fragments, even when lying in the vitreous. This maybe done either through the wound of entrance more or less 186 INJURIES OP THE EYEBALL. enlarged, or throuuh a fresh wound made where the body is seen or believed to lie. Many forms of magnet have been employed, the most successful usually being those in which a probe-ended instrument powerfully magnetized by being attached to the core of an electro-magnetic coil, is introduced into the eye in search of the body. The termi- nal of the instrument used at Moorfields will, when the circuit is complete, lift nine ounces. Though a certain number of eyes have now been saved with useful sight by means of the magnet, it must be remembered that the ex- traction of the foreign body does not insure the safety of the eye; that the eye may inflame or shrink and remain as potent a source of sympathetic disease as before, espe- cially so if iritis or threatened panophthalmitis were present at the time of operation.^ Foreign bodies occasionally be- come embedded at the fundus beyond the dangerous region and cause no further trouble. Iq gunshot cases the shot often passes out through a counter-opening and remains without doing harm in the orbit, though the eye is de- stroyed. Occasionally the choroid and retina are damaged by hemorrhage caused by a shot or bullet traversing the orbit close to but without demonstrable lesion of the sclerotic. (III.) There remain cases of less severe character, in which there is no foreign body in the eye : (1) the wound is in the dangerous region and complicated with traumatic cataract; (2) in the dangerous region without traumatic cataract; (3) the injury is entirely corneal, and therefore not in the dangerous zone, but the lens and iris are wounded; (4) there is wound of cornea and iris only, the ^ Mr. Snell, of Sheffield, who has probably had a lar^rer experience of this method than anyone else, has published (June, 1883) an excel- lent monograph, in which all the cases hitherto recorded are p:iven, in addition to his own. Hirschberg's monograph ou the subject (1885) brings the subject up to later date. INJURIES OF THE EYEBALL. 187 lens escaping. In group (2) there will often be much diffi- culty in deciding what to do, it being presumed that the wounded eye shows no iritis or other signs of severe inflam- mation ; some of the most difficult cases are those of wounds by sharp instruments close to the corneal border, with con- siderable adhesion of the iris, or in which there is evidence that the track lies between the lens and the ciliary pro- cesses, the lens not being wounded, and useful sight remain- ing. If the patient be seen within two or three weeks of the injury, and the sound eye show no irritation, we may safely watch the case for a few days. If decided sympa- thetic irritation be present and do not yield after a few days' treatment, excision is advisable, even though the lens of the wounded eye be uninjured. In regard to group (1), excision is without doubt the safest course in all cases, whether or not the eye be causing sympathetic symptoms, or be itself especially irritable ; for there is little prospect of regaining useful vision in an eye with a ciliary wound and traumatic cataract. In group (3 ) excision is necessary if the wound be very large or irregular, and in some cases with small wound but persistent symptoms. In group (4) removal of the eye is very seldom justifiable, unless the iris having healed into the wound chronic inflammatory changes are present, or severe iritis and threatened pan- ophthalmitis come on. The patient in all open cases must be warned, and must be seen every few days for many weeks. When sympathetic ophthalmitis has set in before the patient asks advice, the rule as to the excision of the ex- citing eye is different. The treatment of wounded eyes which are not excised is the same as for traumatic iritis and cataract, viz., atropine, rest, and local depletion. If seen before inflammation (iritis) has begun, ice is to be used. If the iris have pro- lapsed into the wound the protusion should be drawn 188 INJURIES OF THE EYEBALL. further out and a large piece of iris cut off so that the ends when replaced by the curette may retract and remain quite free from the wound, see Iridectomy; this may be done as much as a week after the injury. Even when seen within an hour or two of the wound, the prolapse can seldom, in my experience, be either returned by manipulation or made to retract by eserine or atropine. It is sometimes important to determine whether an ex- cised eye contain a foreign body. If nothing can be found in the blood or lymph, etc., by feeling with a probe, it is best to crush the soft parts, little by little, between finger and thumb, when the smallest particle will be felt. If a shot have entered and left the eye, the counter-opening may, if recent, be found from the inside, although no irregularity be noticeable outside the eyeball. CHAPTER XI. CATARACT. Cataract means opacity of the crystalline lens, and is due to changes in the structure and composition of the lens- fibres. The capsule is often thickened, but otherwise not much altered. The changes seldom occur throughout the whole lens at once, but begin first in a certain region, e. g., the centre, nucleus, or the superficial layers, cortex, whilst in some forms of partial cataract the change never spreads beyond the part first affected. Senile changes in the lens With advancing age the lens, which is from birth firmest at the centre, becomes harder, and acquires a very decided yellow color ; its re- fractive power usually decreases, its surface reflects more light, and its substance becomes somewhat fluorescent. The result of all these changes is, that at an advanced age the lens is more easily visible than in early life, the pupil be- coming grayish instead of being quite black. This grayness of the pupil may easily be mistaken for cataract, but oph- thalmoscopic examination shows that the lens is transparent, the fundus being seen without any appreciable haze. It has hitherto been supposed that the lens became smaller in old age, but the researches of Priestley Smith have lately shown that the lens continues to increase in all dimensions, so long as it remains transparent. As a rule, however, cataractous lens are undersized. The consistence of a cataract depends chiefly on the patient's age. The wide physical differences between cata- racts depend less on variations in the cause, position, or 190 CATARACT. character of the opacity than on the degree of natural hardness which is proper to the lens at the time when the opacity sets in. Below about thirty-five all cataracts are "soft." Forms of General Cataract. (1.) Nuclear cataract. — The opacity begins in, and re- mains more dense at, the nucleus of the lens, thinning off gradually in all directions toward the cortex, Fig. 64; the nucleus is not really opaque, but densely hazy. As the patients are generally old, nuclear cataract is usually senile and hard, and also often amber-colored or light brownish, like " pea-soup" fog. (2.) Cortical cataract — The change begins in the super- ficial parts, and generally takes the form of sharply defined lines or streaks, or triangular patches, which point toward the axis of the lens, and whose shape is dependent on the arrangement of the lens fibres, Fig. G5. They usually begin at the edge, equator, of the lens, where they are hidden by the iris, but when large enough they encroach on the pupil as whitish streaks or triangular patches. Theyatfect both the anterior and posterior layers of the lens, and the inter- vening parts may be quite clear. Sooner or later the nucleus also becomes hazy, mixed cataract, and the whole lens eventually gets opaque. Some cases of the large class known as " senile" or " hard " cataract are nuclear from beginning to end, i. e., formed by gradual extension of diS'used opacity from the centre to the surface ; more commonly they are of the mixed variety. A few cataracts beginning at the nucleus, and many beginning at the vortex, are not senile in the sense of ac- companying old age, and are, therefore, not hard. Some such are caused by diabetes, but in many it is impossible PARTIAL CATARACT. 191 to say why the lens should have become diseased.' Mey- hofer, observing that opacities in the lens are disproportion- ately common in glassblowers, suggests that radiant heat may act as a direct cause of cataract. Many of them are known as " soft" cataracts when complete. They generally form quickly, in a few months. A few are congenital. Whether nuclear or cortical, they are whiter and more uniform looking than the slower cataracts of old age, and the cortex often has a sheen, like satin or mother-of-pearl, or looks flaky like spermaceti. In some cortical cataracts we find only numerous very small dots or short streaks — "dotted cortical cataract." Occasionally a single large wedge-shaped opacity will form at some part of the cortex and remain stationary and soli- tary for many years. Sometimes in suspected cataract, though no opaque striae are visible by focal illumination, one or more dark streaks, " striae of refraction" — Bowman, are seen with the mirror, altering as its inclination is varied, and having much the same optical effect as cracks in glass ; these " flaws" should always be looked on as the beginning of cataract. Partial Cataract, Three forms need special notice. (1) Lamellar (zonular) cataract is a peculiar and well- marked form in which the superficial laminae and the nucleus of the lens are clear, a layer or shell of opacity being present between them, Fig. 67. An examination of three or four specimens here and abroad shows a degene- rated layer between the nucleus and cortex ; in all the 1 Lowered blood supply from atheroma of the carotid has lately been suffg'ested as a cause in some cases (Michel ) . Cataract does not seem to be often related to renal disease ; but when renal albuminuria is present In a case of cataract, the prognosis for operation is decidedly less favor- able than usual. 192 CATARACT. cases the nucleus has been found degenerated, but it is not yet determined whether this is due to post-mortem change or not (Lawford, Beselin). It is probable that the opacity is present at birth ; it certainly never forms late in life. The great majority of its subjects give a history of infantile convulsions The size of the opaque lamella or shell, and therefore its depth from the surface of the lens, is subject to much variation, and it may be much smaller than is shown in the figure. The opacity is often stationary for years, perhaps for life, but cases are sometimes met with in which we cannot doubt, from the history, that the opacity has, without extending perceptibly, become more dense ; instances of lamellar opacity spreading to the whole lens are, however, apparently very rare. (2) Pyramidal cataract. — A small, sharply-defined spot of chalky-white opacity is present in the middle of the pupil, (at the anterior pole of the lens), looking as if it lay upon the capsule. When viewed sideways it seems to be superficially embedded in the lens, and also sometimes stands forward as a little nipple or pyramid. Fig. 62. It Fig. 62. J Pyramidal cataract seen from the front and in section. consists of the degenerated products of a localized inflam- mation just beneath the lens-capsule, with the addition of organized lymph derived from the iris and deposited on the front of the capsule, the capsule itself being puckered and folded, Fig. 63. It is a stationary form, scarcely ever becoming general. Pyramidal cataract is the result of central perforating ulceration of the cornea in early life, and of this ophthalmia neonatorum is nearlv alwavs the cause ; it is, therefore. PARTIAL CATARACT, 193 often associated with corneal nebula. The contact between the exposed part of the lens-capsule and the inflamed cornea, which occurs when the aqueous hasescaped through the hole in the ulcer, appears to set up the localized sub- FiG. 63. Magnified section through a pyramidal cataract,with the immediately subjacent layers. The fine parallel shading shows the thickness of the opacity, the double (black and white) outline is the capsule ; above and below are the cortical lens-fibres, many being broken up into globules beneath the opacity. Lying upon the puckered capsule over the opacity is a little fibrous tissue, the result of iritis. capsular inflammation. Iritis in very early life may also cause similar opacities at points of adhesion between the iris and lens. The term anterior polar cataract is applied both to the form just described and to certain rare cases in which gen- eral cataract begins at this part of the lens. (3) Cataract, which afterwards becomes general, may begin as a thin layer at the middle of the hinder surface of the lens, posterior polar cataract. Fig. 66. There are many varieties, but in general the pole itself shows the most change, the opacity radiating outward from it in more 9 194 CATARACT. or less regular spokes. The color appears grayish, yellowish, or even brown, because seen through the whole thickness of the lens. Sometimes the opacity is due to formations adherent to the back of the capsule, i. e., in front of the vitreous ; but this can seldom be proved during life. Cata- ract beginning at the posterior pole is often a sign of dis- ease of the vitreous depending on choroidal mischief ; it is common in the later stages of retinitis pigmentosa and severe choroiditis, and in high degrees of myopia with dis- ease of the vitreous. The prognosis, therefore, should al- ways be guarded in a case of cataract where the principal part of the opacity is in this position. When a cataract forms without known connection with other disease of the eye, it is said to be primary. The term secondary cataract is used when it is the consequence of some local disease, such as severe irido-cyclitis, glaucoma, detachment of the retina, or the growth of a tumor in the eye. Primary cataract is symmetrical in most cases, but an interval, which may even extend to several j^ears, usually separates its onset in the two eyes. Secondary cataract, of course, may or may not be symmetrical. Diagnosis of Cataract. — The subjective symptoms of cataract depend almost solely on the obstruction and dis- tortion of the entering light by the opacities. Objectively, cataract is shown in advanced cases by the white or gray condition of the pupil at the plane of the iris; in earlier stages by whitish opacity in the lens when examined by focal light, and by corresponding dark portions, lines, spots, or patches in the red pupil when examined by the ophthal- moscope mirror. Both subjective and objective symptoms differ with the position and quantity of the opacity. When the whole lens is opaque the pupil is uniformly whitish ; the opacity lies almost on a level with the iris, no space intervening, and consequently, on examining by focal light, we find DIAGNOSIS OF CATARACT. 195 that the iris casts no shadow on the opacity ; the brightest light from the mirror will not penetrate the lens in quantity enough to illuminate the choroid, and hence no red reflex will be obtained. Such a cataract is said to be mature or "ripe," and the affected eye will be, in ordinary terms, "blind." If both cataracts be equally advanced, the patient will be unable to see any objects; but he will dis- tinguish quite easily between light and shade when the eye is alternately covered and uncovered in ordinary day- light, good perception of light, p. I., and will tell correctly the position of a candle flame (good projection). The pupils should be active to light and not dilated, the tension normal. In a case of incipient cataract the patient complains of gradual failure of sight, and we find the acuteness of vision impaired, probably more in one eye than in the other, and more for distant than for near objects. In the earliest stages of senile cataract some degree of myopia may be developed (Chap. XX.), or, owing to irregular refraction by the lens, the patient may see with each eye two or more Images of any object close together, polyopia uniocularis. If he can still read moderate type, the glasses appropriate for his age and refraction, though giving some help, do not remove the defect. If, as is usual, he be presbyopic, he will be likely to choose over-strong spectacles, and to place objects too close to his eyes, so as to obtain larger retinal images, and thus compensate for want of clearness. In nuclear cataract, as the axial rays of light are most ob- structed, sight is often better when the pupil is rather large, and such patients tell us that they see better in a dull light, or with the back to the window, or when shading the eyes with the hand. In the cortical and more diffused forms this symptom is less marked. On examining by focal light (the pupil having been di- lated) an immature nuclear cataract appears as a yellowish. 196 CATARACT rather deeply-seated, haze, upon which a shadow is cast by the iris on the side from which the light comes, 3, Fig. 64. On now using the mirror this same opacity appears as a dull blur in the area of the red pupil, darkest at the centre, Fig. 64. Nuclear cataract. 1. Section of lens; opacity densest at centre. 2, Opacity as seen by transmitted light (ophthalmoscope mirror) with dilated pupil. 3. Opacity as seen by reflected light (focal illumina- tion). The pupil is supposed to be dilated by atropine. and gradually thinning off on all sides, so that, at the margin of the pupil, the full red choroidal reflex may still be present ; the details of the fundus, if still visible, are obscured by the hazy lens, the haze being thickest when we look through the centre of the pupil, 2, Fig. 64. If the opacity be dense and large, a faint dull redness will be visible, aiid that only at the border of the pupil. Cortical opacities, if small and confined to the equator, or edge, of the lens, do not interfere with sight ; they are easily detected with a dilated pupil by throwing light very obliquely behind the iris. When large and encroaching Fig. 65. Cortical cataract. References as in preceding figure. on the pupil they are visible in ordinary daylight. They occur in the form of dots, streaks, or wedges ; seen by focal light they are white or grayish, and more or less sharply DIAGNOSIS OP CATARACT. 197 defined according as they are in the anterior or posterior layers, 3, Fig. 65. With the mirror they appear black or grayish, and of rather smaller size, 2, Fig. 65 ; and if the intervening substance be clear, the details of the fundus can be seen sharply between the bars of opacity. Some forms of cataract begin with innumerable minute dots in the cortical layer. Posterior polar opacities are seldom visible without careful focal illumination, when we find a patchy or stel- late figure very deeply seated in the axis of the lens, 3, Fig. 66 ; if large it looks concave, like the bottom of a shallow cup. With the mirror it is seen as a dark star, 2, Fig. 66, or network, or irregular patch, but smaller than when seen by focal light. The diagnosis of lamellar cataract is easy if its nature be understood, but by beginners it is often diagnosed as "nuclear." The patients are generally children or young adults; they complain of "near sight" rather than of Fig. 66. 1 V7 Posterior polar cataract. References as before. " cataract ; " for the opacity is not usually very dense, and whether the refraction of their eyes be really myopic or not, they (like other cataractous patients) compensate for dull retinal images by holding the object nearer, and so increasing the size of the images. The acuteness of vision is always defective, and cannot be fully remedied by any glasses. They often see rather better when the pupils are dilated either by shading the eyes or by means of atropine ; in the latter case convex glasses (-f 4, or -f 4 D.) are necessary for reading. The pupil presents a deeply-seated, 198 OATA RACT slight grayness, 4, Fig. 67, and when dilated with atropine the outline of the shell of opacity is exposed within it. This opacity is sharply defined, circular and whitish by focal light, interspersed, in many cases, with white specks, which at its equator appear as little projections, 3, Fig. 67. By focal illumination we easily make out that the opacity consists of two distinct layers, that there is a layer Fig. 67. Lamellar cataract. Figs. 1, 2, 3, as before. Fig. 4 shows slight grayness of the undilated pupil, owing to the layers of opacity being deeply seated. of clear lens substance, cortex, in front of the anterior layer, and that the margin, equator, of the lens is clear. By the mirror the opacity appears as a disc of nearly uni- form grayish or dark color, sometimes with projections, or darker dots, and surrounded b}^ a zone of bright-red re- flection from the fundus corresponding to the clear margin of the lens, 2, Fig. 67. The opacity often appears rather denser at its boundary, a sort of ring being formed there, and in some cases quite large spicules or patches project from the part. Not only does the size of the opaque lamella, and, therefore, its depth from the surface of the lens, differ greatly in different cases, but its thickness or degree of opacity varies also. The disease is nearly always symmetrical in the two eyes. Occasionally there are two shells of opacity, one within the other, separated by a cer- tain amount of clear lens substance. PROGNOSIS OF CATARACT. 199 The lens may be cataractous at birth, congenital cataract. This form, of which there are several varieties, is nearly always symmetrical, and generally involves the whole lens. Often the development of the eyeball is defective, and though there are no synechise, the iris may act badly to atropine. Cases are seen from time to time in which juvenile or perhaps congenital cataract appears in many members of a family, even in several generations. Prognosis of Cataract, a. Course. — Although opa- cities in the lens never clear up,^ they advance with very varying rapidity in different cases. As a rough rule, the progress of a general cataract is rapid in proportion to the youth of the patient, Cataracts in old people commonly take from one to three years in reaching maturity — some- times much longer ; there are cases of nuclear senile cata- ract where the opacity never spreads to the cortex, and the cataract never becomes " complete," though it may become dry and "ripe" for operation. If the lens be allowed to remain very long after it is opaque, further degenerative changes generally occur ; it may become harder and smaller, calcareous and fatty granules being formed in it ; or the cortex may liquefy whilst the nucleus remains hard, Morgagnian cataract. A congenital cataract may undergo absorption and shrink to a thin, firm, membranous disc. Soft cataract in young adults, from whatever cause, is gen- erally complete in a few months. b. Sight. — The prognosis after operation is good when there is no other disease of the eye, and when the patient (although advanced in years) is in fair general health. It is not so good in diabetes, nor when the patient is in obvi- ously bad health, the eyes being then less tolerant of opera- tion. In the lamellar and other congenital varieties it must be guarded, for the eyes are often defective in other respects, 1 Except sometimes in diabetes (Chap. XXIII.). 200 CATARACT. and sometimes very intolerant of operation ; the intellect, too, is sometimes defective, rendering the patient less able to make proper use of his eyes. In traumatic cataract, of course, everything depends on the details of the injury, but, as a rule, the younger the patient the better the prospect of a quiet and uncomplicated absorption of the lens. In every case of immature cataract the vitreous and fundus should be carefully examined by the ophthalmo- scope, and the refraction ascertained. The presence of high myopia is unfavorable, and the same is true of opaci- ties in the vitreous, indicating, as they usually do, that it is fluid. Any disease of the choroid or retina will, of course, be prejudicial in proportion to its position and extent. In every case, before deciding to operate, the state of the conjunctiva and lachrymal passages, the tension of the eye, and the size and mobility of the pupils to light, are to be carefully noted. Treatment. — In the early stages of senile and nuclear cataract, sight is improved by keeping the pupil moderately dilated with a weak mydriatic solution, one-eighth of a grain of atropine to the ounce, used about three times a week. Dark glasses, by allowing some dilatation of the pupil, also assist. Stenopaic glasses are sometimes useful. With these exceptions, nothing except operative treatment is of any use. The management of lamellar cataract requires separate description. Operations for the removal of cataract are of three kinds: (1) Extraction of the lens entire through a large wound in the cornea, or at the sclero-corneal junction, the lens-capsule remaining behind. By a few operators the lens is removed entire in its capsule. (2) For soft cata- racts, gradual absorption, by the agency of the aqueous humor admitted through needle punctures in the capsule, just after accidental traumatic cataract-needle operations, solution, discission. The operation needs repetition two or EXTRACTION. 201 three times, at intervals of a few weeks, and the whole process therefore occupies three or four months. (3) For soft cataracts, removal by a suction syringe or curette, intvo- duced into the anterior chamber through a small wound near the margin of the cornea, the whole lens having, if thought necessary, been freely broken up by a discission operation a few days previously (Chap. XXII.). Extraction is necessary for cataracts after about the age of forty. The lens from this age onwards is so firm that its absorption after discission occupies a much longer time than in childhood and youth ; moreover, as already stated, the swelling of the lens, after wound of the capsule, is less easily borne as age advances, and hence solution operations become not only slower, but attended by more danger. Indeed, though suction and solution operations are ap- plicable up to about the age of thirty-five, extraction is often practised in preference at a much earlier age. Suc- tion is more difficult, and it is thought by some to be attended by more risk of irido-cyclitis than the " solution '* operation ; its advantage lies in its saving of time, almost the whole lens being removed at one sitting. Evacuation along the groove of a curette barely passed through the wound is a very safe proceeding. If one present a complete cataract whilst the sight of the other is perfect, or at least serviceable, removal of the cataract will confer little immediate benefit to the patient. Indeed, if one eye be still fairly good, the patient will often be dissatisfied by finding his operated eye less useful than he expected, perhaps even not so useful as the other. In senile cataract, therefore, it is usually best not to operate so long as the lens of the other eye remains nearly clear ; but so soon as it becomes sufficiently a6*ected to interfere seriously with vision, extraction of the cataract from the first is advisable, provided that the patient have a fair prospect of life. The cataract in the first eye may be 202 CATARACT. over-ripe and less favorable for operation, if it be left until the second eye be quite ready. The removal of a single cataract in 3'oung persons is often expedient on account of appearance. In all cases of single cataract it must be explained that after the operation the two eyes will not work together on account of the extreme difference of re- fraction. See Anisometropia. Even when both cataracts are mature at the same time, it is safer to remove only one at once, because the after- treatment is more easily carried out upon one eye than both, and because after the double operation any untoward result in one eye adds to the difficulty of managing its fellow ; while a bad result after single extraction enables us to take especial precautions, or to modify the operation for the second eye. Even if the patient be so old or feeble that the second eye may never come to operation, we shall consult his interests better by endeavoring to give him one good eye than by risking a bad result in attempting to re- store both at the same time. Cataract occurring after the age of forty can seldom be safely extracted until it is complete or " ripe." The trans- parent portions of an immature cataract cannot be com- pletely removed, partly because they are sticky, partly because they cannot be seen ; and, remaining behind in the eye, they act as irritants and often set up iritis. In- complete juvenile cataract, e. g., lamellar cataract, may be safely ripened by tearing the capsule with a needle (see Discission and Suction) ; but hard cataract cannot be so treated because the lens is too hard to absorb the aqueous well, and the senile eye is intolerant of injury to the lens. Some years ago, Professor Forster, of Breslau, proposed a plan for hastening the completion of very slow senile cataracts: immediately after the iridectomy he bruises the lens by rubbing the cornea firmly over the pupil with a cataract spoon or other smooth instrument : the capsule is not ruptured, but the lens- FAILURES AFTER EXTRACTION. 203 fibres are broken up or so changed that they often become opaque a few weeks or months after. Priestley Smith and others adopt the safer plan of bruising the lens directly by means of a small bulbous spatula passed through the corneal wound. These methods are very uncertain, sometimes having no effect, but the latter modification maybe employed without risk in suitable cases. More recently McKeown and Wicker- kiewicz have advocated the plan of washing out the capsule, after expulsion of the bulk of the lens, by means of a stream of water or weak antiseptic lotion : eithera syringe or S3*phon may be used. The authors hope that this proceeding, by facil- itating the removal of clear cortical matter, will render the extraction of immature senile cataract safe and expedient. It must be borne in mind, however, that the lens substance is more sticky and adherent to the capsule when clear, and that, there- fore, it ma}- be most difficult of removal by this method, as by others, just when its removal is most important. The method is heing largeh' tried by several operators. The principal causes of failure after extraction of cata- ract are — (I.) Hemorrhage between the choroid and sclerotic com- ing on, usually with severe pain, immediately after the operation. The blood fills the eyeball, and often oozes from the wound and soaks through the bandage. (2.) Suppuration, beginning in the corneal wound, spreading to the iris and vitreous, and in many to the entire cornea, and ending in a total loss of the eye. It occasionally takes a less rapid course, and stops short of a fatal result. The alarm is given in from twelve hours to about three days after operation by the occurrence of pain, inflammatory oedema of the lids, particularly the free border of the upper lid, and the appearance of some muco- purulent discharge. On raising the lid the eye is found to be greatly congested, its conjunctiva oedematous, the edges of the wound yellowish, and the cornea steamy and hazy. In very rapid cases the pupil, especially near to the wound, :10i CATARACT. will already be occupied by lymph. Suppuration i.s prob- ably always caused by infection, though the source of the mischief of course often remains hidden. Chronic dacryo- cystitis is a very dangerous concomitant of cataract opera- tions, the pus escaping through the puncta and infecting the wound. Suppuration is more probable if the wound lie in clear corneal tissue than if it be partly scleral, and if the patient be in bad or feeble health. The use of hot fomentations for an hour three or four times a day, leeches, if there be much pain, and internally a purge, followed by quinine and ammonia, and wine or brandy if the patient be feeble, should be at once resorted to. As to other measures, opinions differ. From w^hat I have seen of my own and others' cases I am, at present, inclined to agree with Horner and those who direct most attention to the vigorous antiseptic treatment of the wound itself; I have found that the actual (galvano-) cautery applied deeply along the whole length of the w^ound is more successful than any other measures, assisted, however, by hot fomentations, and the use of iodoform or of weak lotions of chloride of zinc or bichloride of mercury, and by leaving the eye open.' But only in the cases of moderate rapidity and intensity can we hope, even partly, to arrest the disease, for the great majority^ of these cases go on to suppurative panophthalmitis, or to severe plastic irido- cyclitis with opacity of cornea and shrinking of the eyeball. (3.) Iritis may set in between about the fourth and tenth days. Here also pain, oedema of the eyelids, and chemosis are the earliest symptoms. There is lachrymation, but no muco-purulent discharge, and the cornea and wound usually remain clear. The iris is discolored (unless it happen to be naturally greenish-brown), and the pupil di- lates badly to atropine. Whenever, in a ca.se presenting 1 Mr. C. T. Collins, our house surgeon at Moorfields, suggested to me the la&t-named measure. FAILURES AFTER EXTRACTION. 205 such symptoms, a good examination is rendered difficult on account of the photophobia, iritis should be suspected. If the early symptoms are severe, a few leeches to the temples are very useful. Atropine and warmth are the best local measures. If atropine irritate, daturine or du- boisine should be tried (F. 32, 33). This inflammation is plastic, ending in the formation of more or less dense membrane in the pupil. Such mem- brane by contracting and drawing the iris with it toward the operation scar often contracts and displaces the pupil. Fig. 161 shows this in an extreme degree. The membrane is formed partly by exudation from the iris and ciliary processes, iritis, cyclitis, partly by the lens-capsule and its proliferated endothelial cells, capsulitis. Mixed forms of chronic keratitis and iritis sometimes occur, the corneal haze spreading from the wound in the form of long lines or stripes. Iritis of obstinately plastic type is liable to occur after extraction of cataract in diabetes. (4.) The iris may become incarcerated in or prolapse through the w^ound at the operation or a few days after- ward by the reopening of a weakly united wound. When iridectomy has been done the prolapse appears as a little dark bulging at one or both ends of the wound, and often causes prolonged irritability, without actual iritis. The best treatment is to draw the protruding part further out, and to cut it off as freely as possible, as in acci- dental wounds. The occurrence of prolapse is a reason for keeping the eye tied up longer. The capsule may also be incarcerated in or adherent to the wound after extraction, suction, or curette, simple linear extraction. After-opera- tions are needed if the pupil be much obstructed by cap- sular opacities or by the results of iritis ; but nothing should be done until active symptoms have subsided and the eye been quiet for some weeks. 206 CATARACT. Sight after the removal of cataract. — In accounting for the state of the sight we have to remember that the acute- ness of sight naturally decreases in old age; that slight iritis, producing a little filmy opacity in the pupil, is com- mon after extraction; and that some eyes with good sight remain irritable for long after the operation, and therefore cannot be much used. Thus, putting aside the graver complications, we find that even of the eyes which do best only a moderate proportion reach normal acuteness of vision. Cases are considered good when the patient can with his glasses read anything between Nos. 1 and 14 Jaeger and y^^ Snellen; but a much less satisfactory result than this is very useful. About 5 per cent, of the eyes operated upon are lost from various causes. The eye is rendered extremely hypermetropic by removal of the lens, and frequently there is a good deal of astigmatism due to flattening of that meridian of the cornea which is at a right angle with the operation wound. Strong convex glasses are necessary for clear vision ; these should seldom be allowed until three months after the operation, and at first they should not be continuously worn. Two pairs are needed ; one makes the eye emmetropic and gives clear distant vision (+10 or H D.) ; the other (about + 16 D.) is for reading, sewing, etc., at about 10'^ (25 cm.), as dur- ing strong accommodation. When there is astigmatism it should usually be corrected. As all accommodation is lost, the patient has no range of distinct vision. Lamellar cataract. — If the patient can see enough to get on fairly well at school, or in his occupation, it maybe best not to operate; but when, as is the rule, the opacity is dense enough to interfere seriously with his prospects, something must be done. The choice lies between artificial pupil when the clear margin is wide and quite free from spicules, and solution or extraction when it is narrow, or when large spicules of opacity project into it from the CATARACT FOLLOWING INJURY. 207 opaque lamella, Fig. 67. It is difficult to say which method gives on the whole the better results, and we must judge each case on its own merits. If atropine, b}^ dilating the pupil, improves the sight, an artificial pupil, made by re- moving the iris quite up to its ciliary border, will generally be beneficial ; the clear border of the lens is thus exposed in the coloboma, and light passes through it more readil}^ than through the hazy part. A very good rule is to ope- rate on only one eye at a time, thus allowing the choice of a different operation on its fellow. My own experience is decidedly in favor of removing the lens in the majorit}'" of cases. When a cataractous eye is absolutely blind (no p. 1., see p. 49), some more deeply-seated disease must be present, and no operation should be undertaken ; and when projec- tion and p. 1. are bad, great caution is needed. Cataract following injury Severe blows on the eye may be followed by opacity of the lens, the capsule and often the suspensory ligament being no doubt torn in some part, concussion cataract. Lawford has shown that rupture of the posterior capsule may occur from a blow, while the anterior capsule remains intact (Ophth. Rev., vi. 281). Such a cataract may remain incomplete and stationary for an indefinite period, but often it becomes complete. Trau- matic cataract proper is the result of wound of the lens- capsule ; the aqueous passing through the aperture is im- bibed by the lens-fibres, which swell up, become opaque, and finally disintegrate and are absorbed. The opacity begins within a few hours of the wound; it progresses quickly in proportion as the wound is large and the patient young ; but both the symptoms and consequences are often more severe in old persons. A free wound of the capsule, followed by rapid swelling of the whole lens, may give rise, especially after middle life, to severe glaucomatous symp- toms and iritis. In from three to six months a w^ounded 208 CATARACT. lens will generally be absorbed, and nothing but some chalky-looking detritus remain in connection with the cap- sule. A very fine puncture of the lens is occasionally followed by nothing more than a small patch or narrow track of opacity, or by very slowly advancing general haze. Occasionally partial opacities of the lens caused by injury clear up entirely. The objects of treatment are to prevent iritis by atropine, and by leeching if there be pain ; it is usually safest to leave the wounded lens to become absorbed, but we must be prepared to extract it by linear operation or suction at any time, should glaucoma, iritis, or severe irritation arise. A concussion cataract, however, is seldom completely absorbed ; the lens shrinks and may then become loosened, and fall either into the vitreous or aqueous chamber. I believe, therefore, that it is usually best to remove by operation a cataract following a blow. It will often be observed in both these forms of cataract that the opacity appears at the posterior surface of the lens quite early, whether the wound have penetrated deeply or not. Dislocation of the lens in its capsule is usually caused by a blow on the eye, but may be spontaneous, or congeni- tal ; in either case it is, as a rule only partial. The iris is often tremulous where its support is lost, and bulged forward at some other part where the lens rests against it ; by focal light, or by the ophthalmoscope, the free edge of the lens can be seen as a curved line passing across the pupil; more easily if the pupil be dilated. More rarely the dislocation is incomplete, either into the vitreous or into the anterior chamber. A full-sized lens dislocated into the anterior chamber causes acute glaucoma. Glaucoma, acute or chronic, may also follow at any time after a dislocation, either partial or complete, into the vitreous. Dislocated lenses often become opaque and shrunken, and then either remain loose or become adherent, and in either event are DISLOCATION OF THE LENS. 209 likely, sooner or later, to set up irritation and pain. Such a lens may sometimes be made to pass at will through the pupil by altering the position of the head. The edge of a transparent lens in the vitreous appears, by the mirror, as a dark line ; when in the anterior chamber it appears as a bright line, by focal illumination. Congenital dislocation of the lens is often accompanied by other defects of devel- opment, such as coloboma. For dislocation of lens beneath conjunctiva in rupture of eye, see p. 178. CHAPTER XII. DISEASES OF THE CHOROID. The choroid is, next to the ciliary processes, the most vascular part of the eyeball, and from it the outer layers of the retina, certainly, and the vitreous humor probably, are mainly nourished. Inflammator}^ and degenerative changes often occur, some of them entirely local, as in myopia, others symptomatic of constitutional or of general- ized disease, such as syphilis and tuberculosis. Choroiditis, unlike inflammation of its continuations, the ciliary body and iris, is seldom shown by external congestion or severe pain ; and as none of its symptoms are characteristic, the diagnosis rests chiefly on ophthalmoscopie evidence. Blemishes or scars, permanent and easily seen, nearly always follow disease of the choroid, and such spots and patches are often as useful for diagnosis as cicatrices on the skin, and deserve as careful study. The retina lying over an inflamed choroid often takes on active changes, or be- comes atrophied afterwards ; but in other cases, marked by equally severe changes, the retina is uninjured. Indeed, there is sometimes difficulty in deciding which of these two structures was first affected, especially as changes in the pigment epithelium, which is really part of the retina, are as often the result of deep-seated retinitis, or retinal hemor- rhage, as of superficial choroiditis. Patches of accumulated pigment, though usually indicating spots of former choroid- itis, are sometimes the result of bleeding, either from reti- nal or choroidal vessels, and their correct interpretation mav therefore be difficult. DISEASES OF THE CHOROID. 211 Appearances in health. — The choroid is composed chiefly of bloodvessels and of cells containing dark-brown pigment. The quantity of pigment varies in different eyes, and to some degree in different parts of the same eye ; it is scanty in early childhood, and in persons of fair complexion ; more abundant in persons with dark or red hair, brown irides, or freckled skin ; more plentiful in the region of the yellow spot than elsewhere. In old age the pigment epithelium becomes paler. When examining the choroid we need to think of four parts : (1) the retinal pigmented epithelium, which is for ophthalmoscopic purposes choroidal, seen in the erect image as a fine darkish stippling ; (2) the capil- lary layer, chorio-capillaris, just beneath the epithelium, forming a very close mesh work, the separate vessels of which are not visible in life; (3) the larger bloodvessels, often easily visible ; (4) the pigmented connective-tissue cells of the choroid proper, which lie between the larger vessels. In the majority of eyes these four structures are so toned as to give a nearly uniform, full red color by the ophthal- moscope, blood-color predominating. In very dark races the pigment is so excessive that the fundus has a uniform slaty color. In very fair persons, and young children, the deep pigment (4) is so scanty that the large vessels are separated by spaces of lighter color than themselves. Fig. 34. In dark persons these same spaces are of a deeper hue than the vessels, the latter appearing like light streams separated by dark islands {see upper part of Fig. 70). Xear to the disc and y. s. the vessels are extremely abun- dant and very tortuous, the interspaces being small and irregular ; but toward and in front of the equator the veins take a nearly straight course, converging toward the venas vorticosae, and the islands are larger and elongated. The veins are much more numerous and larger than the arteries. Fig. 69, but we cannot often distinguish between them in 212 DISEASES OF THE CHOROID. life. The vessels of the choroid, unlike those of the retina, present no light streak along the centre. The pigment epithelium and the capillary layer tone down the above contrasts, and so in old age, when the epithelium pigment is bleached, or if the capillary layer be atrophied after superficial choroiditis. Fig. 70, a and h, the above distinc- tions become very marked. A vertical section of naturally injected human choroid is shown in Fig. 68 ; the uppermost dark line (1) is the pigment epithelium ; next are seen the capillary vessels (2), cut across ; then the more deeply-seated large vessels (3), and the deep layer of stellate pigment-cells of the choroid proper (4). Fig. 69 is from an artificially injected human choroid seen from the inner surface. The shaded portion is intended to represent the general effect produced by all the vessels and the pigment epithelium. 'I'he lower part shows the large vessels with their elongated interspaces, as may be seen in a case where the pigment epithelium and chorio-capillaris are atrophied, Fig. 70, 6 ; in a dark eye the interspaces in Fig. 69 would be darker than the vessels. Fig. 68. Human choroid, vertical section. Naturally injected. X 20. The middle part shows the capillaries without the pigment epithelium. Both figures are magnified about four times as much as the image in the indirect o{?hthalmoscopic exami- nation. Ophthalmoscopic Signs of Disease of the Choroid. The changes usually met with are indicative of atrophy. This may be partial or complete: primary, or following inflammation or hemorrhage ; in circumscribed spots and DISEASES OF THE CHOROID. 213 patches, or in large and less abruptly bounded areas. Sec- ondary changes are often present in the corresponding Fig. 69. y\ Vessels of human choroid artificially injected. Arteries cross-shaded. Capillaries too dark and rather too small. The uppermost shaded part is meant to represent the effect of the pigment epithelium. X 20. parts of the retina. The chief signs of atrophy of the choroid are (1) the substitution of a paler color, varying from pale red to yellowish-white, for the full red of health, the subjacent white sclerotic beinof more or less visible 214 DISEASES OF THE CHOROID. where the atrophic changes have occurred; (2) black pig- ment in spots, patches, or rings, and in varying quantity upon or around the pale patches. These pigmentations result, 1st, from disturbance and heaping together of the normal pigment ; 2d, from increase in its quantity ; 3d, from blood-coloring matter left after extravasation. Patches of primar}" atrophy, e.g., in myopia, are never much pigmented unless bleeding have taken place. The amount of pig- mentation in atrophy following choroiditis is closely related to that of the healthy choroid, i. e., to the complexion of the person. Fig. 70. Atrophy after syphilitic choroiditis, showing various degrees of wasting (Hutchinson), a. Atrophy of pigment epithelium. 6. Atrophy of epithelium and chorio-capillaris ; the large vessels exposed, c. Spots of complete atrophy, many with pigment accumulation. Pigment at the fundus may lie in the retina as well as in, or on, the choroid, and this is true w^hatever may have been its origin, for in choroiditis with secondary retinitis the choroidal pigment often passes forward into the retina. When a spot of pigment is distinctly seen to cover over a DISEASES OF THE CHOROID. 215 retinal vessel, that spot must be not only in, but very near the anterior (inner) surface of, the retina ; and when the pigment has a linear, mossy or lace-like pattern, Fig. 81, it is always in the retina ; these are the only conclusive tests of its position. It is important, and usually easy, to distinguish between partial and complete atrophy of the choroid. In superficial atrophy, affecting the pigment epithelium and capillary layer, the large vessels are peculiarly distinct, Fig. 70, a and h. Such "capillary" or "epithelial-' choroiditis often covers a large surface, the boundaries of which are some- times well-defined, sinuous and map-like, but are as often Fig. 71. ill-marked ; in the latter case we must carefully compare different parts of the fundus, and also make allowance for the patient's age and complexion. Complete atrophy is shown by the presence of patches of white or yellowish- white color of all possible variations in size, with sharply- cut, circular or undulating borders, and with or without pigment accumulations, Figs. TO, c, and 71. The retinal 216 DISEASES OF THE CHOROID, vessels pass unobscured over patches of atrophied choroid, proving that the appearance is caused bj some change deeper than the surface of the retina. If the patient comes with recent choroiditis, we also often see patches of palish color, but they are less sharply- bounded and frequently of a grayer or whiter (less yellow) color than patches of atrophy ; moreover, the edge of such Fig. 72. Minute exudations into inner layer of choroid in sj'philitic choroid- itis. Pigment epithelium adherent over the exudations, but elsewhere has been washed off. Ch. Choroid. Scl. Sclerotic. a patch is softened, the texture of the choroid being dimly visible there, because only partly veiled by exudation. If the overlying retina be unaffected, its vessels are clearly seen over the diseased part; but if the retina itself is hazy or opaque, the exact seat of the exudation often cannot be Fig. 73. Section of miliary tubercle. Inner layers of choroid comparatively unaffected. The li£^hter shading, surrounding an artery in the deepest part of the tubercle, represents the oldest part, which is caseating; an artery is seen cut across in this part of the tubercle. at once decided, and this difiBculty is often increased, by the hazy state of the vitreous. Syphilitic choroiditis begins in, and is often confined to, the inner (capillary) layer of the choroid, Fig. 72, and DISEASES OF THE CHOROID. 217 hence it often affects the retina. In miliary tuberculosis of the choroid the overlying retina is clear, and the growth is, for the most part, deeply seated. Fig. 7S. After very severe choroiditis, or extensive hemorrhage, absorption is often incomplete ; we find then, in addition to atrophy, gray or white patches, or lines, which, in pattern and appear- ance, remind us of keloid scars in the skin, or of patches and lines of old thickening on serous membranes. Very characteristic changes are seen after rupture of the choroid from sudden stretching caused by blows on the front of the eye. These ruptures, always situated in the Fig. 74. Ruptures of choroid. (Wecker.) central region, occur in the form of long tapering lines of atrophy, usually curved toward the disc, and sometimes branched. Fig. 74 ; their borders are often pigmented. If seen soon after the blow the rent is more or less hidden by blood, and the retina over it is hazy. The pathological condition known as "colloid disease" of the choroid consists in the growth of very small nodules, soft at first, afterward becoming bard like glass, from the 10 218 DISEASES OF THE CHOROID. thin lamina el a slica, which lies between the pigment epithe- lium and chorio-capillaris. It is common in eyes excised for old inflammatory mischief, and in partial atrophy after choroiditis, Fig. 75. But little is known of its ophthalmo- FiG. 75. Partial atrophy after «-yphilitic choroiditis. Minute growths from inner surface of choroid, showing how they disturb the outerlayers of the retina. X 60. scopic equivalent or its clinical characters. Probably it may result from various forms of choroiditis, and may also be a natural senile change. Hemorrhage from the choroidal vessels is not so often recognized as from those of the retina, but may be seen sometimes, especially in old people and in highly myopic eyes. The patches are more rounded than retinal hemor- rhage, and we can sometimes recognize the striation of the overlying retina. Occasionally they are of immense size. Patches of atrophy may follow. Clinical Forms of Choroidal Disease. (1.) Numerous discrete patches of choroidal atrophy, sometimes complete, as if a round bit had been punched out, in others incomplete, though equally round and w^ell defined, are scattered in different parts of the fundus, but are most abundant toward the periphery ; or, if scanty, are found only in the latter situation. They are more or less pigmented, unless the patient's complexion is extremely fair, Figs. 70, c, and 71. CLINICAL FORMS OF DISEASE. 219 (2.) The disease has the same distribution, but the patches are confluent ; or large areas of incomplete atrophy, passing by not very well defined boundaries into the healthy choroid around, are interspersed with a certain number of separate patches ; or without separate patches there may be a widely spread superficial atrophy with pigmentation. Fig. TO, a and h. These two types of choroiditis disseminata run into one another, different names being used by authors to indicate topographical varieties. Generally both eyes are affected, though unequally ; but in some cases one eye escapes. The retina and disc often show signs of past or present in- flammation. Syphilis is by far the most frequent cause of symmetrical disseminated choroiditis. The choroiditis begins from one to three years after the primary disease, whether this be acquired or inherited ; occasionally at a later period. The discrete variety. Fig. 70, c,where the patches, though usually involving the whole thickness of the choroid, are not connected by areas of superficial change, is the least serious form, unless the patches are very abundant. A moderate number of such patches confined to the peri- phery cause no appreciable damage to sight. The more superficial and widely-spread varieties, in which the retina and disc are inflamed from the first, are far more serious. The capillary layer of the choroid seldom again becomes healthy, and with its atrophy, even if the deeper vessels be not much changed, the retina suffers, passing into slowly progressive atrophy. The retina often becomes pigmented, Fig. 81, its bloodvessels extremely narrowed, and the disc passes into a peculiar hazy yellowish atrophy, "waxy disc," Hutchinson — '' choroiditic atrophy," Gowers. The appearances may closely imitate those in true retinitis pig- mentosa, and the patient, as in that disease, often suffers from marked night-blindness. Such patients continue to 220 DISEASES OF THE CHOROID. get slowly worse for many years, and may become nearly blind. Syphilitic choroiditis generally gives rise, at an early date, to opacities in the vitreous ; these either form large, easily seen, slowly floating ill-defined clouds, or are so minute and numerous as to cause a diffuse and somewhat dense haziness, "dust-like opacities," Forster. (Chap. XYI.) Some of the larger ones may be permanent. In the advanced stages, as in true retinitis pigmentosa, pos- terior polar cataract is sometimes developed. There are no constant differences between choroiditis in acquired and in inherited syphilis; in many cases it would be impossible to guess, from the ophthalmoscopic changes, with which form of the disease we had to do. But there is, on the whole, a greater tendency toward pigmentation in the choroiditis of hereditary than in that of acquired syphilis, and this applies both to the choroidal patches and to the subsequent retinal pigmentation. In the treatment of syphilitic choroiditis we rely almost entirely on the constitutional remedies for syphilis — mer- cury and iodide of potassium. In cases which are treated early, sight is much benefited, and the visible exudations quickly melt away under mercury ; but I believe that even in these complete restitution seldom takes place, the nutri- tion and arrangement of the pigment epithelium and bacil- lary layer of the retina being quickly and permanently damaged by exudations into or upon the chorio-capillaris, as in Fig. 72. In the later periods, when the choroid is thinned by atrophy, or its inner surface roughened by little outgrowths. Fig. 75, or adhesions and cicatricial contrac- tions have occurred between it and the retina, nothing can be done. A long mercurial course should, however, always be tried if the sight be still failing, even if the changes all look old ; for in some cases, even of very long standing, fresh failure takes place from time to time, and mercury CLINICAL FORMS OF DISEASE. 221 has a very marked influence. In acute cases rest of the eyes in a darkened room, and the employment of the arti- ficial leech or of dry cupping at intervals of a few days, for some weeks, are useful. But it is often difficult to insure such functional rest, for the patients seldom have pain or other discomfort. Disseminated choroiditis sometimes occurs without ascer- tainable evidence of syphilis, chiefly about the age of puberty. Such cases often difi'er in some of their ophthal- moscopic details from ordinary syphilitic cases, especially in the immunity of the retina and disc ; and also in the absence of tendency to recur. It is but seldom that any definite cause, such as exposure to bright light, can be plausibly assigned. In choroiditis from any cause iritis may occur. (3.) The choroidal disease is limited to the central re- gion. There are many varieties of such localized change. In myopia the elongation which occurs at the posterior pole of the eye very often causes atrophy of the choroid contiguous to the disc, and usually only on the side next the yellow spot (see Myopia). The term ''posterior staphy- loma " is applied to this form of disease when the eye is myopic, because the atrophy is a sign of posterior bulging of the sclerotic. The term sclerotico-choroiditis posterior is often used, though we but seldom see evidence of exudative changes or hemorrhagic effusions at the fundus in myopia. A similar crescent, but seldom of great width, is very com- monly seen, bounding the lower margin of the disc, in astigmatic eyes ; its widest part nearly always corresponds with the direction of the meridian of greatest curvature of the cornea (Chap. XX.). A narrow and less conspicuous crescent, or zone, of atrophy around the disc is seen in some other states, notably in old persons and in glaucoma, Fig. 96. Separate, round patches of complete atrophy (" punched-out patches") at the central region may occur 222 DISEASES OF THE CHOROID. in myopia with the above-mentioned staphyloma, and must not then be ascribed to syphilitic choroiditis ; in other cases of myopia ill-defined partial atrophy is seen about the y. s., sometimes with splits or lines running hori- zontally toward the disc. Central senile choroiditis Several varieties of disease confined to the region of the y. s. and disc are seen, and chiefly in old persons. A particularly striking and rather rare form is shown in Fig. 76. In others a larger but less defined area is affected. Some of these appearances un- doubtedly result from large choroidal or retinal extravasa- tions, but the origin of the state shown in Fig. 16 is obscure. In these areated forms the large, deep vessels are often much narrowed, or even converted into white lines and devoid of blood-column by thickening of their coats. In another form, Fig. 11, the central region is occupied by a number of small, white or yellowish-white dots, sometimes visible only in the erect image. This condition is very peculiar, and appears to be almost stationary ; the discs are sometimes decidedly pale ; when very abundant the spots coalesce, and some pigmentation is found; sometimes hemorrhages occur. The pathological anatomy and gen- eral relations of this disease are incompletely known; it was first described by Hutchinson and Tay, and is tolerably common. It is symmetrical and the changes may some- times be mistaken for a slight albuminuric retinitis. No treatment seems to have any influence. Every case of immature cataract should, when possible, be examined for central choroidal changes. (4.) Anomalous forms of choroidal disease. — Single, large patches of atrophy, with pigmentation, and not located in any particular part, are occasionally met with. Probably some of these have followed the absorption of tubercular growths in the choroid, while others are the result of large spontaneous hemorrhages ; a blow by a CLINICAL FORMS OF DISEASE. 223 Fig. 76. Central choroiditis. (Weeker and Jaeger.) Fig. 77. ■^ V K,i Ly m ^^K \H- ~^ - W jfl| ^^ M Central guttate senile choroiditis. blunt object on the sclerotic causing local bleeding, or in- flammation and subsequent atrophy, may account for such 224 DISEASES OF THE CHOROID. a patch at the anterior part of the fundus. Single large patches of exudation are also met with, and are, perhaps, tubercular. Choroidal disease in disseminated patches seems sometimes to depend upon numerous scattered hem- orrhages into the choroid, which may occur at different dates, and which lead to patches of partial atrophy with pigmentation. The local cause of such hemorrhages is obscure; the disease may occur in one eye or both, and in young adults of either sex. It may perhaps be called hemorrhagic choroiditis (compare Chapter XYI.). Al- though the changes produced are very gross, some of these patients regain almost perfect sight, a fact, perhaps, point- ing to the deep layers of the choroid as the seat of disease. It is possible that over-use of the eyes or exposure to great heat or glare sometimes causes choroiditis. Single spots of choroidal atrophy, especially toward the periphery, should, no less than abundant changes, always excite grave suspicion of former syphilis, and often furnish valuable corroborative evidence of that disease. The peri- phery cannot be fully examined unless the pupil be widely dilated. A few small scattered spots of black pigment on the choroid or in the retina, without evidence of atrophy of the choroid, often indicate former hemorrhages. Such spots are seen after recovery from albuminuric retinitis with hemorrhages, after blows on the eye, and sometimes without any relevant history. Congestion of the choroid is not commonly recognizable by the ophthalmoscope. That active congestion does occur is certain, and it would seem that myopic eyes are espe- cially liable to it, particularly when over-used or exposed to bright light and great heat. Serious hemorrhage may undoubtedly be excited under such circumstances. In conditions of extreme anaemia the whole choroid becomes unmistakably pale. Coloboma of the choroid, congenital deficiency of the CLINICAL FORMS OF DISEASE. 225 lower part, is shown ophthalmoscopically by a large surface of exposed sclerotic, often embracing the disc, which is then much altered in form, and may be hardly recogniz- able, and extending downward to the periphery, where it often narrows to a mere line or chink. The surface of the sclerotic, as judged by the course of the retinal vessels, is often very irregular from bulging on its floor backward. The coloboma is occasionally limited to the part around the nerve, or may form a separate patch. Coloboma of the choroid is often seen without coloboma of the iris, and when both exist a bridge of choroidal tissue generally sep- arates them in the region of the ciliary body. Cases of so-called coloboma of the choroid at the yellow spot are probably examples of severe fcetal or infantile inflamma- tion of that part. Albinism is accompanied by congenital absence of pig- ment in the cells of the epithelium and stroma of the whole uveal tract (choroid, ciliary processes, and iris). The pupil looks pink, because the fundus is lighted to a great extent indirectly through the sclerotic. Sight is always defective, and the eyes photophobic and usually oscillating. Many almost albinotic children become mod- erately pigmented as they grow up. 10* CHAPTER XIII. DISEASES OF THE RETINA. Of the many morbid changes to which the retina is subject, some begin and end in this membrane, such as albuminuric retinitis and many forms of retinal hemor- rhage ; in others the retina takes part in changes which begin in the optic nerve (neuro-retinitis), or in the choroid (choroido-retinitis); very serious lesions also occur from embolism or thrombosis of the central retinal vessels. The retina may be separated ("detached") from the choroid by serous fluid or blood. The retina may also be the seat of malignant growth (glioma), and probably of tubercular inflammation. In health the human retina is so nearly transparent as to be almost invisible by the ophthalmoscope during life, or to the naked eye if examined immediately after excision. We see the retinal bloodvessels, but the retina itself, as a rule, we do not see. The main bloodvessels are derived from the arteria and vena centralis, which enter the outer side of the optic nerve, about 6 mm. behind the eye; the veins and arteries are generally in pairs, the veins not being more immerous than the arteries ; all pass from or to the optic disc. Fig. 34. At the disc anastomoses, chiefly capillary, are formed between the vessels of the retina and those cf the choroid and sclerotic. As no other anastomoses are formed by the vessels of the retina, the retinal circula- tion beyond the disc is terminal ; and further, as the ves- sels branch dichotomously, and the branches anastomose only by means of their capillaries, the circulation of each DISEASES OF THE RETINA. 227 considerable branch is terminal also. The capillaries, which are not visible by the ophthalmoscope, are narrower than those of the choroid, and their meshes become much wider toward the anterior and less important parts of the retina. At the 3-. s., Fig. 78, the only part used for accurate sight, the capillaries are very abundant {compare Fig. 69) ; but at the very centre of this region, /oueacentraZis, where all the layers except the cones and outer granules are excessively thin, there are no vessels, the capillaries forming fine, close loops just around it. The nerve-fibres in this part of the retina are finer than in other parts ; the}^ seem also to be much more abundant, for Bunge has found that in a case of central scotoma, where only a very small part (^V-th) of the F. was lost, quite a large tract of fibres (^tli of the whole) was atrophied in the optic nerve. The fovea centralis corresponds to an area at the centre of F., measuring onl}' 1^0 iQ diameter ; the part recognized as the macula lutea has an area, on the F., of about 7--' (Bunge). Fig. 78. Bloodvessels of human retina at the yellow spot (artiflcial injection). The central gap corresponds to the Fovea centralis, a. Arteries ; v. Veins ; n. Nasal side (toward disc) ; T. temporal side. The meshes are many times wider at the periphery of the retina. In children, especially those of dark complexion, a pecu- liar, white, shifting reflection, or shimmer, is often seen at 228 DISK ASKS OF THK RETINA. llje y. s. region, and along- the course of the principal ves- sels. It changes with every movement of the mirror, and reminds one of the shifting reflection from " watered" and " shot" silk. Around the y. s. it takes the form of a ring or zone, and is known as the " halo round the macula." When the choroid is highly pigmented, even if this shift- ing reflection be absent, the retina is visible as a faint haze over the choroid like the "bloom" on a plum. Under the high magnifying power of the erect image the nerve-fibre layer is often visible near the disc, as a faintly marked radiating striation. The sheaths of the large central ves- sels at their emergence from the physiological pit, p. 72, show^ many variations in thickness and opacity. In rare cases the medullary sheath of the optic nerve- fibres, w^hich should cease at the lamina cribrosa, is continued through the disc into the retina, and causes the ophthalmo- scopic appearance known as "opaque nerve-fibres." This congenital peculiarity may affect the nerve-fibres of the whole circumference of the disc, or only a patch or tuft of the fibres; it may only just overleap the edge of the disc or may extend far into the retina ; and islands of similar opacity are sometimes seen in the retina quite separated from the disc. It is to be particularly noted that the cen- tral part, physiological pit, of the disc is not affected, be- cause it contains no nerve-fibres. The affected patch is pure white, and quite opaque, its margin thins out gradually, and is striated in fine lines, w^hich radiate from the disc like carded cotton-wool ; the retinal vessels may be buried in the opacity, or run unobscured on its surface, and are of normal size. The deep layers of the affected parts of the retina being obscured by the opacity, an enlargement of the normal " blind spot" is the result. One eye, or both, may be affected. There is seldom any difliculty in dis- tinguishing this condition from opacity due to neuro- rtitinitis. ophthalmoscopic signs. 229 Ophthalmoscopic Signs of Retinal Disease. Congestion. — No amoimt of capillary congestion, whether passive or active, alters the appearance of the retina ; and as to the large vessels, it is better to speak of the arteries as unusually large or tortuous, or of the veins as turgid or tortuous, than to use the general term congestion. Capil- lary congestion of the optic disc may undoubtedly be recognized, but even here caution is needed, and much allowance must be made for differences of contrast depend- ing on variations in the tint of the choroid, for the patient's health and age, and for the brightness of the light used, or, what is the same thing, for the size of the pupil. Caution is also needed against drawing hasty inferences from the slight haziness of the outline of the disc, which may often be seen in cases of hypermetropia, and which is certainly not always morbid. The only ophthalmoscopic proof of true retinitis is loss of transparency of the retina, and two chief types are soon recognized according as the opacity is diffused or consists chiefly of abrupt spots and patches. Hemorrhages are present in many cases of retinitis; but they may also occur without either inflammation or oedema. The state of the disc varies much, but it seldom escapes entirely in a case of extensive or prolonged retinitis. In a large majority of cases of recent retinitis the visible changes are limited to the central region, where the retina is thickest and most vascular. (1.) The lessened transparency which accompanies dif- fused retinitis simply dulls the red choroidal reflex, and the term "smoky" is fairly descriptive of it. The same effect is given by slight haziness of any of the anterior media, but a mistake is excusable only where there is dif- fused mistiness of the vitreous from opacities which are too small to be easily distinguished, and the difficulty is then 230 DISEASES OF THE RETINA. increased because this very condition of the vitreous often coexists with retinitis. A comparison of the erect and in- verted images is often useful, for if the diffused haze noticed by indirect examination be caused by retinitis, the direct examination will often resolve what seemed a uniform haze into a w^ell-marked spotting or streaking. When the change is pronounced enough to cause a decidedly white haze of the retina, there is no longer any doubt. The retinal arteries and veins are sometimes enlarged and tor- tuous in retinitis, and in severe cases they are generally obscured in some part of their course. These forms of uniformly diffused retinitis are usually caused either by syphilis, embolism, or thrombosis. (2.) Near the y. s. a number of small, intensely white, rounded spots are seen, Fig. 79, either quite discrete or Fig. 79. Renal retinitis at a late stage. (Weaker and Jaeger.) partly confluent. When very abundant and confluent they form large, abruptly outlined patches, with irregular bor- OPHTHALMOSCOPIC SIGNS. 231 ders, some parts of these patches being striated, others stippled. (3.) A number of separate patches are scattered about the central region, but without special reference to the y. s. They are of irregular shape, white or pale buff, and some- times striated, Fig. 80; they are easily distinguished from Fig. 80. Recent severe retinitis in renal disease. (Gowers.) patches of choroidal atrophy by their color, the compara- tive softness of their outlines, and the absence of pigmen- tation. In types 2 and 3 some hemorrhages are usually present ; the retina generally may be clear, but more often there is diffused haze and evidence of swelling. The hem- orrhages may be so numerous and large as to form the chief feature, and then the retinal veins will be very tor- tuous and dilated. Forms 2 and 3, which nearly always affect both eyes, are generally associated with renal disease, but in rare 232 DISEASES OF THE RETIiNA. cases similar changes are caused by cerebral disease and other conditions. (4.) Rarely a single large patch or area of white opacity is seen with softened, ill-defined edges, any retinal vessels that may cross it being obscured. Such a patch of retinitis is usually caused either by subjacent choroiditis, or by local phlebitis or thrombosis. Hemorrhage into (or beneath) the retina is known by its color, which is darker than that of an ordinary choroid, but redder and lighter than that of a very dark choroid. Blood may be effused into any of the retinal layers, and the shape of the blood patches is mainly determined by their position. When effused into the nerve-fibre layer, or confined by the sheath of a large vessel, the extravasation takes a linear or streaked form and structure, following the direction of the nerve-fibres ; extravasations in the deeper layers are rounded. Yery large hemorrhages, many times as large as the disc, sometimes occur near the yellow spot, and probably all the layers then become infiltrated, while sometimes the blood ruptures the anterior limiting mem- brane of the retina and passes into the vitreous. Retinal hemorrhages may be large or small, single or multiple ; limited to the central region or scattered in all parts ; linear, streaky, or flame-shaped, punctate or blotchy ; they may lie alongside large vessels, or have no apparent relation to them. The hemorrhage may, as already men- tioned, be the primary change, or may only form part of a retinitis or papillo-retinitis. A hemorrhage which is mottled and of dark, dull color, is generally old. The rate of absorption varies very much ; hemorrhage after a blow is very quickly absorbed, while effusions caused by the rup- ture of diseased vessels in old people, or accompanying retinitis from constitutional causes, often last for months, and leave permanent traces. OPHTHALMOSCOPIC SIGNS. 233 Pigmentation of the retina has been referred to in con- nection with choroiditis. TS^henever pigment in the fundus forms long, sharply-defined lines, or is arranged in a mossy, lace-like, or reticulated pattern, we may safely infer that it is situated in the retina, and generally that it lies along the sheaths of the retinal vessels — compare Fig. 81 with Fig. 78. Pigment in or on the choroid never takes such a pat- FiG. 81. Study of pigment in tlie retina in a specimen of secondary retinitis pigmentosa, seen from the inner (vitreous) surface. tern, being usually in blotches or rings. The two types, however, are often mingled in cases of choroiditis with secondary affection of the retina ; indeed, whenever we decide that the retina is pigmented, the choroid must be carefully examined for evidences of former choroiditis. Spots of pigment may be left after the absorption of reti- nal hemorrhages. Such spots can generalh' be distin- guished from those following choroiditis by their more uniform appearance and by thea))senceof signs of choroidal atrophy. Atrophy of the retina, of which pigmentation of the retina, when present, is always a sign, has for its most con- stant indication a marked shrinking of the retinal blood- vessels with thickening of their coats. When the atrophy follows a retinitis or choroido-retinitis, retinitis pigmentosa, syphilitic choroido-retinitis, etc., all the layers are involved, and the outer layers, those nearest the choroid, earlier than the inner ; but when it is secondary to disease of the optic nerve, optic neuritis, progressive atrophy, and glaucoma, only the layers of nerve-fibres and ganglion cells are atro- 234 DISEASES OF THE RETINA. phied, the outer layers bcinti;- found perfect, even after many years. A retina atrophied after retinitis often does not re or less, from its border. The zone of conjunctiva so in- cluded, together with the whole of its subconjunctival tissue down to the sclerotic, is now carefully removed by the scissors. The bare surface thus left granulates, and finally contracts to a narrow band of white scar-tissue, by which the vessels running to the cornea should be obliterated. The subconjunctival fascia is often found much thickened in these cases. Care must be taken not to make the inci- sion too far from the cornea, lest the insertions of the recti be damaged. The strip removed should extend completely round the cornea ; removal of only a part of the zone is not satisfactory. The symptoms are generally made worse for a time, and the final result is not reached for several months. In some cases the operation has, in my experi- ence, been very successful, whilst in others, without ap- parent reason, it has quite failed of its purpose. Symblepharon, adhesion of lid to globe after destruction of conjunctiva, unless very extensive, can be greatly im- 392 OPERATIONS. proved by operation. In slight canes we lia\ e merely to separate the adhesion from the globe and bring together the edges of the ocular conjunctiva to cover the surface thus exposed and thus prevent reunion. But when the surface exposed by the dissection is large, flaps of conjunc- tiva with broad pedicles must be brought down to cover the deficiency in the manner first proposed by Mr. Teale •/ or mucous membrane may be transferred from the lip of the patient or even from the conjunctiva of a rabbit. Snellen has lately used a flap of neighboring skin with a pedicle, pushing it through a sort of buttonhole in the lid and attaching it in the gap made by separating the adhe- sions. B. Operations on the Lachrymal Apparatus. 1. Lachrymal abscess. (See p. 101.) 2. Slitting up the lower canaliculus This is best done by means of a knife with a blunt or probe point, and a blade narrow enough to enter the punctum. The best forms of these knives are Weber's knife, with a probe end, Fig. 134 ; Bowman's, with nearly parallel borders and a rounded end, Fig. 1.S5, and Liebreich's, Fig. 136. Position as for 1. (I) The lower lid is drawn tightly outward and downward by the thumb. (2) The canaliculus knife is passed vertically into the punctum, then turned horizon- tally and passed on through the neck of the canaliculus till it reaches the bony (inner) wall of the lachrymal sac. It is then raised up from heel toward point, and thus made to divide the canaliculus, care being taken that the neck is freely divided. Liebreich's knife cuts its ow^n way with- out being raised. The low^er canaliculus may also be di- vided with a Beer's knife, Fig. 159, which is run along a 1 Teale, Ophth. Hosp. Reports, iii. p. 253, 1861. OPERATIONS ON LACHRYMAL APPARATUS. 393 fine grooved director, Fig. 133, previously introduced. In cases of mucocele, it is good practice to divide the wall of the sac freely, and some surgeons open the upper as well as the lower canaliculus. The canaliculus requires to be kept open every three or four days till its cut edges are healed, or they will unite again. 3. Probing the nasal duct. — After dividing the canaliculus pass a good-sized lachrymal probe Fig. 134. Weber's canaliculus kuile. Fig. 135. S!^ — ^ Bowmau's canaliculus knife. Fig. 136. 3=^ Liebreich's knife for canaliculus and nasal duct. horizontally along its floor till it strikes the inner, bony, wall of the sac. Then raise it to the vertical position and push it steadily down the duct (downward and a very little outward and backward) till the floor of the nose is reached. Bowman's earlier probes were in six sizes, of which the largest was ^V i'^ch in diameter. Bow- man afterward adopted much larger probes with bulbous ends, and several such patterns are now in use. The probe used should be the largest that will pass easily. 4. A stricture of the duct may be incised with any of the canaliculus knives, although Weber's and Bowman's are 17* 394 OPERATIONS. too slender to be used with safet3^ Liebreich's is intended to be so used, and a special knife for the purpose had pre- viously been introduced by Stilling. The knife is used as a probe, being pushed quite down the duct, then partly withdrawn, turned in another direction, and pushed down again. There is generally bleeding from the nose. In all these procedures we must be certain that the probe or knife rests against the bony (nasal) wall of the lach- rymal sac before it is raised into the vertical direction. If the probe be stopped at the entrance of the canaliculus into the sac, as may easily happen if the canal be not thoroughly slit in its whole length, the lid will be pulled upon and puckered whenever the instrument is pushed toward the nose ; but if the probe have reached the sac, backward and forward movements will not usualh^ cause puckering of the lid. If in the former case the instrument be turned up and an attempt made to pass it down the duct, a false passage will probably be made. The direction of the two nasal ducts is either parallel or such that if prolonged upward they would converge slightly; they very seldom diverge. The probe when in the duct should, even if, as usual, its lower end be curved forward, rest against and indent the eyebrow ; if it stand forward from the brow it is usually in a false passage. Lachrymal syringes are of two kinds : (1 ) Anel's syringe with a nozzle fine enough to pass into the unopened punc- tum, Fig. 137. By injecting a little water into the duct through the canaliculus we can sometimes clear out slight, apparently mucous, obstruction and relieve epiphora with- out cutting or probing ; and by the same method we can often decide whether or not there is an obstruction needing the severer treatment. (2) Hollow probes attached to syringes of various patterns are used for passing down the duct and syringing at the same time. Fig. 138 shows a simple form sold as Bowman's. OPERATIONS FOR STRABISMUS Fig. 137. Fig. 138. 395 wm I Anel's syringe, full size. Bowman's syringe, about half full size. C. Operations for Strabismus. Tenotomy. — The object is to divide the tendon close to its insertion into the sclerotic. In this country Critchett's subconjunctival operation is commonly used ; abroad the operation of Yon Graefe, in which the tendon is more or 396 OPERATIONS. loss exposed, is more often employed. The internal and external recti are the only tendons commonly divided, the internal far the more frequently. Ana3sthesia is seldom necessary except for young children. Instruments: Stop speculum, Fig. 139, straight scissors, with blunted points, Fig. 140, toothed fixation forceps, Fig. 141, strabismus hook. Fig. 142. There are several forms of hook, differing in the length and sharpness of the curve and the shape of the tip. Fig. 189. Stop spring speculum. Operations. Graefe's. — An incision is made transversely over the insertion of the tendon, and, the conjunctiva being pushed aside. Tenon's capsule is opened below the tendon ; the hook is then passed under the tendon, and the latter divided with the scissors. The whole width of the tendon is exposed. The conjunctival wound may be closed by a single stitch. Snellen makes the conjunctival wound paral- lel to the muscle to avoid gaping. The effect in this and all operations may be considerably increased if the various facial or indirect connections of the muscle be divided as well as its tendon. This is done (1 ) by separating the con- junctiva from the fascia and its muscle by a burrowing dissec- tion with the scissors before the tendon is cut ; (2) by freely dividing the fascia above and below the tendon, by cutting with the scissors upward and downward after having divided the tendon itself; (3) by tying the eve out with a OPERATIONS FOR STRABISMUS 39T silk suture passed through the coujunctiva and surface fibres of the sclerotic, close to the outer border of the cornea, and attaching it to the temple for two days by strapping. 398 OPERATIONS. Fig. 142. Strabismus hook (the bent part is represented too thin). CritcheW s operation. — (1.) Introduce the speculum, and ■with the fixation forceps in the left hand, pinch up a fold of conjunctiva over the lower border of the tendon (say of the rif^ht internal rectus) at its insertion ; with the scissors in the right hand make a small opening close to the end of the forceps, and parallel with the border of the tendon. The exposed fascia, capsule of Tenon, is now easily recog- nized ; it is to be pinched up, and an opening made in it corresponding to the conjunctival wound. By taking deep hold with the forceps, both conjunctiva and fascia may sometimes be divided at one stroke. As a rule, both con- junctiva and Tenon's capsule are thicker in children than adults. (2.) Take the hook in the right hand, holding the wound open with the forceps in the left, and pass it, concavity downward and point backward, through the opening in the fascia as far as its elbow, keeping its end alwa^'s flat against the sclerotic. Next turn the end of the hook upward, still guided by the sclerotic, between the tendon and the globe, until its end is seen projecting beneath the conjunctiva above the upper border of the tendon. On now attempt- ing to draw the hook toward the cornea it will be stopped by the tendon. If Tenon's capsule have not been well opened, the hook cannot be passed beneath the tendon nor swept round the sclerotic. (3.) Lay down the forceps, transfer the hook to the left hand, holding its handle parallel with the side of the nose and tightening the tendon by traction forward and outward ; pass the scissors, with the blades slightly opened, OPERATIONS FOR STRABISMUS. 399 into the wound, and push them stvuightui) between theliook and the eye; the tendon is divided at two or three snips with a crisp sound and feelin, common between two and eight or nine months, and does not occur later than about eigh- teen months, after the contagion ; in from two-thirds to three-fourths of the cases both eyes suffer; there is a marked tendency to exudation of lymph, plastic iritis, shown by keratitis punctata, haze of cornea, and less commonly by 430 ETIOLOGY. lymph-noduIes on the iris. In some cases there are symp- toms of severe cyclitis, leading to detachment of retina and secondary cataract, and but little iritis ; but the cyclitis of acquired syphilis does not give rise to ciliary staphyloma. Syphilitic iritis, though sometimes protracted, rarely re- lapses after complete subsidence. Choroiditis and retinitis generally set in rather later, from six months to about two years after the chancre ; seldom as late as four years.^ The two conditions are most often seen together, but either may occur singly ; and in each the vitreous generally becomes inflamed. These conditions are essentially chronic, the retinitis being often, and the choroiditis sometimes, liable to repeated exacerbations or recurrences ; whilst in some cases the secondary atrophic changes progress slowly for years, almost to blindness, often with pigmentation of the retina. Syphilitic choroiditis and retinitis usually affect both eyes, but often in an unequal degree, and even when severe the disease is occasionally limited to one eye. Kera- titis, indistinguishable from that of inherited syphilis, is amongst the rarest events in the acquired disease ; when it occurs it is usually in the secondary stage of the disease. Later periods : Ulceration of the skin and conjunctiva of the lids, gummatous infiltration of the lids and sclerotic, and nodes in the orbit, whether cellular or periosteal, occur but rarely. Oculo-motor paralysis is one of the frequent ocular results of syphilis. It may depend upon gumma, syphilitic neuroma, of the affected nerve or nerves in the orbit or in the skull, or upon gummatous inflammation of the dura mater at the base of the skull, matting the nerves together, or on disease of nerve-centres. The gummatous nerve-lesions seldom occur very late in tertiary syphilis. The optic disc is often inflamed or atrophied as an indi- 1 A few cases are on record in which it appeared not to have begun till about ten years after infection. ETIOLOGY. 431 rect result of syphilitic disease of the eye or of the nervous system ; but the terms " syphilitic optic neuritis" or "syphilitic optic atrophy" are not often applicable in any more direct sense. The retinitis of the secondary stage affects the disc, and, when atrophy of the retina and chor- oid occurs, the disc becomes wasted in proportion ; w^hilst in rare cases the retinitis of secondary syphilis is replaced by w^ell-marked papillitis. Such cases must not be confused with others, still more rare, in which double papillitis, pass- ing into atrophy, occurs with all the symptoms of severe meningitis, in secondary syphilis. Tertiary syphilitic dis- ease, anywhere within the cranium, commonly causes optic neuritis, in the same way as do other coarse intracranial lesions; but neuritis may also be caused more directly by gummatous inflammation of the trunk of the optic nerve, cr of the chiasma. Primary progressive atrophy of the discs occurs in association with locomotor ataxy and oph- thalmoplegia externa of syphilitic origin ; probably in a few instances the optic atrophy occurs alone, or for a time precedes the other changes in syphilitic, as it is known to do in non-syphilitic, ataxy. Sight is liable to be rapidly damaged from severe acute loss of blood, especially from the stomach ; usually both eyes suffer, but often unequally. When seen quite early papillitis has been found, but the cases are often not seen till the appearances of atrophy have come on. 2. Inherited syphilis. — In the secondary stage : Iritis corresponding to that in the acquired disease is seen in a small number of cases, and occurs between the ages of about two and fifteen months. "-It often gives rise to much exudation, leading to occlusion of the pupil, and is fre- quently accompanied by deeper changes, cyclitis and dis- ease of vitreous. It is very often symmetrical, and is much commoner in girls than boys. Choroiditis and retinitis, of preciseh' the same forms as in acquired syphilis, occur at 432 ETIOLOGY. the corresponding- period of the disease, i. e., between six months and about three years of age ; and they show as much (some observers think more) tendency to the degen- erative and atrophic results already described ; in severe cases there are not uncommonly signs of cerebral degene- ration. In the later stages, keratitis, which is the com- monest eye disease caused by inherited syphilis, occurs. It is commonest between six and fifteen years old, but is some- times seen as early as two or three years, and is occasionally deferred till after thirty. The disease is frequently com- plicated with iritis and cyclitis, and, though tending to recovery, shows a considerable liability to relapse. It almost always attacks both eyes, though sometimes at an interval of many months. When the patient is unusually young, the disease as a rule runs a mild and short course. The oculo-motor palsies occur but rarely in inherited syphilis, but a few well-authenticated cases are on record. Smallpox causes inflammation and ulceration of the cornea, leading, in the worst cases, to its total destruction, but in a large number to nothing worse than a chronic vascular ulcer. The corneal disease comes on some days after the eruption (tenth to fourteenth day from its com- mencement), and after the onset of the secondary fever. Iritis, uncomplicated and showing nothing characteristic of its cause, sometimes occurs some weeks after an attack of smallpox. Only in very rare cases do variolous pustules form on the eye, and even then they are alw^ays on the conjunctiva, not on the cornea. Scarlet fever, typhus, and some other exanthemata may be followed by rapid and complete loss of sight, lasting a day or tw^o, showing no ophthalmoscopic changes, and end- ing in recovery. Such attacks are believed to be uraemic, or at any rate dependent on some toxic condition of the blood. A peculiarity of these cases is the preservation of the action of the pupils to light. Very severe purulent or ETIOLOGY. 433 diphtheritic ophthahiiia sometimes occurs during scarlet fever. Diphtheria. — By far the commonest result is paralysis, often incomplete, of both the ciliary muscles, cycloplegia ; the pupils are not afTected except in severe cases, when they may be rather large and sluggish.' The symptoms generally come on from four to six weeks after the com- mencement of the illness, last about a month, and disap- pear completely. Diphtheritic cycloplegia is usually, but not invariably, accompanied by paralysis of the soft palate. In most of the cases seen by ophthalmic surgeons the attack of diphtheria has been mild, sometimes extremely so, the case often being described as "ulcerated throat ;" but in- quiry often yields a history of other and severer cases in the family, and of general depression and weakness in the patient out of proportion to his throat symptoms. We find that most of the patients who apply with diphtheritic cycloplegia are hypermetropic, doubtless because those with normal, and, d fortiori, with myopic, refraction are much less troubled by paresis of accommodation, and often do not find it necessary to seek advice. Concomitant conver- gent squint sometimes develops in hypermetropic children during diphtheritic paresis, owing to the increased efforts at accommodation. Paralysis of the external muscles is occasionally seen ; I have never myself seen any except the external rectus aifected, and recovery has been rapid. Diphtheritic and membranous ophthalmia are occasion- ally caused by direct inoculation of the conjunctiva of the attendant by diptheritic material from the patient's throat ; or in the patient himself by extension up the nasal duct to the conjunctiva. But in many cases of " diphtheritic " and "membranous" ophthalmia the disease seems to be local, the inflammation taking on this special form without 1 Further observations are wanted. 19 434 ETIOLOGY. ascertainable relation to any infectious disease. No donbt there is often ponietbing' peculiar in the patient's health or in the state of his eye-tissues which 4 KX A MI NATION OF RAILWAY EMPLOYES. been our effort to render this more simple, and to so ar- range tbe colors that they may be identified by some num- ber, so that an expert, although absent from the scene, %vould know by these numbers the exact tints selected, and thus be fully competent to declare from them the color- perception of any person whose record had been properly made. From theory based upcm scientific knowledge, and from much experience, I was able to arrange an instru- ment that would have the real colors, and those usually confounded with them, " confusion colors," placed in such relations to each other, and so designated by numbers, as to make an examination for color-blindness possible by a non- professional person, who could conduct the testing, record it properly, and transmit it to an expert capable of decid- ing upon the written results. Hence there is no departure from, the system of matching tints already established, the only novelty being in reducing the number of colors to those similar to the test colors, and to those usually chosen by C(.>lor-blind persons, and so identifying them as to enable an absent expert or superintendent to know precisely what colors had been selected to match the test colors. The theory of the instrument (consisting of a stick with the yarns attached, see Fig. 164), is that color-blindness is most promptly detected by using the light-green test-skein^ and asking that it be matched in color from the yarns on the stick, which are arranged to be alternately green and confusion colors, and are numbered from one to twenty, the person being directed to select ten tints, and the examiner being required to note the numbers of the tints chosen. It will be understood that the odd numbers are the green, and the even ones the confusion colors, and that, if a person has a good color-sense, his record will exhibit none but odd num- bers; whilst, if he be color-blind, the mingling of even num- bers betrays his defect at a glance to the supervising expert or superintendent. EXAMINATION OF RAILWAY EMPLOYES. 465 46G EXAMINATION OF RAILWAY EMPLOYES. There are forty tints on the stick, and the first twenty are given to the detection of color-blindness, using the grcen-tcst, and if the color-sense is deficient, it will surely be revealed. To distinguish, however, between green-blindness and red-blindness, the rose-test is used, and those color-blind will select indifferently, either the blues intermingled with the rose, between figures 20 and 30, or perhaps the blue-green or grays from 1 to 20, and thus reveal their defect, and es- tablish either green- or red-blindness. Finally, the red-test corroborates these results, and satis- fies the most sceptical of color defect, when the " confusion tints " or even numbers between 30 and 40 are selected. On a suitable blank these figures are placed in the order of examination, and a glance of the eye reveals the color- sense of the person examined; since, if anything but odd numbers are chosen, there is a defect ; or if, with test one, anything beyond 20 is chosen ; or if, with test two. any- thing but odd numbers between 20 and 30 ; or, wit'i test three, anything but odd numbers between 30 and 40. The colors can readily be changed on the instrument, if it should be found desirable. It is theoretically and practically a fact, that the tints as arranged in the three sets on the instrument look C|uite the same in color to color-blind persons, and that those having a perfect color-sense can thus form an idea of this infirmity. If, then, green and gray are indistinguishable, and green and red, when of the same depth of color, seem to be entirely the same to the color-blind, it needs no opinion from a scien- tific expert to convince the manager of a railroad that it would be most dangerous to place the lives of people under the guidance of an engineer who could not distinguish, if green-blind, between a soiled white and a green flag, or be- tween a green and red flag, or other signal of these colors. It is a fact that some of the color-blind promptly give EXAMINATION OF RAILWAY EMPLOYES. 467 the proper names to the flags, and answer correctly, when asked what they would do in presence of such signals, but it must be remembered that they may see form perfectly, and have always had some perception of these colors, and do give them their conventional names, perhaps, but that they are unable to distinguish them at once and infallibly, and that it will only require a further extension of our method of testing to demonstrate the inability of persons color- blind to our examination to recognize the signals, by day or night, which are now depended upon to prevent acci- dents of the gravest character. This must be done by de- manding that the signals be matched, and not named, and this is incorporated in the instructions herewith submitted, so that the tints which color-blind men select with the rail- road signals from the instrument may hereafter be known and recorded. My conclusions from a study of the subject in connection with the railway service are : 1. That there are many employes who have defective sight, caused either by optical defects, which are, perhaps, congenital, and which might be corrected with proper glasses, or due to the results of injuries or diseases of the eyes, remediable or not, by medical or surgical treatment. 2. That one man in twenty-five will be found color-blind to a degree to render him unfit for service where prompt recognition of signals is needed, inasmuch as color-blmdness for red and green renders signals of these colors indistin- guishable. It is a fact in physiological optics, however, that yellow and blue are seen by those color-blind for red and green, and that yellow-violet blindness is so rare that it might lead to the use of these yellow and blue colors, in preference to red and green, wherever possible. 3. That color-blindness, although mainly congenital and incurable, is sometimes caused by disease or injury, and that precautions might be needed to have either periodical 468 KXAMliNATloN (j F RAILWAY EMPLOYES. examinations or to insist upon it in cases where men have siiftered from severe illness or injury, or when they have been addicted to the abuse of tobacco or alcohol. 4. That the method, when adopted, will enable the authorities to know exactly how many of their employes are "satisfactory in every particular" as to sight and hear- ing; and that the examination will have the further value of making the division superintendents acquainted with the general aptitude of the men in their divisions as to gen- eral intelligence. 5. That the entire examinations can be made at the rate of at least six men an hour; whilst that for color-sense alone can be done in a very few minutes for each man by an intelligent employe. 6. That to secure the confidence of the employes, and of competent scientific critics, as well as of the public gener- ally, it is advisable to have some oflScial professional specialist to whom all doubtful questions could be referred, and who should be held responsible for the accuracy of the instruments, test-cards, etc., to be put in use, and who should have a general supervision of the entire subject of sight, color-sense, and hearing. 7. That from the impossibility of subjecting the immense number of employes on our large railways to the inspection of the few medical experts available, and to secure the ex- amination of those hereafter to be employed, some eystem of testing by the railway superintendents has become a necessity, and it is believed that the one proposed will an- swer the purpose. EXAMINATION OF RAILWAY EMPLOYES. 469 Pennsylvania Railroad Co:.ipany's Instructions for Examination of Employes as to Vision, Color- blindness, and Hearing. Instructions for examination as to vision, color-blind- ness, and hearing^. — The examination will be made as to vision, color-sense, and hearing, and the following appa- ratus will be used : 1. A card or disk of large letters for testing distant sight. 2. A book or card of print for testing sight at a short distance. 3. An adjustable frame for supporting the print to be read, with a graduated rod attached for meas- uring the distance from the eye while reading. 4. A spec- tacle frame for obstructing the vision of either eye while testing the other. 5. An assortment of colored yarns for testing the sense of color. 6. A watch with a loud tick for testing the hearing. 7. A book or set of blanks for record- ing the observations. 8. A copy of an approved work on " Color-blindness." Acnteness of vision. — For distant vision, place the test- disk or card in a good light twenty feet distant, and ascer- tain for each eye separately the smallest letters that can be read distinctly, and record the same by the number of that series on the card. Range of vision. — For near vision, ascertain the least number of inches at which type D = 0.5 or H, can be read with each eye, and record the result. Field of vision. — Let the examiner stand in front of the examined, at a distance of three feet, and directing the ex- amined to fix his eyes on the right eye of the examiner, and keep them so fixed, let the examiner extend his arm later- ally, and opening and shutting his hands, let him by ques- tions satisfy himself that his hands are seen by the examined 470 EXAMINATION OF RAILWAY EMPLOYES. without changing the direction of the eyes ; recording the result as good or defective, as the case may be. Color-sense. — Three tcst-skeins — A, light-green; B, rose; C, red — will be used with the colored yarns attached to the stick ; of the latter there are forty tints, numbered from 1. to 40, and arranged in three sets — a, b, and c — of which the odd numbers correspond to the colors of the test-skeins, whilst the even numbers are different or " confusion colors." The first set is to test for color-blindness; the second to determine whether it be red or green blindness, and the third to confirm the opinion formed from the first or second test. Place the test-skein A at a distance of not less than three feet, and, without naming the color, direct the person ex- amined to name the color, and to select from the first twenty tints, or set (a), of the yarns on the stick, ten tints of the same color as skein A, stating that they do not match, but are different shades of the same color. Record the number of the tints so selected. Do the same with skeins B and C, using for B the tints from 21 to 30, and for C the tints from 31 to 40. If the odd numbers are selected read- ily, the examination may be gone over very quickly. When color-blindness is detected, any one of the even numbers or " confusion colors " may be used as a test-skein, and the man may be directed to select similar tints, when he will most probably choose odd numbers, which should be recorded, stating the number on the stick of the " con- fusion color" used for a test, and then giving the numbers chosen to match it. Then a soiled ivhite flag should be shown, and the man be directed to select tints to match it, which should be re- corded ; next a green, and finally a red flag. All of the particulars are to be recorded as the examina- tion proceeds, not leaving it to memory. Use the numbers in recording. The letters indicating the set need not be EXAMINATION OF RAILWAY EMPLOYES. 471 used. ^N'ote whether the selection is prompt or hesitating by a distinct mark after the proper word en the blank form. When deficient color-sense is discovered, and varia- tions in the mode of testing arc made by the examiner or examined, they should be noted under remarks, or on a separate sheet to be referred to, if the blank has not room enough. Hearing. — Note the number of feet or inches distant from each ear at which a watch, having a tick loud enough to be heard at five feet, is heard distinctly, using a watch without a tick, or a stop watch, to detect any supposed deception; and the number of feet at which ordinary conversation is heard. Explanations. — The test-card contains letters, numbered from 20 (xx), or D = 6, to 200 (cc), or D = GO. Those measuring three-eighths of an inch, and numbered 20 (xx) or D = 6, are such as a good eye of ordinary power sees dis- tinctly twenty feet or six metres distant. If a man sees distinctly only those marked C (or 100), his acuteness of vision, v., is equal to -f-^^ or ^. If he sees to XX (or 20), then Y. is equal to ||- or 1, and his sight is up to the full standard. This mode of statement indicates the relative value of the sight examined, and should be used in the records. If one eye is |^ or 1, and the other not less than f^ or -Ij^, with or without glasses, the sight may be con- sidered satisfactory. The power of discerning small objects at the reading distance is tested by the small j^rint, and good sight may be assumed if one eye can see at twenty inches the matter marked l* or D = 0.o, whilst the other distinguishes not less than 4} or D= 1.5. The small print should then be brought to the j^oint of nearest vision for each eye, and that point mentioned in inches. A good eye should be able to read Xo. 1 ^ at twenty inches, and have a range of vision up to ten inches. 472 KXAMINATION OF K A I J> W A Y EMPLOYES. The color-test will indicate ^vliether tlic man is deficient in color sense. The colors arc arranged in three sets, one of 20 and two of 10 each — the odd numbers arc the colors similar to the test-skeins, and the even numbers are the " confusion colors," or those which the color-blind will be likely to select to match the sample skeins or colors shown him. The first 20 (a), numbered from 1 to 20, have green tints for the odd numbers or test-colors. In the second (6), 21 to 30, the test-colors are rose or purple, a combina- tion of red and blue ; and in the third (c), 31 to 40, they are red. Ordinarily the test will be with each set separately, but the whole 40 may be employed on any test-skein. Any- thing but green matched with r/reen indicates a defect in the color sense, for which use set (a). The test with the second set indicates whether red or green blindness exists. The odd numbers from 21 to 30 are purple. If either of these is matched with test-skein B, nothing is indicated, as they must appear alike to a color-blind person ; but if blue is chosen, red-blindness is indicated, and if green, then green-blindness is established. The third set (c) is scarcely needed, but may be used in confirmation of, or in connection with, the last, as to red or green defect. \Yhen the numbers of the tints selected are recorded in the proper blank, color-blindness will be indicated in those instances where even numbers appear, and suspicions will arise where numbers beyond 20 are used with test-skein A, and under 21 or beyond 30 with B, and below 31 with C. Further tests should be made of those found to be color- blind with the usual signal flags, requesting them to name each color, shown singly, and to match the colors cf them from the tints on the stick, and with colored lamps ; and finally to state what they understand them to mean as signals. It will be well not to dwell on the examination of a man EXAMINATION OF RAILWAY EMPLOYES. 473 found to be defective in color-sense or in vision, but t;) pass over each examination with the same general care, and afterwards send for those giving indications of defects, to come in singly for fuller examination. The examination should be private as far as practicable, especially excluding persons who are to be subsequently examined. Inability to name color accurately, or to distinguish nicely as to difference in tint, is not to be taken as an evi- dence of color-blindness. In testing as to hearing, if the watch used can be heard at five feet distant, and the person examined hears it only at one foot, his hearing would be 1-5, and may be so recorded in fractions. Conversation in an ordinary tone should be heard at ten feet. It should be understood that all employes examined, failing to come up to the requirements of the above stand- ard, shall be accorded the benefit of a professional ex- amination. When acuteness of vision is below the standard adopted, it may be possible to restore full vision by proper glasses, when it is due to optical defects, known as near- sight, far-sight, or astigmatism, or by other medical or surgical treatment, and useful men may then be retained in the company's service. These rules and regulations, having been approved by the Board of Managers, have been put into effect en the Pennsylvania Railroad, under the general supervision of the writer, and give entire satisfaction.] APPENDIX. FORMIJLJE, ETC. Nitrate of Silver. 1. Mitigated Solid Nitrate of Silver (B. P. 1885): Nitrate of Silver 1, Nitrate of Potash 2. Fused together and run into moulds to form short, pointed sticks. Used for granular lids and purulent ophthalmia. The strength above given is known as No. 1, and is that which I generally use ; three weaker forms are made, known as Nos. 2, 3, and 4, containing respectively 3, 3^, and 4 parts of nitrate of potash to 1 of nitrate of silver. Pure nitrate of silver is never to be used to the conjunctiva. 2. Solutions of Nitrate of Silver : (1) Nitrate of Silver gr. x or xx. Distilled Water gj. Used by the surgeon for purulent ophthalmia, granular lids, and chronic conjunctivitis, and some cases of ulcer of the cornea. 3. (2) Nitrate of Silver gr. j or ij, Distilled Water gj. Used by the patient in various forms of ophthalmia ; only a few drops to be used at a time, and not more than three times a day. All solutions of nitrate of silver should be kept in glass-stop- pered bottles ; any trace of organic matter decomposes the salt, and a black deposit of metallic silver falls to the bottom ; the action of light favors this decomposition : amber-tinted glass is said to counteract the chemical action of light. Dark-blue bottles should not be used, as they only hide the deposit of reduced silver. 476 APPENDIX. Sulphate of Copper. 4. A crystal of Pure Sulphate of Copper, smoothly pointed, may be used for touching granular lids of old standing. 5. Lapis Divinus : Sulphate of Copper 1, Alum 1, Nitrate of Potash 1. Fused together, and camphor equal to 3^5 of the whole added. The preparation is run into moulds to form sticks. It should be kept in a stoppered bottle. Largely used for the treatment of chronic granular lids. 6. Solutions of sulphate of copper or of Lapis Divinus, gr. j in §j of distilled water, are also very useful for many forms of chronic conjunctivitis. Lead Lotion : 7. Liquor Plumbi Subacetatis (B. P.) 5j. Distilled Water Oj. (1 in 100.) Used in chronic conjunctivitis vhen the cornea is sound, and in inflammation of the eyelids and lachrymal sac. Spirit Lotion : 8. Rectified (or Methylated) Spirit giv, Water §xvj. Used as an evaporating lotion to allay or prevent inflammation of the wound after operation on the eyelids. 9. Lead and Sjnrit Lotion : Spirit Lotion Oj, Liquor Plumbi Subacetatis (B. P.) '^\], Used in the same cases when there is no fear that the cornea is abraded or ulcerated. A better antiphlogistic than spirit alone. Mercury : 10. Since the publication of Sattler's experiments on anti- septics in 18S3, weak Solutions of Perchloride of Mercury have come largely into use for cleansing the conjunctiva, eyelids, etc., APPENDIX. 477 before, during, and after operations, this salt being, according to that author, the best available germicide. A solution of 1 grain in 5000 of water (common or distilled) (= gr. j in fl. ^xij) may be freely used for the above purposes, and a stronger one (1 to 2500) (=gr. j in fl. gvj) as a lotion for catarrhal ophthalmia, etc. Some surgeons use much stronger solutions. The Moorfields Pharmacopoeia has a lotion containing 1 grain in fl. gviij, orlin 3500. The officinal solution (liq. hydrarg. perchlor.) contains chloride of ammonium also, and is decomposed and rendered almost inert if diluted with common, instead of distilled, water ; but a solution of perchloride alone in common or distilled water is stable. (Mar- tindale's Extra Pharmacopoeia.) 11. Calomel Poivder : Used for dusting on the cornea in some cases of ulceration. It is flicked into the eye from a dry camel-hair brush. 12. Yellow Oxide of Mercury {^^ Yellow Ointment,^ ^ ^' Pagen- stecher^s OintmenV) : Yellow Oxide of Mercury gr. xxiv, Vaseline §j. (1 in 20.) 13. "Weaker preparations, containing gr. viij or less of the yellow oxide to ,^j (1 in 60 or less), are often better borne. Used in many cases of corneal ulceration and recent corneal nebulae ; a morsel as large as a hemp-seed being inserted within the lower lid, by means of a small brush, once or twice a day. It is also suitable for ophthalmia tarsi. In some of the continental eye hospitals, where it is the custom for this remedy, amongst others, to be applied by the surgeon him- self, stronger preparations are used. 14. Yellow Ointment with Atropine : Yellow Oxide of Mercury gr. viij or less, Atropine gr. \, Vaseline 5J- Used in the same way as 12 and 13. 15. Red Oxide of Mercury : Red Oxide of Mercury gr. xxiv or less, Vaseline 51. 478 APPENDIX. Used for ophthalmia tarsi, etc. Was formerly used for corneal ulcers and nebulae; but the yellow oxide, which being made by precipitation is not crystalline, is now generally preferred because less irritating.! 16. Nitrate of Mercury {Citrine Ointment'): Unguentum Hydrargyri Nitratis (B. P.) 3j> Vaseline or Prepared Lard S'^ij* Used in the same cases as 15. 17. Iodoform : Iodoform may be used either in substance or as an ointment made with vaseline. Iodoform gr. x to xxx or more, Vaseline §j. Ung. lodoformi (B. P. 1885) : Iodoform gr. xlviij, Benzoated Lard §j. 18. lodol, which is odorless, may be used in the same way. The precipitated iodoform (impalpable powder) should be used in preference to the ordinary, or crystalline, form, for the eye. Sulphate of Zinc : 19. Sulphate of Zinc gr. j or ij, Water or Rose Water 3J« Chlobide of Zinc : 20. Chloride of Zinc gr. ij, Water gj. If there is a deposit, add of dilute hydrochloric acid just enough to make a clear solution. 1 The ointment known as " Singleton's Golden Eye Ointment" ap- pears to contain a crystalline red oxide in fine powder as its active ingredient. A sample, kindly analyzed for me by Mr. S. Plowman, contained 70 grains of the oxide to the ounce. APPENDIX. 479 21. Chloride of Zinc Paste ( Caustic) : (i;^ Chloride of Zinc 1, Wheat Hour 2, 3, o: 4. Water enough to make a thick paste. (St. Thomas's Hospital.) (2) Allow solid Chloride of Zinc to deliquesce, add a little glycerine, and make into a paste with powdered Sanguinaria. The glycerine prevents hardening on keeping. (St. Thomas's Hospital.) (3) Chloride of Zinc 480 grains (8), Wheat flour ISO grains (3), Water or Liquor Opii Sedativus, fl. §j (8). (Middle- sex and Moorfields Ophthalmic Hospitals.) (4) Chloride of Zinc 1, Freshly-burned Plaster-of-Paris 2. Made into a paste with a few drops of water. (Druitt's " Vade Mecum," 9th ed.j (5) Chloride of Zinc 1, Oxide of Zinc 1, Wheat flour 2. Water enough to make a stiflf paste, which is made into caustic points. (Squire, 13th ed.) It would seem from the above that the exact composition of the paste is not of much importance. It would be desirable to have the point settled. Alum: 22. A stick of pure crystalline alum forms a very useful ap- plication for mild or long-standing cases of granular conjunctiva, and for many forms of chronic palpebral conjunctivitis. It may be used by the patient himself without the slightest risk. 23. Lotion-. Alum gr. iv to gr. x, Water gj* The above lotions are in common use in the milder forms of acute and chronic ophthalmia. The chloride of zinc occasionally irri- tates ; it is specially used in purulent and severe catarrhal oph- 480 APPENDIX. thalmia instead of the weak nitrate of silver lotions. The stronger alum lotion is often used in the same cases. The alum and sul- phate of zinc lotions may be used unsparingly to the conjunctiva ; the chloride, even in severe cases, not more than six times a day. Carbonate of Soda : 24. Carbonate of Soda gr. x, Water gj. Used for softening the crusts in severe ophthalmia tarsi. A small quantity of the lotion, diluted with its own bulk of hot water, to be used for soaking the edges of the eyelids for ten or fifteen minutes night and morning. Tar and Soda : 25. Carbonate of Soda 3J=5S, Liquor Carbonis Detergens 3J to 5^^> Water to Oj. Used in the same cases as the last. Borax : 2tj. Biborate of Soda gr. x to xx, Water §j . Used in the same cases as the last. Quinine Lotion : 27. Sulphate of Quinine gr. iij, Acid. Sulph. dil. (B. P.) just enough to dissolve, Water gj. Used in diphtheritic ophthalmia. Boric Acid Lotion : 28. Boric Acid 4, Water 100 by weight. Used as an antiseptic before and after operations on the eyeball, and in the treatment of suppurating ulcers of the cornea. Boric acid in very fine powder may be used for dusting on to the cornea in cases of severe suppurating ulcer ; it causes scarcely any paiu and may be applied as often as three times a day. The crystals are difficult to powder finely, but an almost impalpable amorphous powder, obtained by preventing regular crystallization, can be had. APPENDIX. 481 Mr. Martindale has made for me some soluble styles contaiuing about 60 per cent, of boric acid, for use in cases of lachrymal ob- struction with much secretion of mucus. Solutions of boric acid often tarnish steel ; instruments should therefore not be left in them. Boric Acid Oixtmext (B. P. 1885) : Boric Acid gr. Ixviij to gj of Paraffin. Carbolic Acid Lotiox : 29. Aiisolute Phenol 5, Water by weight 100. Used in purulent ophthalmia. It is important to use absolutely pure carbolic acid for the conjunctiva. Severe irritation often follows if any other varieties are employed. Lotion of snlicylic acid is so irritating to the surface of the eye that it can seldom be used. The same objection applies to salicylic wool used for dressing the eye after operations . 30. Cocaine. Cocaine was brought into clinical use in September, 1884, at Vienna, and in Loiidon and elsewhere early in October. A two per cent, solution of a salt of cocaine dropped into the con- junctival sac causes smarting for about half a minute, followed by numbness, rising to complete anaesthesia of ocular conjunctiva and cornea in about two to five minutes ; in three to five minutes after the maximum is reached, feeling begins to return, but slight numbness continues for about twenty minutes. There is often a feeling of coldness as sensation is returning. Coacine also causes widening of the palpebral fissure by retraction of the upper and lower lids, whitening of eyeball from contraction of bloodvessels, mydriasis, very slight weakness of Ace, and perhaps lowering of the eye tension. These efi"ects last about half an hour, except the myd.riasis, which remains in some degree about twenty-four hours. The pupil dilated by cocaine remains active to light and Ace. ; if atropine be added the pupil becomes larger than from either drug singly. Eserine quickly and fully overcomes the etfect of cocaine. Ace. is completely paralyzed for a short time if cocaine be used every few minutes for about an hour. These eflfects of cocaine (except the last) are explicable on the supposition that it causes spasm of the sympathetic nerve- fibres to the eyelids, iris, and 21 482 APPENDIX. superficial bloodvessels ; whether a similar contraction of the arteries of the ciliary muscle, brought about by the repeated use of the drug, explains the fleeting paralysis of Ace. is open to question. Cocaine has no ascertainable action on the vessels of the retina and choroid. Cocaine is thought by some to aid the action of eserine in chronic glaucoma, when the two are used together ; this is intelligible if cocaine acts by contracting the ciliary arteries. In ophthalmology cocaine is used chiefly for anaesthfsia before operations on the eyeball, and painful applications to the palpe- bral conjunctiva. For the former, a freshly made two per cent, solution of perfectly pure hydrochlorate of cocaine in freshly boiled distilled water is the safest preparation ; but gelatine discs of the pure Fait, if free from hygroscopic tendency, may be safely used. Solutions in oil or vaseline are uncleanly and not suitable for surgical purposes. Watery solutions of cocaine should be used quite fresh ; even if made with boracic acid or camphor water, they often, if kept, grow fungi, and are then unsafe. Bichloride of mercury in suflBcient quantity to prevent growth, sometimes, in conjunction with cocaine, causes considerable haziness of the cornea. Even cocaine alone, if too freely used, causes dryness, loosening, and even separation of the corneal epithelium : the desiccation of the corneal epithelium is said to occur in direct pro- portion to the frequency of use of the cocaine and of exposure of the cornea to the air, rather than to the strength of the solution employed. Not more than three applications need be made, within five minutes, before operations for cataract, etc. Cocaine has been accused of producing glaucoma, but, as far as the few recorded cases show, without much reason. For deadening granular lids, or similar conditions, a much stronger solution must be painted, over the afl"ected surface (I use a 20 per cent, solution or the solid salt). For small tumors about the lid, etc., a 4 per cent, solution is injected in ditl'erent directions at the base of the growth. Lamella Cocain^e (B. P. 1SS5) 2^0 S^"- ^" each. If the eye be congested or inflamed cocaine acts much less per- fectly on the conjunctiva; but it acts as well upon an ulcerated as upon a healthy cornea. As the cocaine takes effect only on the part which it touches, the solution must be made to flow all over the cornea and conjunctiva ; and as it penetrates little, if at all, it must be injected under the conjunctiva if we wish to render the later (tenotomy) stage of a squint operation painless, or to excise the APPENDIX. 483 eyeball under its influence. Cocaine as ordinarily used does not seem to affect tiie sensibility of the iris, at any rate no such action has been proved ; injection into the anterior chamber for this pur- pose is not practicable, even if safe. Cocaine is used in acute iritis in conjunction ^yith atropine, with the idea that it will assist the anodyne and mydriatic effects of the latter. My own experience does not enable me to speak strongly on this point. For producing rapid but brief paralysis of Ace. (in ametropia) a solution containing 2 per cent, of cocaine and 2 per cent, of homa- tropine is recommended by Mr. Lang, and is convenient in suitable eases ; the maximum effect is gained in from 20 to 60 minutes, but soon begins to decline. Faiutness and other signs of nervous depression have been re- ported as due to cocaine, even when used to the eye alone. I believe that these symptoms are generally due to reaction after the mental strain attending an operation of which the patient is conscious ; for before cocaine was used we were familiar with the occurrence of faintness and vomiting from time to time when eye operations had been undergone without anaesthesia. Mtdkiatics and Myotics : 31. (1) Strong Atropine Drops: Liquor Atropinse Sulphatis (B. P.) (Sulphate of Atropia gr. ix, Camphor water gxvjss). Used in cases where the rapid and full local action of the drug is required. For many purposes atropine drops may be used con- siderably weaker than the above. Atropine (a single drop, of 2 grains to gj; or about 0.5 per cent.) begins to dilate the pupil in about fifteen minutes, and to paralyze the accommodation a few minutes later ; it produces wide dilatation of the pupil (S to 9 mm.) in 30 to 40 minutes, and full paralysis of accommodation in about 2 hours. Both remain at their height for 24 hours, and the effect does not pass off entirely until from 3 to 7 days, the accommoda- tion recovering rather sooner than the pupil. If stronger solutions be used several times, the action continues longer. The effects of atropine are only very temporarily and imperfectly overcome by eserine. Atropine slightly lowers the tension of the healthy eye, but usually increases the tension in glaucoma. 484 APPENDIX. (2) Weak Atropine Drops : Sulphate of Atropia gr. ^'^ to |, Distilled water 5J. Used when, for optical purposes, it is desired to keep the pupil dilated for a long time, as in iraraature nuclear cataract. A single drop about three times a week will generally suffice. Very weak atropine acts naore on the pupil than on the accommodation. Solutions of sulphate of atropine keep for an indefinite time ; the flocculent sediment which often forms does not impair their efficiency. The mydriatics and myotics may be used in the form of ointment with vaseline or castor oil, and a smaller percentage of the drug is then necessary ; the alkaloids themselves must be used, their salts not being soluble in fats and oils. (3) Ung. Atropinm (H. P. 1885) : Atropine gr. viij, Rect. Spirit 5ss, Benzoated Lard ,5J« This ointment is needlessly strong for most purposes ; 1 grain to 1 ounce is usually enough. (4) Lamellce Atropince (B. P. 1885) ^-^^-^ gr. in each. 32. Daturine : Sulphate of Daturia gr. iv, Distilled Water §j. Used as a mydriatic in cases where atropine causes conjunctival irritation. 33. Duboisine : Sulphate of Duboisia gr. j. Distilled Water §j. A mydriatic, acting more quickly and powerfully, and passing ofi" in a shorter time, than atropine. It is tolerated in cases where atropine causes conjunctivitis. To be used with caution, as well- marked toxic symptoms are sometimes caused. Duboisine begins to act on the pupil and accommodation in less than ten minutes, produces full mydriasis in less than twenty minutes, and complete cycloplegia in about one hour. The maximum effect does not last quite so long as, and the eflfect passes off completely rather sooner than, that of atropine. Duboisine APPENDIX. 485 seldom breaks down iritic adhesions which have already resisted atropine. Its chief use seems to be for cases in which atropine causes irritation. 34. Homatropine : Hydrobromate of Homatropine, gr. iv, Distilled Water gj. A mydriatic, acting rather more quickly and passing off much sooner than atropine ; very convenient, therefore, for dilating the pupil for ophthalmoscopic examination. Homatropine begins to act on the pupil and accommodation in from five to fifteen minutes ; the greatest dilatation of pupil (usually, however, rather less than that obtained by atropine) is reached in about fifty minutes, and complete or nearly complete cycloplegia in an hour or rather less (with the solution of gr. iv to 5j). The full efi"ect is only maintained, however, for an hour, more or less, and both pupil and accommodation usually recover completely in twenty-four hours or less. Its action is quicker and rather more powerful if it be used with cocaine. See Cocaine. 35. Eserine (Physostigmine) (alkaloid of Calabar Bean) : (1) Sulphate of Eseria gr. iv. Distilled Water gj. Used in mydriasis and paralysis of the accommodation, whether caused by atropine or by nerve-lesions in some forms of corneal ulcer and in acute glaucoma. (2) A weaker solution (gr. j to ^j) is often better borne. Eserine begins to contract the pupil and cause spasm of the accommodation in about five minutes ; its maximum eflect is reached in twenty to forty-five minutes. Its full eflfect on the accommodation lasts only an hour or two, but the pupil does not completely recover for many hours, sometimes two or three days. A very weak solution acts more on the pupil than on the accom- modation. Eserine causes pain in the eye and head, arterial ciliary congestion, and twitching of the orbicularis ; the pain, sometimes severe, seldom lasts long. Eserine often lessens the tension in primary glaucoma. (3) Lamellce Physostigmine^ (B. P. 1885) jqVo g^- ^^ each. 486 APPENDIX. All the mydriatics and myotics may be obtained in the form of small gelatine discs of known strength (made by Savory and Moore, and by Martindale), which are sometimes more convenient than the solutions. Of the mydriatics, horaatropine and duboisine are much the most expensive. 36. Belladonna Fomentation : Extract of Belladonna 5i to ij, Water Oj. Warmed in a cup or small basin, and used as a hot fomentation in suppurating and serpiginous ulcers of cornea. 37. Pilocarpine for Subcutaneous Injection : Hydrochlorate of Pilocarpine gr. v, Distilled Water 3j' Dose, Tr^iij, gradually increased, to be injected daily or less often. Used in cases of retinal detachment, choroiditis, and retinitis. 38. Pilocarpine Drops: gr. iv to 5J. Pilocarpine is a myotic, like eseriue, but its action is much weaker. 39. Steychxia for Subcutaneous Injection : Liquor Strychninse (B. P.) gr. iv to §j. Dose, two minims (-^^ grain), gradually increased, for subcu- taneous injection. To be injected once a day. 40. " Jequirity" seeds, obtained from a leguminous plant, are used in South America for tlie cure of granular lids. They can now be readily obtained in moderately fine powder. The infusion is made by soaking the powder in cold water for a couple of hours, or better, in water at 120O F., allowing it to stand till cool, and straining through muslin ; it is then ready for use, but will remain active for several days. When obviously decomposed (fetid) it is no longer active. The simple powder dusted into the conjunctiva is said to be active, but two or three trials which I made with it were negative. The action of Jequirity probably depends upon a nitrogenous ferment — not, as was for a time believed, upon a specific microbe. A substance possessing the peculiar properties of the natural seed APPENDIX. 48*7 has been separated by more than one experimenter, but does not appear to be procurable in the market ; it is difficult to make, and its composition seems to varj. As the intensity of action of Jequirity infusions of the same strength varies very much in different persons, and is sometimes very severe, it is best to use a weak preparation (1 grain of powder in 100 grains of water, or 5i to fl.gxijss) for all cases at first. A single prolonged application, or several applications within a few minutes, to the everted lids will suffice. 41. Bandages for the eyes may be of thin flannel or soft calico. A linen or cotton bandage, about ten inches long, with four tails of tape, or a loop of tape embracing the back of the head (Liebreich's bandage), is very convenient after the more serious operations. An ordinary narrow flannel bandage is better when much pressure is wanted, or if the patient be unruly. The soft, elastic, woven bandage, known as the "Leicester" bandage, is even pleasanter than flannel. When absolute exclusion of light is desired, it is best to use a bandage made of a double fold of some thin black material. Fine old linen is better than lint for laying next the skin in dressings after operations. 42. Shades may be bought at the opticians' and chemists' ; or may be made of thin cardboard covered with some dark mate- rial, or of stout dark-blue paper, like that used for making grocers' sugar bags. Shades of black plaited straw are also very light and convenient. Shades, to be effectual, should extend to the temple on each side, so as to exclude all side light. 43. Protective Glasses. Various patterns of glasses are made for the purpose of protect- ing the eyes from wind, dust, and bright light. The glasses are either flat, or hollow like a watch-glass, and are colored in various shades of blue or smoke tint. The most effectual are the ones known as "goggles ;" in these the space between the glass and the edge of the orbit is filled by a carefully-fitting framework of fine wire gauze or black crape, by which side wind and light are excluded. A small air pad of thin India-rubber tubing makes the frame fit still more closely. 488 APPENDIX. Otlier forms, kiiDWii as " horseshoe'" or "D," and "domed" or "hollow" glasses are also iu common use. 44. Test Types. Snellen's types for testing both near and distant vision under an angle of five minutes can be obtained through Queen & Co., 924 Chestnut St., Philadelphia. The types which I generally use for testing near vision are those used at the Moorfields Hospital, where they may be obtained. They can also be bought, conveniently mounted, of Queen & Co., 924 Chestnut St., Philadelphia. These types nearly resemble those of Jaeger, and though less correct theoretically than the corre- sponding type of Snellen's scale, are more convenient in practice for testing the reading power. There are several other sets of test types which it is unnecessary here to particularize. A convenient set of tests, small enough to be carried in the pocket, can be obtained through Queen & Co., 924 Chestnut St., Philadelphia. It consists of types for near and distant vision, a pupillcmeter for measuring the pupil, a set of colored stuffs for color-blindness, and a small series of lenses for testing refraction. This case is intended chiefly for ward work and general medical cases. It may be also bought without the lenses. 45. Ophthalmoscopes. It is impossible to say that any ophthalmoscope is the best. When expense is not a great object, it is always better to have one of the so-called " refraction ophthalmoscopes." In these a number of small lenses are placed in a disc behind the mirror, the disc being made to revolve by finger pressure so as to bring the lenses one after another opposite the sight-hole. For medical ophthal- moscopy it is not essential to have so many lenses ; about four concave and two convex will enable an erect image to be easily obtained in most cases; Lieb.'-eich's "small" ophthalmoscope and Oldham's ophthalmoscope are both very convenient forms for such use, and cost less than half as much as the refraction instruments. Every ophthalmoscope case should contain two large "objective" lenses for the indirect examination, focal illumination, and mag- nifying ; one may be of 2^, the other 3^ inches focus. For the detection of incipient opacities in the lens, for direct examination without atropine, and for retinoscopy, a plane mirror is very useful 1 N O ^ ^ > z I f Lr 160 128 U E Z Y P N VDFl APPENDIX. 489 in addition to the ordinary concave one. It gives a weaker illu- mination. Such a plane mirror may be had cheaply as a separate instrument for the waistcoat pocket, but I much prefer it and the concave one for indirect examination, mounted back to back (see below). Of the refraction ophthalmoscopes there are now a great many patterns, differing in the number and size of the lenses, the size of the mirror and lens-bearing disc, and other details. Usually the disc contains 20 to 24 lenses, and one empty circle. In the simpler forms about half the lenses are + and half — . But in others the number of powers is immensely increased by combining lenses of different strengths, e. g., the disc may contain 24 -f- lenses, whilst a single movable — lens, rather stronger than the highest +, is placed behind the disc over the sight-hole ; by placing it opposite the sight-hole and then bringing the various + lenses over it in suc- cession, a series of 25 — powers, or 49 in all, will be obtained. In order to avoid the error caused by looking obliquely through a lens, all the better instruments (e. g., Loring's, Couper's, Morton's, and others) are so arranged that the mirror can be suflSciently inclined to receive the light, whilst the lens-bearing disc remains at right angles to the observer's line of sight. Generally speaking, the English and American instruments are much better made than the French. Of the simpler forms with only one mirror, the one introduced by Dr. Gowers is fairly efficient. Of the more expen- sive forms, several good ones have been derived from an early model by Mr. Laidlaw Purves, both of which may be procured from Queen & Co., 924 Chestnut Street, Philadelphia. The latest form of this instrument, made by Mr. Ferrier for myself, has three mirrors (two of them back to back in a single ring) mounted on a rotating carriage like the "nose-piece" of a microscope; it is ex- tremely convenient and accurate. For the application of the "nose-piece" principle to the ophthalmoscope we are indebted to Mr. Lindsay Johnson. Mr. Couper's and Mr. Morton's models are very excellent and deservedly popular. In a good refraction ophthalmoscope the mirror should be thin and the sight-hole per- forated ; the lens-disc thin and working as close to the back of the mirror as possible ; the lenses evenly mounted, centred truly, either thoroughly covered up or easily accessible for cleaning, and not less than 5 mm. in diameter. 21* 490 APPENDIX. 46. Perimeters. The most convenient forms have an arrangement for registering the field automatically on a chart fixed behind the centre of the are> A very complete, but complicated and expensive, one, is McHardy's ; Priestley Smith's, much simpler and cheaper, is for most purposes as useful. Blix's self-registering perimeter is well spoken of by Dr. Berry. All of which may be obtained from Messrs. Queen. 47. The "Clock-face" for testing astigmatism can be had at Queen's. 48. The set of Colored Wools recommended by Prof. Holm- gren, af Upsala, for testing color-blindness, can be obtained for about 81.50, from Queen & Co. In the colored plate copied by permission from Prof. Holmgren's work, De la Cecite cles Couleurs, etc., 1877, the horizontal stripes I, Ila, and 116, show the colors which it is, as a rule, most convenient to use as tests ; and the short vertical stripes are the colors most likely to be confused with these by those afi!'ected with the ordinary forms of color-blindness. Thus, No. 1 will be confused with one or more of such buffs, pinks, etc., as Nos. 1 to 5 ; in slight de- grees of color-defect the confusions will be limited to these pale colors. In higher degrees of color-blindness stronger or more saturated colors will be confused ; Ila, for example, or even a stronger rose color, may be confused, on the one hand, with a full blue or purple, Nos. 6 and 7 ; or, on the other, with a full gray or green, Nos. 8 and 9. Taking a diff"erent series of equally saturated colors, the scarlet lib may be confidently identified with dark green or brown, Nos. 10 and 11, or with light bright green and yellow-brown, Nos. 12 and 13. The confusion colors, Nos. 1 to 13 on the plate, are given merely as samples of the colors most commonly confused with the respective test-colors ; iji practice a much larger series should be employed; the more critical the patient, the larger is the number of shades and colors requisite ; even markedly color-blind persons do not always match exactly the same colors with the tests. Colored worsteds are used because it is easier to obtain a very large series in this material than in any other. The manner in which a color-blind person behaves will often ex- 3 4 5 I I II II a. 6 7 II 8 9 II ir b. 10 11 II ii 18 II [See page 490. APPENDIX.. 491 cite suspicion of his defect. He will perhaps place doubtfully side by side with I, such a color as No. 2 or 5, to see whether or not they are alike, and finally will decide that they are not quite of the same color, though "rather alike." In such cases, and again in others, where perhaps the patient does not understand what is wanted, the diagnosis may often be made certain in the following manner: Take two colors over which the patient is stumbling, or on which he cannot express himself, say Nos. Ha and a lighter shade of 9, add a third of the same dominant color as 9, but of a markedly different shade, such as 10 or 12 ; now ask him which pair is more alike, Nos. lla and 9, or Nos. 9 and 10 ; if he says Ila and 9 are more alike he is color-blind, and is judging of their similarity by the shade, that is, the amount of white contained in each of them, and not by their color. It is easy to vary this test according to the requirements of the case. Another good method is to tell the patient to pick out all the skeins of one color, say green, without requiring him to match them precisely with any test skein ; if decidedly color-blind, he will con- fidently select not only those which are green, but a number of others, usually gray ones. Or we may say : "Do you see any green skeins among them ?" If color-blind lie will say "No," or hesitate, or make the same mistakes as above. A special arrangement of the wools, enabling a quick, accurate, and uniform record of color-perception to be made, has been de- signed by Dr. William Thomson, of Philadelphia, and is obtain- able from Queen & Co. (Supplement, page 465.) Of the many other tests for color-blindness the following may be mentioned : Stilling's Tables consist of colored letters or patterns printed on a groundwork of one of the "confusion colors." They are pre- ferred by some to Holmgren's wool. Donders's method determines the color-sense (or color-defect) quantitatively by means of a light of known intensity, which passes through apertures filled by diflferently colored glasses ; these are recognized at a specified distance if the color-sense is normal. Mr. Jeaffreson (of Newcastle) has lately constructed an ingenious apparatus in which the colored wools, fixed in radii upon a rotating disc, can be successively brought opposite to stationary patches of the respective confusion colors, which are placed just beyond the circumference of the disc : Lancet, July 17, 1886. 492 APPENDIX. Bull (of Cliristiauia) has introduced a quantitative test, based upon the smallest amount of color which, mixed with gray, can be recognized by the normal eye. (Obtainable from Queen & Co.) Rows of colored spots, those in each row containing a different quantity of gray, are painted in oil colors on a black background. The normal eye will distinguish the colors even in the grayest row; the color- blind will, according to the degree of defect, con- fuse complementary colors in some or all of the rows. I find Bull's tables very useful, but like all painted and lithographed surfaces they reflect too much light, and thus, unless held exactly in the right position, they shine and their color is altered. Unless very carefully used. Bull's and Jeaffreson's tests are, I think, less trustworthy than a good set of wools. An explanation of the colored plate is given on p. 490 ; it is not intended to be used as a test, but only as an illus- tration of the colors commonly confused. I X D E X Abbreviations. 25 Aberratiou, chromatic, 61 spherical, 30 Abrasion of cornea, 132, 181 Abscess, episcleral, 165 of cornea, 133 of lachrymal gland, 319 sac, 101, 103 orbital, 318 Abscission of eyeball, 402 Accommodation, errors, 326 examination, 49 in myopia, 327 influence of age npon, 361 paralysis of, 377 region and range of, 361 relative, 50 spasm of, 330 Accommodative asthenopia, 273, 343 Action of drugs on iris and ciliary muscle, 374 Acuteness of sight, 48 Advancement of muscle, opera- tion for, 399 of Tenon's capsule, 401 Albinism. 225 Albuminuric retinitis, 230, 238, 439 Alcohol, amblyopia, 437 Amaurosis, 264 single, 262 Amblyopia, 264 alcohol, 437 bisulphide of carbon in, 438 central, 267 congenital, 264 diabetic, 440 from defective retinal im- ages, 266 Amblyopia from injury to one eye, 274 from suppression of images, 264 hereditary, 269 hysterical, 272 in ametropia, 266 I potatorum, 437 I quinine, 439" I tobacco, 269, 437 Ametropia {any permanent error in refraction of the eye), 326 Amyloid of conjunctiva, 123 Anaemia, pernicious, eye diseases in, 441 Anaesthesia in ophthalmic sur- gery, 426 of retina, 272 Angle of emergence, 27 of incidence, 27 visual, 38 a, 58 An-iso-metropia {unequal re- fraction in the two eyes), 358 Anterior chamber, foreign body I in, 405 I in paracentesis, 405 focus of eye, 39 polar cataract, 193 ; staphyloma, 167 j Apparent size of objects, 61 j Aqueous, turbidity of, 153 I Arcus inflammatory, 150 i Arcus senilis, 149 Argyll Robertson's svmptom, 452 Arlt's operation for entropion, 385 Arterial pulsation, 441 Artificial eye, 402 494 1 NDBX. Artiacial pupil, 408 vitreous, 403 Asthenia retime, 273 Asthenopia {weakness of eyes; any condition in which the eyes cannot be used for long together), 273 accommodative, 273, 343 muscular, 273, 367 Astigmatism, 34!) after extraction of cataract and iridectomy, 2U6, 351 causes of, 352 clock-face for, 355 detection of, 80, 87 irregular, 352 methods of testing, 354 principal meridian, 351 regular, 351 traumatic, 181 visual acuteness in, 358 Atrophy of choroid, 212, 215 in myopia, 334 optic (see also Neuritis), 257 after embolism, 243 after neuritis, 253 after orbital cellulitis, 457 clinical aspects of, 258 fields of vision in, 260 from pressure, 258 in ataxy, 2G1, 451 in hydrocephalus, 258, 450 post-papillitic, 253 primary, 258, 451 prognosis in, 260 progressive, 258, 451 pupils in, 260 sight in, 259 uniocular, 262 varieties of, 258 Atropine, action on healthy eye, 50, 51, 483 effect on tension, 483 in cataract, 200 in corneal ulcers, 136, 139 in glaucoma, 298 in iritis, 160 irritation, 124 Axial myopia, 328 Axis, optic, 58 principal, of a lens, 29 secondary, of a lens, 29 visual, of eye, 38, 58 Badal's operation, 404 Bandages, 487 after cataract operations, 422 after excision of eye, 401 in iritis, 161 in ophthalmia, 111 in ulcers of cornea, 138 Basedow's disease, 455 Binocular field of vision, 46 Bisulphide of carbon, amblyopia from, 438 Black eye, 317 Blennorrhoea of conjunctiva, 105 Blepharitis, 91 treatment of, 94 Blepbaroplasty, 389 Blepharospasm, 128 Blindness of one eye, undis- { covered, 266 I Blinking, in hypermetropia, 343 Blood in A. C, 153, 179 I in vitreous, 284 : Bloodvessels of choroid, 212 i of eye, external, 52 of retina, 74, 226 Blows on the eye, 179 Bone in eye, 44 , Bony tumor of lid, 309 Brain (see Cerebral). I Buller's shield, 108 Buphthalmos, 149 Burns of eye, 182 Burow's operation, 384 Canaliculus, diseases of, 100 operations, 392 Cancer, rodent, 96 Canthoplasty, 390 Canthotomy, 136 Capsulo-pupillary membrane, 163 Cataract, 189 artificial maturation of, 202 atropine in, 200 cause of, 190 concussion, 207 INDEX 495 Cataract, congenital, 199 consistence of, 189 cortical, 190, 196 diabetic, 440 diagnosis, 194 discission, 200, 424 dotted cortical, 191 extraction, 200, 415 after operations, 205 causes of failure, 203 history, 421 iritis after, 204 suppuration after, 203 forms of general, 190 glasses, 206 hard, 190 immature, 195 in myopia, 200, 335 lamellar, 191, 197, 206, 459 mature, 195 mixed, 190 Morgagnian, 199 nuclear, 190 operations, 200, 415 over-ripe, 199 polar, anterior, 193 posterior, 193, 197 primary, 194 prognosis, 199 pyramidal, 192 ripening of, 202 secondary, 194 senile, 190 sight after removal, 199, 206 soft, 191 solution, 200, 424 suction, 201 symptoms, 194 traumatic, 184, 207 treatment, 209 zonular {see Lamellar). Catarrhal ophthalmia, 111 Caustics, injuries by, 182 Cavernous sinus, thrombosis of, 319 Cellulitis of orbit, 318, 457 Central choroiditis, 222 nervous system, eye diseases, 448 scotoma, 268, 441 Centre of rotation of eye, 39 Cerebral tumor, neuritis in, 255, 448 syphilis, neuritis in, 449 Cerebritis, neuritis in, 450 Cerebro-spinal meningitis, eye diseases, 435 Clialazion, 94 Chancre on conjunctiva, 97 on eyelids, 97, 429 Cliemosis, 106 Clierry-red spot, 243 Chicken-pox, eye disease, 434 Chloride of zinc paste, 479 Cholesterin in vitreous, 283 Chorio-capillaris, 211 Choroid, appearances in disease, 212 in albinism, 225 atrophy of, 212 colloid W, 217 coloboma of, 224 congestion of, 224 diseases of, 210 hemorrhages in, 218 healtiiy, 211 lamina elastica, 218 myopic changes, 221 nsevus of, 325 rupture, 179, 217 sarcoma, 312 tubercle, 216, 222, 442 vessels of, 74 Choroidal atrophy in myopia, 221, 334 disease with cataract, 222 exudation, 216 hemorrhages, 218, 334 results, 222 Choroiditic atrophy of disc, 219 Choroiditis, anomalous forms of, 222 anterior, 166 central guttate, 223 senile, 222 disseminata, 219 hemorrhagica, 224 in hydrocephalus, 450 in myopia, 221 senile, 222 superficial, 215 syphilitica, 216 Ciliarv arteries, 52 496 I N LEX. Ciliary body, sarcoma of, 312 congestion, 54, 152 muscle in astigmatism, 354 in myopia, 330, 335 paralysis of, 180. 377, 433 region, diseases of, 164 Circumcorneal zone, 54, 152 Clear sight, optical conditions, 39 Cocaine, 481 Cold in iritis, 161 Coloboma of choroid (congenital cleft in choroid) , 224 of iris {deft in iris, congeni- tal or the result of iridec- tomy), 163 Color-blindness, 278 in atrophy, 260 tests for, 461, 490 Color-perception, testing, 47, 461 Colored vision, 276, 461 Colors, field of vision for, 46, 279 _ *' Commotio retince.^ 181 Congenital absence of iris, 162 cataract, 199 coloboma, 163, 224 dermoid cysts, 325 tiunor, 308 dislocation of lens, 208 fibro-fatty growths, 309 irideremia, 162 ptosis, 98 Congestion, choroidal, 224 ciliary, 55 circumcorneal, 54 conjunctival, 55 episcleral, 55 in iritis, 152 of optic disc, 250 of retina, 229 varieties of, 52 Conjunctiva, amyloid of, 123 burns of, 182 cauliflower warts of, 307 diseases, 105 lupus of, 307 nitrate of silver staining of, 151 primary shrinking of, 125 tubercle of, 307 Conjunctiva, tumors of, 307 Conjunctivitis (see Ophthalmia). Contagion, conjunctival, 105, 110 Convergent squint (see Strabis- mus). Convulsions and lamellar cata- ract, 454 Coredialysis, 179 Cornea, abrasion, 132, 181 abscess, 133 burns, 182 conical, 141 operations for, 407 diseases of, 126 fluorescence of, 127 focal length of, 39 foreign body in, 181 ground-glass, 127 herpes of, 129 inflammation of, 126 inspection of, 43 irregularity of surface of, 43 lead deposit, 150 operations, 404 j removal of foreign bodies j from, 404 I steaminess, 126, 149 ; tj-ansplantation of, 128 transverse calcareous film, 149 tubercle of, 316 ulceration, 107, 126 atropine in, 139 cauterization of, 406 crescentic, 132 dendritic, 135 eserine in, 139 fomentations, 138 from exposure, 140 infective, 132 in meningitis, 140 paracentesis, 138 phlyctenular, 129 section for, 138 serpiginous, 133 seton for, 137 suppurating, 133 treatment, 135 varieties of, 129 vascular recuirent, 131 Crescents in astigmatism, 221 N D E X . 497 Crescents in myopia, 221, 234 Critcliett's operation for squint, 398 : Crystalline lens, spherical aber- ration of, 30, 40 focal length of, 39 Cnp, physiological, 72 in glaucoma, 291 Cutaneous horn, 95 Cyclitis, 168 suppurative, 170 syphilitic, 430 traumatic, 170 i Cyclo-iritis {see Sclero-). j Cyclo-keratitis (see Sclero-). j Cycloplegia {paralysis of ciliary ' nmsde), ISO, 377,' 433 diphtheritic, 433 Cysticercus cellulosse, 284, 447 , Cystic tumors in lids and orbit, 323 ! Cysts of conjunctiva, 308, 309 of iris, 315 i of margins of lids, 95 ] Dackvo-cystitis, clironic {in- \ Jlarnmation of lachrymal sac). 101 i Dacryo-liths, 100 i Dacryops, 309 " Dangerous zone," 172 i Daturine, 484 I Day-blindness, 276 ! Deceutred lens, 36 i Delirium after eye operations, l 422 I Dermoid cysts of eyebrow, 325 ' tumor of eyeball, 308 Detachment of retina, 234 ! in myopia, 335 Diabetes, eye diseases in, 440 Diabetic amblyopia, 440 j cataract, 440 I retinitis, 440 I Dioptre, 40 Dioptiic system of spectacle lenses, 40 Diphtheria, eye disease, 433 Diphtheritic paralysis of accom- j modation, 433 ] of recti muscles, 433 ophthalmia, 112, 433 Diplopia (see also Strabismus and Paralysis), 60, 362, 363 binocular, 60 chart, 371 crossed, 365 examination, 60 homonymous, 345, 365 uniocular, 60 Direct examination, 66, 75 Discission of cataract, 200, 424 Dislocation of lens, 181, 208 Disseminated choroiditis, 219 sclerosis, eye diseases in, 453 Distichiasis, 120 Double sight, 60 Drugs, action on ciliary muscle and iris, 374 Duboisine, 484 EccHYMOSis in catarrhal oph- thalmia, 110 of eyelids, 317 Echinocoocus, 447 Ectropion, operations for, 389 Eczema, marginal, 92 Embolism of eye in pyaemia, 436 of central artery, 242 Emmetropia, 326 Emphysema of orbit, 317 Endemic nyctalopia, 275 Enophthalmos, 317 Entozoa in eye, 447 Entropion, organic, 120, 383 operations for, 382 spasmodic, 382 Epicanthus, 98 Epilation, 93, 381 Epiphora, 92, 98 Episcleritis, 164, 309 Epithelioma of conjunctiva, 309 " Erect image," 67 Erysipelas of face, blindness from, 457 Erythropsia, 276 Eserine, 485 action on healthy eye, 485 in glaucoma, 299, 485 in mydriasis, 485 in ulcers of cornea, 139 Eversion of upper lid, 381 Evisceration, 403 498 INDEX Examination, focal, 63 of blooflvt'ssels of eye, 52 of color-perception, 46, 279, 461 of cornea, 43 of eye, external, 43 of field of vision, 44 of mobility of eye (field of fixation), 57 of pupils, 50 of railway employes, 461 of refraction of eye, 78 of tension, 43 ophthalmoscopic, 65 direct, {i6, 69 indirect, 65, 69 Excision of eye, 401 in sympathetic disease, 173, 176 rules for, 184, 305, 316 Exclusion of pupil, 155 Exophthalmic goitre, 456 Exophthalmos, pulsating, 322 Exostoses, ivory, of orbit, 322 Extraction of cataract (see Cataract). Eye disease in relation to gen- eral diseases, 429 protrusion of, 62 refracting surfaces of, 38 Eyeball, foreign bodies in, 185 Eyelids, diseases of, 91 tooth in, 309 tumors, 307 bony, 309 fibrous, 309 wounds of, 320 Facial nerve, paralysis of, 455 " False image," 60, 369 " Far point," 50 Feigned blindness, 37, 277 Fibro-fatty growth, 309 Field of fixation, 57 of vision, 44 Fifth-nerve paralysis, 455 Filtration scar, 301 Flap extraction, 420 Flittering scotoma, 447 Focal illumination, 63 interval, 351 Focus, anterior, of eye, 38 Focus, conjugate, of a lens, 31 principal, of a lens, 30 viitual, of a lens, 31 Foreign body in eye, 185 in orbit, 320 on cornea, 181 Forster's operation, 202 Fourth-nerve paralysis, 370, 377 Foren centralis, 74, 227 Fracture of orbit, 317, 320 BVontal sinus, distention of, 321 Functional disorders of sight, 264 Fundus, central region of, 74 of eye, definition, 67 examination of, 69 Fungus in canaliculus, 100 Fusion power of ocular muscles, 36 Gelatinous exudation in an- terior chamber, 153 General diseases causing eye dis- ease, 429 paralysis of insane, eye dis- eases, 451 Giddiness from ocular paralysis, 372 Glasses, protective, 487 (see Spectacles). Glaucoma, 286 absolute, 290 acute, 289 after extraction of cataract, 304 atropine in, 298 causes, 298 chronic, 287 cornea in, 148, 289 cupping, 291 eserine in, 299 field of vision in, 289 hemorrhagic, 305 "intlammatory," 288 malic/num, 304 mechanism, 294 neuralgia preceding, 298 operations, 299, 409 premonitory stage, 287 primary, 286 prognosis, 302 remittent, 289 INDEX. 499 Glaucoma, sclerotomy, 300 secondary, 157, 2S6, 304 to anterior synechia, 304 to cataract extraction, 304 to dislocation of lens, 20S, 304 to posterior synechia, 157 to sympathetic iritis, 174, 304 to tumor, 305, 314 second operation, 303 simplex, 288 subacute, 288 theory of iridectomy, 299 treatment, 299 vitreous humor in, 295 (rlioma of retina, 310 i Goitre, exophthalmic, 456 Gonorrhoeal ophthalmia, 105 ' rheumatic iritis, 444 Gout, eye diseases, 445 cyclitis, 168, 445 iritis, 158, 445 Grafe's operation for squint, 396 Grafting, 390 Granular lids, 114 opjithalmia. 114 I results, 119 I Granuloma of iris, 315 Graves's disease (see Goitre). Gummatous sclerotitis, 166 tarsitis, 307 Gunshot injuries, 183, 321 j Hard cataract, 190 Heart disease, eye diseases in, 441 Hemeralopia (day -blindness), 276 Hemianopia, 270, 451 Hemorrhage after extraction. 203 choroidal, 179, 213, 218, 224, 334 conjunctival, 110 in h-itis, 153 in renal retinitis, 231 into anterior chamber, 153, 180 into optic nerve, 2-J3 vitreous, 180, 282, 284 Hemorrhage, intra-ocular, 179 orbital. 517 retinal, 232, 241, 436, 441 in blood diseases, 436 secondarv, after iridectomy, 414 causing glaucoma, 306 Hereditary amblyopia, 269 disease of retina, 246 gout, eye diseases, 445 syphilis, eye diseases. 431 Herpes of conjunctiva. 111 of cornea, 129 zoster, eye diseases, 454 Homatropine, 485 Homonymous diplopia {see Di- plopia). ' Hyalitis {inflammation of vitre- \ oils (see Vitreous). I Hydatid of orbit, 323 I Hydrocephalus, eye diseases, 450 Hydrophthalmos, 149 Hyperaesthesia of retina, 272 Hypermetropia, 340 acquired, 343 axial, 340 haze of disc. 229 tests for, 347 Hyphfema (blood in lower part of anterior chamber), 153 Hypopyon (pus in lower part of anterior chamber), 134, 153 ulcer, corneal section, 406 Hysterical amblyopia, 272 from injurv to one eye, 272 ocular paralysis, 378 ICE-BLIXDXESS, 275 Idiopathic phthisis bulbi, 170 Image formed by lenses, 32 retinal size of, 61 I E. 39 influence of lenses on, 39 Indirect examination, 65, 69 Infra-trochlear nerve, stretch- ing, 404 Injuries of eyeball, 178 of orbit, 317 Insufficiency, muscular, 330 Intra-ocular tumor, 310 500 INDEX Intra-ocular henioirhage (see Hemorrhage). " Inverted image," 65 Iodoform in purulent ophthal- mia, 108 Iridectomy, 411 distortion of image after, 39 exciting glaucoma in other eye, 298 in cataract extraction, 417 in corneal opacity, 408 in corneal ulcer, 139 in glaucoma, 299, 408 in iritis, 161 Irideremia, congenital, 162 Irido-choroiditis, 168 plastic, 159 Irido cyclitis, 170 traumatic, 170 Iridodesis, 410 Iridoplegia (paralysis of iris), 376 reflex, 376, 452 Iridotomy, 410 Iris, absence of, 162 coloboma, 163 color, 52, 153 cysts, 315 diffused sarcoma of, 315 diseases, 152 epithelial tumor, 315 granuloma, 315 normal action of, 373 operations, 408 paralysis, 180, 377 tremulous, 179 tubercle, 315 tumors, 315 vessels of, 154 wounds of, 184 Iritis, 152 after extraction, 204 atropine in, 160 causes of, 158 chronic, 159 cold in, 161 gelatinous exudation, 154 glaucoma secondary to, 157, 174 gonorrhoeo-rheumatic, 444 gouty, 159, 445 heat in, 160 Iritis, heredito-gouty, 159, 445 hypopyon, 153 in corneal ulcer, 132, 160 in diabetes, 440 in interstitial keratitis, 146 iridectomy, 161 leeches in, 161 pain in, 156 paracentesis, 160 plastic, 159, 174, 205 pupil in, 154 recurrent, 158 results, 156 rheumatic, 158, 440 serous, 156, 168 suppurative, 153, 170, 203 sympathetic, 173 syphilitic, 158 tension in, 154 traumatic, 162, 170 treatment, 160 with nodules, 153, 158 Iritomy, 410 Irritation, sympathetic, 173 Ischcemia retince, 244 Ivory exostosis, 322 Jequirity, 486 ' in trachoma, 122 Keratitis, diffuse, 142 interstitial, 142, 432 iritis in, 145 marginal, 129, 144 parenchymatous, 142 punctata, 148, 168, 174 secondary forms, 147 strumous, 129, 142 syphilitic, 142, 430, 432 Kerato-malacia, 141 Keratoscopy, 82 Kidney disease, eye diseases in, 439 Lachrymal apparatus, diseases, 99 canaliculi, diseases, 100 conjunctivitis, 102, 123 gland, diseases, 319 abscess, 101, 319 tumors of, 324 obstruction, 100 INDEX. 501 436 108 1 Lachrymal puncta, alterations, 99 sac diseases, 101, 393 abscess, 101 stricture, 100, 393 treatment of, 102 Lachrymation, 99 Lamellar cataract, 197, 206 treatment, 206 and convulsions, 454 Lamina crihrosa, 72, 257 Lateral sclerosis, eye diseases 451 Lead opacity of cornea, 150 poisoning, eye diseases Lebrun's extraction, 419 Leeches in iritis, 160 in purulent ophthalmia Lens, axes of, 29 concave, 29 convex, 29 crystalline, changes pre- ceding cataract, 191 dislocation, 181, 208 examination, 64 mycpia due to changes 'in, 340 senile changes, 189 definition, 28 equator of, 190 foci of, 31 images formed by, 32 refraction by, 28 refractive power of, 34 signs for convex and con- cave, 41 spherical aberration, 30 Lenses, numeration of, 40 decentering of, 36 table of spectacle, in dioptres and inches, 42 Leprosy, eye disease in, 446 Leucocythgemia, eye diseases iu, 441 Leucoma, 127 Lice on eyelashes, 96 Liebreich's operation, strabis- mus, 399 Light, effect of intense, 247 Limeburn, 182 Linear extraction, 418 Lippitudo, 92 Locomotor ataxv, cycloplegia, 451 diplopia, 452 iridoplegia, 376, 452 optic atrophy, 261, 451 Lupus, 306 conjunctival, 306 Macula lutea, 74, 227 Magnet for removal of iron chips, 185 Malarial fever, eye diseases, 435 Malignant tumors (see Tumors). Malingering, 37, 277 Marginal keratitis, 129, 144 Measles, eye diseases, 434 Megalopsia, 276 Megrim, eye symptoms, 447 Meibomian concretions, 95 cyst, 94, 381 Membranous ophthalmia, 112, 433 Meningitis, after excision, 403 epidemic cerebro-spinal, eye diseases, 435 ocular paralysis, 377 optic neuritis, 450 recovery with optic atrophy, 450 syphilitic, 449 tubercular, 443, 450 ulceration of cornea in, 140 Mercurial teeth, 457 Metastatic growths, 312 Micrococcus of trachoma, 117 of purulent ophthalmia, 106 Micropsia, 276 Mobility of eye, examination, 56 in myopia, 56, 329 Molluscum contagiosum, 95 Moon-blindness, 275 Morgagnian cataract, 199 Mucocele, 101 Muco-purulent ophthalmia, 110 Mules's operation, 403 Mumps, eye diseases, 434 Mitscos volitantes, 276, 330 Muscular asthenopia, 273, 330 Mydriasis (persistent dilatation of pupil), paralytic, 379 traumatic, ISO 502 INDEX. Mydriatics, action, 483 Myopia, 327 accommodation, 326 axial, 328 causes, 335 clioroidal changes, 226, 334 complications, 330 crescent, 221 examination, 330 Myopia from conical cornea, 340 from incipient cataract, 340 of curvature, 339 retinal images in, 39, 329 spectacles, 337 strabismus in, 329 symptoms, 329 tests for, 330 traumatic, 179 treatment, 336 Myosis {perdstent contraction of pupil), 456 in spinal disease, 452 paralytic, 376 Myotics, action of, 486 N^vus of lids and conjunctiva, 324 Nasal duct, diseases of, 100 probing. 102, 393 " Near point," 49 Nebula, 127 Nerve, facial, paralysis, 455 fifth, paralysis, 455 fourth, paralysis, 370, 377 optic, inflammation (see Neuritis). atrophy (see Atrophy), sixth, paralysis, 369, 377, 453 sympathetic, paralysis, 456 third, paralysis, 371, 453 Nerve-fibres, optic, opaque, 228 Neuralgia, eye symptoms, 4-18 preceding glaucoma, 298, 448 neuritis, 448 Neuritis, optic, appearances, 250 axial, 270 descending, 248 etiology, 255 in cerebral tumor, 448 in cerebritis, 450 I Neuritis, optic, in lead-poison- ing, 256 in meningitis, 450 in syphilitic brain dis- ease, 256, 449 loss of blood in, 256, 431 pathology, 249 pupils in, 256 retro-ocular, 256, 267 sight in, 254 Neuro-retinitis, 254 Neurotomy, optico-ciliary, 402 Night-bliiidness, 219 functional, 275 Nitrate of silver in corneal ulcer, 136 in ophthalmia, 108, 110, 111 staining conjunctiva, 151 Nodal point of eye, 38 Nyctalopia {night-blindness) , 219 endemic, 275 Nystagmus, 380 in disseminated sclerosis, 380 miners', 380 Objects, apparent size of, 61 Oblique illumination, 63 Occlusion of pupil, 155 Ocular paralysis, causes, 377 (see also Paralysis). Onyx, 134 Opaque optic nerve-fibres, 228 Operation for abscess of orbit, 318 for abscission of eye, 402 for artificial pupil, 408 for canthoplasty, 390 for cataract, 200, 415 causes of failure, 203 extraction, 413 modified linear, 418 needling, 424 old flap, 419 short flap, 419 simple linear, 418 solution, 424 suction, 426 for conical cornea, 407 for distended frontal sinus, 322 INDEX. 503 Operation for division of canthus, 136 for ectropion, 388 for entropion, organic, 383 spasmodic, 382 for epilation, 381 for eversion of eyelids, 381 for evisceration of eyeball, 403 for excision of eye, 401 for foreign body on cornea, 404 for inspection of cornea in pbotopliobia, 382 for iridectomy, 411 for iridodesis, 410 for iridotomy 410 for lachrymal abscess, 101 stricture, 393 for Meibomian cyst, 381 for paracentesis of anterior chamber, 405 for peritomy, 391 for ptosis, 390 for readjustment, 399 for sclerotomy, 414 for slitting canaliculus, 392 for strabismus, 395, 400 for stretching infra-troch- lear nerve, 404 ! for symblepharon, 391 for trichiasis, 383 Operations, 381 lachrymal, 392 on cornea, 404 on eyelids, 381 on iris, 408 Ophthalmia, 105 after exanthems, 111 catarrhal, 110 chronic, 122 croupous, 112 diphtheritic, 112, 433 follicular, 116 from atropine, 124 from cold, 112 from drugs, 124 from eserine, 124 from irritants, 112 gonorrhoea], 105 granular, 114 results of. 119 Ophthalmia, granular, treat- ment of, 118 impetiginous, 112 in eczema, 112 in erysipelas, 112 in herpes zoster, 112, 454 marginal, 131 membranous, 112, 433 mucopurulent, 110 neonatorum, 105 prevention of, 110 palpebral, 125 phlyctenular, 129 purulent, 105 treatment of, 108 pustular, 129 rheumatic, 112, 443 strumous, 129 tarsi, 91 Ophthalmitis, sympathetic, 173 Opht/ialmo/jlegia externa, 372, 421 interna, 377 Ophthalmoscope, 488 how to use, 67 refraction, 80 Ophthalmoscopic examination, 65 direct method, 66, 77 in myopia, 77 indirect method, 65, 69 Optic disc, atrophy, 257, 451 congestion, 250 healthy, 71 physiological cup, 72 variations in color of, 72 nerve, diseases of, 249 (see also Neuritis and Atrophy) . from syphilis, 256, 431 injury to, 262 pathological changes, 248 sclerosis, 258 sheath of, 249 tumors, 324 papilla, 71 Optical outlines, 25 Optico-ciliary neurotomy, 402 Orbicularis, paralysis, 99, 456 spasm, 128 504 INDEX Orbit, abscess of, 318 cellulitis of, 318 diseases of, 317 emphysema of, 317 foreign body in, 320 pulsaiing tumors of, 322 ' tumors, 317, 321 wounds of, 320 Oscillation of pupil, 51, 173 P A N N u s (extensive superficial \ vascularity of cornea), V20 \ phlyctenular, 131 trachomatous, Hi) Panophthalmitis, 170 purulent, 170 pyaemic, 436 traumatic, 170, 184 Papillitis {inflammation of optic disc {see Neuritis). Papillo-retinitis, 238, 255 Paracentesis of anterior cham- ber, 405 for corneal ulcer, 138 for glaucoma, 300 for iritis, 160 Parallactic movement Paralysis, associated, central, 453 diphtheritic, 433 in spinal disease, ocular, 377, 451 causes, 377 treatment, 379 of cervical sympathetic nerve, 456 of ciliary muscle, 180, 377. 433 of external ocular muscles, 372 of rectus (6th N.), 369 of facial nerve, 455 of fifth nerve, 455 of internal ocular muscles, 180, 377 of iris, 180, 377 of superior oblique (4th N.), 370, 377 of third nerve, 371 peripheral, 450 syphilitic, 430, 432, 453 Paralytic myosis, 376 236 453 452 Paralytic mydriasis, 377 Pediculus pubis, 96 "Pemphigus" of conjunctiva, 125 Perforating conjunctival ulcer, 130 Perimeter, 45, 490 Periostitis of orbit, 318 Peritomy, 122, 391 Phlyctenular affections, 111, 129 pannus, 131 Photopho])ia, 128, 136 Phthisis bulbi, idiopathic, 170 Physiological cup, 72 Physiology of internal muscles of eye, 373 Pigment in retina, 233, 244 in choroid, 215, 219, 245 Pilocarpine for detached retina, 236 Pinguecula, 308 Pohjopia unioodaris, 195 Polypus lachrymal, 101 Posterior nodal point, 38 polar cataract, 193, 197 staphyloma, 221, 334 synechia, 152 total, 155 Preliminary iridectomy, 417 Presbyopia, 359 in myopia, 361 table, 362 Primary optic atrophy, 257, 419 Prisms, action of, 27, 35 numbering of, 42 uses of, 35, 339 Prismatic spectacles, 339 Probing nasal duct, 393 Progressive optic atrophy, 258, 451 Projection, 28 Prolapse of iris, 205 in cataract extraction, 205, 423 in sclerotomy, 300. 415 Proptosis, 62, 321 in orbital disease, 322 Protective glasses, 487 Pseudo-glioma, 311, 435 Pterygium, 308 Ptosis (falling of upper Jid), congenital, 98 INDEX. 605 Ptosis from granular lids, 122 operations, 390 paralytic, 371 traumatic, 318 Pulsating tumor of orbit, 322 Pulsation, retinal, in aortic dis- ease, 441 Punctum, displacement of, 99 Pupil (see also Iris, Synechia). actions, in health, 50 contraction from congestion, 51 examination, 50 exclusion, 155 inactivity of, 51 in diphtheritic cycloplegia, 433 influence on sight, 40 in head injuries, 449 in iritis, 154 in optic atrophy, 260 in neuritis, 2.:)7 in spinal disease, 452 occlusion of, 155 size of, in anaemia, 52 j total post, synechia, 155, 304 why black, 65 Pupillary membrane, remains of, 163 Pupilloscopy, 82 Purpura, eye disease, 435 Pustular ophthalmia, 129 Pyaemia, eye disease, 436 Quinine amblyopia, 439 lotion in diphtheritic oph- thalmia, 114 "Rainbows" in glaucoma, 287 Readjustment of ocular mus- cles, 399 Recurrent vascular ulcer, 131 Reflex iridoplegia, 376, 452 Refraction, 25 by a prism, 27 by a cylindrical lens, 350 determination by ophthal- moscope, 78 by retinoscopy, 82 errors, 326 of light, 25 Refraction of the eye, 37 Refractive index, 25 Relapsing fever, eye diseases, 435 Relative accommodation, 50 Renal disease, eye diseases, 439 Retina, anaesthesia, 272 appearances in disease, 229 in health, 73, 226 atrophy, 233 bloodvessels, 74, 226 concussion, 181 congestion, 229 detachment, 179, 234, 335 diseases, 226 functional diseases, 275 glioma, 226, 310 hemorrhage in, 232 hyperaesthesia, 272 pigmentation, 232, 244 "shot-silk" appearance, 228 tubercle, 226 vessels of, 74 white patches, 231, 238 Retinal embolism, 242, 442 hemorrhage, 241, 436, 441 in blood diseases, 436, 441 image, 38, 39 in myopia, 39 influence of lenses on size, 39 thrombosis, 242, 442 Retinitis, albuminuric, 230, 238, 439 renal disease in, 240 upoplectica, 241 difiused, 229 hoemorrhagica, 241, 445 from anaemia, 441 from intense light, 247 from lead, 436 from leucocythaemia, 441 from malarial disease, 435 pigmentosa, 233, 244 renal {see Albuminuric), syphilitic, 236, 430 with choroiditis, 210, 214, 233 with optic neuritis, 238, 254 Retinoscopy, 82 Rheumatism, eye diseases, 443 22 506 1 NDEX. Rheumatism, in ophthalmia neo- natorum, 445 Ring-scotoma, 238 Ripening cataract, operation, 202 Rodent ulcer, 96 Rotation of eye, centre of, 39 Rupture of choroid, 179, 217 of eyeball, 178 Saemisch's operation, 138 Sago-grain granulations, 115 Salmon-patch, 143 Sarcoma of choroid, 312 of ciliary body, 312 of front of the eye, 310 of iris, 315 of sclerotic, 310 Scalds of eye, 182 Scarlet fever, eye disease, 113, 432 Scarring of conjunctiva, 119 Scleral ring, 71 Scleritis, 164 gummatous, 166 Sclero-iritis, 166 Sclero-keratitis, 166 Sclerosis of optic nerves, 258, 261 Sclerotic rupture, 178 wounds, 186 Sclerotico-choroiditis, posterior, 221 Sclerotitis, scrofulous, 166 Sclerotomy, 300, 414 Scotoma {an area of defect or blindness in the visual field) , 268 central, 268 flittering, 447 Scrofulous eye diseases, 446 sclerotitis, 166 Scurvy, eye disease, 436 Secondary cataract, 194 divergence, 369 glaucoma, 286, 304 keratitis, 147 operations for cataract, 423 squint, 57 Senile changes in accommoda- tion, 361 in choroid, 222 in lens, 189 Senile failure of vision, 48 Septicaemia, eye diseases, 436 Serous iritis, 156, 168 Serpiginous ulcer, 132 Setons in svphilitic keratitis, 146 in ulcers of cornea, 137 Shades, 487 Shadow-test, 82 Short sight, 327 Sight, acuteness, 48 tests for, 48 after cataract operations, 199, 206 field, 44 for colors, 279 in optic atropy, 258 neuritis, 253 optical conditions of clear, 39 Silver-staining of conjunctiva, 151 Sloughing of cornea, 107 Smallpox, eye disease, 432 Snellen's operations for trichia- sis, 386 Snow-blindness, 275 Soft cataract, 191 Solution of cataract, 200 Sparkling synchysis, 283 Spasm of accommodation, 330 Spectacles in astigmatism, 357 in anisometropia, 358 in hj'permetropia, 347 in myopia, 336 in presbyopia, 361 lenses, table of, 42 prismatic, 339 Spinal cord disease, eye diseases, 451 Spongy exudation in iritis, 154 Spring catarrh, 123, 131 Squint {see Strabismus). Staphyloma (a bulging of the sclerotic or cornea), 167 anterior, 167 posterior, 221, 334 Stillicidium lacrimarum, 99 j Stomatitic teeth, 457 j Strabismus, alternating, 57, 345 I angular measurement of, 59 apparent (footnote), 58 INDEX 507 Strabismus, causes, 366 concomitant, 58, 345 convergent, 58, 344, 364 definition and varieties, 57, 363 divergent, 57, 365 examination, 57 from disuse, 368 in hyi3ermetropia, 344 in myopia, 329, 367 latent divergent, 367 measurement of, 58 operation for, 395 paralytic, 58, 368, 372 peculiarities of, 372 periodic, 58, 345 primary, 58 secondary, 58 spontaneous disappearance of, 265, 349 Streatfeild's operation for tri- chiasis, 386 Strise of refraction, 191 Strumous eye diseases, 446 oplithalmia, 129 Stye, 93 Suction of cataract, 201 Suppression of image, 264 Suppuration after extraction, 2U3 Sycosis tarsi. 91 Symblepharon, 182, 391 Sympathetic inflammation, 171, 173 irritation, 171, 173 nerve, paralysis of, 456 ophthalmitis, 174 theories of, 171 treatment of, 175 Synchysis, sparkling, 283 Syndectomy, 122 Synechia (adhesion of iris), an- terior, 184 causing glaucoma, 157 posterior, 152 total posterior, 155, 304 Syphilis, acquired, choroiditis, 430 eye diseases, 429 iritis, 429 keratitis, 246, 430 ocular paralysis, 430 ! Syphilis, acquired, retinitis, 430 ] brain disease, 256, 431 I inherited, choroiditis, 432 eye diseases, 431 iritis, 431 keratitis, 141, 432 ocular paralysis, 63 retinitis, 432 orbital disease, 321 sclerotitis, 166 tarsitis, 308 ulcers of eyelids, 97 Syphilitic, optic atrophy, 431 neuritis, 431 teeth, 457 Syringes, for cataract suction, 426 lachrymal, 394 Tarsitis, syphilitic," 308 Teeth in lamellar cataract, 459 syphilitic, 146, 457 Tenotomy, 395 Tension of the eyeball, examina- tion, 43 diminished, 170 increased, 286 in glaucoma, 286, 288, 293 in intra-ocular tumors, 298, 311 in iritis, 154 in paralysis of the fifth nerve, 298 variation, 44 Test-types, 48, 488 Third-nerve paralysis, 371 Thrombosis of cavernous sinus, 319 of retinal artery, 242, 442 vein, 241 Tinea tarsi, 91 Tobacco amblyopia, 269, 437 Total posterior synechia, 155, 304 Toxic amblyopia, 269 Trachoma, 114 coccus of, 115, 117 Traumatic astigmatism, 181 cataract, 207 cycloplegia, 180 irido-cyclitis, 159, 170 iridoplegia, 180 508 I N D f; X Traumatic iritis, 159 myopia, 181 panophthalmitis, 170, 184 \ ptosis, 318 Trichiasis, 120 Tubercle of choroid, 216, 222 442 of iris, 315 ! Tuberculosis, eye diseases, 442 , Tumors, intra-ocular, 310 j malignant, 309 i of eye, 307 of eyelids, 307 of front of eyeball, 307 of orbit, 321 Typhus fever, eye disease, 432 Ulcers of cornea (see Cornea), of lids, lupous, 97 rodent, 96 syphilitic, 97 Undiscovered blindness of one eye, 266 Unequal refraction of the two eyes, 358 Uraemic amaurosis, 433 V Y OPERATION for ectropion, 389 Van Millingen's operation for trichiasis, 387 Vense vorticosae, 211 Vessels of anterior part of eye- ball, 52 Virtual image, size, 32 Vision (see Sight). field of (see Field and Sight). Visual angle, 38 Visual axis, 39, 48 Vitreous, diseases of, 281 dust-like opacities, 281 examination, 77, 282 liemorrhage, 284 in choroiditis, 219, 285 traumatic, 284 humor, cholesterin in, 283 in glaucoma, 294 inirido-eyclitis, 168, 285 in myopia, 284, 335 in retinitis, 285 opacities, 281 parasites in, 284 Warts, 95 conjunctival, 307 "Watered-silk" appearance of retina, 228 Watery eye, 99 Waxy disc, 219, 245 Whooping-cough, eye disease, 434 Woolly disc, 253 Wounds of eyeball, 181, 183 rules as to treatment, 184, 186 Wounds of eyelids, 320 of orbit, 320 Xanthelasma palpebrarum, 95 Xerosis of conjunctiva, 125 Yellow spot, 74 Zone, dangerous, 172 Zonular cataract (see Lamellar). Catalooue of Books PUBLISHED BY Lea Brothers & Company, 706, 708 & 710 Sansom St., Philadelphia. The books in the anoexed list will be sent by mail, post-paid, to any Post Offioe in the United States, on receipt of the printed prices. No risks of the mail, however, are assumed, either on money or books. 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In one 8vo. volume of about 50 pages, with 44 wood- cut^' and 7 plates showing colors of 56 tests. Cloth, $3 25. Just ready. C IN HEALTH AND DISEASE. In one 12mo. volume of 590 pages. Cloth, $2.. See Series of Clitiicul Manuals, p. 13. YOUAG (JAMES K.). ORTHOPAEDIC SURGERY. In one 12mo. volume of 400 pages, with illustrations. Prei)aring. ^^^"^- ■^''■''- Date Due SEP 4 19/4 1 1Q7'1 SEP \ 1 J i T MSL LIBRARY PRINTED IN U.S.A. CAT. NO. 24 161 Bra Nettleship, Edward Diseases of the eye WWIOO NUT5d 1890 SSU E D TO ^/^;^ ) WWlOO 1890 Nettleship, Edward Diseases of the eye MEDICAL SCIENCES LIBRARY UNIVERSITY OF CALIFORNIA, IRVINE IRVINE, CALIFORNIA 92664