THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA LOS ANGELES MICHEI LOUTFALLAH MEDICAL OPHTHALMOSCOPY MAXUAL AND ATLAS OF MEDICAL OPHTHALMOSCOPY BY W. E. GO WEES, M.D., F.E.S. FELLOW OF THE BOYAL COLLEGE OF PHYSICIANS CONSULTING PHYSICIAN TO UNIVERSITY COLLEGE HOSPITAL PHYSICIAN TO THE NATIONAL HOSPITAL FOB THE PABALYSED AND EPILEPTIC THIRD EDITION Revised throughout, with numerous additions and additional Illustrations EDITED WITH THE ASSISTANCE OF MAECUS GUNN, M.B., F.E.C.S. 8UBGEON TO THE BOYAL LONDON OPHTHALMIC HOSPITAL, HOOBFIBLDS OPHTHALMIC SURGEON TO THE NATIONAL HOSPITAL FOB THE PARALYSED AND EPILEPTIC PHILADELPHIA P. BLAKISTON, SON, & CO. 1012, WALNUT STREET 1890 PREFACE TO THE THIRD EDITION. IN preparing this, the third edition of "Medical Ophthal- moscopy," the whole work has been subjected to a revision sufficiently thorough to involve additions and alterations on almost every page and in almost every paragraph. An endeavour has been made to embody in it whatever of real value has been added to our knowledge, since the appearance of the last edition, and to present the facts to the reader in the aspect that they bear to the author, as viewed in the light of his personal experience. Accordingly, in many parts various statements have been not only added to, but recast in what will be found, it is hoped, a more practical form. The microscopic figures that were represented on photo- lithographic plates in preceding editions have been re- engraved as phototype blocks, and appear, in this edition, in the text of the work, in connection with the subjects to which they refer. Other ophthalmoscopic figures, prepared in the same way, have also been added. The cases that were described in full in previous editions have served their purpose, and the extended and extending use of the ophthal- moscope in medicine has made such facts as they illustrated familiar alike to physicians and students. Brief epitomes have, therefore, been substituted, and placed in relation to the facts that the case illustrates. Instead of these, an account is given of the most convenient procedure in draw- ing the appearances that are seen in the eye. It is hoped A X VI PREFACE. that these hints may, at least, have the effect of leading students to adopt a practice that will be found to be of great value, even beyond the subject to which it is applied. I have had, in this edition, the help of Mr. Marcus Grunn, who has conferred on the work the advantage of a final revision, and has also superintended its passage through the press. To his knowledge and care the reader is largely indebted. I may add the following extract from the preface to the first edition, published in 1879 : " With one or two exceptions all the cases described and figured were met with in the course of purely medical work, chiefly at University College Hospital, and at the National Hospital for the Paralysed and Epileptic. In the preparation of the illustrations, great care has been taken to secure the utmost possible exactness. The autotype plates are repro- ductions of sepia drawings ; and this method has been chiefly employed because by it a more exact representation of delicate pathological appearances can be obtained than by chromo-lithography. This method has also the advantage of fixing the attention on the changes of form, rather than upon the alterations in colour, which, important as they are, very often mislead the inexperienced. Chromo-litho- graphy has been employed for some subjects in which the changes of tint are of predominant importance. It is intended that the autotype plates should be studied by the aid of the descriptions prefixed to them, and it is believed that, thus examined, those who are accustomed to the use of the ophthalmoscope will not miss the absent colours. With one or two exceptions," specified on p. 305, " the drawings were all made by the direct method of examination." W. E. GOWEBS. 50, QUEEN AXNE STREET, July, 1890. CONTENTS. PAGE INTRODUCTION 1 PART I. CHANGES IN THE RETINAL VESSELS AND OPTIC NERVE OF GENERAL MEDICAL SIGNIFICANCE. The Retinal Vessels ... ... ... ... 7 Size 8 Arrangement ... ... ... ... ... ... ... ... 12 Course 13 Structural Changes ... ... ... .. ... ... ... 13 Aneurism ... ... ... ... ... ... 15 Circulation ... ... ... ... ... ... ... ... 18 Pulsation 18 Anaemia ... ... ... ... ... ... ... ... 22 Hypersemia ... ... ... ... ... ... ... ... 24 Haemorrhage ... ... ... ... ... ... ... ... 25 Thrombosis 30 Embolism 33 The Optic Nerve 40 Congestion ... ... ... ... ... ... 44 Neuritis ... ... ... ... ... ... ... ... ... 46 Pathological Anatomy ... ... ... ... 57 Symptoms ... ... ... ... ... ... 67 Causes ... ... ... ... ... ... ... 75 Duration ... ... ... ... ... ... ... ... 76 Relation to Encephalic Disease ... ... ... 78 Varieties 92 Diagnosis ... ... ... ... 94 Prognosis ... ... ... ... ... ... 100 Treatment 100 Atrophy 102 Characters ... ... ... ... ... 103 Causes ... ... ... ... ... ... 110 Pathological Anatomy ... ... ... ... ... ... 116 Symptoms ... ... ... 119 Vlll CONTENTS. Atrophy of Optic Nerve (continued) Diagnosis ... ... ... ... ... ... ... ... 128 Prognosis ... ... ... ... ... ... ... ... 130 Treatment 131 The Retina 132 The Choroid . 135 PART II. Ol'HTHALMOSCOPIC CHANGES IX SPECIAL DISEASES. Diseases and Injuries of the Nervous System : Diseases of the Brain ... ... ... ... ... 137 Anaemia and Hypenemia ... ... ... ... ... ... 137 Inflammation ... ... ... ... ... ... ... ... 140 Haemorrhage ... ... . . ... ... ... ... ... 142 Softening ... ... ... ... ... ... ... ... 146 Embolic 146 Thrombosis ' .; 150 Primary ... ... .. ... ... ... ... ... 154 Abscess... ... ... ... ' ... ... ... ... ... 155 Tumours ... ... .... ... ... ... ... ... 156 Labio-glossal Paralysis ... ... ... ... ... ... 168 Intra-Cranial Aneurism ... ... ... .. ... ... 168 Internal Hydrocephalus ... ... ... ... ... ... 169 Diseases of the Membranes of the Brain : Meningeal Growths ... ... ... ... ... ... ... 170 Meningitis 171 Simple 172 Tubercular ... ... ... ... ... ... ... 173 Syphilitic 177 Haemorrhagic Pachymeningitis ... ... ... ... 177 Cerebro-Spinal 178 Traumatic... ... ... ... ... ... ... ... 178 Diseases of the Cranial Bones ... ... ... ... ... ... 179 Diseases of the Orbit 180 Injuries to the Head 183 Diseases of the Nose... ... ... ... ... ... ... ... 187 Insolation and Heatstroke 188 Diseases of the Spinal Cord : Inflammation ... ... ... ... ... 189 Sclerosis : Posterior: Locomotor Ataxy ... ... ... ... ... 190 Lateral 195 Insular 195 Caries of the Spine 196 Injuries to the Spine 197 CONTENTS. IX Functional Diseases of ths Nervous System : PAOK Exophthalmic Goitre 198 Chorea 198 Neuralgia and Migraine ... ... ... ... ... ... 200 Epilepsy 201 Hysteria 204 Insanity ... ... ... ... ... ... ... ... ... 204 General Paralysis ... ... ... ... ... ... ... 205 Mania 207 Melancholia 208 Dementia 208 Diseases of the Urinary System : Bright's Disease 208 Diabetes 227 Diseases of the Circulatory System : Diseases of the Heart ... ... ... ... ... ... ... 232 Diseases of the Vessels ... ... ... ... ... ... ... 235 Diseases of the Blood : Plethora 236 Anaemia : Acute 236 Chronic 242 Pernicious ... ... ... ... ... ... ... ... 244 Leucocythsemia ... ... ... ... ... ... ... ... 247 Purpura 263 Scurvy ... ... ... ... ... ... ... ... ... 254 Diseases of the Lungs ... ... ... ... ... ... ... 254 Diseases of the Digestive Organs ... ... ... ... ... ... 255 Diseases of the Sexual Organs ... ... ... ... ... ... 256 Diseases of the Skin... ... ... ... ... ... "... ... 257 Chronic General Diseases : Tuberculosis ... ... ... ... 257 Morbid Growths... ... ... ... 263 Syphilis 263 Rheumatism ... ... ... 267 Gout 267 Lead Poisoning ... ... ... 269 Alcoholism ... ... ... 273 Tobacco Poisoning 275 Quinine ... ... ... 277 Bisulphide of Carbon 278 Other Poisons ... ... ... 279 Acute General Diseases : Typhus Fever 279 Typhoid Fever 280 Relapsing Fever Measles 282 Scarlet Fever 282 Variola 284 X CONTENTS. Acute General Diseases (continued) PAOK Acute Rheumatism ... ... ... ... ... ... ... 284 Malarial Fevers 284 Erysipelas ... ... ... ... ... ... 288 Diphtheria ... ... ... ... ... ... 289 Parotitis 290 Tonsillitis 290 Whooping-Cough ... ... ... ... ... ... ... 290 Cholera 291 Pyaemia and Septicaemia ... ... ... ... ... ... 291 Ophthalmoscopic Signs of Death 297 APPENDIX. How to Sketch the Fundus Oculi... 299 CONTENTS. XI DESCRIPTION OF THE PLATES. PLATE PAGE I. Congestion and inflammation of optic disc in cerebral embolism and tumour ... ... ... ... ... 305 II. Atrophy of disc, consecutive and simple, in 'cerebral, orbital, and spinal disease ... ... ... ... ... ... 307 III. Optic neuritis in caries of bone, chronic meningitis, and cerebral tumour ... ... ... ... ... ... 310 IV. Optic neuritis in syphilitic disease of brain ... ... ... 311 V. Optic neuritis in cerebral tumour ... ... ... ... 313 VI. Optic neuritis in cerebral tumour ... ... ... ... 315 VII. Optic neuritis in syphilitic disease (unilateral) ; epilepsy, ansemia, and lead poisoning ... ... ... ... 316 VIII. Neuro-retinitis in chlorosis ... ... ... ... ... 318 IX. Retinal haemorrhage, optic neuritis, &c., in kidney disease ... 319 X. Acute and chronic retinal changes in kidney disease... ... 320 XI. Retinal changes in pernicious ansemia and leucocytluemia ... 320 XII. Retinal changes, aneurisms, &c., in kidney disease ; embolism of retinal artery in cardiac disease ,,, ... ... 321 MEDICAL OPHTHALMOSCOPE INTKODUCTION. THE ophthalmoscope is of use to the physician because it gives information, often not otherwise obtainable, regarding the existence or nature of disease elsewhere than in the eye. This information depends upon the circumstance that we have under observation 1. The termination of an artery and the commencement of a vein, with the blood circulating in each. 2. The termination of a nerve, which, from its close prox- imity to the brain, and from other circumstances, under- goes significant changes in various diseases of the brain, and in affections of other parts of the nervous system. 3. A nervous structure the retina, and a vascular structure the choroid which also suffer in a peculiar way in many general diseases. For the efficient use of the ophthalmoscope in medical practice, the student must be familiar with the use of the instrument; he must also be familiar with the normal fundus oculi, with the changes in its appearance (congenital and other) that are of no significance, and also with those that are ocular in origin, such as posterior staphyloma, glaucomatous excavation, and the like. An acquaintance with these must be gained from the ophthalmic surgeon before inferences can safely be drawn regarding the signifi- cance of other alterations met with in various diseases. The following pages assume the possession of a general knowledge of the use of the instrument, but a few words B 2 MEDICAL OPHTHALMOSCOPY. regarding some points which are of special importance may be of service. A first requisite in medical ophthalmoscopy is familiarity with the direct method of examination. The disc is then seen magnified many times ; and this method may show minute changes of the highest significance, which cannot otherwise be detected, or the true nature of appearances which, seen by the indirect method, are obscure. But both methods should always be employed. Not only has each its special advantage, but the two together often give information which neither alone affords. Another requisite is skill in the examination without dilatation of the pupil. In most eyes much can be seen with the pupil undilated often all that is necessary, and almost always enough to determine whether or not there is more to be learned by dilatation. The coincident paralysis of accommodation is a source of annoyance, and is especially resented by patients when there is no disease of the eye itself. If the sight has not been previously affected, it often happens that in brain diseases there is a subsequent failure of sight, due to changes, neuritis, atrophy, &c., which after- wards progressed. The failure of sight in such cases is often ascribed by the patient, not unnaturally, to the effect of the mydriatic. 1 For the same reasons one pupil only should be dilated at a time, unless the sight of both eyes is already impaired. If it is a matter of indifference which is chosen, an eye, the sight of which is impaired, should be chosen in preference to the other. These disadvantages have been lessened by the use of other mydriatics than atropine, or by using eserine when the examination is over, to contract the dilated pupil. Homatropine, however, has largely superseded atropine as a dilator, since the paralysis of accommodation passes off in a few hours, and the 1 " If we use the ophthalmoscope, or if we use atropine, or if we apply a blister to the head, or adopt any new kind of treatment, the patient may blame us for his blindness, if he saw well before such procedures. A patient who reads the smallest print and supposes his sight to be good, may have double optic neuritis. The use of atropine affects his sight for near objects INTRODUCTION. 3 dilatation of the pupil seldom persists more than a day. Cocaine is likewise a useful mydriatic, on account of the short duration of its effects, and from the facility with which they yield to eserine. Its use is particularly indicated where there is any danger of exciting increased tension in the eye- ball by ordinary mydriatics. In making an examination with the ophthalmoscope, it is best to look at the eye first from a distance, in order to ascertain whether the red reflection from the fundus is clear. This at once gives information regarding the presence or absence of opacity of the lens or vitreous, or may reveal iritic adhesions conditions which convey important informa- tion, and explain what would otherwise be a puzzling obscurity of detail. Next, the refraction of the eye should be roughly estimated by observing if the vessels of the retina can be distinctly seen from a distance, and, if so, whether they move in the same direction as Ihe observer's head (hypennetropia) , or in the opposite direction (myopia). The knowledge of the condition of the eye thus gained is of much importance, since in myopia the details of the fundus appear, by the indirect method, small, and in hypermetropia they appear large. If necessary, the refraction may be more accurately ascertained by the use of a refraction ophthalmoscope : the lens needed to correct it, if the observer's refraction is normal, is the indication of the degree of error. It is frequently necessary to examine patients in bed. The indirect method of examination can be applied as readily to a patient in bed as to one sitting on a chair, the gravely, and if, from the advance of the neuritic process, what I may call retinal sight fails before the effect of the atropine has passed off, he very naturally blames us for the subsequent permanent affection of his sight. A patient, when asked how long his sight had been bad, replied, 'Only since the drops had been put in.' "We must, then, when we discover neuritis, sight being good, tell the patient that his eyes are not really good, and that we are anxious about his sight. Whether we give this warning or not, we shall be blamed by an unintelligent patient for 'tampering with his eyes.' We must, however, act for our patient's good, regardless of selfish con- siderations. In very many cases we can see enough for diagnostic purposes without using atropine." Hughlings-Jackson, Lectures on Optic Neuritis, " Med. Times and Gaz.," September 16, 1871. B 2 MEDICAL OPHTHALMOSCOPY. most convenient place for the light being on the pillow above the patient's head. Even in daylight little difficulty is experienced unless the pupil is small, but the examination is facilitated by a screen of some kind, even by the shade of an umbrella. The direct method presents more difficulty ; a convenient position is at right angles to the patient, with the lamp on the opposite side of the patient's head. All who have employed the ophthalmoscope in medical practice will agree with Hughlings-Jackson in urging the routine use of the instrument in all diseases in which ophthalmoscopic changes are, even occasionally, met with. It often happens that unexpected information is gained regard- ing the nature of the disease, or its probable consequences. It has been remarked that the medical ophthalmoscopist should possess familiarity with those changes in the eye which are of purely ocular significance. It is of equal importance that he should be familiar with those con- genital changes in the eye which are of no significance. Many of these will be alluded to in describing the morbid appearances with which they are most liable to be confounded. One or two, which give rise to special trouble to the beginner, may be here briefly mentioned. One of these io the variation in the colour of the optic disc. It has been well remarked that the tint of the optic disc may vary as much as the tint of the cheek It is always redder in the young than in the old. In the latter the redness has often a grey tint mingled with it. In the young the tint may even be scarcely or not at all paler than that of the adjacent choroid. When the choroid is bright in tint, the apparent redness of the disc is increased by indirect examination with a wide pupil and a bright light, and is a very frequent source not only of error in diagnosis but of scientific mis- takes. It is the sharpness of the edge of the disc to which attention should be especially directed. When the physiological cup is very large, the vascular portion of the disc is confined to a narrow rim at the side, often much narrower than that shown in PI. III. 1, which represents a large but not very large cup. When the part of INTRODUCTION. O the disc occupied by the nerve fibres is reduced to, say, one- half of that shown in the figure, the fibres are so crowded together that the choroidal limit is often less distinct than normal, and the central white cup may be mistaken for the disc, the edge being regarded as part of the fundus. Know- ledge of this danger, however, will be sufficient to prevent an attentive observer from falling into this error ; there is no confusion on direct examination. White patches near the disc, due to choroidal atrophy and to opaque nerve fibres, sometimes present puzzling appear- ances (Fig. 1). The recognition of choroidal atrophy by the greyish-white tint of the sclerotic, by the pigment disturbance, and by the comparative absence of change in the retinal vessels, is usually one of the first points learned. Now and then a narrow posterior staphyloma may surround, or almost surround, the disc, and its edge may be mistaken for the edge of the disc, which then ap- pears white with a red centre, an appearance with which I have known beginners to be much puzzled. (It is well to remember that posterior staphyloma may be seen occasionally FKJ. 1. OPAQUE NERVE FIBRE*, Surrounding optic disc, and concealing the vessels in that neighbourhood. 6 MEDICAL OPHTHALMOSCOPY. in hypermetropic eyes, as well as in the myopic eyes, in which it is so common.) The white patches of opaque nerve fibres (such as are shown in Fig. 1) are characterized by their position, adjacent to the disc ; by the peculiar shape of the spot, which, if large, follows the course of the nerve fibres ; by the partial concealment of the vessels; the feathery edge; and by the centre of the disc being commonly unconcealed. When a small patch lies near, but separated from the disc, the resemblance to an inflammatory exudation may be very close ; the characters of its edge, and the absence of other changes, will usually enable its nature to be recognized. 1 Peculiar white films sometimes lie in front of the vessels on the disc, looking like fragments of tissue paper or white gauze, and allowing the vessels behind to be dimly seen. These may be left by a pathological process, but they seem to be occasionally congenital, and caused by an undue development of tissue at the back of the vitreous. When congenital, the vessels are merely concealed ; when patholo- gical, they are constricted. In one case which came under my observation, a congenital film extended over the upper half of the disc, and ended on one side in a reflected edge. In considering what may be learned regarding the con- ditions of the general system by observation of the fundus oculi, it will be convenient to consider, in the first place, specially those intra-ocular changes which are of general medical significance, viz., the changes in the vessels and the circulation ; the changes, inflammatory and atrophic, in the optic nerve ; and, more briefly, the alterations in the retina and choroid ; and secondly, the changes which are met with in special diseases of the nervous and general systems. 1 It is of great importance that the aspect of these opaque nerve fibres should be familiar. They sometimes give rise to curious errors in dia- gnosis. I was once taken to see a patient in whom a large and charac- teristic patch of this description was supposed to be of syphilitic origin, and to indicate that a cerebral affection, from which the patient was suffering, was of the same nature. PART I. CHANGES IN THE RETINAL VESSELS AND OPTIC NERVE OF GENERAL MEDICAL SIGNIFICANCE. THE EETINAL VESSELS. IN no other structure of the body are the termination of an artery and the commencement of a vein presented to view, and information regarding the general state of the vascular system is often to be gained from an inspection of their size, texture, and the conditions of the circulation within them. It must be remembered, however, that the vessels there seen are of very small size. One of the primary divisions of the retioal artery, large as it appears to direct ophthalmoscopic examination, is in reality so small as to be scarcely visible to the unassisted eye, being less than the y^j-th of an inch in diameter, and the smallest vessels visible with the ophthal- moscope are not more than the T tT^th of an inch in diameter. But these, it must also be remembered, are considerably larger than capillaries. The retinal capillaries are always invisible, and, away from the optic disc, they are never so numerous as to occasion any recognizable reddish tint. The red colour of the fundus oculi is due to the choroidal vessels. A second point to be remembered is that the red lines spoken of as the retinal arteries or veins are not the vessels themselves, but the columns of blood within them. The walls of the vessels are, as a rule, invisible ; they are always invisible to the indirect method of examination, but by the direct method the walls of the larger branches may be some- times seen, as fine white translucent lines along the sides of the red column of blood, most distinct where one vessel passes over another. They are best seen by feeble illumina- 8 MEDICAL OPHTHALMOSCOPY. tion, and especially by so moving the mirror as to render the illumination slight and oblique. Sometimes, as will be described immediately, the outer coat of the vessel is so thick as to be very conspicuous. The paler line which runs down the centre of each vessel is probably a reflection of the light from the middle of the anterior surface of the column of blood. It is distinct only when the vessel lies in a plane at right angles to the line of observation. If the vessel, in consequence of an antero-posterior curve, ceases to be in a plane at right angles to the line of observation, this central reflection is no longer visible, and the whole width of the vessel is of the same dark colour as the edge. In the case of veins this change is very striking, and the greater amount of colour makes these por- tions appear darker in tint than the rest. 1 Many examples of this will be found in the appended plates, as in I. 4, II. 1, III. 2, 4, Y. 5, 6, &c. STZE. In estimating variations in size of the retinal vessels allowance must be made for the refraction, i.e., magnifying power of the eyeball, remembering that, by the indirect method of examination, in myopic eyes the details appear small, while in hypermetropic eyes the objects appear large. In the direct method there is less variation, because, for distinct vision, the myopic refraction requires correction by a lens. The apparent size of the disc may be taken as the guide to the amount of magnification. There is no very exact method of estimating the absolute size of the vessels. 2 Sometimes, however, the alteration is such as to be at once evident and unquestionable. A little custom will enable a distinct deviation from the normal to be readily recognized. 1 It is probable that such portions of the veins are especially dark, since, by their obliquity to the line of vision, this passes through a greater amount of blood ; the light reflection from behind is thus lessened, the choroid being much paler than the blood in the veins. Hence the change in tint is far greater in the veins than in the arteries, which are nearly of the colour of the choroid . 2 If a wire grating is fixed in front of the light used for the direct exami- nation, the lines of the wires are seen on the fundus, and can be used for measurement. An instrument for use with any light, with wires a definite distance apart, is described in previous editions of this book. CHANGES IN THE RETINAL VESSELS, ETC. 9 Special attention must be given to the number of primary branches of the vessel. It often happens that veins are thought to be pathologically large, merely because they are few. The relative size of the arteries and veins can be observed with more exactness than their absolute size. In comparing the two it is usually desirable to have the pupil dilated, since the vessels have often to be traced for a consider- able distance from the disc. A difficulty arises from the fact that the distribution of the arteries and veins corre- sponds approximately, but not exactly. Sometimes two arterial branches accompany one venous trunk : sometimes two veins accompany one artery. But in each eye there is usually at least one set of vessels which have a nearly identical course and distribution, run side by side, and are available for comparison. When this is the case it will be found that, as a rule, the width of the artery is about two- thirds or three-quarters that of the vein. An alteration in this relation may arise from a change in the size of the artery or of the vein. The change may be so considerable that its nature is at once evident: e.g., the veins may be obviously wider than normal, or the artery unquestionably narrower, perhaps visible as a mere line even by the direct method of examination (PL IX. 4, XII. 2, 3). When the difference is slighter, we have to form an opinion as to the change on which it depends (whether enlargement of vein or diminution of artery) by our knowledge of the normal size of the vessels an approximate absolute estimation. A little familiarity with the appearance of the vessels under normal conditions will commonly enable an opinion to be formed as to the direction in which the change exists. Equality in size of the arterj r and vein is usually due to dilatation of the artery. When the relative size of the artery is smaller than that given (f or ) it is generally due to one of three causes : (1) Venous distension, general or local ; (2) Imperfect filling of atonic veins, in consequence of which they are flattened at right angles to the line of observation : (3) Contraction of the arteries, wkich may occur from general anaemia (in which case the veins are large 10 MEDICAL OPHTHALMOSCOPY. and atonic) or from primary arterial contraction, as sometimes in Bright's disease (in which tho veins also are commonly small), or from local obstruction to the entrance of blood. Vein*. Increased width of the veins, therefore, usually means their dilatation, either from distension or from atony, and this effect is commonly uniform. The central reflec- tion is preserved in normal characters. A varicose condi- tion has been observed in a few cases, but is of doubtful significance. A remarkable example of moniliform dilata- tion has been figured by Liebreich in his Atlas. The distension may be part of a general venous fulness, as in cases of cardiac or pulmonary obstruction ; or it may be of local origin. Increased intra-cranial pressure of rapid development, probably causes at least a transient increased fulness of the retinal veins. When of slow development, this effect is rare, in consequence of the anastomoses of the orbital and facial veins. Thus the veins may become large in acute, and not in chronic, hydrocephalus. The same effect may be, it is commonly believed, the conse- quence of distension of the sheath of the nerve, and of pressure within the sclerotic ring. The former will be considered in connection with neuritis ; its precise influence is difficult to estimate. The influence of the rigid sclerotic ring cannot be regarded as demonstrated beyond question. It is said to intensify the effect of an obstruction, but the evidence is hypothetical. A very efficient cause of disten- sion of the veins is their compression by inflammatory products within the optic papilla. Extreme distension occurs also in cases of thrombosis in the central vein of the retina behind the globe. Increased width of vein, however, does not necessarily imply over-distension. A .vein which is underfilled may present an increased width. Usually, if the quantity of blood within a vein is less than normal, its contractile power enables it to adapt itself to the diminished bulk of the contents; it retains its cylindrical form, and both appears and is narrower. But in states of anaemia, the atony of the vein may prevent it from following the contents in calibre, CHANGES IN THE RETINAL VESSELS, ETC. 11 and retaining the cylindrical form. It may then have a more or less elliptical lumen (the same circumference enclosing a smaller area as an ellipse than as a circle), and in the retina, in 'consequence of the intra-ocular pressure, the flattening always takes place in the plane of 'the retina, at right angles to the line of vision, and the vein appears of undue width. At the same time the central reflection is altered, becoming commonly indistinct, but sometimes unduly broad. This condition of the veins is seen especially in extreme anaemia, and in leucocythsemia, as in the accompanying figure (see also PI. XI. 1 and 2). In these cases the arteries are usually smaller than normal, and so the contrast between the veins and arteries is enhanced. Diminution in the size of the veins is probably always the result of diminished supply of blood. The arteries may be diminished in size by causes similar to those which lead to increased width of the veins, such as local obstruction to the entrance of blood. The latter does FIG. 2. BKOAD RETINAL VEINS AND NARROW ARTERIES. From a case of leucocythseraia. 12 MEDICAL OPHTHALMOSCOPY. not appear to result from general intra-cranial pressure, probably because of the resistance afforded by the strong walls of the arteries. It is doubtful whether effusion into the sheath of the nerve is capable of diminishing the blood supply. It is certain, however, that the pressure of in- flammatory products within the papilla, and especially their cicatricial contraction, may cause sufficient constriction of the artery to lead to a great diminution in the size of its branches. Haemorrhage around the vessel, or the pressure of growths, may have the same effect. In no condition, however, does the diminution in the size of the vessel reach such a degree as in obstruction by embolism (PI. XII. 2 and 3). General underfilling of the arterial system, as in cholera, may lead to a great diminution in the size of the arteries, their strong muscular coat maintaining their adapt- ation to the blood within them. Mere atony does not cause the increase in width in the arteries which is observed in the veins, because persistent spasm of the arteries is capable of causing a permanent diminution in their size. I have repeatedly observed this narrowing, especially in cases of Bright's disease, in the branches beyond the disc. It reaches its height when papillary obstruction is superadded, and then a degree of diminution in the size of the arteries may be seen, rarely if ever observed in obstruction from neuritis without kidney disease (see PI. IX. 3 and 4). Two remark- able cases observed by Ramorius suggest that spasm of the retinal arteries may be a consequence of malarial poisoning (see Part. II, "Malarial Fevers"). Dilatation of the arteries is due to a vaeomotor influence, and is conspicuous in some cases of exophthalmic goitre, in which over-action of the heart is superadded. It is doubtful whether the latter cause alone ever produces visible dilatation of the retinal vessels. ARRANGEMENT. The anatomical arrangement of the vessels varies considerably in different individuals, and is, in itself, of little medical significance. The number of branches into which the primary trunk divides, and the CHANGES IN THE RETINAL VESSELS. ETC. 13 number of tributary veins, should be noted in connection with the apparent size of the vessels. There is one point, however, which does possess indirect medical significance. The general arrangement of the vessels in the two eyes is usually similar. Moreover, similarity in vascular arrange- ment may be inherited. I have seen, for instance, a peculiarity in the course of the retinal vessels in a mother exactly reproduced in the eye of her daughter. This is a striking proof of the transmission of vascular arrangement in general; upon this depends the vascular strain, and, in part at least, the occurrence and locality of vascular degene- ration, and even of vascular rupture. Thus, inspection of the retinal vessels suggests to us one way in which a tendency to cerebral haemorrhage, or softening from atheroma, may be inherited. COURSE. The course of the retinal vessels usually pre- sents few tortuosities, and those which exist are lateral, in the plane of the retina. A considerable increase in tortuosity may be associated with a nsevus of the adjacent part of the skin. 1 The arteries are rather more tortuous in hypermetropic eyes than in others. When the vessels are elongated by their distension or atony, these lateral curves are exaggerated. Antero-posterior curves, at right angles to the plane of the retina, are indicated by the change in the central reflection already mentioned, by the relative displace- ment of parts at different levels on movements of the ob- server's head, and sometimes by slight obscuration of the vessel at the lowest point of the curve. They always indi- cate irregularities in the retina in which the vessels lie, commonly swelling, as in retinitis and retinal oedema. STRUCTURAL CHANGES. Most changes in the tissue of the retinal vessels are visible only to the direct method of examination. The commonest change is an increase in the 1 See Allen Sturge in " Clin. Soc. Trans.," vol. xii. 1879, p. 162. For cases of idiopathic tortuosity of retinal vessels, chiefly affecting the veins, sec Benson, "Trans. Ophth. Soc.," vol. ii. p." 55; Nettleship, ibid. p. 57; Stephen Mackenzie, ibid. vol. iii. p. 101 ; all with accompanying drawings. 14 MEDICAL OPHTHALMOSCOPY- amount of tissue of the wall, especially of the outer coat, so that the red column of hlood is bounded by distinct white lines. Such an appearance may be seen in most cases in the healthy fundus near the centre of the disc. At the point at which the vessels emerge from the disc they are, the arteries especially, often surrounded by this white tissue, sometimes like a little cloud upon them, and from it prolongations may be traced along the chief vessels. When a vessel curves over the edge of a hollow central cup, and is seen foreshortened, the white tissue of the wall often appears as a ring around the blood-column. When a disc is very full coloured, whether normally or from pathological causes, this white tissue is rendered by contrast very conspicuous, and may easily be mistaken for a pathological condition (PI. I. 2). The difficulty is increased by the circumstance that it is sometimes a morbid appearance, left by preceding inflamma- tion. In this case, however, it is usually accompanied by distinct constriction of the vessels, and it often extends along them beyond the limits of the disc. It has been thought that this tissue is sometimes a result of chronic congestion of the disc, insufficient to cause such an " exudation " as shall distinctly constrict the vessels. This is possible, but the condition is so common without either congestion or in- flammation, that the presence of this appearance alone deserves little weight. An undue visibility of the wall of the vessel is said to be sometimes caused by a " sclerosis " of the middle coat, a con- dition of thickening of the coat which, under the microscope, bears considerable resemblance to the appearance presented by lardaceous degeneration. In very rare cases, there is such a thickening of the outer coat of the vessel, or an increase in its perivascular sheath, that the tissue is visible, not merely at the sides of the vessel but in front of it, concealing the red reflection from the column of blood within it, and broad white bands then in- dicate the position and course of the vessel. These bands may cease suddenly, so that lengths of red blood may alter- nate with the white bands. This condition has been seen CHANGES IN THE RETINAL VESSELS, ETC. 15 in Blight's disease, and a well-marked example is shown in PL XII. Fig. 1 ; it is then perhaps similar to the fibroid thickening around the vessels found in other organs. Some- times a vessel may be narrowed at the affected area ; more commonly its calibre is unaffected. In the case figured it is seen to affect the arteries only. In most inflammatory conditions, leucocytes accumulate in the perivascular sheaths, and in the retina they may give rise to an appearance similar to that just described ; this has been termed " perivasculitis." According to Liebreich, by a careful comparison of the relative width of the column of blood and of the white band, an opinion may be formed of the position of the new tissue, whether in or outside the wall of the vessel. Fatty degeneration of the vessels is sometimes met with as a senile change, or after inflammation. It affects chiefly the outer coat, but has only been recognized by microscopical examination, and there is doubt whether it can be detected during life. In senile fatty degeneration of the outer coat of the retinal vessels, calcification of the degenerated portion has been found after death. Actual atheroma i.e., endarteritis de- formans has not, so far as I am aware, been found in the retinal vessels after death ; and in cases in which it is well marked elsewhere I have often looked for appearances in the retina suggesting its existence, but without success. The retinal arteries are far below the size in which atheromatous changes are common. They have been said to present undue tortuosity in this condition. 1 ANEURISM. The retinal arteries are occasionally the seat of aneurismal dilatation. Instances of it are, however, rare, probably on account of the support which is afforded to the vessels by the vitreous humour. When aneurism does occur, its significance is important, because in no other way can the existence of aneurisms on vessels so small as those of 1 Concerning so-called " Arteritis obliterate," see Furstner, " Centralbl. .f. Nervenkr.," 1882, and "Centralbl. f. Augenheilk.," 1882, p. 509. 16 MEDICAL OPHTHALMOSCOPY. the retina be ascertained. Dilatations of such small vessels are commonly not associated with aneurisms on large arteries, but when minute aneurisms exist in the retina they almost always exist also in the small arteries of other organs. Two forms of aneurisms have been observed : (1) aneurisms of some size on the primary branches of the central artery on the disc : (2) miliary aneurisms of the arterial twigs in the retina, and of the small capillary vessels. (1). Very few instances of the larger aiieurismal dilatations are on record. One, which was described by Sous, 1 occupied the upper two-thirds of the disc, was oval in form, and pre- sented distinct pulsation, synchronous with the radial pulse. The arterial branches in the retina were very narrow. The patient was a woman, aged sixty-four. (2) . Miliary aneurisms were found post mortem by Liou- ville, 2 in cases in which cerebral haemorrhage resulted from the rupture of similar aneurisms in the brain. The largest was about the size of a pin's head; they were chiefly situated at the branchings of the vessels. In one case they were widely distributed through the body, being found on the minute arteries of the pericardium, mesentery, &c. They are frequently found in glaucomatous eyes. I have seen them during life on small arteries in a case of Bright's disease, in which there was extensive cardiac and vascular disease (PI. XII. 1). The lower branch of the artery is seen to present three globular dilatations in its course, the third being just in front of a narrowed segment. The general characters of these aneurisms are there seen. The central reflection of the artery is widened at the dilatation in accord- ance with the altered surface of the blood within the vessel. The wall of the aneurism is, of course, invisible, just as is the wall of the vessel elsewhere ; its existence is declared by the change in the form of the column of blood. Bouchut 3 has figured two examples of a series of fusiform dilatations of the retinal arteries in general paralysis of the insane. Hi& figures, however, suggest considerable exaggeration. 1 "Ann. d'Ocul.' 1865, liii. p. 241. - "Comptes Rend." 1870, Ixx. p. 498. 3 "Atlas d'Ophtalmoseopie Medicale et Cerebroscopie. " CHANGES IN THE RETINAL VESSELS, ETC. 17 The recognition of these minute arterial aneurisms presents little difficulty. The contours of the arteries must be fol- lowed from the disc to the ora serrata by the direct method of examination. A twist in a vessel may cause the appearance of a local bulging which may look like an aneurism, but a care- ful examination will prevent error. Minute hsemorrhages in the course of the vessels can be readily distinguished from aneurisms by the irregularity of the outline of the clot. Aneurisms, as a rule, contain fluid blood, and present a bright central reflection, which is absent in the extra- vasation. It must be re- membered, however, that a miliary aneurism has been found surrounded by a halo of extravasa- tion. The centre of any haemorrhage situated at the bifurcation of a vessel should therefore be care- fully scrutinized. A very rare condition has been figured by Galezowski, which might easily be mistaken for multiple sacculated aneurisms ; it consists of numerous mi- nute secondary glioma- tous growths, connected with the retinal arteries. Some, however, were of large size, and unconnected with the vessels, and none presented any visible reflection. 1 1 In the " Trans. Ophth. Soc.," vols. iii. p. 108, and vi. p. 336, a striking instance of aneurisnial dilatations of retinal arteries and veins is recorded by Story and Benson. The case affords a valuable illustration of the manner in which aneurisms may result from damage done to the walls of small vessels, by an inflammation of the walls as part of a general inflammation of the structures in which the vessels lie. The history of the case is unfortunately defective, but it is possible that the primary affection of the retina was syphilitic, and syphilis is known to be a cause of aneurisms of the cerebral arteries. FIG. 3. CAPILLARY ANKUKISMS, AND VARICOSE CAPILLAUIE.S. a e From a case of diabetes with retinal haemorrhages (from preparations by Mr. Nettleship). At a, b, and e the aneurisms are situated laterally, at c in the course of a capillary, and at d at the bifurca- tion of a vessel ( x 150). /, Varicose capillaries from a case of Bright's dis- ease ( x 150). 18 MEDICAL OPHTHALMOSCOPY. The retinal capillaries may present aneurism al dilatations sacculated in form, and also varicose dilatation. Examples of these are represented in Fig. -J, from a case of glycosiiria described by Dr. Stephen Mackenzie. 1 Haemorrhages into the retina and vitreous were observed during life. Capillary aneurisms, from a case of Bright's disease, are also shown in the same figure. CHANGES IN THE CIRCULATION. The central artery of the retina brings blood to the eye from within the cranial cavity ; the blood comes from an artery which also supplies part of the cerebrum and me- ninges : the retinal vein returns the blood chiefly to a cranial sinus. Hence the intra-ocular circulation has been regarded as a portion of the cerebral circulation, as participating in the same influences, and presenting the same modifications. This is, no doubt, true to some extent. At the same time it is probable that the consequences of the common origin of the cerebral and ocular blood- supply have been exaggerated. It is important to bear in mind that the intra-ocular circula- tion is peculiar in its rigid enclosure in a small chamber, in which it is always exposed to a certain amount of elastic pressure. Moreover, the anastomosis between the orbital and facial veins tends to prevent a close correspondence between the intra-cranial and intra-ocular veins. The relation be- tween the cerebral and ocular circulation is unquestionably greatly modified by these and other influences. PULSATION. Arterial. As a rule, before reaching arteries so small as those of the retina, the pulse- wave has become so feeble, the current so equable, that visible pulsation can no longer be perceived. The pulsation is also diminished by the normal pressure within the eye ; this, in giving support to the retinal vessels, necessarily lessens their distension. If, however, the current be rendered less equable by an increase in the disproportion between the continuous flow and the intermitting wave, arterial pulsation may sometimes be 1 "Ophth. Hosp. Rep.," December, 1877. CHANGES IN THE RETINAL VESSELS PULSATION. 19 perceived. Locally, this disproportion may be increased by a Change in the intra-ocular tension : thus a temporary distinct arterial pulsation usually results from the artificial production of increased tension by pressure on the globe with the finger. Again, a diminution of intra-ocular tension may, perhaps, sometimes occasion visible arterial pulsation. 1 In conditions of acute anaemia from haemorrhage, the continuous flow of blood into the small vessels may be feeble, and the pulse-wave then becomes distinctly visible. 2 But it is especially when the pulse-wave is increased in strength and suddenness that it becomes visible in the retinal arteries. This increase is developed in aortic regurgitation, and in that condition spontaneous pulsation of the retinal arteries is especially frequent, as Quincke, 3 Becker, 4 and Fitz- gerald, 5 first pointed out. It is more distinct, the greater is the hypertrophy of the left ventricle, and is absent only when the heart is greatly weakened, when much aortic con- striction coexists, or the amount of regurgitation is small. It may be seen best in the vessels on the disc, but can often be recognized far towards the periphery of the retina, and in this latter respect is distinguished from the pulsation due to mere increase of intra-ocular tension. It consists, like the pulsation of other vessels, in a widening and an elongation. The widening is best seen behind a division at a considerable angle, and is best recognized by attending to the central re- flection. The elongation of the vessel is best seen where an artery lies in an S curve, especially towards the periphery, or when it forms a curve along the edge of the disc (Becker). 1 Such a diminution is said sometimes to occur in the course of typhoid fever, and pulsation has been observed in the retinal artery in this disease by Schmall. See "Retinal Circulation and Arterial Pulse in General Disease," " V. Graefe's Archiv.," xxxiv. 1, p. 37, and " Oph. Rev.," 1888, p. 268. 2 An arterial pulse has also frequently been observed by Schmall in cases of chlorosis. Here, as in anaemia generally, Rahlmann ascribes the pulsation to hydrsemia, but Schmall considers it due to " a certain amount of cardiac contraction, combined with sudden relaxation of the heart muscles, occurring in certain states of low arterial tension." (Op. cit.) 3 " Berlin Klin. Wochenschr. , " 1868, No. 34, and 1870, No. 21. 4 "Arch. f. Ophth.,"xviii. 206296. 5 "British Med. Journal," Dec. 23, 1871, p. 723. Dr. Stephen Mackenzie has also recorded several cases (" Med. Times and Gaz. ," 1875, vol. i.). 20 MEDICAL OPHTHALMOSCOPY. In a case of supposed aneurism of the arch of the aorta, Becker found marked pulsation in the left eye, while in the right only a trace of pulsation could with difficulty be detected. Pulsation in an extreme degree appears to be sometimes physiological. It was present in a man under my care who had also a very faint diastolic basic murmur but no hyper- trophy or dilatation of the left ventricle, so that there was certainly not enough aortic regurgitation to account for the pulsation. A capillary pulse could readily be obtained in the forehead. The increased pulsation seemed to be in the small arteries only, since at the wrist, even when the arm was raised, the artery had the normal pulse-characters. In the eye, pulsation was conspicuous in both arteries and veins, and slight pressure on the globe increased it to such an extent that some veins on the disc, of full size in the diastole, actually disappeared at each systole. Moreover, the diastole of the arteries corresponded to the systole of the veins, and the pulsation in the latter must therefore have been due to the mechanism to be presently mentioned. Capillary pulsation has been described in aortic regurgita- tion a pulsatile redness of the disc due to the intermitting distension of the capillaries in consequence of the great fall of pressure between the successive pulses. Such an appear- ance is, however, very rare, and can seldom be detected even when a pulsatile blush is visible on the forehead. Tenons. Pulsation in the retinal veins may frequently be observed as a normal condition, chiefly in the large branches upon the optic disc, 1 especially where the veins curve down the sides of the cup. It is almost constant in aortic regurgitation, and is much more frequently con- spicuous in this disease than the arterial pulse. Several explanations have been given of the venous pulse. The theory which is, perhaps, the most plausible explains the pulsation by supposing that where the artery and vein are near together, in the sclerotic ring or optic 1 Messrs. Lang & Barrett found a venous pulse on the disc in 73 '8 per cent, of the eyes examined by them at Moorfields. " Ophth. Hosp. Rep.," vol. xii. p. 60. CHANGES IN THE RETINAL VESSELS PULSATION. 21 nerve, the arterial distension compresses the vein and causes a temporary obstruction to the return of the blood. The nearer the two are, the more readily will this effect be produced, and the more slight a morbid increase needs to be for the artery to transmit an inverse pulsation to the vein. Coccius suggested that the venous pulse depends directly on the intra-ocular tension, being analogous to that whicli occurs in glaucoma, and may be produced artificially by pressure on the eyeball. Every time the pulse- wave reaches the intra-ocular arteries, their distension causes a sudden increase in the intra-ocular tension, which com- presses most the thinner walled veins, and lessens the amount of blood in them. Hence the contraction of the veins should correspond to the arterial diastole, to the pulse-wave, and the dilatation of the veins to the arterial systole, to the interval between the pulse-waves. As a rule, however, this is not the case : the distension of the veins nearly corresponds in time with the arterial dis- tension. Hence, Stellwag von Carion imagined that the extension of the sclerotic by the increased intra-ocular pressure at each pulse stretches the lamina cribrosa, and narrows its meshes so as to compress the vein. According to Donders, the increased intra-ocular pressure acts directly on the venous trunks in the optic disc, hindering the return of blood. Similarly, Jacobi, on the grounds of the common limitation of pulsation to the papilla, suggests that the increased intra-ocular pressure, depressing the papilla, augments the curve of the veins, and so causes a sudden obstruction to the circulation through them. Helfreich, on the other hand, considers that the venous pulse is due to a pulse in the cerebral veins, grounding his opinion on experiments that show the tension in these to be high, and that they pulsate. He states that the venous pulsation is synchronous with the cardiac diastole, and that it is seen only on the disc, because of the firmer support of the veins away from the disc. 1 It has, however, been mentioned 1 Ophtk Congress, Heidelberg, 1882, and "Ophth. Review," 1882, p. 408. 22 MEDICAL OPHTHALMOSCOPY. (p. 18) that the physical conditions in the eye are not exactly similar to those in the hrain. Helfreich's theory seems to account for the coincidence of arterial swelling and venous swelling, but so also does the juxtaposition of the arteries and veins within the sclerotic ring mentioned above. If Helfreich's theory be correct, should not the pulsation be an invariable thing ? Putnam and Wadsworth (of Boston, U.S.A.) have described 1 an intermitting variation in size of the retinal veins, occurring independently of the pulsation, synchronous with the heart's action, and having a period of about five respirations, i.e., about that of the variations in arterial tension found to occur in animals. Their observations have not yet been confirmed. ANAEMIA OF THE RETINAL VESSELS may be part of general anaemia, or may be due to local pressure upon the artery, and transient anaemia is probably sometimes due to the vasomotor nerves. When due to local causes (" retinal ischaemia " of the Germans) there is usually simultaneous pressure on the retinal vein, which runs side by side with the artery. The arteries are then unduly narrowed ; whether the veins are distended or not depends on the rapidity or slowness with which the obstruction is developed. This condition is constantly seen during the contraction of inflammatory tissue in the papilla. In rare cases, in which the pressure is on the artery immediately after its entrance into the optic nerve, and behind the vein, which enters a little in front of the artery, the arteries may be narrowed without any distension of the veins. Spasm of the retinal vessels has been supposed to occur in epilepsy, and also to be the cause of " retinal epi- lepsy," i.e., epileptiform amaurosis. I have examined the retina in many cases of epilepsy immediately after fits without observing any marked change in the arteries. During several epileptiform convulsions, I have kept an artery and vein in view throughout the fit, by the direct 1 "Journal of Nervous and Mental Disease," October, 1878. CHANGES IN THE RETINAL VESSELS ANAEMIA. 23 method of examination, but have seen no change in the artery. The vein was distended during the cyaiiotic stage. General defective blood-supply is much less evident in the vessels of the eye than elsewhere : probably because the intra-ocular tension effects a regulation of the size of the retinal vessels (Donders) . Loss of blood, for instance, causes but a slight change in the retinal vessels, except an increased disproportion between the arteries and the veins, due in part to contraction of the arteries, and in part to atony and flattening of the underfilled veins. The effect of haemor- rhage on the size of the vessels soon passes off, because the volume of the blood is quickly reproduced by the passage into, and retention in it, of liquid from the tissues and alimentary canal. 1 A similar condition of the retinal vessels to that seen in acute anosmia was observed by v. Grraefe in cholera. During the stage of collapse the arteries became narrow, the veins dark, but of normal width. Spontaneous pulsation appeared in the arteries, and was attributed to cardiac weakness, but may, perhaps, have been due to the diminution of the volume of the blood, rendering the amount ejected from the left ventricle at each systole so 'small that the shock (pulse- wave) predominated over the movement of the blood. The acute cerebral anaemia of syncope is probably attended by a similar condition of the retina, and to it the transient blindness which sometimes succeeds syncope may be due. Conditions of general defective blood-supply render the disc paler, but the variations in the tint of the disc, under physiological conditions, are so great that it is only by com- parison of the state of the disc with its appearance in the same patient at another time, that any information can be gained from it. The other eye is usually affected in the same degree, and is not, therefore, available for comparison. 1 In some observations on the effect of venesection in the corpuscular richness of the Llood, kindly made for me by Mr. W. S. Tuke, on some patients of Mr. Wharton Jones, it was found that the fall in the number of blood-corpuscles indicating the dilution of the circulating blood to reproduce its volume, took place in the course of an hour. It was found also that the fall was greater than the amount of blood lost could account for i.e., that the hydrsemia became for a time excessive, a fact which may account for the reputed influence of slight, quick loss of blood. 24 MEDICAL OPHTHALMOSCOPY. HYPERJEMIA OF THE RETINAL VESSELS. (A.) Active Con- gestion. Apart from the active congestion of commencing inflammation and of purely ocular conditions, such as refrac- tive asthenopia, and exposure to excessive light, &c. (which are not considered here), an increased supply of blood to the retina may be due to whatever causes an overfilling of the whole or part of the arterial system of which the retinal artery forms part. Of these, excited action of the heart is the most potent. The retinal arteries may be seen to be large, and sometimes, though rarely, to pulsate, and the communicated pulsation in the retinal veins may also, commonly, be observed. When the overaction is long- continued, haemorrhages may occur. A similar overfilling may occur from obstruction in another region of the internal carotid. Dilatation of the arteries, as in exophthalmic goitre, may also cause active hyperaemia. (B.) Passive Congestion. Passive congestion of the retinal vessels may occur from local or general causes. The causes of local obstruction to the return of blood from the eye are, for the most part, the same as those of local arterial anemia. The most intense passive congestion ever seen is met with in thrombosis of the retinal vein. Pressure on the cavernous sinus only causes transient passive congestion of the retinal veins, on account of the free connection of the orbital and facial twigs. Passive congestion from general causes is very common, and results from whatever hinders the return of the blood from the head, or obstructs the circulation through the chest. The congestion of the eye is thus part of a cephalic congestion, or of a general venous stasis. The former com- monly results from pressure on the jugular or innominate veins. The general congestion is the result of some pul- monary or cardiac obstruction, acute or chronic. The com- mon acute causes are cough, effort, and an epileptic fit. The ophthalmoscope shows the retinal veins in these condi- tions to be greatly distended. Unless, however, there is also disease of vessels, haemorrhages rarely occur, no doubt in consequence of the support afforded to the vessel by the vitreous humour. The intra-ocular tension, and therefore CHANGES IN THE RETINAL VESSELS HAEMORRHAGE. 20 the external support, is probably augmented during these conditions of increased strain, in consequence of the fulness of the capillary vessels. It is true that the most intense con- gestion, such as that of suffocation, sufficient to cause death, does usually lead to retinal haemorrhages, but minor degrees of congestion rarely do so unless the vessels are diseased. It is very common, for instance, for a violent cough, or an intense asphyxial stage of an epileptic fit, to cause rupture of a subconjunctival vessel, and a consequent extravasation, but it is extremely rare for any retinal vessel to give way. I have often, in such cases of epilepsy, searched the retina for extravasation, but the search has always been unsuccessful. In whooping-cough, retinal extravasations have been seen only in extremely rare cases. Chronic general causes of passive congestion are chiefly heart disease (especially mitral) and emphysema of the lungs. In the general venous distension of congenital heart disease cyanosis the retinal vessels participate, often con- spicuously. The venous distension may be extreme, and may be accompanied by normal arteries, or the arteries may be also large. The blood in the arteries and veins may be abnormally dark. Sometimes the retinal tissues are thickened. The congestion from emphysema of the lungs, and from dilatation of the right heart, is also often very marked. The retinal veins become much distended and tortuous, and the smaller branches, ordinarily invisible, may become conspicuous. HJEMORRHAGE. Rupture of retinal vessels and consequent extravasations of blood are very common in many morbid states, and are frequently of important general significance. They may occur as part of inflammation of the retina, and such cases will be considered subsequently. More frequently they are dependent directly on general conditions, or on retinal disease consequent on general conditions. They vary much in size, number, position, and aspect. They may be so small as to be visible only as a spot or line on direct examination, or they may be three or four times 26 MEDICAL OPHTHALMOSCOPY. the diameter of the optic disc. There may be only one or two, or innumerable extravasations may exist over the whole fundus. When few they are commonly seated near the disc or in the neighbourhood of the macula lutea; when numerous, the largest are often situated near the macula. They often follow the course of vessels, especially the veins, but not unfrequently the arteries. Their shape and aspect depend very much on their position in the substance of the retina , The commonest seat is in the layer of nerve fibres. The fibres are separated, not torn, by the extravasation, and the blood lies between them, extending along their course in the direc- tion of least resistance. Hence the smaller ha?morrhage& are linear, the larger striated in part or altogether, and they often radiate from the disc. Such hcemorrhages are shown in PL Y. 4, YI. 1, IX. 1, 2, X. 1, XI. 1. The next most frequent seat is in the inner nuclear layer. Here there is no tendency to striation ; the extravasations are round or irregular (as in PI. YI. 4, XII. 1). If the extravasation in this position is large it may separate the retina from the choroid, while a haemorrhage in the nerve-fibre layer may break through into the vitreous. This sometimes happens- in Bright's disease, as in one case which came under my observation. 1 The patient, a girl of seventeen, was admitted under Sir Wm. Jenner, suffering from chronic Bright's disease and hemiplegia. On admission there was well-marked albu- minuric retinitis of the usual type. A fortnight later, a haemorrhage occurred, partly obscuring the fundus. It did not become diffused, but remained attached to the retina by a pedicle. Now and then, especially in the neighbourhood of the macula lutea, the blood may be extravasated in a thin film between the retina and the vitreous. Such an extravasation is commonly very irregular in shape, the irregularity being sometimes increased by the extension of processes of blood into the vitreous. Occasionally a large hemispherical haemorrhage is found at the macula, bounded superiorly by a straight horizontal line. Here the blood seems to See also " Ophth. Review," vol. vii. p. 132. CHANGES IN THE RETINAL VESSELS HEMORRHAGE. 27 be effused between the internal limiting membrane of the retina and the hyaloid membrane, which are more loosely attached to each other in this situation than elsewhere. The blood quickly gravitates to the lower part of this space, where it is confined by the comparatively close connection between the above-mentioned membranes there existing, and we thus get a haemorrhage of the characteristic hemispherical form. The more recent the haemorrhage the brighter is its colour. Old haemorrhages may be almost black. Haemorrhages may cause permanent white spots. There may be a haemorrhage one day, and the next a white spot in its centre. As the blood goes (which it does quickly), a white patch may remain, never so large as the haemorrhage. It is doubtful whether extravasations into the retina occur, however small, except from actual rupture of vessels; 1 probably the extravasations are conditioned by degeneration of minute vessels, sometimes by such capil- lary aneurisms as are shown in Fig. 3. White spots or brilliant plates of cholesterin are often seen in the retina adjacent to, or left by, extravasations (PL XI. 1). These spots, when small, may be granular ; when large, they may be filmy. They are probably due to fatty degeneration of the disturbed retinal elements or of the effused blood. Small extravasations are readily absorbed; larger ones more slowly. Sometimes pigmentary degeneration results, and an irregular black spot is left. The white spots disappear very slowly, and white granules may remain for a long time. Symptoms. Small haemorrhages, away from the centre of the retina, may give rise to no symptoms. Larger ones cause loss of vision at the spot from the local damage to the retina, the loss being serious in proportion to the proximity to the macula lutea, in which a small extravasation may cause permanent loss of central vision. A ring of haemor- rhage around the macula may cause considerable central amblyopia (PI. XL 2). Occasionally the patient is con- scious of the red colour of the extra vasated blood (see 1 According to Leber they are frequently due to diapedesis. "Graefe u. Saemisch's Handbuch," vol. v. p. 557. 28 MEDICAL OPHTHALMOSCOPY. under "Leucocythsemia"). At the moment of extravasation there may be no symptoms, or there may be sudden dimness of sight, or there may be ocular spectra. Causes. Haemorrhage into the retina, as elsewhere, depends on one or both of two causes increased intra- vascular pressure, decreased strength of vascular wall. Local increased blood pressure is a common cause. In optic neuritis with much constriction of the veins, the whole fundus may be covered with extravasations (PI. VI. 1). Similar extravasations may attend all forms of retinitis. They may be large and abundant in thrombosis of the retinal vein, as Michel has shown (see p. 31). General increased blood-pressure is an occa- sional cause. High arterial tension may often be traced in cases of retinal haemorrhage in which no other cause can be discovered. But it is, on the whole, a rare accident, consider- ing the frequency with which high tension exists. Its rarity may be due to the efficient support of the retinal vessels, as explained in the description of the effects of passive conges- tion. It is sometimes seen when hypertrophy of the left ventricle can tell unduly on the vascular system. In the peculiar vascular condition which attends arrested menstrua- tion, haemorrhages occasionally occur : more rarely in sup- pression of some other habitual discharge. Mr. Spencer Watson 1 has recorded an instance of extensive retinal extra- vasation in a woman at the climacteric period, in whom there was high arterial tension, which was ultimately relieved by a copious epistaxis. Another cause is sudden loss of blood (see " Acute Anaemia "). In some cases of heart disease, especially when conjoined with degenerated vessels, numerous extravasations occur into the retina, with signs of parenchymatous retinitis, venous distension, and diffuse cloudiness. This condition has been called " haemorrhagic retinitis." It may occur without any recognizable cardiac disease in apparently healthy persons after middle life, and is often unilateral. It probably is the result, in some> cases, of thrombosis in the retinal vein. Mr. Hutchinson has adduced strong evidence to show that it is 1 " Trans. Ophth. Society," vol. i. p. 41. CHANGES IN THE RETINAL VESSELS HAEMORRHAGE. 29 occasionally due to a gouty diathesis, acquired or inherited (see Part II., "Grout"). Degeneration of the retinal vessels is a frequent .cause of haemorrhage, although it is not often that it can be demon- strated post-mortem. It is doubtless owing to this degenera- tion that retinal extravasations are so common in certain general blood diseases, especially in kidney diseases and diabetes, pernicious anaemia, leucocythsemia, ague, purpura, scurvy and pyaemia, and many exhausting conditions, such as over-lactation. In some of these cases, as pyaemia and leucocythsemia, the blockade of vessels may assist. Capillary aneurisms from a case of retinal haemorrhage in diabetes and diseased capillaries in renal retinitis are shown in Fig. 3. Jaundice is also an occasional cause of retinal haemorrhage. Apart from these blood diseases, retinal haemorrhage may occur from simple senile vascular degeneration. In such cases it is sometimes produced by violent effort, such as that of a cough, or in straining during defaocation. In all conditions of vascular degeneration its occurrence is of im- portance, on account of its occasional association with cerebral haemorrhage. This is well exemplified in the case of leuco- cythsemia (q. v.}. Sometimes retinal haemorrhage results from blows upon the eye or skull. Rarely haemorrhages are observed in young persons without discoverable cause. A remarkable series of cases in young men has been recorded by Eales, of Birmingham. 1 The only etiological condition with which it could be associated was habitual constipation. The cases will be again alluded to in the section on " Affections of the Digestive System." The prognosis depends on the position of the haemorrhage, and 011 the extent to which its causes are under control. It is worse when there are signs of general retinitis. The chief local treatment is the application of cold and gentle pressure on the eyeball, to give temporary support to the vessels, and obtain contraction. Other measures are those suited for the general state, and for haemorrhage elsewhere. 1 " Birm. Med. Review," July, 1880, j. 262. 30 MEDICAL OPHTHALMOSCOPY. Haemorrhage from the choroidal vessels is rare, and pos- sesses little medical significance. THROMBOSIS. Veins. Thrombosis is occasionally observed in smaller branches of the veins, which then lose their double contour i.e., their central reflection disappears, and they appear dark and large, their branches being unduly con- spicuous. The condition usually depends on local causes, and has little general significance. 1 Thrombosis may also occur in the central vein of the retina behind tjie eye. It is met with chiefly in the old, in whom thrombosis elsewhere is common, and has been seen in associa- tion with senile gangrene of the foot (Angelucci). But it occasionally occurs also in younger persons, in association with heart disease, aortic and mitral. Of four cases recorded by Angelucci, 2 three were in young persons, aged twenty- one, twenty-three, and twenty-four. In these it is ap- parently due to phlebitis. In one case 3 the vein at the spot thrombosed was thickened to three times the normal size, chiefly from changes in the external coat. The new tissue consisted of concretions such as are met with in psammo- mata, and was ascribed to an inflammatory process in the connective tissue of the central canal of the nerve. The thickening of the vein was so great that it must have compressed the artery. It is somewhat remarkable that the accident does not more frequently follow a primary neuritis. Only one case has been recorded in which thrombosis was supposed to have resulted from a primary inflammation. 4 The symptoms observed have presented considerable varia- 1 Under the title "Primary Retinal Phlebitis," Mules has lately recorded two cases where the thrombosis was confined to branches of the central vein. There was no local disease found to account for the condition, but evidence of choroiditis subsequently appeared in one of the cases. The general bearing of the thrombosis is not apparent, though Mules considers that, in one of the patients, the phlebitis was due to gout. In neither was there any optic neuritis. See "Trans. Ophth. Soc.," vol. ix. 1889, p. 130. " * "Ann. d'Ocul.," 18SO, ii. 3 Angelucci: " Kl. Monatsbl.," August, 1878; Zehender : " Bericht iiber 11 Versam. Ophth. Ges 1.," p. 182. 4 Fox and Brailey : " Ophth. Hosp. Rep.," vol. x. pt. ii., June, 1881, p. 205. CHANGES IN THE RETINAL VESSELS THROMBOSIS. 31 lion. There is always sadden failure of sight, often dis- covered on waking in the morning. It is usually incomplete, and soon presents slight improvement. In the most severe cases observed by Michel, 1 the ophthalmoscopic appearances were those of an intense haemorrhagic retiuitis. The veins were extremely distended and tortuous; the retina around the papilla was suffused with blood, beyond this zone of extravasation were circumscribed haemorrhages, and around the macula lutea there was a greyish discoloration. The vitreous sometimes became opaque. In other cases, in which it was assumed that the occlusion of the vein was incom- plete, there were merely broad striated haemorrhages around the papilla, and round and oval haemorrhages towards the periphery, the arteries being indistinct, and the veins dark and tortuous. In still slighter cases, supposed to be of the same nature, there were no haemorrhages, but merely a disproportion between the arteries and the veins. In most instances the disc was little affected. That haemorrhages may be absent even when the occlu- sion of the vein is complete, is proved by the case recorded by Augelucci, 2 in which thrombosis of the retinal vein, 1 mm. behind the lamina cribrosa, was associated with senile gangrene of the foot. The veins were tortuous, but there were no haemorrhages. In the case recorded by Fox and Brailey glaucoma super- vened, but the evert is exceptional ; in most recorded cases the tension of the eye was normal. In thrombosis of the retinal vein the loss of sight is less complete than in embolism of the artery, and the ophthal- moscopic appearances differ in that the arteries, as a rule, although they may be slightly narrowed, are not empty, or filiform, in the enormous distension of the veins, and in the circumstance that venous pulsation can usually be observed, and that the veins may appear interrupted here and there. But in some cases the appearances simulate those of embolism very closely. There may be a cherry-red spot at the macula, 1 " Archiv f. Ophtli.," vol. xxiv. pt. 2, p. 37. 2 " Klin. Monatsbl.," October, 1878. See also the same, January, 1880. 32 MEDICAL OPHTHALMOSCOPY. and in severe cases (probably in which the central artery is compressed by the distension of the vein from clot, or by the thickening of the wall which caused the thrombosis) the arteries may be extremely narrow, the veins partly emptied of blood, and the disc pale. These were the appearances in a case recorded by Angelucci, 1 in which the thrombosis was demonstrated post-mortem. Artery. Thrombosis has been observed in the retinal artery with ocular signs identical with those of embolism, to- be described immediately. In a case recorded by Sichel it was conjoined with foci of softening and small haemorrhages in the brain. Thrombosis in the ophthalmic artery occurs as a very rare event, and probably always as the result of thrombosis in the internal carotid. I am not aware that any case has been observed during life, but some years ago I made- a necropsy on a case in which this accident had occurred. The patient, an aged man, had suffered from cerebral soften- ing in the region supplied by the left middle cerebral artery, which was much diseased. A fortnight or three weeks before his death, there was no ocular or ophthalmoscopic change. He lay in a comatose condition, and his eyes were not again examined. Post-mortem, a recent clot was found extending down into the intra-cranial portion of the left internal carotid, fully distending it, and passing also into the commencement of the ophthalmic artery, which, however, near the eyeball, was pervious, being only partially obstructed by clot. The eyeball was quite rotten, the sclerotic of a brownish colour, and giving way before the scissors like brown paper. The retina was greatly atrophied, reduced to two- thirds of its normal thick- ness. Its several layers were no longer recognizable. The outer half was occupied by a thick layer of nuclei, apparently representing the two nuclear layers. Its inner half consisted of a series of lacunse, limited by the remains of the thick- ened vertical fibres. No nerve-fibre layer, ganglion cells, or molecular layers could be discovered. A case of the same character, but in which a freer collateral circulation was. established and the retinal changes were slighter, has been 1 Loc. cit 1878. CHANGES IN THE RETINAL VESSELS EMBOLISM. 66 recorded by Yircliow, and is described further on in the section on "Softening of the Brain." Parinaud 1 relates a case of thrombosis of the central artery of the retina, followed by symptoms of cerebral softening, in a woman aged seventy- one, who was suddenly seized with dimness of vision in the left eye, accompanied by the appearance of green and yellow spots on a grey ground. A few days later there was a central scotoma with pronounced peripheral limitation of the field of vision, and loss of colour-sense. Ophthalmoscopically the only change observed was a diminution in the calibre of both veins and arteries, followed ten days later by oedema of the retina with haemorrhages, and capillary congestion around the macula. Three months later there was atrophy of the disc, and several branches of the central artery were filiform and white. Subsequently she developed loss of memory, aphasia, and hallucinations. Priestley Smith 2 has urged that arterial thrombosis is the lesion in many cases that are thought to be embolism. He regards, as its causes, heart-failure (either from organic disease or other cause), spasm of the vessels or disease of their walls, and blood-states. The transient failure of sight in the opposite eye at the onset he ascribes to spasm of the retinal vessels. EMBOLISM. The central artery of the retina is not unfre- quently occluded by an embolus, and the occurrence is of much medical interest. Nowhere else can the phenomena of vascular occlusion be observed during life. The accident is commonly the consequence of heart disease, and is sometimes the first thing which draws attention to the existence of the cardiac affection. It was so in the case of a girl who came under my observation suffering from sudden loss of sight in one eye. On examination she was found to have a loud, distinct presystolic murmur. There was no previous history of rheumatic fever or scarlatina, and there were absolutely no symptoms pointing to cardiac disease beyond the affection of sight. Embolic infarction in other organs in many cases 1 " Gaz. Med. de Paris," 1882, p. 627. 2 " Oplith. Rev.," vol. iii I) 34 MEDICAL OPHTHALMOSCOPY. coexists, and the ocular accident may indicate the nature of disturbance elsewhere. It occasionally coexists with cerebral embolism, and may even furnish a warning of the proba- bility of the latter, as in a case recorded by Landesberg, in which the ocular embolism was followed, a week later, by loss of consciousness and hemiplegia. This patient suffered at different periods from embolism of eacli retinal and one cerebral artery. The cerebral and ocular accidents may occur simultaneously. The diagnosis of cerebral embolism is usually sufficiently clear without it, but its occurrence is an important corroborative, and almost demonstrative, proof of the nature of the cerebral lesion. Retinal, as cerebral, embolism is rather more frequent on the left than on the right side. Its common cause is, as already stated, cardiac disease, especially mitral stenosis. It has also been observed in atheroma of the aorta and in febrile diseases, pregnancy, and Bright 's disease, probably from the formation of a clot and its detachment. It may, therefore, occur at any age. A case at seventy-four years of age has been recently recorded lay Hirschberg. 1 The position of the obstruction may be in the trunk, or in one of the branches. In each case there is sudden and com- plete loss of sight, persistent when the obstruction is in the trunk and is permanent. 2 In rare cases the loss of sight is not instantaneous, but comes on in the course of a few minutes, commencing at the periphery. When the obstruction is in a branch, the loss of sight usually rapidly clears, except from that portion of the retina which is supplied by the occluded vessel. The arteries beyond the obstruction are deprived of their supply of blood, and contract, so that to the ophthalmoscope they appear as fine lines only (PI. XII. 2). They commonly, 1 "Arch, f. Augenheilkunde," vol. v., April, 1879, p. 166. 2 Should the retina be nourished in part by a cilio-retinal artery, embolism of the trunk of the central vessel will not cause complete loss of sight, since the retinal area corresponding to the distribution of the abnormal artery will retain its function. Such a case is recorded by Benson (" Ophth. Hosp. Rep.," vol. x., pt. iii., 1882, p. 336). CHANGES IN THE RETINAL VESSELS EMBOLISM. 35 however, retain their red colour, because the contraction does not obliterate their cavity, although reducing it almost to capillary dimensions, and there is still a narrow column of blood within them. Towards the periphery, however, they are so small as to be invisible. The delicate wall of the vessel is unrecognizable, except in the larger vessels, where, on account of its contracted state, it is more distinct than normal, and appears as a white line on each side, bound- ing the narrow, red column. When the obstruction is com- plete and no collateral circulation is established, the red column may disappear, and only a white line indicate the position of the empty vessel, which gradually becomes trans- formed into fibrous tissue (PL XII. 3). In this drawing the arterial branch which passes upwards and to the left is represented only by a branching white line, while one which passes vertically upwards, and is not quite empty, is bounded on each side by a white line. Sometimes detached columns or cylinders of blood are seen in the arteries and in the veins, moving onwards in pulsatile jerks. This is probably seen only when the obstruction is incomplete. The veins are narrowed, but less than the arteries. They are sometimes, but not always, broader towards the periphery than near the disc. The optic disc is paler than normal, and the pallor gra- dually increases. The retina undergoes very marked changes, consequent on the disturbance of its nutrition. It presents a greyish or white opacity, always most marked around the macula lutea (PI. XII. 2), and commonly also conspicuous around the disc. This opacity may come on in a few hours, but sometimes not for some days. The opacity usually stops short of the fovea centralis, leaving it of a bright red colour, so red that it was thought to be extravasation, but it is now generally believed that the tint is merely the effect of contrast with the adjacent pale opacity. The latter is believed to depend on oedema of the nerve-fibre layer, and the thinness or absence of that layer at the fovea centralis to be the cause of the usual freedom of that part from opacity (Liebreich). But occasionally the fovea may be as opaque as its vicinity, as in 36 MEDICAL OPHTHALMOSCOPY. PI. XII. 2. Here I found the opacity to depend 011 much graver structural alterations than are usually supposed to exist. Besides evidences of oedema, there was an infiltration of all the retinal layers with lymphoid cells, similar to those of the nuclear layers, so that the thickened vertical fibres were the only structural elements which could he dis- tinguished. The layer of rods and cones was destroyed, probably during life, in the region of the macula, because the pigment-epithelium was in contact with, and adherent to, the outer nuclear layer. In other places the thickened vertical fibres were widely separated. Haemorrhages are sometimes met with. The opacity com- monly disappears in the course of a few weeks, but may leave YIG. 4. EMBOLISM OF THE CENTRAL ARTERY OF THE RETINA (PL. XII. Longitudinal section through the artery, one-eighth of an inch (3 mm.) behind the eyeball. On each side the nerve-fibres are indicated, and between these and the vessel is much loose connective tissue. Within the contracted vessel is an oval granular mass, and in front of this is a .small round body ( x 300). CHANGES IN THE RETINAL VESSELS EMBOLISM. 3? white spots, due to foci of degeneration. The edges of the optic disc are usually hazy. In most cases the pallor per- sists and increases, and passes into the whiteness of atrophy, which, at last, resembles closely simple atrophy, except m the extremely small size of the vessels. The plug has in several cases been found after death, commonly just behind the bifurcation of the artery, in other cases in its course. In a case of embolism of the middle cerebral, and retinal artery, probably occurring simultaneously (figured in PI. XII. 2), the artery in the nerve contained an oval granular embolus (Fig. 4). Other smaller fragments were seen in the narrowed arteries, upon the disc. Very rarely the circulation gets re-established by the normal course. Columns of blood appear in the arteries, in part interrupted, and for a long time easily broken up by pressure. The arteries continue below normal size. Vision may be recovered, especially at the periphery, rarely at the centre. Commonly, however, obstruction remains complete The retinal artery is regarded as a "terminal" artery- i.e., one that has no anastomoses. In most cases verv little collateral circulation is set up : the arteries remain narrowed to lines as far as they can be traced. But they are visible in almost all cases as red, not as white, lines. Hence they must contain blood, persistent and therefore circulating, which has come from some slight collateral anastomoses, or from the obstruction being incomplete. Sometimes the arteries again become pervious although diminished in size. It is probable that this is due, in some cases, to the partial restoration of the channel of the artery, and in other cases to the establishment of considerable collateral circulation. In PL XII. 2, for instance, the arteries are filiform only upon the disc, and as far as they remain unbranched ; beyond this, they have nearly their normal size. A similar case has been recorded by Knapp. This points strongly to the establishment of a collateral circulation, probably by connection with the long ciliary arteries, although, in the researches of Leber, such connections could not, in the normal condition, be demonstrated. It is commonly supposed that the chief connection between the 38 MEDICAL OPHTHALMOSCOPY. retinal and ciliary vessels is by means of the vessels of the optic disc, but it is doubtful whether it is by this means that a collateral circulation takes place. The arteries are never filled in the neighbourhood of the disc, but at a distance from it. A collateral circulation in the disc may maintain the blood-supply needful to preserve the red colour of the filiform arteries, but certainly does not maintain the peripheral circulation in most of the cases in which this is re-established in a considerable degree. Probably, as Mauthner has suggested, there are, in different cases, very variable anastomoses. The re-establishment of the circulation a few hours after the obstruction, has been observed by Wood White and by Eales. 1 In each case recovery of sight occurred. It is probable that the clot either became broken up or so moved as to allow the blood to pass. In Wood White's case the event was apparently produced by pressure on the globe by the finger. The fact is of interest in connection with the occasional transient duration of the symptoms of cerebral embolism. In PL XII. 3 the vessel, which is still pervious, though narrowed, is bordered for a distance by the fine white line indicating the wall thickened by contraction. The blood column within it, narrow as it is, still presents a central reflec- tion, and towards the periphery the vessel again widens out exactly as in the other case, shown in Fig. 2 of the same plate. This broadening of the peripheral portion of the vessel nearly to its normal calibre indicates that blood enters it beyond the narrowed portion by some junction with other arteries. 2 1 " Ophth. Rev.," vol i., pp. 43 and 139. Mules also has recently recorded a case where plugging of a branch of a retinal artery disappeared, under mas- sage of the globe, about an hour after its occurrence. The visual field was restored forthwith, with the exception of a small area corresponding to the immediate neighbourhood of the embolus. ("Trans. Ophth. Soc.," vol. viii., 1888, p. 151). 8 It is greatly to be desired that, in any post-mortem examination of a case in which there has been embolism of the retinal artery, and in which such collateral circulation is established, a ligature should be placed around the artery, or around the optic nerve in front of the entrance of the artery, and the ophthalmic artery then injected, so as to discover the channels by which the circulation is established, and which elude observation under normal conditions. CHANGES IN THE RETINAL VESSELS EMBOLISM. 39 In partial embolism the segment of the retina, to which the occluded branch goes, becomes opaque, and is sometimes the seat of numerous haemorrhages. Both opacity and extrava- sations ultimately disappear. The corresponding portion of the optic disc may be normal, as in the case shown in the figure, or it may be atrophied. In one case on record it was hypersemic (De Weaker). The corresponding vein is at first distended, afterwards smaller than normal. Embolism of the trunk of the central artery commonly causes complete and persistent loss of sight. When the occlusion is of a single branch, there may be a complete initial loss of sight, due probably to the plug causing a temporary obstruction in the trunk of the artery before it passed on to the branch in which it was arrested. Occa- sionally, in such cases, the blindness has remained complete, although the ophthalmoscope afterwards demonstrated that only one branch of the artery was occluded. The general retinal anaemia may, in such cases, have been so prolonged that the nerve elements suffered a shock, damaging their nutrition beyond the power of recovery on the succeeding restoration of the circulation. Commonly, in such cases, the permanent loss PIG. 5. DTAGBAM OF RIGHT FIELD OF VISION IN PARTIAL EMBOLISM OF THE CENTRAL ARTERY OF THE RETINA. The descending branches of the central artery were normal, but those pro- ceeding upwards were empty. The shaded area indicates the portion of the field in which sight was lost. The asterisk indicates the position of the fixing point, the dot that of the blind spot. 40 MEDICAL OPHTHALMOSCOPY. is of a portion of the field corresponding to the distribution of the branch plugged. When this is one of two primary- divisions of the artery, the loss may amount to one-half of the field ; when of a smaller branch, to a quadrant, or the like. There was a loss of nearly one-half in the case figured in PI. XII. 2, in which one branch running upwards and outwards is completely obliterated, and others running up- wards and inwards are partially obliterated. The loss was that shown in the adjacent diagram of the field of vision (Fig. 5). Occasionally, sudden blindness has occurred, and-the retinal arteries have appeared narrow, recovering their normal size after a short time, with restoration of vision, as in the cases of "Wood White and Bales, discussed above. Arterial ischaemia, similar to that which results from embolism, has been ascribed to a retro-ocular haemorrhage around the artery compressing it. The ophthalmoscopic distinction of this from embolism is uncertain, and probably depends rather on the incompleteness of the ultimate obstruc- tion than on any differences in the early retinal appearances. It is said to occur in cases in which there is a general tendency to haemorrhage, and to be the precursor of cerebral extravasation. An interesting case, probably of this character, . is related by Hutchinson. 1 It is possible that some of the cases supposed to be of this character have been really cases of thrombosis in the central vein compressing the artery (see p. 30). THE OPTIC NERVE. The alterations in the optic nerve, as seen at its entrance into the eye, are among the changes in the fundus oculi of greatest importance to the physician. It may be well, before describing those changes, to consider some points, regarding its structure and appearance, a knowledge of which is essential for a correct understanding of the pathological changes. In the optic disc we have presented to view the termination of a nerve a structure consisting of nerve fibres, a little supporting connective tissue (especially abundant around the 1 "Ophth. Hosp. Rep.," October, 1874, p. 51. CHANGES IK THE OPTIC NERVE. 41 central vessels), and a number of blood-vessels, for the most part capillaries, which confer on the disc its tint. The nerve fibres radiate and spread out in the retina, but not equally on all sides, being few on the temporal side, towards the macula lutea, and numerous on the nasal side and especially above and below. The minute vessels of the disc are derived partly from the posterior ciliary (choroidal) arteries, and partly from the central retinal artery, twigs from both of which commonly unite in forming the " circle of Haller," a series of vessels which surround the optic nerve behind the disc. The con- nective tissue between the bundles of nerve fibres is small in quantity, but contains scattered nuclei. The opening in the sclerotic is funnel-shaped, the wider part being posterior. The termination of the nerve fits pretty closely into the inner, smaller, part of the opening, while the space between the nerve and its outer sheath, " vaginal space," passes up into the posterior part of the opening (Fig. 16). The separation of the optic nerve fibres to radiate into the retina leaves the central hollow known as the " physiological cup," the size and depth of which are determined by the arrangement of the nerve fibres. The vessels are chiefly developed among the nerve fibres and towards the surface of the disc, and hence the central cup is always much paler than the periphery. It is commonly white, but sometimes mottled grey from the reflection of the white trabeculse of the " lamina cribrosa," which closes in the sclerotic foramen, and through the meshes of which the greyer, now non- medullated, nerve fibres pass. The tint of the circum- ferential portion of the disc is, as already explained, deepest where the nerve fibres are most numerous, and hence the nasal half of the disc is naturally redder than the temporal half. The arrangement of the nerve fibres also causes the side of the central cup to be steep on the nasal and shallow on the temporal side, the difference being proportioned to the inequality with which the nerve fibres are distributed. When the fibres are almost all packed on the nasal side, the cup may be very large, and extend on the temporal side to the margin of the disc. Often, however, there is no paler central cup. 42 MEDICAL OPHTHALMOSCOPY. The boundary of the " disc," as commonly recognized, is the choroidal ring, i.e., the edge of the opening in the choroid corresponding to that in the sclerotic. The latter is usually the smaller of the two, and hence a narrow rim of sclerotic commonly appears within the choroidal edge, and is known as the "sclerotic ring." It is often visible only on one side. At the passage of the nerve fibres over the edge of the sclerotic, they curve a little above the level of the retina, and this slight prominence has suggested the name of " optic papilla" as a designation for the area of entrance of the optic nerve. The trunk of the optic nerve possesses a double sheath : the inner is delicate, closely invests the nerve, and is con- tinuous with the pia mater of the brain. The outer sheath is thicker and fibrous, blends in front with the sclerotic, and is continuous at the optic foramen with the dura mater. There is not, as was once thought, a reflection of the arachnoid at the optic foramen, and thus the vaginal space of the optic nerve i.e., that within the outer sheath is continuous with the subarachnoid and subdural spaces around the brain. This vaginal space is traversed by tracts of tissue connecting the two sheaths. At the anterior extremity of the nerve, the space passes within the posterior part of the sclerotic opening, and is, according to some authorities, closed ; but, according to others, it is continuous with lymphatic spaces in the substance of the optic nerve, and probably also in the retina. The optic nerve, at its entrance into the eye, undergoes certain pathological changes in common with the retina. When the retina is generally inflamed, and when it is atrophied, the optic "papilla" participates in the change. But it also undergoes inflammatory changes independently of the retina. The pathological conditions of the papilla resolve them- selves, from their clinical features, into two groups, in- creased vascularity, commonly with increased prominence ; diminished vascularity, commonly with shrinking. The states characterized by the former are more or less inflam- matory, and are often included under the generic term CHANGES IN THE OPTIC NERVE CONGESTION. 43 " optic neuritis." Those characterized by the latter signs are accompanied by wasting of the nerve tissues, and are included under the generic term " optic nerve atrophy." It must be remembered that the term " optic nerve " is employed in two senses to designate the whole nerve, and also its intra-ocular termination as seen with the ophthalmo- scope. To prevent the confusion arising from this double use of the words, it has been proposed by Leber to use the terms " optic nerve " and " optic neuritis " when speaking of the whole nerve, employing only the words " papilla " and " papillitis " to designate the intra-ocular termination of the nerve and its inflammation. This distinction has not, how- ever, come into general use in this country. The custom of employing the term "optic neuritis" as a designation for the intra-ocular inflammation, makes it inconvenient to restrict it to inflammation of the nerve trunk, but for the former condition the synonym " papillitis " is very useful. The characters of these morbid states may be thus tabu- lated : A. Morbid states of the optic nerve, characterized by in- creased vascularity or signs of inflammation. 1. Simple congestion of the disc; undue vascularity, redness, softening but no obscuration of the edge, and no swelling. 2. Congestion with oadema of the disc (slight neuritis or papillitis) ; increased redness, with slight swell- ing; obscuration of the edge of the disc, complete to the direct examination, incomplete to indirect examination. 3. Neuritis, or papillitis; increased redness and swell- ing, with obscuration of the edge of the disc, com- plete in degree, partial or total in extent. B. Diminished vascularity and signs of wasting. 1. Simple atrophy; increased pallor from the first; " primary atrophy." 2. Congestive atrophy ; secondary to congestion ; pallor slowly succeeding simple congestion. 44 MEDICAL OPHTHALMOSCOPY. 3. Neuritic atrophy, succeeding pronounced neuritis ; " consecutive atrophy," " papillitic atrophy." 4. Atrophy succeeding choroiditis and retinitis ; " cho- roiditic " and "retinitic atrophy." A.. MORBID STATES CHARACTERIZED BY INCREASED' VASCULARITY OF THE DISC, OFTEN WITH SIGNS OF 1NFLAMMA TION. SIMPLE CONGESTION. Increased redness is the universal expression of tissue hypereBmia. But it is of less value as a sign of hypersemia of the optic disc than in the case of most tissues, on account of the great variation in the amount of natural redness. Attention to tint of disc alone is a prolific source of error in ophthalmoscopy. It is as if a small portion in the centre of the cheek were examined to determine whether or not there was pathological hypersemia. Nevertheless, ahnormal redness of the disc does occur as a morbid state, and, although in itself a sign of little value, it derives importance from certain concomitant conditions. It is significant (a) when it possesses special characters to be immediately described ; (6) when developed under observation ; and (c) when it is notably greater in one eye than in the other : but even in the latter case there is room for error in the possibility of a natural difference, or that the paler eye may present an abnormal decrease in redness. There are certain characters which aid very much in the recognition of the pathological increased vascularity. First, morbid redness has usually a tendency to invade the physio- logical cup, and often, especially when the cup is small and shallow, to obscure it altogether. Secondly, pathological redness has a tendency to render the sclerotic ring or the edge of the choroid indistinct ; to blur the sharpness of the outline of the disc. The change, when very slight, may be best appreciated by examination with the indirect image (PL I. 1). It is due to the circumstance that the seat of the vascularity is the layer of nerve fibres, and it may extend in CHANGES IN THE OPTIC NERVE CONGESTION. 45 front of the edge of the disc ; and it is often attended with a little swelling of the nerve fibres or effusion of fluid, which conceal the structures beyond. The term " congestion "is, I think, best restricted to those cases in which the increased vascularity exists alone, with so little structural change, that the edge of the disc can still be perceived by both methods of examination, although not so sharp as natural. The redness is different from the ordinary tint of the discs. It is brighter, softer, somewhat velvety in aspect, sometimes finely stippled. Occasionally, however, the tint of a disc thus changed may be positively paler than normal, although the uniformity of the colour, and the softened edge, afford evidence of the pathological character of the change on which it depends. This paler tint is often seen when the condition is passing into atrophy. The retinal vessels are usually unchanged ; their walls are often con- spicuous, by contrast with the redness of the disc, as white lines bounding the blood column, and any white connective tissue which surrounds them at the point of emergence is also unduly conspicuous (PI. I. 2). The appearance is suggestive of the white tissue being a pathological result of the hyper- semia. It is probable that it is so, but the appearance is too common as a physiological condition to have much value. Its distinctness possesses a little significance, as due to the invasion of the middle of the disc by the hypersemia. Occasionally, when the hypersemia of the disc is the expres- sion of graver changes behind the eye, the arteries may be narrowed in consequence of retro-ocular pressure. The condition thus described as " simple congestion " of the disc is usually a chronic state, and corresponds, pro- bably, to the condition which has been called by Clifford Allbutt "chronic neuritis." The evidence that there is actual inflammation does not seem sufficient to warrant the application to this state of the term " neuritis," especially as there are forms of true neuritis characterized by extreme chronicity. It is rare, I think, that such simple hypersemia is the first stage of an actual neuritis. In the latter, swelling comes on part passu with the hypersemia i.e., congestion 46 MEDICAL OPHTHALMOSCOPY. with oedema, rather than simple congestion, is the first stage of neuritis. The simple congestion is occasionally seen as a substantive condition, and ma}', in rare cases, precede atrophy. The condition may be the expression of a state of congestion and degeneration in the whole optic nerve, or be apparently limited to the optic disc. It is not unusual in cases of hypermetropia. It may occur as a consequence of injuries, blows, &c., in the neighbourhood of the eye. The affection of sight which results from the use of tobacco may be attended with this state. It occurs also, probably, from other toxic agents, as lead. It has been observed by Clifford Allbutt in general paralysis of the insane; and, although some other observers have failed to find it, one case under my observation presented it very distinctly. It has also been described by the same writer as accompanying atrophy in locomotor ataxy ; but in that disease, although often looked for, it has not been found by others or by myself. It is sometimes present in cases in which there is reason to believe a similar condition exists in the brain. The figures PL I. 1 and 2 are from a patient with cerebral embolism, in whom the condition came on in association with secondary brain irritation mental failure and rapid wasting in the paralyzed limbs. I have seen a similar appearance in acute mania. Microscopical examinations of the disc in this state are rare. Clifford Allbutt examined one case and found only distension of the minute vessels with that granular degenera- tion of the nerve fibres present in all forms of atrophy. OPTIC NEURITIS OR PAPILLITIS. CONGESTION WITH (EDEMA (PI. I. 3 and 4) is really the first stage of papillitis. The normal rosy tint of the disc becomes increased ; its edge is blurred, but is recognizable on indirect examination. There is a pale reflection from the adjacent retina, surrounding the disc with an indistinct halo (Plate I. 3). On examining the disc by the direct method, the morbid appearance is much more marked (Plate I. 4). The edge of the disc is lost, and the opacity is seen to be in part the result of an undue distinctness of the CHANGES IN THE OPTIC NERVE NEURITIS. 47 radiating striation of the nerve fibres as they course on to the retina. It must be remembered that this striation is often visible as a normal condition, especially above and below. Where the aggregation of the fibres is very close, the central cup being of large size, the appearance of commencing oedema may be closely simulated. In the latter condition, however, there is from the first more or less invasion of the central cup, which soon becomes obscured. The increased vascularity of the disc may be striated at the periphery. There is often distinct swelling. The centre of the papilla may be, as in the figures referred to, much redder than the periphery, on account of the slighter central swelling allowing the vascularity of the disc to be perceived. . In the periphery the tint of the choroid is concealed. The retinal vessels may be normal, or the veins may be enlarged. It is important to note that the direct examination renders these changes more distinct. If the obscuration of the edge of the disc is apparent only, in consequence of the similarity in tint of the disc and the adjacent choroid, the edge of the disc is more distinct on direct than on indirect examination. When the indistinctness of the edge is due to the opacity of the structures in front of it (except in the very slightest form), the edge is less distinct on direct than on indirect examination. This is no doubt due mainly to the fact that the illumination is stronger and the plane of focus is less exact in the indirect method, so that the choroidal edge and the tissue in front of it are in view at the same time ; whereas the direct method of examination, by its higher magnification and more exact focussing, shows the tissues in front of the edge so as to increase the concealment of the latter. This fact will often be found of service in distinguish- ing between a normal redness and an abnormal obscuration of the disc. Of course, it will not distinguish the latter from the cases just mentioned, in which there is a slight physio- logical obscuration of the edge by nerve fibres. This condition of oedema is usually an acute affection, and is commonly the first stage of neuritis. It is said to be an effect of pressure on the retinal vein, causing passive conges- 48 MEDICAL OPHTHALMOSCOPY. tion of the retinal vessels, and it has been described as the result of the general passive congestion of heart disease. In these cases it may be associated with retinal haemorrhages. It may, however, occur as the first stage of neuritis without the least sign of mechanical congestion. In the case figured, there was probably a syphilitic intra-cranial node or growth. NEURITIS (PAPiLLiTis). 1 From congestion with oedema to actual inflammation the transition is one of degree. It seems better to restrict the term neuritis, or papillitis, to those cases in which the swelling and opacity are sufficient to conceal the edge of the disc both on direct and indirect examination. This condition is found in most cases to result not merely from vascular congestion and oedema, but from changes in the nerve fibres and connective tissue, such as we regard as evidences of inflammation. The change may completely veil the whole or only half the disc ; and from such a slight degree of neuritis to the most intense form we may have every gradation, characterized by very considerable differences in appearance. These variations in the appearance of the disc in different cases, and supposed differences in their origin, have led to the establishment of two varieties of the affection, " descend- ing neuritis," and the " choked disc," " Stauungs-papille." The grounds on which these divisions have been made are, as will be shown, uncertain, and it is better in the first place to consider the common features which all forms of papillitis possess. The supposed varieties and theories of this origin will be then better understood. A case of optic papillitis of considerable intensity presents, in the course of its development, certain stages, the general features of which are usually recognizable. The transition from one to the other is, of course, a gradual one, and cases are seen which present appearances intermediate between the several stages. Moreover, at any stage, the morbid process may stop, remain stationary for a time, and then recede. This may occur spontaneously or as the result of treatment. 1 Plates I. 5, 6, II. 1, III., IV., V., VI., VII. CHANGES IN THE OPTIC NERVE NEURITIS. 49 Thus certain forms of neuritis maybe distinguished according to the intensity of the changes, but our knowledge of the conditions on which they depend seems insufficient at present to distinguish them as varieties otherwise than as varieties of intensity, on whatever differences of mechanism they may ultimately be proved to depend. The first stage of optic neuritis is that which has been already described as " congestion with oedema " a condition of increased redness, swelling, and cloudiness, masking the edge of the disc to direct, but leaving it perceptible to indirect,* examination. In this condition the microscope reveals no sign of tissue inflammation. The second stage, that of actual, but slight, neuritis, is characterized by the disappearance of the edge of the disc even to indirect examination (PL I. 5). The transition from the disc to the retina is gradual, the edge is " blurred," and its position has to be guessed at. When this is the case, the disc always, I believe, presents not only oedema but also changes in its tissue elements which indicate a process of inflammation proliferation of nuclei, escape of leucocytes, and degeneration of nerve structures changes similar to those which are regarded in all organs as indicative of inflammation. The red tint of the disc becomes more marked, so that it may be almost the same as that of the adjacent choroid, or it assumes a reddish grey tint, which is very characteristic, and the disc loses its normal semi-translucent appearance. The swelling increases, and is easily recognized, even on indirect examination, by the relative displacement of different parts on lateral or vertical movement of the lens. The striation of the periphery, perceptible in the first stage, increases, but becomes redder. It is due not only to the swelling and opacity of the nerve fibres, but also to the minute vessels which course between them. In the centre of the disc the redness is stippled or uniform, not striated, and the centre is commonly distinctly darker red than the peri- pheral portion (PI. I. 6). The centre may be red, and the periphery greyish red. The striated edge passes, by grada- tion, into the tint of the adjacent fundus. The physiological 50 MEDICAL OPHTHALMOSCOPY. cup often disappears during the stage of oedema ; if large, a trace of it may remain to the stage of commencing neuritis, hut is rapidly encroached upon and covered in hy the swell- ing of the papilla (see PI. III. 2, in which it has almost disappeared) . White lines and spots are not uncommon, especially in the cases in which the changes remain of slight degree. They often correspond to the position of arteries (PL III. 3). The swelling and obscuration may involve all parts of the 'disc equally, especially in the more acute forms of neuritis, or it may be much more marked on the nasal than on the temporal side of the disc. The difference may be so great that the position of the edge of the disc may be distinct on the temporal side, while the nasal edge is completely obscured by opaque tissue a condition which may for brevity be termed " hemi-neuritis " (PI. Y. 1, 2, 4). Haemorrhages are not uncommon in this stage, sometimes on the surface of the swelling, or even on the least changed part of the disc (PI. V. 1) or just beyond its edge (PI. V. 4). They are always small. The arteries usually present little change in the slighter stage of neuritis, although often recognized with difficulty on account of the colour of their blood corresponding to the tint of the disc. They are a little concealed at their emergence, but have a nearly straight course. Arterial pulsation has been observed by Graefe 1 and Becker. 2 The veins lose their central reflection as they pass down the sides of the swelling, and appear dark. They may or may not present dilatation, indicative of mechanical congestion. In the early stage of papillitis from tumour, as a rule, they less frequently present dilata- tion than in that from meningitis. As the papillitis goes on, the swelling increases, and becomes often so great, that there may be a difficulty in seeing the surface of the swelling by the direct method without the use of a convex lens. The veins, as they curve down the sides of the swelling, appear still darker and 1 "Arch. f. Ophth.," xi. pt. 1, 201, and xii. pt. 2, 131. J "Wien. Med. Wochenschrift," 1873, p. 34. CHANGES IN THE OPTIC NERVE NEURITIS. 51 foreshortened, and are concealed, just beyond its edge, in the adjacent retina (PL III. 4, IV. 1, V. 6). The veins commonly now present some enlargement, often considerable, and the arteries are narrowed. They may be indistinct upon the disc, being concealed by the tissue. The arteries are always more concealed than the veins. The vessels are often lost to view at the centre of the swelling (PL I. 6, IV. 3, V. 5), although there may be a depression where they emerge. This central depression is sometimes large, in con- sequence of the neuritic swelling being chiefly located on the edge of the disc (PL VII. 1) a condition which has been distinguished as " perineuritis." The swelling increases, not only in height but in lateral extent, and partly displaces, partly invades, the adjacent part of the retina, often having a diameter two or three times that of the optic disc. There are, however, rarely signs of any general disturbance of the retina. Extravasations of blood may occur on the surface of the swelling, and not uncommonly white, flake-like spots may appear upon it, often concealing the vessels (PL III. 3, IV. 1, VI. 2). Occasionally a white spot is surrounded by a halo of haemorrhage (PL VI. 2). Sometimes similar spots exist in the retina close to the edge of the disc. A large number of cases proceed no farther than this stage. Signs of passive congestion of the veins may or may not be present. If not present before, they may be developed during the subsidence of the neuritis, especially if quick absorption of the inflammatory products cannot be obtained. Neuritis of this stage may clear completely (PL IV.), the inflammatory products being for the most part removed, and those which remain merely causing a little increase of tissue in the middle of the disc. The subsidence is marked by a diminution in the height and extent of swelling, and in its redness. At first it may appear somewhat more opaque (PL VI. 3), but becomes less so as the swelling subsides. The position of the edge of the choroid becomes appreciable, and gradually clearer, first on the temporal, and then on the nasal side. The disc has a " filled in " aspect (PL VI. 5), and both arteries and veins may be narrowed and partly 52 MEDICAL OPHTHALMOSCOPY. concealed on its surface. This is especially the case when the new tissue-elements in the disc have been sufficiently abundant to develop signs of strangulation during the in- flammatory stage (PL VI. 1 and VIII. 1). When this is not the case, as in PL III. 5 and 6, IV. 1 and 2, the disc may rapidly clear in the centre, as well as in the periphery, and the physiological cup be quickly reproduced. Often, however, white lines along the vessels indicate the remnants of preceding inflammation (PL IV. 2, II. 4), and the vessels may be a little narrowed. Commonly, when the inflamma- tory swelling has been marked, a disturbance of the pigment- epithelium leads to a narrow zone of atrophy adjacent to the disc (PL II. 4, IV. 4). Whether or not there are signs of mechanical congestion in the stage of neuritis just described, a further increase in the inflammation is invariably accompanied with signs of com- pression of the vessels, and strangulation of the inflamed papilla, with a rapid and intense increase in the mischief. The tumour formed by the swollen papilla becomes much more promiment, and extends laterally in all directions, even as far on the temporal side as the macula lutea. The form of the swelling varies ; sometimes it remains conical, but usually the sides become steeper, and the top more or less flattened. The sides may even overhang so that the tumour has a fungiform shape, and the vessels, as they pass over the side, may be concealed by the edge of the SAvelling, and reappear in the fund us in a different position. Good examples of this intense strangulated neuritis are represented on the next page (Figs. 6 and 7, and at PL VI. 1). The arteries are much narrowed, and often altogether invisible on the swelling, being buried in its substance, and appearing first in the retina, a little distance from its edge. The veins are often concealed on the disc, at least in part, but some of them are usually visible towards the edge of the swelling, and are greatly distended. When the amount of swelling is extreme, all the vessels may be concealed, as in PL VI. 1. Haemorrhages are frequent and extensive, and are commonly situated on the edge rather than on the CHANGES IN THE OPTIC NERVE NEURITIS. 53 surface of the swelling (PI. VI. 1 and VIII. 1). The over- hanging edge may be infiltrated with blood. The veins may FIG. 6. ACUTE OPTIC NEURITIS IN A CASE OF CEREBRAL TUMOUR. * There are great swelling of the disc, which is surrounded by radiating haemorrhages, and, at the macula, a star-like arrangement of white spots. . No albuminuria, and no history of syphilis. FIG. 7. ACUTE OPTIC NEURITIS. The veins and arteries are both concealed by the swelling. The veins are distended, while the arteries are narrowed. Numerous white patches are scattered over the swollen papilla. 1 After Edmunds, "Trans. Ophth. Soc.," 1884, p. 291. 54 MEDICAL OPHTHALMOSCOPY. be concealed beyond the edge of the swelling, and often present many curves and twists, sometimes corkscrew-like from their elongation. The tint of the strangled swelling is usually a full red, mottled and streaked from enlarged vessels and small extravasations. The striation due to the nerve fibres is commonly lost. The retina adjacent is often the seat of haemorrhages, which may extend along the vessels from the disc. Not unfrequently secondary changes occur in the retina over a wide extent. Haemorrhages, usually striated and situated in the nerve-fibre layer, may be scattered over the whole fundus (PI. VI. 1). The veins are often distended, and may be tortuous for a long distance from the disc. The ultimate distension of the veins may be as great in the papillitis which succeeds a descending neuritis (see Pigs. 18, 23, &c.) as in that which is supposed to be limited to the eye. The retina, in rare cases, presents areas of opacity, diffuse and cloudy, or localized and white, and often occur- ring along the course of the vessels (PL VIII. 1). When the swelling of the retina is very intense it may become thrown into folds. On examining such an eye, bright streaks will be seen running in different directions, frequently arranged radially around the macula, probably due to the reflection of the light from the summit of the folds. The time taken for the development of these changes varies within wide limits. A neuritis may remain for months and even years in the slighter degree, or most intense strangula- tion may be developed in a few weeks. Subsidence of Neuritis. The gradual subsidence of the slighter degrees of neuritis has been already traced. In the more intense forms, in which strangulation has occurred, -the stage of subsidence presents certain peculiar features. The venous distension gradually lessens after the strangulation has existed for a time, and the veins may become narrow before other signs of strangulation subside. In PL VI. 1 they are much smaller than in the earlier stage of strangulation shown in PL VIII. 1. This is probably because the compression of the arteries becomes sufficient to lessen the blood-supply to such an extent as to permit the veins to recover nearly their CHANGES IN THE OPTIC NERVE NEURITIS. 55 normal calibre. When the strangulation is less intense, the oommencement of subsidence may be attended with an increase in the mechanical distension of the veins, and increased narrowing of the arteries. The redness of the swelling lessens, haemorrhages, as a rule, cease to occur, 1 and some of the blood already extravasated disappears. The tumour lessens in height and in extent, and, if fungiform, again becomes conical (PL VI. 3). The highest portions of the swelling gradually become pale ; the sloping sides and adjacent part of the retina may present a darkish dis- -coloration, into which the central pallor passes gradually (PL II. 1, IV. 5, V. 6, VI. 3). The centre of the .swelling soon presents a distinct depression, from which the vessels emerge often concealed by whitish tissue. Over the swelling the course of the veins becomes more distinct. The arteries may be still concealed, their more rigid, straight course having caused them to be buried in the new tissue more deeply than the veins, which were pushed up before it, and the paler tint of the arteries also renders them less con- spicuous. The concealment of the veins beyond the edge of the disc is even greater than it was before, in consequence of the curve of the inelastic vessels into the retina being increased :as the swelling subsides (PL VI. 4 and 5). Slowly the pallor increases and the swelling lessens, although the con- striction of the vessels may increase, in consequence of the cicatricial contraction of the newly-formed tissue. Occasion- ally, when large vessels appear on the papilla during the neuritis, these become tortuous, and gradually disappear during subsidence (PL IV. 5). As the white area narrows to near the limits of the disc, the edge of the choroid and sclerotic appear, dim'ly at first (PL VI. 4, left edge), then more distinctly. The disc has a white " filled-in " look (PL VI. 5, VIII. 2), the vessels are constricted, and it is very long before any central depression is developed on the disc, although ultimately the contraction of the fibrous tissue, as in other cicatrices, proceeds to an extreme degree, and the 1 Very rarely fresh haemorrhages form adjacent to the papilla during the : stage of subsidence, as in PI. VI. 4. 56 MEDICAL OPHTHALMOSCOPY. disc may again become hollow (PI. IV. 6). The lamina cribrosa is, however, usually permanently veiled, an important characteristic of this form of atrophy. The retinal pigment and choroid are frequently disturbed near the disc, and a zone of irregular pigmentation with slight choroidal atrophy is left, causing the disc to have irregular edges, but this zone- is not always proportioned to the amount of inflammatory disturbance, and if slight the disc may ultimately come to have a clean-cut edge. At first the disc is usually very white, rarely grey, with white lines along the vessels (PL II. 2, upper half). When it has reached the retinal level, however, although it may appear white to the indirect image, a faint grey tint is usually perceptible on direct examination, and as the contraction increases this grey tint becomes more marked, and the ultimate appearance of the disc is usually distinctly grey to direct examination, although often white to indirect examination. Very rarely the inflammation may subside irregularly, clearing from one part of the disc, while the other still presents the characters of neuritis (PI. II. 2). The retina undergoes certain changes during this period of subsidence. Haemorrhages upon it are usually soon absorbed, but sometimes undergo transformation into spots of pigment. Some extravasations lead to the formation of white spots in the retina. This is especially the case near the disc, where the nutrition of the retina is always a good deal disturbed by the adjacent inflammation. These white spots, which depend on fatty degeneration, either of fibrin or of the retinal elements, and persist after the blood has been removed, commonly originate close to the borders of the neuritic swelling ; but as the latter subsides and contracts, they are left behind, and are often one or two discs' breadth from the edge of the sclerotic ring, and they may then puzzle the observer from their resemblance in character and position to the spots of albuminuric retinitis. A group of such spots, mid- way between the disc and macula lutea, is seen in PI. VI. -3. The degenerative changes which occur when the inflammation is very intense, and of wide extent, may leave an appearance CHANGES IN THE OPTIC NERVE NEURITIS. 57 strikingly similar to that of the albuminuric affection. If the swelling approaches the macula, degeneration occurs among the radiating fibres of the fovea ceutralis, causing spots identical in appearance, and probably in nature, with those which in renal disease form the familiar stellate figure around the macula. A striking instance of this is shown in PI. VIII. 2. The distinction, as will be subsequently explained, consists mainly in the evidence the disc affords of a consider- able antecedent neuritis. Frequently, as the retina becomes atrophied, slight pigmentary deposit takes place in it, espe- cially around the macula lutea, and sometimes the atrophy is accompanied by wide-spread slight disturbance of the pigment-epithelium . When a neuritis has lasted a long time, and the veins have been persistently stretched over the swelling, they may be so permanently elongated that the subsidence of the neuritis, instead of being attended with a diminution in their tortuosity, is accompanied by an increase in their curves. This is shown in PI. VL 4 and 5, in which also a very rare circumstance is presented the occurrence of recent extensive hemorrhages during the stage of subsidence. Second Attacks of Neuritis. If a disc has become com- pletely atrophied it is very rarely again the seat of inflam- mation. In one case, however, of a boy aged twelve (under the care of Dr. Hughlings-Jackson), who had double optic atrophy, and absolute blindness due to intra-cranial disease some years previously, distinct double papillitis occurred in the atrophied discs, associated with symptoms of intra-cranial tumour. When, however, atrophy is partial or absent, in rare *cases two attacks of neuritis may occur. In one case, for instance, a patient suffered without doubt from a cerebral tubercle, and died from an attack of tubercular meningitis. The former had probably become quiescent, and the neuritis which it caused subsided, leaving partial atrophy. The discs again became swollen and obscured with the symptoms of meningitis. PATHOLOGICAL ANATOMY. In the condition described as MEDICAL OPHTHAJJ1OSCOPY. " congestion with oedema," the microscope reveals less pro- minence than was observed during life, because the swelling FIG. 8. OPTIC NEURITIS ; NERVE-FIBKE LAYER. The fibres are separated by numerous round and oval spaces, due to cedema. The nuclei are unduly numerous, and lie in groups, which indicate the fasciculi, (x 150.) FIG. 9. SECTION THROUGH THE OUTER PART OF AN INFLAMED PAPILLA. (a) Pigment-epithelium, (b) Layer of rods and cones, (c, d) The nuclear layer, (e) The inner molecular layer. (/) Ganglionic cell layer, (g) The greatly swollen nerve-fibre layer, containing many leucocytes, many of them surrounding the vessels, (x 150.) CHANGES IX THE OPTIC NERVE NEURITIS. 59 depended on distended vessels and effused serum. The nerve fibres are separable with abnormal readiness, and are divided by spaces which during life were occupied by serum (Fig. 8). The fibres themselves may present slight varicosity. There is no increase in the connective- tissue elements, and there are no products of degeneration of the nerve fibres. The retina is normal to the edge of the ohoroid, its nerve-fibre layer being alone increased in thick- ness by the conditions mentioned as causing the swelling of the papilla. Sometimes the retinal layers may be displaced outwards a short distance. In the stage of developed neuritis (Figs. 16 21, &c.), the microscope reveals a considerable swelling of the papilla, often two or three millimetres above the level of the FIG. 10. SECTION THROUGH AN ARTERY AND VEIN IN THE SAME PAPILLA. (a) Distended vein ; (b) contracted artery with thick walls. FIG. 11. OPTIC NEURITIS; COL- LECTION OF LEUCOCYTES IN A PERIVASCULAR SPACE, (x 150.) FIG. 12. SECTION THROUGH AN INFLAMED PAPILLA. The vessels are distended with corpuscles, and several of them surrounded by leucocytes. The nerve fibres, separated by oedema-spaces, course upward and to the left, and at right angles to them are seen some fine connective-tissue (supporting) fibres. ( x 120.) 60 MEDICAL OPHTHALMOSCOPY. choroid. There is usually a central depression, which may be larger and deeper than the ophthalmoscopic examination sug- gested. The swelling may be very distinct to naked-eye exa- mination (Figs. 27, 28, p. 65), and haemorrhages may be seen upon it. Thus, mere inspection of the fundus after removal may show the previous existence of papillitis. The swelling is due to several conditions, the relative degree of which varies much in different cases : (1) The vessels, large and small, are distended with blood (Fig. 12). (2) Spaces between the nerve fibres sometimes indicate the persistence of oedema (Fig. 8). (3) Many nuclei are seen, some of which are leucocyte-like corpuscles, most abundant around the vessels, which may be encrusted by a thick layer (Figs. 9/r, 11, 12, &c.); they are sometimes grouped into dense masses FIG. 13. GRANULE-CORPUSCLES, &c. From the substance of the papilla in a case of optic neuritis. (Glycerine preparation; x 100.) FIG. 14. VARICOSE NERVE FIBRES From an inflamed papilla in a case of tubercular meningitis. ( x 200.] FIG. 15. DEGENERATION OF NERVE FIBRES. From the substance of an inflamed papilla in a case of tumour of the lower part of right middle cerebral lobe. Highly magnified. (After Pagen- stecher and Genth.) CHANGES IX THE OPTIC NERVE NEURITIS. 61 {Figs. 9 and 17). Similar corpuscles lie in greatly increased numbers between the bundles of nerve fibres. Some of these are nuclei belonging to a system of connective-tissue fibres which run at right angles to the nerve fibres (indicated in Figs. 8 and 11). These fibres may be themselves swollen. (4) The nerve fibres present changes, which contribute, in varying degree, to the production of the swelling. They are irregularly thickened, and the enlarge- ments may be varicose, moniliform, or knob-like (Fig. 14), often containing granules or fatty globules from degenera- tion of the myelin. The swellings may attain a large size, as in the accompanying figure (Fig. 15). Free aggregations of fatty globules and granules may also be found, commonly enclosed in a cell wall (" granule-cor- puscles ") (Fig. 13) ; they may assume a colloidal appear- ance ("corpora amylacea "). Many of these are simply OPTIC NEURITIS IN A CASE OF CEREBRAL TUMOUR. FIG. 16. Section through the centre of the papilla, showing the swelling of the outer part and a cential depression, almost to the choroidal level. The nerve fibres can still be traced, separated by leucocytes. The same infiltration is to be seen in the nerve. The sheatk is not distended, but its lining membrane is infiltrated with leucocytes. FIG. 17 The same papilla near the edge. On the left the deeper layers of the^retiua are seen thrown into folds. (See p. 64.) 62 MEDICAL OPHTHALMOSCOPY. the detached degeneration-swellings of the nerve fibres. They are best seen in glycerine preparations. These products of degeneration give rise, by their aggregation, to the larger white spots seen with the ophthalmoscope. (See Fig. 7.) Other spots are apparently due to aggrega- tions of leucocytes. The vessels may have their walls thickened by nucleated tissue, and sometimes by a clear, finely fibrillated substance (Fig. 22). The vessels do not usually present any evidence of compression in the sclerotic ring, but commonly appear to be narrowed, often considerably, in the thickest part of the swelling, and the veins are again enlarged as they pass down the sides. The veins are usually very large, the arteries narrow. The former, after curving down the sides of FIG. 18. SECTION OF THE PAPILLA IN A CASE OF CEREBRAL TUMOUR. There is considerable swelling, greater on one side. The commencement of the retina is displaced some distance from the edge of the sclerotic ring. Infiltration of leucocytes in the papilla and nerve-sheath , but the latter not distended. ( x 20.) FIG. 19. SECTION THROUGH THE MIDDLE OF THE SAME Disc. The central depression remains, although much narrowed. The central vein is seen divided longitudinally. Neither in the sclerotic ring nor behind it does the vein present any trace of compression, (x 8.) CHANGES IX THE OPTIC NERVE NEURITIS. 63 the swelling, descend into the substance of the swollen retina, even into the nuclear layers, and rise again into the layer of the nerve fibres. Sometimes two such curves may exist (Fig. 23). The retina is displaced from the edge of the choroid, often as far as a millimetre from the sclerotic ring. Its layers at the commencement usually present considerable change. The nerve-fibre layer is thickened by a slighter degree of the changes which cause the swelling of the disc. The nuclear layers are increased in thickness and often blended together, and the nuclei more or less separated and grouped FIG. 21. FIG*. 20 AND 21. SECTIONS THROUGH THE PAPILLA iy A CASE OF OPTIC NEURITIS DUE TO CHRpxic CEUEBUITIS. (Case published by Dr. H. Jackson in " Ophth. Hosp. Rep.," vol. viii. p. 445. ) The papilla is slightly swollen, and has displaced the retinal layers. In Fig. 20 a vein is seen becoming compressed in passing through the inflamed retina, but it will be noted that in Fig. 21 there is no sign of compression, as the central nerve passes through the sclerotic ring. ( x 15.) See also chapter on " Softening of the Brain." Fie. 22. PART OF A SECTION OF AX INFLAMED PAPILLA IN A CASE OF OPTIC NEURITIS. An artery (below) and a vein (above) exhibit thickening and fibrillation of their outer coats. Below is a small vessel showing similar changes. The surrounding tissue is infiltrated with leucocytes. ( x 100.) 64 MEDICAL OPHTHALMOSCOPY. into vertical columns by the displaced fibres of Muller (Fig. 9). The retina may present (as here) slight curves due to its displacement, most marked in its outer (deepest) layers, and effecting detachment of the retina, the space between the bacillary layer and choroid being occupied by serum. These curves may be visible with the ophthalmoscope as pale bands, parallel to the edge of the papilla (PI. VII. 1). Fio. 23. SECTION THROUGH THE SWOLLEN PAPILLA IN A CASE OF OLP CHRONIC MENINGITIS, WITH INFLAMMATORY GROWTHS IN THE CONVEXITY OF THE BRAIN. (See PI. VI. 2 and Fig. 33.) At the edge of the swelling a large vein forms two vertical curves iu the substance of the thickened retina, the lower curve reaching the inner nuclear layer. The retinal layers are displaced. On the right side the pigment-epithelium has disappeared in the portion from which the retina has been pushed away ; on the left side the epithelium persists in this situation, (x 15.) FIG. 24. SECTION THROUGH THE RETINA, Some distance from the disc in the same case. The vein occupies two-thirds of the thickness of the retina, and in one or two places has encroached on the nuclear layers. ( x 50. ) FIG. 25. SECTION THROUGH A HEALTHY OPTIC NERVE. For comparison with the subsequent figures. CHANGES IN THE OPTIC NERVE NEURITIS. 65 The pigment-epithelium may persist up to the edge of the sclerotic, or it may disappear in the area from which the retina has been displaced (Fig. 23). Often the choroid undergoes atrophy close to the. edge of the sclerotic. The changes in the papilla always become much slighter at the sclerotic ring, and may appear to cease there. Commonly, however, large numbers of nuclei lie among the nerve bundles in and just behind the lamina cribrosa, where such nuclei are in health most abundant. The sclerotic ling may appear distended, the nerve tissue occupying closely its funnel-shaped area. The appearance of distension is partly, if not entirely, FIG. 26. TRANSVERSE SECTION THROUGH THE OPTIC NERVE HALF AN INCH BEHIND THE EYE. In a case of early optic neuritis. Thickening and infiltration of sheath. Very little change at present in the nerve. ( x 150.) FIG. 27. FIG. 28. POSTERIOR SEGMENT OF EYEBALL AND OPTIC NERVE. From a case of chronic traumatic meningitis, showing the distension of the sheath of the nerve and the swelling of the papilla. (Natural size, after Pagenstecher and Genth.) F 66 M fc'-DICAL OPHTHALMOSCOPY. due to the shape of the ring, as may be seen by comparing Fig. 17 with Fig. 23. In the latter the appearance of excavation of the edge of the sclerotic is present on the right side only, and an interval exists between it and the nerve fibres, occupied only by the fibres of the lamina cribrosa. The sheath of the optic nerve is often distended with fluid, sometimes slightly, sometimes considerably. The dis- tension is greatest a short distance behind the eye, and narrows close to the sclerotic, having thus a pyriform shape (Fig. 27). In cases of old neuritis the sheath may be enlarged but empty, showing previous distension. Micro- scopically the nerve may appear normal, the nuclear increase near the lamina cribrosa being absent farther back. More commonly signs of inflammation may be traced throughout the nerve ; the nuclei are increased in quantity, its trabeculae thickened and the vessels distended (Figs. 29 and 30). The inner sheath is often crammed with nuclei, and the connective tissue between the inner and outer sheath increased (Fig. 26). The nerve fibres may present evi- dence of degeneration (Figs. 29 and 30). These changes, slight or considerable, may often be traced back as far as the chiasma, in front of which they are sometimes much ' ^^^ Fiu. 29. SECTION THROUGH THE OPTIC NERVE, JUST BEHIND THE SCLEROTIC. FIG. 47. FIG. 48. SECTIONS THROUGH THE OPTIC NERA-E IN A CASE OF CHRONIC CEREBRITIS ( x 100). FIG. 47. Just behind the globe, containing many leucocytes within the fasciculi. FIG. 48. Just in front of the commissure. There is more infiltration with leucocytes, and the connective tissue septa are more thickened and irregular. CHANGES IN THE OPTIC NERVE NEURITIS. - 5 (Fig. 45). In front of the optic commissure (Fig. 46) the changes from old inflammation were intense. No sign of adjacent meningitis was noted at the post-mortem examination, but there were old adhesions over the tumour on the upper part of the frontal lobe. In this case it seems probable that descending neuritis had taken place, and that the link between the intense neuritis behind, and the intense papillitis in front, was the slight change in the trunk of the nerve. Hence it seems that a very slight amount of descending change may lead, in cerebral tumour, to an intense papillitis. With this case may be compared another, of a man who was in the London Hospital under the care of Dr. Hughlings-Jackson, in which the appearance of the papilla was declared by an authority so decisive as that of Mr. Gouper to be that of a " choked disc." No tumour, meningitis, or mechanism for " choking " was, however, discovered within the cranium. But the trunk of the nerve presented changes very similar to those in the case just mentioned, not, however, more intense at its posterior portion. Similar changes were found throughout the brain by Dr. Sutton, and it can hardly be doubted, taking the symptoms and anatomical changes together, that a condition, which must be regarded as " chronic irritation or inflamma- tion " affecting the brain, had passed down the optic nerves and appeared as an intense papillitis, with signs of strangu- lation, due to the compression of the vessels within the papilla. A similar case has been recorded by Stephen Mackenzie. 1 It seems from these facts that (1) a descending neuritis cannot be excluded from an examination of a small portion of the trunk of the nerve, and (2) that a change in the nerve revealing itself as a very slight deviation from the normal, may serve to convey a condition of irritation to the eye sufficient to light up considerable papillitis. The frequency with which evidence of descending neuritis may be traced is confirmed by the observations of S.Mackenzie, 2 1 " Brain," July, 1879, p. 269. 2 Loc. cit. and "Trans. Ophth. Soc.," vol. i. p. 94. DO MEDICAL OPHTHALMOSCOPY. Brailey, 1 Edmunds and Lawford, 2 Poncet, 3 and others. Mackenzie has also pointed out that on no other theory than that of an inflammation travelling down the nerve tissue can we explain a unilateral neuritis on the side opposite to a cerebral tumour. It has been maintained by Kuhnt 4 that the descent of inflammation from the brain to the eye is by the perivascular sheaths of the vessels, which are, he states, continuous with the pia mater of the brain, and Gayet 5 would ascribe a share also to the sheaths of the posterior ciliary vessels. The evidence of inflammation away from the vessels prevents us, however, regarding them as the exclusive agents, but pathological evidence of their participation in the transmission of the inflammation has been also brought forward by Edmunds and Brailey. 6 It has been pointed out that the sheaths of the nerve, inner and outer, often present considerable changes, which make it probable that the inflammation passes along them to the eye. That it may do so independently of distension of the sheath is shown by two cases of optic neuritis and meningitis due to fracture of the skull, recently recorded by Edmunds, 7 in which the space between the sheaths of the nerve was occupied by " a dense mass of inflammatory products." These facts suggest the following conclusions regarding .the production of papillitis in intra-cranial disease: That in cases of cerebral tumour evidence of descending inflammation may be traced in sheath or nerve, much more commonly than current statements suggest, while in cases of meningitis the evidence of such descending inflammation is almost invariable. That the resulting papillitis may be, and remain, slight, 1 "Trans. Ophth. Soc.," vol. i. p. 111. 2 Ibid., p. 112, and loc. cit. at p. 82. 3 Disc, at the International Med. Congress, 1881. 4 In a communication to the International Medical Congress at Amsterdam ("Ann. d'Oculist.," vol. Ixxxii. 1879, p. 180). 6 Ibid., p. 181. 6 "Ophth. Hosp. Rep.," vol. x. p. 138. 7 "St. Thos. Hosp. Rep.," vol. xi. 1881. p. 71; "Trans. Ophth. Soc.," vol. iii. p. 140. CHANGES IN THE OPTIC NERVE NEURITIS. 91 or may become intense and present the appearances of mechanical congestion. The causes of this difference we do not yet know. That such mechanical congestion does not, as a rule, result from compression of the vessels in or just behind the sclerotic ring, but always, when intense, from compression by inflam- matory products in the substance of the papilla. It must not be forgotten that an increase in the size of vessels may be of reflex vaso-motor origin as in all inflamed parts. That while slow increase of intra-cranial pressure has no effect on the retinal vessels, a sudden increase hinders the escape of blood from the eye for a time, and may intensify a papillitis originating in another way. That distension of the sheath of the nerve alone is probably insufficient to cause papillitis by its mechanical effect, but may perhaps intensify the process otherwise set up, especially if the fluid possesses an irritative quality, and if (as Schmidt- Bimpler asserts and Leber denies) it can find its way into the lymphatic spaces of the optic disc. 1 There being thus little evidence that a mechanical impe- diment to the return of blood from the eye induced either by intra-cranial pressure, by distension of the optic sheath, or by the pressure of the sclerotic ring ever plays any considerable part in the production of optic neuritis, the use of the term " choked disc " or " stauungs-papille," as indi- cative of a supposed mechanism, is to be deprecated in our present state of knowledge. The occurrence of a process of strangulation is not denied ; it is often conspicuous enough, but it is produced in the inflamed papilla and not behind the eye, and occurs in all cases of a certain intensity. In this outline of the facts regarding the origin of optic neuritis, the hypothesis that the mechanism is a reflex vaso- motor influence has been necessarily unnoticed, because the known facts have no bearing upon it and give it no support. It presupposes a special reflex relation not known to exist 1 The latest theory of Leber, viz., that papillitis is an extension of inflam- mation from the periphery of the nerve at the anterior extremity of the sheath, is not supported by any anatomical evidence. 92 MEDICAL OPHTHALMOSCOPY. and a mechanism for the production of inflammation the efficiency of which is equally unknown. l VARIETIES. The chief varieties which have been usually insisted on are those distinguished by v. Graefe as " descend- ing neuritis " and the " choked disc." The facts already mentioned make it more than doubtful whether the patho- logical basis of the distinction is correct, and it is generally admitted that the supposed distinctions cannot be relied upon. The aspect of the disc varies very much in the same case at different times ; at one time the characters may be those supposed to be indicative of a descending neuritis, and at another time those ascribed to the " choked disc." But the appearance in different cases also frequently continues dif- ferent throughout their whole course. These characters are so various, and the intermediate forms are so numerous, that it is exceedingly difficult to separate any varieties as special "forms." Some cases certainly present throughout cha- racters which are regarded as those of descending neuritis especially slightness of swelling, a tendency for the changes to be most intense in the peripheral part of the papilla, leaving the centre little affected, absence of haemorrhages, the presence of white spots, isolated or about the vessels, and a striation depending rather on conspicuousness of nerve fibres than on vaseularity. These changes are seen, for instance, in PI. III. 3 and 5, and also of a wider extent and greater intensity in PL VI. 2. On the other hand, great swelling, with vaseularity and distended veins, such as is seen in PI. I. 6, III. 4, and still more in PL VI. L, charac- terizes other forms. But in the case whose disc is shown in Fig. 16, descending neuritis presented the characters of 1 A fuller consideration of the theory, and the arguments against it, will be found in some remarks I made in the discussion on optic neuritis at the Ophthalmological Society, March 10, 1881 ("Transactions," vol. i. p. 105). Similar arguments were brought forward by Leber at the discussion at the International Congress. The reflex theory has been revived by Loring ("New York Med. Journ.," June, 1882) in special connection with the fifth nerve, but still as a pure theory, which, while unsupported by facts (and even opposed by them), clearly merits detailed discussion. CHANGES IN THE OPTIC NERVE NEURITIS. 93 the choked disc, while the changes in PL V. 1 and 2, 3 and 4, slight as they are, were in each case associated with the symptoms of intra-cranial tumour. Until we know more of the relation between pathological process and ophthalmoscopic appearance, it seems far better to found varieties purely on clinical characters. Of varieties so founded the following have seemed to me the most marked. 1. Slight Papillitis, including the condition described above as congestion with oedema, in which the changes are so slight as to dim, but not obscure, the edge of the disc on indirect examination, although it may be invisible, wholly or in part, to direct examination (PI. I. 3, 4, III. 3, 5, V. 1, 2, 3, 4. 2. Moderate Papillitis. Obscuration of the edge of the disc, or of the affected portion, complete, even to indirect examina- tion ; swelling moderate, commonly reddish ; veins natural or large ; sometimes white tissue about the vessels, close to them or extending for some distance on the disc (PI. I. 5, 6, III. 4, IV. 1, 3, V. 5, 6, VI. 2). 3. Intense Papillitis. Great swelling ; veins at first large and arteries small ; many haemorrhages ; retina often involved by direct damage or by haemorrhages. Always succeeds a slighter stage in which the evidence of strangulation may be at first little marked (PL VI. 1, VIII. 1). The forms in which the changes involve the adjacent retina are often termed " neuro-retinitis circumscripta ; " and such widespread change as is presented in PL VIII. 1, although originating in the papilla, merits such a designa- tion. But in most cases, even in such as PL VI. 1, the retina is only affected adjacent to the papilla, or elsewhere is merely the seat of extravasations ; and since there is no general inflammation of the retina, the term " retinitis " seems unnecessary. Retro-ocular Neuritis. The change known as such an interstitial inflammation of the nerve is a mixed condition of inflammation and atrophy, revealed in the disc, if revealed at all, by the signs of simple congestion, rarely those of slight 94 MEDICAL OPHTHALMOSCOPY. papillitis, and soon passing on to atrophy with narrowed vessels. Little is known of the exact anatomical changes in this form, except in the variety which has been termed axial neuritis (Forster), in which chronic inflammation occupies the axis of the "nerve, and causes a central scotoma. It will he described further in the section on " Atrophy." Retro-ocular Perineuritis is a condition of chronic inflam- mation of the sheath of the nerve leading to thickening of its tissues, and purulent infiltration among the trabeculae. The nerve may suffer from compression, or from a state of inter- stitial neuritis which may spread to it from the sheath. It has been found in periostitis of the orbit (Homer), and in thickening of the cranial bones constricting the optic nerve (Michel). It causes papillitis in some, perhaps in all cases,. but this does not necessarily assume the appearance described on p. 51 as " perineuritis." DIAGNOSIS. The diagnosis of optic neuritis is often easy,, but sometimes presents great difficulty. Of all its signs that which first attracts attention as the most conspicuous feature the increased redness is of least value, except in conjunction with other characters. As already more than once stated, the redness of a disc free from neuritis may nearly equal that of the adjacent choroid. The signs which are of greatest diagnostic value are (1) obscuration of the edge of the disc and (2) swelling. These, in conjunction with increased redness, or change of colour to a tint not normally seen (such as the peculiar lilac-grey so often presented), constitute the characteristic symptoms. The obscuration of the edge is especially significant. It indicates undue opacity of the tissue (layer of optic nerve fibres) in front of the edge. Most of the nerve fibres pass along the course of the great vessels, above and below the disc, and they often normally obscure the edge of the disc slightly in these situations. Sometimes they are densely packed, also, on the nasal side, especially when the central cup is very large, and a slight obscuration is produced there also ; but in these cases, as a rule, the large size of the physiological cup indicates the close arrangement CHANGES IN THE OPTIC NERVE NEURITIS. 95 of the fibres, the obscuration is slight and occurs in the normal situations, and the edge of the disc is elsewhere quite sharp. In these cases another character may occasionally be observed in a slight degree, which, in more intense form, is conspicuous in neuritis the radiating striation at the edges of the disc. Normally this is seen where the nerve fibres are most closely aggregated, especially above and below ; in morbid states it is to be observed all round the disc, although most intense where the nerve fibres are grouped, and it is then due not merely to pale lines (from swollen fibres with increased opacity), but in part, also, to red lines, fine vessels lying between the fibres. The second indication of neuritis is the existence of distinct swelling. The prominence of one object in the fundus above the level of an adjacent object e. g., of a vessel on the edge of the physiological cup above a vessel at its bottom is appre- ciated in the direct method of examination by moving the head of the observer from side to side, or up and down, as far as possible without losing sight of the objects. Their rela- tive position undergoes an appreciable alteration proportioned to the difference in level, and is easily recognized. By the indirect method of examination the same result may be obtained by a lateral or vertical movement of the lens, which produces the same effect as a corresponding movement of the observer's head (the " parallactic test" of Liebreich). "With the binocular ophthalmoscope these measures are unnecessary, the difference of level being apparent just as with the stereo- scope. When the difference of the level of two objects is very great, as, for instance, in extensive swelling of the disc, a convex lens behind the mirror may be necessary before a clear view of the top of the swelling is obtained, the refraction of the eye being normal and the fundus visible without a lens. The difference between the strength of the convex lenses required to just render objects indistinct on the level of the retina and on the apex of the swelling, furnishes a measure of the height of the swelling. Normally the surface of the papilla is a little anterior to the plane of the retina, hence the term "papilla." The amount of 96 MEDICAL OPHTHALMOSCOPY. this prominence varies in different cases. It is always greater where the nerve fibres are chiefly aggregated in the proximity of the retinal vessels, above and below, so that a transverse section through the disc may show scarcely any appreciable prominence, while a vertical section may present distinct prominence. The more closely the nerve fibres are aggregated in one part of the circumference of the nerve, the greater is the prominence. Occasionally, but not often in a normal eye, it is sufficient to be readily appreciable by the movement of the head in direct examination. As a rule, a promi- nence which is readily recognized is pathological. In morbid states, every degree of elevation may be met with. The Diagnosis oj the Cause of PapilUtis. The first question which presents itself in a given case is Is the neuritis due to intra- cranial disease or to some other cause ? The answer to this must, of course, depend on the presence or absence of indications of disease of the brain, or of such disease of the general system as is known to be accompanied by optic neuritis. The ophthalmoscopic characters of the neuritis will lead us a little way, but not far. A high degree of neuritis, with intense strangulation (such as the discs shown in PL VI. 1 and VIII. 1), is seldom met with except in cases of cerebral tumour and some forms of primary neuritis. The slighter degree of neuritis not uncommon in cerebral tumour, chronic meningitis, and other intra-cranial diseases, and the neuritis which occurs in Bright's disease, lead poisoning, &c., may resemble one another very closely. The neuritis of Bright's disease sometimes presents white spots in and close to the disc, but the same appearance may be, and often is, seen in the neuritis of intra-cranial disease. (Fig. 7.) White spots in the retina away from the disc, with papillitis of a slight degree, and pre- senting no evidence of a preceding more intense affection, is very suggestive of renal neuritis. The small cloudy spots seen, for instance, in PI. IX. 2 (near the left edge of the figure) , are of more significance than the minute white spots near the macula, such as are shown in PL IX. 3, although the latter are suggestive of renal disease when they occur with CHANGES IN THE OPTIC NERVE NEURITIS. 97 a papillitis of slight degree and recent origin. Succeeding neuritis, or accompanying a neuritis which is subsiding, they are of much less significance, being often the relics of the mischief caused by simple inflammation ; and how closely these may simulate the appearance of a renal retinitis is shown by Fig. 6 and PL VIII. 2. Although an appearance of so striking an aspect is very rare, a few white spots near the macula lutea are very commonly left by neuritis such as are seen in PI. VI. 1 and 3. The signs of a previous neuritis of considerable intensity a prominent mass of tissue in front of the disc such as is seen there in Fig. 3, or a " filled-in " disc with evident compression of vessels, as in PL VIII. 2 rarely coincide with a similar appearance in renal retinitis, although such a coincidence is seen in PL IX. 4. In such a case as is there figured the diagnosis of the cause of the neuritis could scarcely be made by the ophthalmoscope alone. But attention must always be paid to the degree of the present inflam- mation, or the evidence of its degree in the past afforded by the amount of new tissue formed. It is upon the independent signs of one or the other causal condition that the diagnosis must chiefly turn. In referring neuritis to cerebral mischief, it must not be forgotten that, on the one hand, optic neuritis due to a cerebral tumour may be accompanied for a time by no signs of intra-cranial disease, and, on the other hand, that an optic neuritis due to a general disease may be accompanied by symptoms suggestive of cerebral disturbance, especially headache, vomiting, and even, in some cases, convulsions. Striking instances of the former were afforded by two children whom I saw at the same time in the Great Ormond Street Hospital. One was a boy under the care of Dr. Barlow, with a tubercular growth within the right eyeball, and well-marked neuritis to be seen in the left eye (PL III. 4). The only other symptom suggestive of intra- cranial mischief was an occasional attack of vomiting during many months that he remained under observation. The neuritis was of the character highly suggestive of intra- cranial tumour, but the possibility that the mischief in one H 98 MEDICAL OPHTHALMOSCOPY. eye might have caused the neuritis in the other, suggested extirpation of the eye which was the seat of the tumour. It had, however, no influence; and when the boy died, about a year after, scrofulous cerebral tumours were found. The other case (under the care of Dr. Gree) was a child aged nine years, who was' admitted having had occasional attacks of headache and vomiting. During the intervals she seemed perfectly well. No symptoms referable to the nervous system could be detected. She had, however, double optic neuritis. Gradually unsteadiness of gait showed itself, and increased until she was unable to stand, and she ultimately presented all the symptoms of cerebellar tumour. Such facts show that the suspicion of intra-cranial disease in cases of optic neuritis can only be discarded after long observation, if indeed it can ever be given up until some other cause presents itself. This is especially the case when the neuritis is chronic : very acute neuritis is nearly always accompanied by symptoms indicative of the disea.se causing it. Tuber- cular tumours of the brain frequently cease to trouble the patient or his optic nerves, and the cessation is permanent. On the other hand, neuritis due to general disease may be accompanied by symptoms suggestive of cerebral mischief. The disc shown in PL IX. 3 is that of a man who com- plained of almost constant severe headache and occasional attacks of sickness. The ophthalmoscope showed well-marked neuritis, moderate in degree, and on first inspection no retinal disturbance was detected. It was thought, for the moment, to be a case of cerebral tumour. On looking more carefully by the direct method, however, near the macula lutea were seen a number of minute white spots inconsistent with the slight degree of neuritis. The urine was at once examined, and found to be loaded with albumen, and on further examination hypertrophy of the heart and a hard pulse were found, with some signs of ursemic mischief. He died of uraemia not long after. The history of the case shown at PL IX. 2 is similar, except that the evidence of cerebral disturbance here was mental change, not headache. Another case impressed itself very strongly upon me many years CHANGES IN THE OPTIC NERVE NEURTTIS. 99 ago, when, as a resident in University College Hospital, I was first working with the ophthalmoscope. A man was admitted with convulsions, and comatose. An examination of the eyes showed double optic neuritis, and a diagnosis of cerebral tumour was at once ventured on. The patient died in a few hours, and the necropsy revealed contracted kidneys and a normal brain. A mistake of this kind is easily made, especially if the examination is confined to the indirect method; but I think that the mistake may generally be avoided by the direct method of examination , which has, in all cases I have since seen, disclosed slight retinal alteration inconsistent with the form of the neuritis. Examination of the urine should, of course, never be neglected. Headache and vomiting are, then, the signs of least value as indications of an intra-cranial cause of neuritis. Convulsion is also of little value unless it is of a form which indicates local brain disease, i.e., local in distribution or in commencement. In all obscure cases, search must be made for any other cause of optic neuritis, especially lead poisoning. In cases of lead poisoning renal disease is very frequent, and that cause for neuritis must be excluded before the affection can be referred to plumbism. In these cases also doubt may be felt as to whether the mischief is not due to cerebral disease, because lead poisoning is sometimes accompanied with two forms of cerebral disturbance delirium and convulsion. In the case presenting the neuritis shown in PL VII. 6 there was extreme cerebral disturbance, apparently the consequence of the lead poisoning ; and, on the other hand, I have lately had under my care several cases in which recurring con- vulsions, precisely like those of idiopathic epilepsy, were due to the same cause. One other fact must be mentioned in connection with the diagnosis of the cause of optic neuritis. In many cases in which slight neuritis of chronic course is associated with symptoms which would scarcely suggest the existence of disease such as would cause neuritis, hypermetropia exists. This combination may be noted, for instance, in chlorosis (as in the case figured in PL VII. 5), in epilepsy, apparently 100 MEDICAL OPHTHALMOSCOPY. idiopathic, and other slight symptoms of cerebral disturbance. It is doubtful, in the present state of our knowledge, what share is to be attributed to the hypermetropia in the pro- duction of the neuritis, and from the commonness of hyper- metropia the coincidence may have been accidental, but the fact deserves notice. PROGNOSIS. The prognosis in optic neuritis is necessarily a source of considerable anxiety. In few cases can it be said that vision is not in danger of impairment and even of loss. The prognosis must be formed by a careful study of the conditions on which impairment of sight depends, as stated on p. 72. The prospect is better in the slighter degrees of papillitis, and better in proportion to clironicity of course, and dependence on causes which can be treated. It is worse when there is reason to believe that there is much retro-ocular mischief ; worse in proportion to the evidence the ophthalmoscope affords of a process of compression going on in the disc ; worse in proportion to the intensity of the changes ; and worse in the loss of sight which comes on during the recession of the inflammation than in that which comes on during its height. The cause of the optic neuritis must influence our prognosis more than any other condition. It is better in syphilitic than in scrofulous cases, and better in these than in cases of disease of other forms. Even in syphilitic mischief, however, the prognosis must be guarded if the intra-ocular changes are considerable. It is not probable that the optic neuritis is, itself, syphilitic in nature. Its subsidence depends rather on the subsidence of the syphilitic intra-cranial disease, than on the influence of the remedy on the intra-ocular process, and it is not uncommon to have considerable failure of sight during the subsidence of the neuritis in such cases. For- tunately when the subsidence of the neuritis has ceased, there is a greater tendency to improvement of vision, and this may be considerable in degree (see " Consecutive Atrophy "). TREATMENT. Very little can be done for the direct treat- CHANGES IN THE OPTIC NERVE NEURITIS. 101 ment of optic neuritis. The treatment is that of the intra- cranial mischief, or general disease, which is its cause. Beyond this, local measures, leeches and the like, are little likely to influence the progress of the disease. The puncture of the distended nerve-sheath has been advocated by De "Wecker, and performed by him and by Mr. Power, and recently in a number of cases by Mr. Brudenell Carter and Mr. Bickerton. 1 It is based on the theory that the distension of the sheath is the cause of the intra-ocular neuritis, a theory which, it has been seen, cannot yet be considered as proved. Improvement has followed the operation in a few of the cases, but it must be tried in a much larger number of cases before a decisive opinion can be formed. During neuritis the eyes should be used as little as may be, and such conditions as intensify intra-ocular congestion should be avoided, e.g., exposure to cold, and all causes of mechanical congestion, straining, cough, &c. Ice to the forehead has been recommended by Pfliiger. Optic neuritis is so frequently associated with syphilitic disease of the brain and its membranes, and the evidence which may seem to exclude the suspicion of syphilis is so often misleading, that the administration of iodide of potassium should be a rule in almost all cases in which the age of the patient is such that acquired syphilis is possible. Iodide, in large doses, secures a more prompt improvement than mercury, and does no harm if the disease is not syphilitic in nature. Additional benefit may, however, result from the subsequent use of mercury. The completeness of recovery depends on the promptness with which the progress of the disease can be checked. Even in syphilitic cases it must be remembered that, the intra-ocular neuritis being probably not syphilitic in nature, although the consequence of syphilitic brain disease, the remedy employed does not influence the inflammatory products in the papilla, as it does the disease in the brain. As it has just been stated, in many cases of syphilitic disease of the brain with optic neuritis, in which the cerebral symp- toms have cleared, and the neuritis has subsided under 1 " Oph. Rev.," 1888, vol. vii. p. 300. 102 MEDICAL OPHTHALMOSCOPY. appropriate treatment, sight has become damaged during the subsidence of the neuritis, apparently very much as it would have done had the cerebral disease not been syphilitic in nature. It is the recession of the cerebral trouble which permits the recession of the neuritis, and the ocular damage bears, in most cases, a direct proportion to its duration. Hughlings- Jackson believes that iodide of potassium is some- times useful when there is no syphilis. lodoform, internally and externally, has been advocated by Landesberg. Where the disease is not syphilitic it is often scrofulous, and here also great good can be done by appropriate especially tonic treatment. Commencing neuritis may subside entirely and leave no trace, under the influence of such treatment. But unfortunately we are able to influence such disease much more slowly than we can influence syphilitic disease, and if neuritis be already well developed, it is rarely that loss of sight can be prevented. B. MORBID STATES OF THE OPTIC DISC CHARACTERIZED USUALLY BY LESSENED VASCULARITY AND SIGNS OF WASTING. ATROPHY OF THE OPTIC NERVE. Under many circumstances the fibres of the optic nerves undergo wasting or degeneration. This occurs when the eye has been greatly damaged by any cause, and possibly when complete opacity has rendered the cornea or lens, for a long time, impermeable to rays of light. It has been seen to occur as a consequence of the inflammation of the intra-ocular end of the nerve, or of its whole trunk ; the wasting thus produced is termed " consecutive," " post-papillitic," or " post-neuritic atrophy." In other cases the wasting is preceded by no visible inflammatory disturbance, and such are termed "simple atrophy." Nevertheless, in rare cases, an atrophy is preceded by the signs of simple congestion of the disc, and such cases may be termed " congestive atrophy." It is probable that the pathological condition of the optic nerve in this form is really a chronic inflammation, partial or diffuse, of which the intra-ocular signs of congestion, &c., are the indication, but CHANGES IN THE OPTIC NERVE - ATROPHY. 103 it is convenient, for clinical reasons, to consider it among the forms of atrophy. Lastly, atrophy may succeed choroiditis and retinal disease. Atrophy, not consequent on any obvious ocular change, was found by Vulpian in about 4 per cent. (19 out of 500) autopsies on old persons at the Salpetriere. In an equal number (21) there was atrophy consequent on an ocular disease. 1 S. The nutrition of the nerve fibres, and that of the capillary vessels which confer on the disc its normal rosy tint, are so associated that atrophy of the fibres is accompanied in nearly all cases by an atrophy of the capillaries, and the pallor thus produced constitutes the most salient sign of the atrophy of the nerve. The atrophied nerve commonly shrinks, and occupies less bulk than the normal nerve. This is not attended by any diminution in the size of the optic disc, since the latter is determined by the size of the sclerotic opening. The shrinking is indicated by a slight recession or " excava- tion " of the disc. In some cases there is a diminution in size of the retinal vessels, but this is an inconstant character. These signs will be considered in detail. Pallor. The vascularity of the optic nerve, as has been before pointed out, is estimated by the tint of its intra-ocular termination, the " optic disc." In judging of the colour of the disc it is important to examine it with a weak illumination, and by the direct method, in order to let as little light as possible be reflected. In a strong light a faintly-tinted object will appear white. 2 Hence the importance, to recog- nize a slight coloration, of employing a weak illumination. The ophthalmoscope of Helmholtz, consisting of plates of 1 Table given by Galezowski, ' ' Sur les Atrophies de la Papille du N"erf Optique." " Journal d'Ophtalmologie," Jan., Feb., and March, 1872. 2 With very intense illumination, even a strongly-tinted object will appear white. This is because all objects reflect some of all rays, and absorb none entirely. If the waves impinging be sufficiently numerous i.e., the light very intense so many waves of all lengths are reflected that the object appears white, the waves of the length chiefly reflected being no longer preponderant, although they become preponderant on weakening the light. 104 MEDICAL OPHTHALMOSCOPY. thin glass, is especially useful for this purpose. A plane mirror may be employed instead. If this is not available, the light of the illuminating lamp should be turned low. It is as essential to be aware of the normal variations in colour for the estimation of a pathological pallor of the optic disc, as it is for the recognition of congestion. The varia- tions on the negative side are not, perhaps, so considerable as are those on the positive side, but they are sufficient to render familiarity with the appearance of the normal disc essential to prevent mistakes in estimating the slighter degrees of atrophy. As a rule, the disc becomes paler as life advances, and a slight grey tint becomes mingled with the red, but the latter is still perceptible. The physiological cup, if slight, is often indistinct late in life. Thus, a tint which is normal in the old, would be suggestive of atrophy in the young. Again, when the general fundus is unusually dark, the disc will seem to be abnormally pale, simply as an effect of con- trast. In anaemia, also, the disc may become paler, but the change of tint from this cause is not considerable, and is insignificant in comparison with the normal variations in colour of the disc. It never constitutes an element of difficulty in the recognition of atrophy. When a pathological pallor of the disc is pronounced, it extends over the whole area of the disc, but commencing pallor may be most marked in that part of the disc which is normally palest, i.e., the temporal side, where the nerve fibres are least numerous. The change in this part, however, is only of significance in individuals in whom the "physiological cup " is small, and the temporal half of the disc normally possesses a distinctly vascular tint. In a great number of cases, in which the physiological excavation is large, and slopes gradually to the sclerotic ring on the temporal side, this portion of the disc may be normally almost as pale as in atrophy. The part on which attention should be chiefly fixed is, therefore, that which normally possesses considerable vascularity, the nasal portion. The tint may be observed to become gradually paler, the red sometimes simply fading, and leaving a white colour in its place ; in other cases a grey CHANGES IN THE OPTIC NERVE ATROPHY. 105 becomes mingled with the red, and gradually preponderates as the red tint fades, and ultimately a pure grey is left. If the examination is made with daylight, the tint is often a greenish-grey. These two varieties constitute in their extreme forms the white and grey forms of atrophy respec- tively. Intermediate forms are often seen, and to the direct method of examination some grey tint may always be dis- tinguished, even in the discs which appear of tendinous or chalky whiteness to the indirect method of examination. This grey mottling tends to increase as time goes on. The slight grey tint in " white atrophy " is similar to that normally seen at the bottom of the physiological cup. This tint is, however, scattered over the disc, and the central cup is often distinguishably whiter or greyer than the rest. The aspect of the disc, whether white or grey, is not definitely related to the form or cause of the atrophy, and hence it is undesirable to employ it as a basis for classification. The atrophy leaves the edge of the disc very distinct and sharp. The sclerotic ring is much more clear than it is normally, but it may not at first be recognized by the indirect method, as it is not differentiated from the white surface, as it is from the rosy tint of the normal disc. The sharpness of the edge is due, not only to its clearness, but also to the fact that the choroid preserves its normal characters to the margin, and gives to the clear outline a peculiar sharp-cut aspect, which is the characteristic of " simple atrophy." Pigmentary deposits on the edge of the disc are, like the edge itself, abnormally distinct. Excavation. In simple atrophy of the nerve, the surface of the disc is depressed in proportion to the wasting of the nerve-trunk. This varies, however, in the different forms of atrophy, because the wasting of the nerve fibres is, in some forms, combined with wasting of the connective elements, and a great shrinking of the nerve in size, while in other cases the wasting of the fibres is accompanied with an overgrowth of connective tissue, which may to some extent compensate for the shrinking due to the atrophy of the nerve elements, and may even prevent any diminution in bulk of the nerve.. 106 MEDICAL OPHTHALMOSCOPY. Thus, in some cases, the depression of the disc is considerable, and in others it is slight or absent. Its special character is that it affects the whole disc, and commences at the sclerotic ring. It may often be recognized by the change of level of the retinal vessels at the spot, most distinct on lateral move- ment of the observer's head. Normally, it will be remembered, the depression of the centre of the disc never begins at the sclerotic ring, except that in some cases of large normal cups it may commence at the ring on the temporal side. Above, below, and at the nasal side i.e., in the position of the large vessels the normal excavation never commences at the ring, within which there is always a zone of nerve tissue, commonly the most prominent portion of the disc. Hence the change of level of the large vessels at the ring becomes an important sign of tfce atrophic excavation. The size and form of the resulting excavation depend on two things the amount of shrinking of the nerve, and the size and form of the normal cup. The wasting of the edge of the cup tends to lessen the steepness of the side or sides, and to give its form a funnel shape. The mottling of the lamina cribrosa may become very distinct at the bottom of the excavation, and this in some cases, it is said, in which before the atrophy no physiological depression existed. Where the normal cup was large, the excavation may reveal the lamina cribrosa in almost the whole extent of the disc, the grey mottling corresponding to the bundles of degenerated nerve fibres, the white intervals to the meshes of the lamina. It is believed that some share in the excavation is due to the atrophy of the small vessels, which conferred on the normal disc a certain amount of turgescence. De Wecker suggests that as the nerve has its consistence lessened, the normal intra-ocular pressure may assist in producing the excavation. It has been said that the more connective tissue is deve- loped in the atrophied nerve, the slighter is the shrinking of the trunk. This is especially the case in the grey atrophy, in which the nerve may retain its normal size. The de- CHANGES IN THE OPTIC NERVE ATROPHY. 107 pression in the disc may be less in these cases than in the whiter form of simple atrophy, but it is not, as has been said, absent, and it is often considerable. Among the remains of the diverging nerve fibres, there is little connective tissue developed, and the wasting of the fibres here is compensated for to a much less extent than in the trunk of the nerve. The Retinal Vessels. In some cases of simple atrophy of the optic nerve the retinal vessels become reduced in size, in others they do not. In the grey atrophy, as a rule, the vessels undergo little or no change, but they are occasion- ally narrowed. In simple white atrophy they present no alteration in some cases ; in others, the arteries gradually become smaller, the veins undergoing little diminution. After a time the veins also may shrink. They are reduced in size in cases in which there is a retro-ocular neuritic process, but this, without evidence of neuritis in the disc, cannot be regarded as the cause of their shrinking in all cases. Their atrophy seems sometimes to be part of the atrophy of the nerve-fibre and ganglion-cell layers of the retina, which is usually associated with atrophy of the nerve. Why they should shrink in some cases and not in others is at present unexplained. Initial Signs of Congestion. In describing simple conges- tion of the disc, it was pointed out that it may terminate in atrophy. The disc has, at first, a dull-red tint, with a soft- looking surface, the redness being uniformly distributed over it. The edges of the disc are less sharply defined than in health; they are visible, but are softened. It is this uniform distribution of the tint, and softness of the edge, which give to the disc its special character. The congestion may persist for a long time, but commonly, as time goes on, the disc slowly becomes paler, and ultimately a condition of greyish-white atrophy is reached. Occasionally the disc presents at first, for a short time, a slight degree of oedema as well as congestion, shown by slight swelling. The patho- logical process, in many cases of atrophy, seems to be of the nature of a chronic inflammation. It is readily intelligible that in some cases the signs of slight inflammation should be 108 MEDICAL OPHTHALMOSCOPY. visible in the disc during the early stage. The cases in which it is met with are especially those which result from injury and from toxic causes. This state of chronic inflammation behind the eye, retro-ocular neuritis, may be diffuse and affect the whole nerve, or partial and involve only a segment of the nerve (segmental neuritis), or its central portion (axial neuritis). The vessels often present much earlier and more considerable narrowing than in simple atrophy, and in the disc around them much white tissue becomes developed. It is to be noted, however, that in some conditions of undoubted retro-ocular neuritis, there may be no signs of inflammation or congestion of the disc, but only that of simple atrophy, and hence it is convenient to consider this form in the present section. The mischief is commonly at some distance behind the eye. Atrophy after Intra- Ocular Neuritis ; "Consecutive Atrophy" or " Papittitic Atrophy" The newly-formed inflammatory tissue-elements of papillitis are in part removed, and in part transformed into connective tissue, which gradually shrinks. The pale swelling left by the inflammation (PL II. 1, IY. 5, VI. 3), large in proportion to the intensity of the process, slowly subsides, until it is confined within the limits of the disc, and slowly reaches the level of the retina (Fig. 49). The soft edges which at first limit the pale swelling gradually become more sharply defined. The recession of the swelling FIG. 49. VERTICAL SECTION THROUGH THE OPTIC Disc ix A CASE OF POST-PAPILLITIC ATROPHY, DUE TO TUBERCLE OF THE CEREBELLUM. The retinal layers are displaced, and the bundles of fibres in the optic nerve are separated. A vessel is seen divided longitudinally. Neither within nor behind the sclerotic ring is it compressed. Within the papilla, how- ever, its branches are very narrow, (x 15.) CHANGES IX THE OPTIC NERVE ATROPHY. 109 from the edge of the choroid often shows that the latter has been damaged, and has undergone irregular atrophy adjacent to the edge of the disc (PI. II. 4, IY. 4), which thus has a more or less irregular outline. The substance of the disc has a " filled-in " look, from the new tissue within it (PL VIII. 2), and is commonly white, or rarely greyish in tint (PI. II. 2, upper half). The vessels, whether pre- viously narrowed or not, usually become narrowed by the contraction of this new tissue, and may be partly concealed by it at their origin, or in their course over the disc. The tissue along their walls is often distinctly whiter than the rest of the disc, and when the latter is grey the contrast between it and the perivascular tissue may be very marked (PI. II. 2). Often white lines are to be traced along the narrowed vessels for some distance from the disc (PL II. 4) . They are probably due to thickening of the outer coat, perhaps originating in the migration of white corpuscles along the perivascular sheaths (Fig. 11), and the trans- formation of these into connective-tissue elements. Ulti- mately, the contraction of the tissue may cause an excavation of the disc, even in the centre (PL II. 4, IY. 6), and there is only the adjacent choroidal disturbance and the narrowing of the vessels, to indicate the origin of the atrophy. The excavation rarely, however, becomes sufficient to reveal the lamina cribrosa. (Of. Figs. 3 and 4, PL II.) The disc usually remains for a long time white to the indirect examina- tion ; sometimes its tint is slightly rosy. Ultimately, however, FIG. 50. SECTION THROUGH THE OPTIC NERVE IN THE SAME CASE AS THE PRECEDING FlGTJRE. The fasciculi of degenerated nerve fibres are infiltrated with nuclei, and cells of irregular shape. The septa between the bundles are a little thickened. x 100.) 110 MEDICAL OPHTHALMOSCOPY. it becomes distinctly greyish, especially on direct examination, and with feeble illumination. In some cases the inflammation may not have damaged the choroid, although causing destruc- tion of the nerve fibres, and in such a case the edge of the disc may be sharply defined, and if, as is the case sometimes when the inflammation is moderate, the narrowing of the vessels is slight in degree, the appearance of the disc may resemble very closely the disc in simple atrophy, and be quite indistinguishable from that left by retro-ocular neuritis. Choroiditic Atrophy. The atrophy of the disc, which is often seen after choroido-retinitis, is sometimes white or grey and resembles primary atrophy ; but sometimes it presents special features, being characterized by a peculiar reddish, or yellowish-red tint of disc, uniform in distribu- tion, sometimes with slight blurring of its edges, and usually by a marked wasting of the retinal vessels, which may be diminished in number as well as in size. The recognition of this variety of choroiditic atrophy is of considerable importance, because, unless the result of retinitis pigmentosa, it is almost always the consequence of syphilitic disease, acquired, or more frequently, inherited. It con- stitutes a sign of inherited syphilis of great importance. In most cases the disturbance of the retinal pigment is distinct and characteristic. CAUSES. Simple atrophy of the optic nerve may be a primary change, or may be secondary to some lesion, trau- matic or other, which interferes with the structural integrity of the nerve. These two varieties may be distinguished as " primary" and " secondary" atrophy, and are especially cha- racterized by the circumstance that in primary atrophy the loss of sight coincides in origin and progress with the visible atrophy, but in secondary atrophy the loss of sight occurs first, and the signs of nerve degeneration are not . observed until a subsequent period. It is doubtful whether the two forms can be distinguished by the ultimate aspect of the disc. It has been proposed to divide the primary atrophies into two classes, according as the process commences by degeneration CHANGES IN THE OPTIC NERVE ATROPHY. Ill of the nerve elements, or by growth of the interstitial tissue, with secondary damage to the nerve fibres. The distinction has been especially insisted on by Charcot and by Abadie, on grounds of etiology, pathology, and symptoms. Our knowledge at present is scarcely sufficiently definite to make a sharp distinction generally useful, if indeed it is founded on a correct basis. The careful discussion of the subject by Duwez deserves perusal. 1 Primary Atrophy often comes on without known causes. It is sometimes, however, distinctly hereditary, and one very remarkable form (carefully studied by Leber) affects all the males of a family soon after puberty. The atrophy is here really preceded by a slight neuritis, and its occurrence seems to be associated with a neuropathic type of family. 2 The male sex is, apart from this variety, more prone to optic nerve atrophy than the female. Seventy-five per cent, of all cases occur in men, and most cases occur in adults. A considerable number of the cases of primary atrophy are associated with spinal disease and are distinguished as " spinal atrophies." Cases of optic nerve atrophy, in which there are no .symptoms of other affection of the nervous system, are usually classed as " simple progressive atrophy " an inconvenient designation, since the cases of spinal atrophy are also progressive. The class probably includes several distinct forms which are not yet differentiated. The group of " spinal atrophies " of the optic nerve is of great medical interest and practical importance. The most important is the atrophy which so often accompanies loco- motor ataxy. This form is regarded as the most typical example of the " parenchymatous," i.e., primarily neural form. It is usually a grey atrophy in ophthalmoscopic aspect, without diminution in the size of the vessels. A large number of primary atrophies are of this variety. The tabetic symptoms may be long delayed, and many such cases 1 In the " Dictionnaire Encyclopedique des Sciences Med.," torn. xvi. pt. 1, p. 319. 2 See also a paper on this subject by S. H. Habershon : "Trans. Ophth. Soc.," vol. viii. 1888, p. 190. 112 MEDICAL OPHTHALMOSCOPY. have been regarded as independent atrophy (see Part II., " Diseases of the Spinal Cord "). It has been indeed suggested by Charcot that almost all cases of primary atrophy are of this form, that the subjects of them, if they do not present spinal symptoms when seen, will do so at a future period. This is certainly incorrect. It is probable, from the facts observed by Uhthoff, 1 that not more than one-half of the cases of primary atrophy are associated with disease of the spinal cord. A similar atrophy may be observed occasionally in general paralysis of the insane, and also, although rarely, in dissemi- nated (insular) sclerosis, and in lateral sclerosis of the cord. The form which occurs in general paralysis is described by Clifford Allbutt as often preceded by distinct signs of con- gestion of the disc. This is doubted by many, and is certainly very often not to be observed, but in one or two cases I have seen marked congestion of the discs in general paralysis, although unable to follow them to the atrophic stage. The pathology of the connection of the optic nerve atrophy and the spinal cord changes is still obscure. The fact that in locomotor ataxy the atrophy may reach an advanced degree when the change in the spinal cord is still in its earliest stage, and even when the latter is confined to the lowest part, makes it probable that the optic change is an associated and not a sequential lesion. At present this pro- bability is not lessened by the discovery of J. Stilling 2 that some fibres of the optic nerve can be traced into the medulla oblongata as far as the inferior olivary body. It must be remembered that the optic nerve is, develop- mentally, a direct prolongation of the central nervous system, and that, anatomically, it resembles the white matter of the brain and spinal cord. The importance of this relationship, in connection with the question of the independent origin of changes in the optic nerves and in the spinal cord, has been called attention to by Grunn. 3 1 "Arch. f. Ophth.," vol. xxvi. 1881, pt. 1, p. 277. 2 " Centralblatt f. prakt. Augenheilk.," Dec. 1880, p. 377. 3 "Brit. Med. Journal," 1885, ii. p. 688. CHANGES IN THE OPTIC NERVE ATROPHY. 113 The atrophies of the optic nerve which are not associated with spinal disease have been ascribed to various causes, the influence of some of which is uncertain. Such are : cold, sexual excess, menstrual disturbance, gastro-intestinal affec- tions, migraine. With better reason they have been ascribed in rare instances to syphilis, diabetes, intermittent fever, and some acute specific diseases, and the facts regarding their relation to these will be considered in Part II. In a con- siderable proportion of the cases of primary atrophy uncon- nected with spinal disease, no adequate cause can be ascer- tained. Tobacco and bisulphide of carbon certainly, alcohol and lead possibly, cause amblyopia, and may cause partial atrophy, but this is usually preceded by signs of congestion or even inflammation, and there is reason to believe that, in the case of tobacco at least, the lesion is a neuritis in the axis of the nerve. Primary atrophy usually affects both eyes, commonly one much more, and earlier than, the other, and in rare cases one only. Secondary Atrophy results from lesion of the optic centres or fibres. A cortical lesion in the brain about the supra- marginal gyrus (Ferrier) may, there is reason to believe, entail loss of sight of the opposite eye. This, although the decussation at the chiasma is certainly in man incomplete, is explicable by Charcot's at present unproved theory of a complemental decussation at the corpora quadrigemina. A lesion outside the hinder part of the optic thalamus causes, according to this theory, loss of sight of the opposite eye and of the opposite half of the field of vision of the same side. It is probable that such damage does not for a long time cause atrophy of the disc. The case from which PL II. 5 is taken makes it probable that such atrophy after a time does ensue ; and the same conclusion is suggested by a case recorded by Bernhardt. 1 Lesions of one optic tract causing bilateral symmetrical hemianopia, seldom produce distinct ophthalmoscopic changes. Some observers have described an ultimate slight pallor of the corresponding halves of the 1 "Berl. kl. Wochenschrift," 1872, No. 30. 114 MEDICAL OPHTHALMOSCOPY. discs, but this is not often distinct. In one case of long* duration, in which the hemianopia was complete and per- sistent, in the course of years the whole of the disc of the eye in which the area lost was on the temporal side (and therefore greatest), became perceptibly paler than the other, the tint of the two being at first equal. A similar slight pallor of the disc opposite to the cerebral lesion has been noted by others in cases of hemianopia of long duration. Pressure on the chiasma or nerves at the base of the brain is a common cause of optic nerve atrophy without neuritis. In the case figured in PL II. 4, although there had been slight neuritis, the atrophy was probably due to this cause. The pressure may be that of tumours growing from any of the adjacent structures, exostoses from the bone, or aneurisms from the adjacent arteries. It not uncommonly results from internal hydrocephalus the distended third ventricle com- presses the chiasma directly, pressing first on the upper and posterior aspect, where, as Michel has shown, a depression may be thus produced. 1 Meningitis is another cause which, while commonly producing optic papillitis, if extending to the nerve, may, in rare cases, cause blindness and atrophy without intra-ocular inflammation, by pressure without in- flammatory invasion, or it may cause blindness and atrophy out of proportion to neuritic mischief, and often after the inflammation of the papilla has subsided. It is probable that the local neuritis in these cases is often much more intense than is suggested by the degree of intra-ocular inflammation. It is said that obstruction, by embolism or thrombosis, of one middle meningeal artery, which supplies the dura mater around the optic foramen, may be followed by atrophy of that optic nerve. Tumours, exostoses, and meningitis may damage the nerves in front of the chiasma, and so affect the two eyes equally, or one to a much greater extent than the other, or one exclusively. The atrophy from these causes is white or grey. 1 Compression and flattening of the chiasma from ventricular distension was noted by Cheselden in the last century. (" Phil. Trans.," No. 337, p. 281.) CHANGES IN THE OPTIC NERVE ATROPHY. 115 Damage to the optic nerves causing atrophy may also occur in the optic foramen or in the course of the nerve through the orbit. Narrowing of the foramen by bony thickening, and rheumatic or syphilitic or traumatic mischief, producing pressure at the back of the orbit, close to the foramen, are not rare causes of atrophy. Blows on the head commonly produce atrophy by direct injury to the nerve, but it is pro- bable that they occasionally cause, by the effect of the shock,. a gradual degeneration. The ultimate atrophy which results from these causes is usually more or less distinctly grey in aspect, and the grey tint may be as marked as in the form sup- posed to be characteristic of spinal'disease (see PL II. Fig. 3). Mischief in the orbit may cause a process of " retro-ocular neuritis." This is assumed when transient signs of congestion are present in the disc, accompanied by constriction of vessels and the development of tissue adjacent to them ; so that ultimately there is considerable narrowing of the retinal vessels, as in the atrophy which is consecutive to intra-ocular neuritis. Sometimes the signs of neuritis are more marked. The nerve may be thus damaged by the extension of inflam- mation to the orbit in erysipelas of the face. Papillitic or consecutive atrophy results from intra-ocular neuritis, as already described. Retinal and Choroiditic Atrophy. Lastly, damage to the retina entails an atrophy of the optic nerve, which pro- gresses, sometimes slowly, sometimes quickly, but is usually incomplete. Now and then atrophy of the optic nerve follows a cause which seems to act by giving a shock to the retina,, that leaves no trace behind e.g., the complete amaurosis,. which may accompany the onset of embolism of one branch of the retinal artery, and is usually temporary, may some- times be permanent, even though all the other branches of the retinal artery are previous. Atrophy sometimes follows a blow on the eye, as in a case related by Laqueur, in which a blow caused complete amaurosis without visible changes in the fundus, and simple atrophy followed. Such cases are of medical interest on account of the light they throw on the action of some general causes. It is rarely that any con- 116 MEDICAL OPHTHALMOSCOPY. siderable degree of atrophy follows retinitis. Commonly, the cause of retinal atrophy is obvious on ophthalmoscopic examination, and the medical interest of this form is sub- ordinate to that of the retinal change. After choroiditis the disc has often a yellowish-red tint, as already described (p. 110). ANATOMICAL CHANGES. Atrophy of the optic nerve is never confined to the papilla ; the changes are marked throughout the whole length of the nerve, and in primary atrophy are usually equally distributed. The size of the nerve varies very much ; in some forms of primary atrophy it is markedly smaller than normal, somewhat translucent but scarcely grey, and under the microscope may present merely a wasting of all the structures of the nerve, fibres and con- nective elements, with, especially in recent cases, products of the degeneration of the nerve fibres, granules and globules of fat, compound granule cells, " corpora amylacea," and other products of degeneration of the nerve fibres. The position of the latter may at first be marked by rows of fatty particles. In other cases the nerve may be little diminished in size, but may present under the microscope a great increase in the interstitial connective tissue, fibres, and cells, with disappearance of the nerve tubules. Commonly the change is greater in the circumferential portions of the nerve than in the central. 1 Occasionally the reverse is the case. In atrophy from pressure on the nerve, its size is usually greatly reduced, and the increase of connective tissue is very considerable. In primary grey atrophy the nerve trunk is usually little reduced in size, and is grey and gelatinous in appearance. Microscopically, it presents an increase in the connective tissue trabecula3, and an atrophy of the nerve fibres. The medullary sheath first disappears, and afterwards the axis cylinder. It is said that the nerve fibres may be reduced to fine fibrous threads. Products of myelin degeneration may be found in the earlier stages. Sometimes the change is 1 Leber: "Arch. f. Ophth.," xiv. p. 182. CHANGES IN THE OPTIC NERVE ATROPHY. 117 peculiar ; there developes round the vessels a peculiar gelatinous-looking tissue containing a few nuclei and indis- tinct concentric fibrillation. The normal arrangement of the trabeculae disappears, and a section of the nerve (Fig. 51) shows islets and tracts of this tissue, in the centre of each of which a vessel can be traced. They may occupy at least half the area of the section. Between them lie the fasciculi of degenerated nerve fibres with little increase in their interstitial tissue. In the case figured, the atrophy was confined to one optic nerve, and its cause was obscure. The same histological condition may be present in the grey atrophy of locomotor ataxy. 1 In other cases of grey de- generation (according to Leber's observations) the change may be more uniformly distributed through the fasciculi. The degeneration is sometimes found in certain areas much more intensely than elsewhere. In a case of locomotor ataxy in which sight was not known to be impaired, I found only a great increase of tissue, consisting of nuclei and fibres, at the nodal points of the trabeculse, and a little gelatinous- FIG. 51. GREY ATROPHY OF OPTIC NERVE : TRANSVERSE SECTION, MIDWAY BETWEEN THE EYEBALL AND THE OPTIC FORAMEN. The trunk of the nerve was grey, and gelatinous in aspect, and was not diminished in size. The other optic nerve was healthy. The nerve fibres are completely degenerated, a granular tissue representing them. The normal trabeculse have disappeared, and through the section of the nerve are scattered tracts and islets of a slightly fibrillated, in places almost homogeneous, colloid looking tissue. These tracts enclose vessels which can be distinguished, small in size, and with thickened walls, in the centre of each. ( x 150.) 1 Cf. Perrin and Poncet's " Atlas" Atrophy of the Optic Nerve. 118 MEDICAL OPHTHALMOSCOPY. looking tissue immediately adjacent to the wall of the vessel. It would probably be unjustifiable to assume that this repre- sents the commencement of the process of change. Histology has not hitherto afforded much information as to the initial lesion in these cases. It is on the symptoms that the theory of a primary nerve degeneration is based. In cases of primary atrophy of the nerve the retina is degenerated only in its inner layers nerve-fibre and ganglion-cell layer, as Yirchow first showed. 1 The other retinal elements may persist in a perfectly normal condition even for many years. Pen-in and Poncet could find no change, except in the two inner layers, in a case of ataxy in which sight had been lost for thirty years. The degeneration from damage to the trunk of the nerve ascends to the chiasma, and descends to the eye. It is long in passing the chiasma, and, even with complete atrophy of one optic nerve, the optic tracts are only slightly reduced in size, that on the side opposite the affected nerve being rather smaller than the other, without naked-eye evidence of de- generation ; and I have found that the microscopic changes are nearly equally distributed through the two. 2 When both optic nerves are degenerated the optic tracts may pre- sent the same condition, traceable (as Tiirck pointed out) as far as, and involving, the external corpora geniculata. Consecutive or Posf-papittitic Atrophy. The microscope shows the substance of the disc to be occupied by nucleated connective-tissue fibres, among which, commonly, few or no traces of nerve fibres are to be discerned. Often, however, the nuclei, by their grouping, indicate the position of the intervals between the fasciculi of former nerve fibres. The retinal layers are displaced outwards (Fig. 21), an im- portant sign of the preceding swelling, and both they and the commencement of the choroid may present some dis- turbance. The atrophy of the rest of the retina is confined to the inner layer, especially affecting the layer of nerve fibres. 1 Virchow's " Archiv," vol. x. 1856. 2 " Centralblatt f. die med. Wissensch.," 1878, No. 31. CHANGES IN THE OPTIC NERVE ATROPHY. 119 SYMPTOMS. The symptom of atrophy is affection of sight proportioned to the damage to the nerve fibres. The patient becomes conscious of a cloud over objects, which increases ; of difficulty in seeing certain minute objects, such as small print : and sometimes of a dark area in some part of the field of vision. Examination shows a change in sight in three directions (1) diminished acuity of vision ; (2) altera- tion in the field of vision ; (3) altered perception of colours. 1. Diminution in the acuity of vision is invariable when the atrophy is pronounced ; it is almost always more con- siderable in one eye than in the other. In estimating it care must be taken to ascertain and correct any errors of refraction and defects of accommodation. It may vary from a slight degree to complete loss. It is commonly, but not always, proportioned to the degree of change in the optic nerve visible with the ophthalmoscope. 2. Alteration in the field of vision may be of several kinds. It is almost as constant as the diminution in the acuity of vision. The form is commonly a limitation at the margin of the field, progressing concentrically until only a small central area is left, such as is shown in Fig. 52. Such a limitation TIG. 52. CONCENTRIC LIMITATION OF LEFT FIELD OF VISION IN A CASE OF ATROPHY OF THE OPTIC NERVE. The outer boundary of the figure is the limit of the normal field. The inner white area is the area of the restricted field. 120 MEDICAL OPHTHALMOSCOPY. may progress much more on one side of the field than on the other, or it may progress much more in one part of the field than in another, so as to cause a sector-like defect. Occa- sionally the diminution is limited to one-half of the field, vertical or lateral. Lastly, in some cases, the first loss is a central one, in the middle of the field, a " central scotoma," as it has been termed. There is often in these cases dimness of the peripheral vision, without concentric narrowing of the field. 3. Colour-Blindness. In many cases the perception of colours is perverted. There are two methods of testing colour- vision. If the patient possesses sufficient intelligence, he may be asked to identify certain colours. If the patient is unintel- ligent, the " confusion method" must be adopted, by which the colours which are seen alike are ascertained. The former method, however, sometimes gives the more valuable in- formation. Modern physiological speculation suggests that there are four fundamental colours, related in complementary pairs, red and green, yellow and blue. The area of the field of vision in which these colours are seen varies for each. If coloured objects are moved from the centre of the field to the peri- phery, the first simple colour to be unperceived is green, the next red, and yellow and blue are lost near the edge of the field for white. Commonly yellow is lost before blue, but sometimes the latter is lost first. If the distance at which each colour ceases to be distinguished in various parts of the field is marked upon a chart, we have a series of concentric lines such as shown in Fig. 53, in which the most internal is the field for green, and the most external the field for yellow, the outer circle being that for white. The amount of light influences very much the area of the fields, and those shown in Fig. 53 were taken upon a dull day, and present the minimum normal fields. Fig. 54 shows the respective fields of larger size, and the blue field the most extensive. Compound colours are lost sooner than their constituents, and the inner circle in Fig. 54 represents the field for violet, which is even smaller than that for green. CHANGES IN THE OPTIC NERVE ATROPHY. 121 Commonly, in atrophy of the nerve, the first defect is for green and red, and blue and yellow are lost subsequently. The order of affection is commonly that in which the fields are arranged on the retina. The simple colour first lost in passing from the centre to the periphery of the retina is that first lost in atrophy, green ; and the last to be lost is blue or yellow. 1 Thus a girl, lately under observation, suffering from disseminated sclerosis and commencing grey atrophy, recognized, with the affected eye, every colour except green, which she called red or brown. In another case there was entire loss of perception for green only. Occasionally red appears to be lost first. A patient with ataxy and advanced FIG. 53. A REPETITION OF FIG. 39. DIAGRAM SHOWING THE FIELDS OF COLOUR- VISION IN A NORMAL EMMETROPIC EYE ON A DULL DAY. The fields are each rather smaller than on a bright day. The asterisk indi- cates the fixing point, the black dot the position of the blind spot. (Usually the blue field is larger than the yellow.) 1 It is doubtful whether this is true of violet, which is a compound colour. In some cases (it is said in hysterical amblyopia Charcot) violet is first lost. Sometimes, however, it persists to the last. Abadie suggests, on the theory that the same fibres conduct all colour impressions, that the first degenerative change in the fibre interferes with its power of conducting the special impres- sion excited by green rays, and the further changes abolish its power of conducting the impressions excited by other rays, in the order above given. ("Ann. d'Oculistique," 1878.) 122 MEDICAL OPHTHALMOSCOPY. atrophy (under the care of Dr. Buzzard) stated that the first loss of the sense of colour of which he was conscious, was ihat he could see no colour in a scarlet geranium. Bed gravel looked grey to him. Soon afterwards the grass also looked grey, and he could not, at a little distance, distinguish it from the gravel. When examined, violet alone was seen as a colour, he said it looked blue. A medium blue was seen as white. Cases have also been met with by UhthofC, Leber, and Treitel in the stage in which perception of red was lost and of green was preserved. The loss of perception of colour is often rather a colour amblyopia than blindness, large pieces of colour may be seen when small spots are not. The fields for colour-vision may present alterations similar to those already described as occurring in the field for white. Abadie 1 has lately attributed especial, and certainly undue, FIG. 54. FIELDS OF VISION FOB DIFFERENT COLOURS. (After Snellen and Landolt.) w, white ; B, blue ; Y, yellow ; R, red ; G, green ; v, violet. These are probably the maximum normal fields for each colour. 1<( Ann. d'Oculistique," 1878, and Lebris, "These sur les Differentes Jormes de 1'Atrophie de la Nerf Optique." Paris, 1878. CHANGES IN THE OPTIC NERVE ATROPHY. 123 importance to the loss of colour- vision as a supposed distinc- tion of the parenchymatous from the interstitial forms. It is probably of little significance as regards these forms. The most characteristic loss usually attends interstitial processes. Relation of Symptoms to Form of Atrophy. It was suggested by Leber that the central fibres of the optic nerve, on their emergence, probably occupy the most superficial of the nerve-fibre layers of the retina, and have the longest course, while the fibres in the circumference of the nerve lying deepest in the retina end soonest. On this theory a con- centric limitation of the field was ascribed to an affection of the axial fibres of the nerve, the central scotoma to that of the circumferential fibres. Forster, however, reversed this theory, ascribing the central scotoma to an affection of the axial fibres of the nerve. Recent investigations have conclusively proved that Forster's view is nearer the truth. Two cases have been published, one by Samelsohn, 1 the other by Nettleship and Edmunds, 2 in each of which a central scotoma was found to be due to the degeneration of a tract of fibres, which at the back of the orbit occupied the axis of the nerve, but in front of the entrance of the central artery lay on the outer side. Thus the hypothesis of Forster that a central scotoma might be an indication of " axial neuritis " 3 is verified. Moreover, the converse verification has been afforded by a case recorded by Wilbrand and Biswanger, 4 who found that a peripheral defect in the field of vision was due to an affection of the circumferential portion of the optic nerve. Concentric limitation of the field is very common in all forms of atrophy. In the spinal and simple progressive forms it most frequently begins on the outer side, but may com- mence on the inner side above or below. The acuity of vision may fail at the same time, or may remain normal until 1 "Centralbl. f. med. Wissensch.," 1880, p. 418. 2 " Trans. Ophthalmological Society," vol. i. 1881, p. 124. 3 See Wilbrand : " Klin. Monatsbl. f. Augenheilk.," Dec. 1878 4 " Centralblatt f. med. Wissensch.," 1879, p. 923, from the " Breslauer Artzl. Zeitschrift," 1879. 124 MEDICAL OPHTHALMOSCOPY. the field is reduced to a very small area. "When acuity is preserved, if the limitation is regular and sharp, central colour-vision may be normal, but the fields are reduced in area, preserving their normal relation to the field for white. When the limitation, although sharply defined, is irregular, colour- vision is usually much impaired (Nettleship 1 ). If, with considerable concentric narrowing, acuity of vision has failed greatly, colour- vision is usually much impaired or lost. A loss of one-half of the field of vision (apart from cere- bral hemianopia) is met with chiefly in secondary atrophy, especially when the cause is pressure on the chiasma, the temporal halves of the fields being then usually lost (see p. 72). But a loss of one-half of the field is met with in rare cases of primary atrophy. Thus in a case of grey atrophy associated with locomotor ataxy, the patient averred that he rapidly lost vision outwards in each eye. When he came under observation there was entire loss of the right field and loss of the temporal half of the left field, the loss including the fixing point (Figs. 55 and 56). Precisely the same affection of sight was present in a case of tabetic atrophy described by Treitel. 2 R L FIG. 55. FIG. 56. FIELDS OF VISION IN A CASE OF LOCOMOTOR ATAXY WITH GKEY ATROPHY. The shading indicates loss. The outer dotted line indicates the field for blue, the inner that for yellow. 1 " British Med. Journal," 1880, ii. 779. 2 " Arch. f. Ophth. " vol. xxv. 1879, p. 61. CHANGES IN THE OPTIC XERVE ATROPHY. 125 Sector-like defects in the field are met with in secondary atrophy, especially in cases of injury to the trunk of the nerve at the posterior part of the orbit. They also occa- sionally occur in simple progressive atrophy and in spinal atrophy. A well-marked instance of this condition in spinal atrophy is shown in Figs. 57 and 58. The patient was in the earliest stage of locomotor ataxy. The optic discs were grey and the vessels small ; vision was E. T V, L. ~. Sector-like defects in primary atrophy may be, as in this case, symmetrical, but they are sometimes unilateral, as in a tabetic atrophy recorded by Uhthoff, 1 where in one eye there was a defect of the upper and inner quadrant, and in two cases described by Treitel there was a defect in the inner and lower part in the right eye, as in the case figured. Central scotomata are usually transversely oval, extending from the blind point to the fixing point, sometimes involving both, sometimes one only. It is uncertain at which point they usually commence. The periphery of the field is usually normal, but it may probably sometimes be restricted. There is always a loss of colour-vision, and this may be greater and occur earlier than that for white. Red and green are first, and may be only lost. Central scotomata for red are SECTOR-LIKE DEFECT IN FIELDS OF VISION IN A CASE OF SPINAL ATROPHY. The shading represents amblyopia, the black loss. The dotted line shows the boundary of the field for red. Where it is absent the field ceased so gradually that its limit could not be ascertained. 1 "Arch. f. Ophth.," vol. xxvi. 1880, pt. 1, p. 277. 126 MEDICAL OPHTHALMOSCOPY. shown in Figs. 59, 60, and 61. They are met with in cases of axial neuritis and degeneration, and especially in cases of amblyopia from tobacco. That the latter depends on the same LEFT FIG. 59 DIAGRAM OF THE LEFT FIELD OF VISION FOR RED IN A CASE OF TOBACCO AMBLYOPIA. The outer line is the boundary of the normal field for white. The boundary of the outer shaded area is the minimum normal field for red. Red could, however, be seen only in the inner white area, and it could not be seen in the central shaded area around the fixing point (*). The black dot indicates the position of the blind spot. (For the chart from which this diagram was prepared I am indebted to Air. Nettleship. ) FIG. 60. FIG. 61. CENTRAL SCOTOMATA FOR RED, EMBRACING FIXATION POINT AND BLIND SPOT. No loss for white but considerable amblyopia (16 Jager). The patient had smoked half an-ounce of shag daily. The dotted line represents the peripheral boundary of the field for red. (Nettleship.) CHANGES IN THE OPTIC NERVE ATROPHY. 127 pathological condition (axial neuritis) is probable, both from the character of the affection of vision and from the fact that signs of congestion or slight neuritis are often observed at the papilla. A central scotoma is occasionally met with in consecutive (papillitic) atrophy. It may occur also in the atrophy which succeeds loss of blood, and is probably pro- duced by neuritis. Central loss is occasionally met with in simple progressive atrophy, but in spinal atrophies it is extremely rare has been said, indeed, never to occur. In a case under my care, however, there was central scotoma (Figs. 62 and 63), associated with the symptoms of lateral and posterior sclerosis of the cord, and some cerebral degene- ration ; the existence of slight papillitis makes it probable that axial neuritis existed, and, since the patient smoked a little, the influence of tobacco cannot be entirely excluded. Peripheral areas of vision, with general loss, are met with only in cases of orbital inflammation or in consecutive (papillitic) atrophy. The changes in the latter are often very irregular. There may be general concentric limitation of the field, or, less commonly, a central loss, rarely sharply defined. Failure of colour-vision is very frequent, but is often less regular in order than in primary atrophy (see "Neuritis," p. 71). The colour fields may present very CENTRAL SCOTOMATA IN A CASE OF DEGENERATION OF THE SPINAL CORD. There was a rather larger central loss for red and green, but the peripheral arublyopia for these colours was also considerable. 128 MEDICAL OPHTHALMOSCOPY. irregular defects, as in Figs. 64 to 66, representing the fields for white, red, and green in a case of post-neuritic atrophy. That for yellow and blue was normal, except for a limita- tion below, and to the inner side, corresponding to the field for white. They were taken nine months after the subsi- dence of neuritis, when acuity had improved to %. Uhthoff once met with a central scotoma for blue only. As a rule there is more or less correspondence between the pallor of the disc and the failure of sight. When it is considered, however, that the tint of the disc depends on its blood-vessels, and the amount of vision on the integrity of the nerve fibres which merely pass through the disc, and have a long course on each side of it, it is not surprising to find that the correspondence between the tint and vision is not always close. A very remarkable case has been recorded by Krenchel, 1 in which the optic discs of a boy became " as white as porcelain," although vision was normal. After some time, however, sight failed with great rapidity. DIAGNOSIS. The diagnosis of simple atrophy of the optic nerve rests especially on the change of colour, and the chief difficulty in the diagnosis is due to the degree of pallor sometimes seen as a physiological condition. The existence of amblyopia, otherwise unexplained, is strong evidence that the pallor is pathological. The pallor of the temporal half of the normal disc may be great when the physiological cup is large, and, as already stated, may easily be mistaken for w. R. G. FIG. 64. FIG. 65. FIG. 66. FIELDS OF VISION FOR WHITE, RED AND GKEEN IN A CASE OF PAPILLITIC ATROPHY. Y ' Hospitals Tklende," 1878, quoted in Virchow's Jahrnsbericht," 1878, vol. ii. p. 474. CHANGES IN THE OPTIC NERVE ATROPHY. 129 atrophy. It is certain that many normal cases have been described as " atrophy of the temporal half of the disc." It is doubtful whether an atrophy is ever, except in toxic cases, confined to the temporal half of the disc, in which, ordi- narily, the nerve fibres are very few. Although it is true that a slight degree of atrophy may produce the most distinct changes in this half of the disc, yet some pallor is always to be recognized, in such cases, in the nasal as well as in the temporal half. The diagnosis of the congestive variety of atrophy presents greater difficulties, but rests on the uniform distribution of the redness, its soft, velvety surface, the slight blurring of the edge of the disc, in com- bination with defective vision. Beginners sometimes mistake the white crescent of " pos- terior staphyloma " for part of the disc, and thus think the outer part of the disc, the colour of which is of such special significance, is white. Occasionally, especially in myopic eyes, the choroid presents a zone of atrophy, soft edged, around the entire circumference of the disc, which then has an unusual and puzzling appearance. In both these cases, however, attention to the fact that the pale zone encloses a well-coloured disc will prevent mistake as to its real nature. The excavation which accompanies the pallor is of secondary diagnostic importance, and it is not often that a difficulty in distinguishing atrophy from other forms of excavation arises. It may, however, occur. A large physiological cup may be bounded by a narrow rim of deeply- coloured disc, the boundary of which from the choroid may not be apparent on a cursory inspection by .the indirect method of examination, and the large, deep, sometimes grey, cup may be mistaken for the disc. A careful inspection of the edge will prevent doubt, and the examination by the direct method at once shows the source of the error. The excavation of atrophy commences at the sclerotic ring, and this is a character also of another form of excavation, namely, that of glaucoma. But the depth of the glauco- matous cup, its vertical sides, and the course of the vessels K 130 MEDICAL OPHTHALMOSCOPY. over the edge, and their subsequent disappearance, are diagnostic, especially since the pain which is so common (though not invariable) in glaucoma is never present in simple atrophy. PROGNOSIS. The prognosis of atrophy of the optic nerve, on whatever cause it depends, is always unfavourable in pro- portion to the actual destruction of fibres which has, taken place, and to the extent to which the causes influencing the disease are beyond control. Simple primary atrophy is usually due to a tendency to degeneration beyond all influ- ence, and the prognosis is, in this form, the least favourable. This is especially the case when the atrophy is associated with symptoms of degeneration elsewhere in the nervous system. Secondary degeneration is often the consequence of the operation of causes which may pass away, and the prognosis is less uniformly grave than in primary degene- ration. It must, however, always be somewhat uncertain, since it is often very difficult to form an accurate opinion of the nature of the process causing the damage to the nerve, on which the secondary degeneration depends. In the congestive form the prognosis is perhaps rather better than in the other forms. In the atrophy which is consecutive to intra-ocular neuritis, we are able to form a more accurate estimate of the course of the affection by the fact that, as long as the new tissue of the disc goes on contracting, the damage to the nerve fibres increases, and the sight will go on failing. If sight is lost from such contraction some time before it reaches its maximum, the prognosis is very grave. If, however, the loss of sight is incomplete, or only becomes- complete when the subsidence is nearly over, some sub- sequent slow improvement may be hoped for, and this may, in less severe cases, be very great. In a case which I have published elsewhere, 1 for example, probably of tumour in the middle lobe of the cerebellum, there was at first double optic neuritis, with great swelling. On the subsidence of the optic neuritis, six months later, it had diminished in both eyes to 1 "Trans. Ophth. Soc.," i. 117. CHANGES IN THE OPTIC NERVE ATROPHY. 131 Y 1 ^-. After this the disc atrophied, but at the same time vision improved, until, fifteen months after the first obser- vation, it had risen to f , and the pupils, which had shown formerly no reaction to light, again acted mormally. Under all circumstances, it is unhappily true that a disc which has lost all its normal tint never regains its vascularity, and useful vision is scarcely ever recovered. Some prognostic indications may also be drawn from the form of the affection of sight. The gravest, that which indicates not merely damage, but destruction of nerve fibres, is considerable contraction in the field of vision. In propor- tion as this is extensive the prognosis is grave. Lessened acuity of vision is of less serious prognostic significance. The change in colour- vision is least grave when this depends on a toxic cause, or on neuritis ; but is most grave when it is due to a primary degeneration, and occurs early. Central scotomata rarely go on to complete atrophy. Although the chance of restoration of useful vision in pro- nounced atrophy is small, in some cases the progress of the disease may be arrested, for a time or permanently, and even improvement obtained, occasionally considerable in degree. TREATMENT. The treatment of optic atrophy is essentially that of the general condition on which it depends toxic influences ; excesses, sexual, physical, mental ; cerebral and spinal disease, the " neuropathic constitution," &c. The treatment of many forms of atrophy which are due to an isolated ocular condition is beyond the scope of the present work. Cerebral processes may be to some extent influenced by treatment. Although it is not certain that there is such a thing as an actual syphilitic atrophy, yet atrophy does often result from syphilitic intra-cranial disease, and may greatly improve with the removal, by appropriate tieatment, of its cause. Scrofulous brain disease, again, may often be bene- ficially influenced, and its effects greatly lessened. In other cases counter-irritation, local depletion, purgation, and the like, effect good. In cases of primary atrophy, which are the result of a 132 MEDICAL OPHTHALMOSCOPY. neuropathic tendency, the treatment has to be directed to the general health, and nervine tonics are the chief agents to be employed. Nitrate of silver has been found useful in some cases : in others phosphorus, in others strychnia. The hypo- dermic injection of strychnia, so useful in amblyopia without ophthalmoscopic signs of atrophy, is of little service where these are present. Quinine and iron are in some cases very useful. When perception of light is not entirely lost, the retina may be readily stirmilated by an interrupted voltaic current, so as to give rise to a sensation of light, and this has suggested repeated stimulation of this character as a means of treating optic nerve atrophy. Some improvement, following treat- ment with the continuous current, has been observed by Pye-Smith l and Gunn 2 in a few of their cases ; the ex- perience of others has also been generally unfavourable. I have tried it in many cases, but without results which could reasonably be ascribed to the treatment. THE EETINA. Apart from the vessels and the optic disc, the changes in the retina which are of medical importance, are those which are special to certain general diseases, such as syphilis, albu- minuria, leucocythaemia, pernicious anaemia, and the like. They will be described in detail in Part II., in the sections on the ophthalmoscopic changes in the several diseases. The only common feature which these morbid states possess, is the development in the retina of haemorrhages and white spots and patches. The haemorrhages, their characters and signi- ficance, have been already described (p. 25). It may be convenient briefly to describe the forms of white patches which the retina may present under pathological conditions. A diffuse, slight opacity of the retina may be due to the derangement of its normal structure, resulting from the effusion of serum among the structures which compose it. Such diffuse opacity occurs in embolism, neuritis, and 1 " British Med. Journal," May 18, 1872. 2 "Ophtk. Hosp. Rep.," vol. x. pt. 2, June, 1881, p. 161. CHANGES IN THE RETINA. 183 albuminuric retinitis, but in all, and especially in the latter, it is usually associated with structural changes. Circum- scribed opaque white spots are due to change other than that of simple oedema, and commonly of four varieties : (1) Fibrinous exudations which undergo coagulation ; (2) the accumulation of corpuscles, similar in appearance to those of the nuclear layer, and also to the white corpuscles of the blood, so that it is doubtful from which source they are de- rived ; (3) fatty degeneration of the retinal elements, perhaps also in part of fibrine from the serum effused in simple oedema, and of the remains of blood clot ; (4) a fibroid change, a process of " sclerosis " of the retinal elements is described as an occasional cause of a white spot, but is more frequently confined to the perivascular tissues and vessel- wall. These conditions are frequently combined. The fatty degeneration may exist alone, as the sole cause of a white spot. Corpuscular accumulation usually involves a good deal of fatty degeneration in the cells and in the disturbed retinal elements. Sclerosis of the retinal structures is also in most cases associated with fatty degeneration. It is often impossible to say, from the ophthalmoscopic appearance, on what change the white spot depends. Minute granular-looking spots, brilliantly white, are commonly due to fatty degeneration of retinal structures or of leucocytes, &c. Larger white spots, if soft edged, are commonly effused fibrine or accumulations of leucocytes, especially if situated beneath the nerve-fibre layer. Fatty degeneration of the retinal structures is, however, commonly associated. White spots in the superficial layer of the retina, most common in Bright's disease, are due usually to degeneration of the nerve fibres. Growths in the retina sometimes occur in cases in which there are other growths elsewhere. The disc shown in PI. III. 4 was from a boy who had cerebral tubercles, and whose other eye was the seat of a tubercular growth behind the retina. The occurrence of miliary tubercles of the retina has been suspected by many observers. White spots are sometimes seen adjacent to the disc in cases of tubercular meningitis, and such a spot in one case I found to be made up of 134 MEDICAL OPHTHALMOSCOPY. lymphoid cells like those of the nuclear layers in which it was situated. Bouchut has seen white spots at a distance from the disc, near the vessels. Microscopically, he always found them to contain only products of fatty degeneration. He suspected them to be caseous tubercles, but there was no direct evidence that this was their nature (see Part II.). Since the white spots in the retina which have been de- scribed, are present in many forms of retinal disease which occur secondarily to, and are significant of, general diseases, it is of great importance to distinguish them from other appearances which have a different significance. First, it is necessary to distinguish whether the white spot is in the retina or in the choroid. Most choroidal white spots are due to atrophy of the choroid, and their distinction is easy. The atrophy of the choroidal pigment permits the white sclerotic to shine through ; some choroidal vessels may have escaped destruction and course across the white patch ; its edge is always more or less irregular, and usually much pig- mented ; or the choroid may exhibit adjacent slighter dis- turbance. It is easy to recognize by the " parallactic test " (also in the direct method by attention to the time required for the necessary change of accommodation) , that the exposed sclerotic is some distance behind any retinal vessels which pass in front of it. Occasionally, however, a white spot in the choroid is due to a recent formation, an inflammatory " exudation," or a growth such as tubercle. This is pro- minent, and may be difficult to distinguish from a white spot due to change in the nuclear layers of the retina. In some cases a little pigmentary disturbance in the neighbour- hood may be seen ; in others the white surface is distinctly so far behind the retinal vessels as to be obviously at the cho- roidal level. If sufficiently prominent to disturb the course of the retinal vessels, the prominence may be recognized and seen to be considerable in degree. In other cases, the con- ditions of origin of the spot may assist the diagnosis. It must be remembered that large choroidal exudations may cause opacity of the overlying retina. White spots due to the persistence of the white substance CHANGES IN THE CHOROI1). 135 of the retinal nerve fibres, or to connective tissue at the back of the vitreous, may be mistaken for new formations in the retina. They have been already spoken of. Pigmentary de- posits in the retina may be left after extravasation of blood, but such are always small. More extensive pigmentation is commonly the result of the accumulation in the retina of its disturbed pigment, and is a consequence of choroido- retinitis, or it is a result of the so-called retinitis pigmentosa. Retinitis pigmentosa appears to have some obscure con- nection with morbid states of the nervous system. It occurs, as Liebreich first pointed out, very frequently in the offspring of marriages of consanguinity. It has been thought to be con- nected with inherited syphilis, but the evidence on the subject scarcely supports the theory. It often occurs, however, in families in which there is a history of nervous disease. This is well illustrated by three out of four cases of the disease narrated by Mr. Nettleship. 1 Of the first patient, two cousins were epileptic and two insane. Of the second, the grandfather and great aunt were insane, and an aunt half imbecile, and a brother paraplegic. Of the third patient, the mother was epileptic, and probably also suffered from retinitis pigmentosa. THE CHOBOLD. Choroidal changes, like those of the retina, are for- the most part the result of special diseases, and their characters will be described in greater detail in Part II. Haemorrhages are rarely seen, although their consequences are sometimes met with. The common changes consist in white spots and the disturbance of the choroidal pigment, which so constantly results from any changes in its structure. The white spots are either new formations or patches of atrophy. The distinc- tions between them have just been alluded to in describing the diagnosis from retinal changes. White spots, not atro- phic, are the result of inflammation, or growths tubercle or lymphadenoma. The latter are extremely rare, and only occur when the general lymphatic disease is well marked. Tubercles are isolated and small rarely large. Pigment 1 " Ophth. Hosp. Rep." ix. 170. 136 MEDICAL OPHTHALMOSCOPY. may be seen adjacent to the older formations. The evidence of the general disease is almost always so prominent as to prevent the possibility of error. In acute choroiditis the white patches are large and numerous : the signs of the dyscrasise associated with growths are absent, and there is often a well-marked history of syphilis. The results of previous choroiditis are very conspicuous atrophic and pig- mentary changes, often associated with pigmentary deposits in the retina. It must be remembered that this pigment frequently occupies only or chiefly the peripheral portions of the choroid, and an examination confined to the neighbour- hood of the optic disc may be insufficient to discover it. The changes are very important, on account of the frequency with which the inflammation causing them is the result of syphilis. They are also interesting to the physician as associated, in some other cases, with evidence of a family tendency to nervous disease. 1 It is possible that inherited syphilis may be the link between these morbid states. Choroidal exudations (local) sometimes occur about puberty, resembling choroidal tubercles, and it has been suggested that these are really foci of scrofulous or tuberculous inflammation. Chronic choroidal degenerations sometimes occur as a senile change, possibly in consequence of general arterial degeneration. 2 Circumscribed changes may result from haemorrhage. Amyloid degeneration of the choroidal arteries was found by Kuapp in a case in which haemorrhage occurred. Embolism of choroidal vessels was believed by Knapp to be the cause of morbid appearances in two cases of heart disease observed by him. 3 In each there was sudden affec- tion of sight, at first general and then central, accompanied by achromatopsy. Corresponding to the scotoma, there was a localized retinal opacity with hyperoemia. The opacity, ascribed to effusion, extended to the optic disc. Sight, and the appearance of the fundus, ultimately became normal. 1 Instances of this have been related by Mr. Nettleship. (" Ophth. Hosp. Rep.," ix. 178.) 2 Hutchinson and Tay : "Ophth. Hosp. Rep.," vol. viii. Poncet : "Ann. d'Oculist.," 1875. 3 " Arch. f. Ophth.," Bd. xiv. PAET II. OPHTHALMOSCOPIC CHANGES IN SPECIAL DISEASES. DISEASES AND INJUEIES OF THE NERVOUS SYSTEM. DISEASES OF THE BRAIN. IN diseases of the brain, two forms of ophthalmoscopic change may be met with : Firstly, those which are a con- sequence of the general condition by which the cerebral disease is produced associated changes ; and, secondly, those which are the consequence of the cerebral disease consecu- tive changes. ANAEMIA AND HYPER.EMIA OF THE BRAIN. It has been supposed that the state of the circulation in the eye and brain correspond, and that the anaemia and hypersemia of the brain are revealed by similar conditions in the fundus oculi, and especially in the vessels of the retina and optic nerve ; the vascularity of the choroid being too great to permit of the recognition of any change in its circulation. But, as already stated (p. 19), this conclusion, if true at all, is true only within narrow limits. Local influences, chiefly perhaps the intra-ocular tension, so in- fluence these vessels, that they undergo little alteration when changes occur in the condition of the vessels of the brain. The eyeball participates in variations in the blood- supply to the whole head, but it does not share simple 138 MEDICAL OPHTHALMOSCOPY. vascular states of the brain (in which the rest of the head does not participate) to a degree that can render it an index to the existence of those states. This statement applies especially to the retinal vessels : it is in these that alterations can be most readily perceived. It applies also to the optic nerve ; but in this, alterations are more readily produced by encephalic changes, although to only a slight extent and not, perhaps, in a direct manner. Cerebral Hyperwmia. There is no sufficient evidence to show that the vascularity of the disc or retina participates in any transient cause of cerebral congestion, unless the whole head suffers. But in some cases of long-continued vascular disturbance, and in morbid states which are ascribed, with some probability, to cerebral congestion, ophthalmoscopic changes are sometimes to be seen a transient increase of colour, sometimes with slight blurring of the edge. But in most of these cases there is evidence of grave functional disturbance of the brain or prolonged hypersemia. Instances are such congestions as are shown in PI. I. 1 and 2, and the bright injection of the discs described by Macnamara as occurring during the headache produced by exposure to the tropical sun, increasing to papillitis when actual meningitis is developed. This conclusion the absence of any marked vascular alteration in the eye in changes in the cerebral circulation is at variance with early statements and a priori theories ; but it is abundantly supported by skilled observers. 1 1 See, for instance, the statements of Manz, Schmidt-Rimpler, and others, at the discussion at Heidelberg, reported in the " Ann. d'Oculistique," vol. Ixxiv. 1875, p. 262, et seq. It must be remembered that " congestion of the brain" as a name is exceedingly convenient, especially to those who are called " ready dia- gnosicians," but for whom "unscrupulous namers " would be a more exact designation. Apart from these, however, the condition is invoked with a readiness that cannot but excite surprise in those who know how different is the significance of the symptoms it is considered to cause. Further, the evidence that may suffice for " practical diagnosis " is often wholly inadequate for scientific reasoning. Very red discs, simply suggestive of cerebral congestion alone, prove nothing. To be of significance the redness must lessen in an unequivocal degree as the symptoms go. AXJEMIA OF THE BRAIN. 139 Lastty, it is probable that when cerebral hypersemia is due to blood states, the cause may also influence the optic disc and induce congestion. But this has [not yet been proved. Amemia of the Brain is rare as a primary vascular con- dition, except as part of a general cephalic anaemia. It is possible that in the same stage of an epileptic fit in which there is pallor of the face, there may also be pallor of the disc ; but no evidence of this fact has at present been obtained, and it is unlikely. Indeed, it is questionable whether any diminution in the tint of the disc has ever been observed to coincide with a diminution in the amount of blood within the brain alone. It is not probable that there is such a diminution at the onset of an epileptic fit ; the pallor of face usually precedes instead of following the onset. When the cerebral anaemia is part of a similar state affecting the whole head, the retina certainly participates, although it is not ofteu that an opportunity is obtained of observing this with the ophthalmoscope. But loss of function of the retina affords evidence of its participation; transient loss of sight, probably from this cause, may follow syncopal seizures. In an instance that came under my observation, a lad engaged in a stooping occupation in a hot crowded room, felt faint, and went out into the cool night-air. On re-entering the room he could not see : the room was absolutely dark to him. After sitting still for a few minutes sight slowly returned. It is hardly conceivable that the loss of sight was the result of anaemia of the brain, because the other cerebral functions were scarcely affected, and the loss of sight persisted after he otherwise felt quite well. Probably the retina shared the cephalic anaemia (due to heart-failure), and suffered in function more and longer than the brain. 1 1 This fact is one ot some significance. It suggests how extremely sensitive the retina is in its function, and therefore must be in its nutrition, to sudden influences. 140 MEDICAL OPHTHALMOSCOPY. INFLAMMATION OF THE BRAIN. Acute general inflammation of the brain cannot occur except in association with meningitis. The latter is the predominant lesion, and to it the symptoms are customarily ascribed. Certainly, of ophthalmoscopic changes in acute inflammation of brain without meningitis, we know nothing. Of course such cases of " active hypersemia " as those described in the last section, as occurring from the effects of insolation, may be regarded as cases of encephalitis. There is no sharp line to be drawn between " active con- gestion " and " inflammation," but there appear to be no pathological facts to warrant us in regarding the morbid process in these cases as actual inflammation. Local acute inflammation is probably always secondary. But it is probable that any local inflammation of the brain will cause neuritis if it continues for a sufficient time. There is, however, a class of cases to which the term " chronic encephalitis," or, perhaps, more accurately, " chronic cerebritis," appears fully applicable, and in which there may be very marked ophthalmoscopic changes. These cases pre- sent evidence of mental and motor failure, the latter may be local and attended by convulsion. Death may be preceded by coma. Headache is often severe. There are not the tremors or mental peculiarities of general paralysis, the symptoms resembling much more closely those of cerebral tumour. Post-mortem there is no sign of meningitis ; the brain may present evidence of degeneration, sometimes of wasting, but no " focal " disease. Such cases may be attended by optic papillitis very similar to that found in cerebral tumour, due most probably to the propagation of an irritative process from the cerebrum along the nerves. A well-marked case of this kind has been described by Hughlings-Jackson. 1 Dr. Button's microscopical examination of the convolutions showed 1 " Ophth. Hosp. Rep.," viii. 445. INFLAMMATION OF THE BRAIN. 141 only an undue number of the " spherical nuclear bodies," and in places, instead of the normal pyramidal nerve cells, were large numbers of staining nuclei, with unstaining cell-bodies around them. In places these nuclei were aggregated into groups of ten or twenty. The neuroglia was more granular than that of a healthy brain. The optic nerves, examined by myself, presented the characteristics of moderate papillitis, the swollen papillae being infiltrated with nuclear bodies similar to those seen by Dr. Sutton in the brain. Similar corpuscles were so abundant throughout the optic nerves as to justify the assumption that the neuritis had been " descending " (Pigs. 47, 48). A case published by Noyes, in 1873, was probably similar. Double optic neuritis, passing into atrophy, was accompanied by severe pain in the head, and paralysis of various cerebral nerves and unsteady gait. After death, no lesion of the brain was discovered. More recently, a well-marked case of the same kind, also accom- panied by optic neuritis, has been recorded by Stephen Mackenzie. 1 In the rare cases in which haemorrhage, or softening from vascular occlusion, causes optic neuritis, the effect is doubtless produced through the agency of secondary inflammation. Cases are sometimes met with in which we have a diffi- culty in assigning to inflammation or growth the chief share in the morbid process. Such cases may be accompanied by descending neuritis, and simulate closely the symptoms of cerebral tumour. PL VI. Fig. 2 shows the optic disc in such a case. In this case, local injury, years before, had caused the production of cheesy degenerating tissue beneath the membranes over certain convolutions, and a more widely spread but irregularly distributed meningitis had led to vascular disease, from the effects of which the patient died. The optic nerves were infiltrated with leucocytes, and " miliary abscesses " were found in the optic tracts (Figs. 23 and 33). 1 " Brain," vol. ii. p. 257. 142 MEDICAL OPHTHALMOSCOPY. CEREBRAL HEMORRHAGE. Associated Cluing es. The common form of cerebral haemorrhage is due to the rupture of " miliary aneurisms " ; that is, minute arteries suffer in the nutrition of their wall, which yields before the blood-pressure, and the dilatations thus produced are called aneurisms. The conditions which give rise to these aneurisms seldom influence the arteries of the retina, but the capillaries suffer in a similar manner very frequently, and thus small extravasations occur. In Fig. 3, p. 17, are shown capillary aneurisms from a case in which cerebral and retinal haemorrhages coexisted. These associates, retinal and cerebral aneurisms, occur, however, almost exclusively r in kidney disease. Aneurisms on small arteries, the true "miliary aneurisms," are rare. Probably this is due to the uniform support afforded to the arteries of the eye. Aneurisms are also depicted in PL XII. from a case in which all the conditions for the production of cerebral haemorrhage were present in extreme degree. It is taken from a woman aged thirty-six, who had advanced kidney disease with great cardiac hypertrophy, and very high arterial tension. On ophthalmoscopic examination there was obvious change in the coats of all the branches of the retinal artery chiefly thickening of the outer coat. There were several large haemorrhages, and in a few places aneurismal dilatation of the vessel. Retinal Hemorrhages, however, are present in a consider- able number of cases of cerebral haemorrhage, and furnish an indication of considerable value. Their most frequent cause is that which is the most frequent cause of cerebral haemor- rhage, Bright's disease, especially the granular kidney. They may exist, as in PI. IX. 1, without any other retinal change, or may form part of the special retinitis (PI. X. 1 and XII. 1). In either case they indicate the existence of the conditions which favour vascular degeneration and rupture. In the retina shown in PI. X. 1, for instance, CEREBRAL HAEMORRHAGE. 143 capillary dilatations and other changes were found. The retinal haemorrhages are often associated with cardiac hypertrophy. They thus may accompany all the most potent causes of cerebral haemorrhage. It must not be con- cluded, however, that the presence of albuminuric retinitis proves a cerebral lesion to be haemorrhagic. The disease of the kidneys is a cause, not only of the minute aneurisms that lead to haemorrhage, but also of the atheroma of the larger arteries that leads to thrombosis within them. Hence, softening due to the closure of atheromatous arteries is often associated with retinal changes due to kidney disease, and the latter have little weight in the differential diagnosis. They point strongly to one of these two lesions, but leave uninfluenced the indications furnished by the state of the heart and the character of the onset. In other conditions retinal haemorrhages have a similar significance. They point to a state in which cerebral haemor- rhage is likely to occur. Their significance is also more decided, since these other causes of retinal haemorrhage do not produce arterial atheroma. They occur, for example, in pernicious anaemia (PI. XI. 1) and in leucocythaemia (PL XI. 2), and in the latter disease the brain stands second in frequency as the seat of internal haemorrhage. 1 But although retinal haemorrhages point to the existence of conditions such as may lead to cerebral haemorrhage, and are thus of great importance as indications of the need for care in avoiding the exciting causes of haemorrhage, their signifi- cance as indications of the probability of the occurrence of apoplexy may be overrated. They are not uncommon, as in old and gouty persons, who do not suffer subsequently from cerebral haemorrhage. Perhaps this is, in part, due to the fact that the conditions in which they arise are such that many other causes of death coexist. Moreover, the existence of the conditions favourable to an event does not necessarily involve a balance of probability in favour of the occurrence of that event. 1 Retinal haemorrhages not included. See the writer's article on " Leu- cocythsemia," "Reynolds' System of Medicine," vol. v. 144 MEDICAL OPHTHALMOSCOPY. Among the very rare causes of cerebral haemorrhage are syphilis and heart disease; the occasional changes in the fundus may thus conceivably be of service in the differential diagnosis, that from heart disease being embolism. The coincidence has not, however, been hitherto observed. One reason for this may be that the haemorrhage from these causes is usually due to the rupture of an aneurism, and is seldom survived. Consecutive Changes. Haemorrhage into the substance of the brain is not usually attended with any ophthalmoscopic changes. So rarely have any alterations in the fundus been seen, that they may be said almost never to occur during the first few weeks after the onset. Neuritis has, however, been met with in a few instances. But its rarity is so great that the question arises whether, when met with, it has really been due to the cerebral lesion ; and the question is certainly justified, because other causes of optic neuritis are seldom absent in cerebral haemorrhage. Kidney disease and constitutional gout are sufficient to explain the occurrence of optic neuritis when it exists alone, and equally so when it is met in associa- tion with a malady that has not yet been proved to be, alone, an adequate cause. But here, as in so many other conditions, the insufficiency of a cause acting alone, does not exclude some influence when it is in association with some other cause. There is evidence that inflammation of the brain will produce optic neuritis, and that any process that excites second- ary inflammation may therefore assist in the causation. Haemorrhage always causes such secondary inflammation, just as does a traumatic lesion of the brain. Indeed cerebral haemorrhage may be regarded as a traumatic lesion which has no external origin. Although the secondary inflammation seems to be insufficient, alone, to excite optic neuritis, it may determine the occurrence in conjunction with so potent a cause as the blood-state of gout, or that produced by kidney disease. This is probably the explanation of the few cases in which considerable optic neuritis has been observed in cases of pure haemorrhage. One such case has been described by Hughlings- Jackson ; ten weeks after an attack of cerebral CEREBRAL HAEMORRHAGE. 145 haemorrhage, the discs presented the appearances of the later stage of neuritis. The patient died a week subsequently, and the necropsy revealed a large extravasation into the middle cerebral lobe, and a few specks of haemorrhage into the corpora quadrigemina. Another case is recorded by Bristowe. 1 The haemorrhage was in the posterior part of the optic thalamus. Robin 2 mentions a case with well-marked neuritis, such as is met with in tumours, in which the autopsy revealed a clot of blood, the size of a walnut, compressing the pons. In this case the neuritis can hardly have been the result of the extravasation. In a case described by Gemuseus, 3 double neuro-retinitis was observed during life, and, after death, numerous haemorrhages were found in the brain. In many cases of intense optic neuritis met with in cerebral haemorrhage, the blood has been extravasated into a soft growth in the brain, to which the neuritis has really been due. In one case, in which the neuritis had been watched during life, a careful observer who made the post-mortem reported a large clot surrounded by secondary softening, but the latter was really a very soft grey glioma into which the haemor- rhage had occurred. When, however, the haemorrhage is into the meninges, ocular changes may exist slight optic neuritis. The haemor- rhage may pass into, and distend, the sheath of the optic nerve, as has been found (in a case of my own) in meningeal haemorrhage from fracture of the skull, in rupture of an aneurism of the middle cerebral (Mackenzie) , in rupture of an intra-cerebral extravasation into the meninges (Michel), and in haemorrhagic pachymeningitis (Manz). Opacity and blur- ring of the outline of the disc with slight swelling may be thus produced. Retinal extravasations may co-exist, as in a case figured by Poncet. 4 Early changes in the papilla, in a 1 " Trans. Ophth. Soc.," vi. 363. 2 " Des Troubles Oculaires dans les Maladies de 1'Encephale," Paris, 1880, p. 284. 3 "Klin. Monatslil. f. Augenheilk.," 1880, p. 380. 4 " Atlas " of Perrin and Poncet. L 146 MEDICAL OPHTHALMOSCOPY. case of undoubted cerebral haemorrhage, would thus be evi- dence that the blood was effused into the meninges. It is said (by Knapp and Liebreich) that a peculiar pigmentation of the outer peripheral part of the disc, within the sclerotic ring, may be an ultimate consequence of such haemorrhage. In rare cases optic nerve atrophy has been met with in association with cerebral haemorrhage. Thus a case is recorded by Vulpian 1 in which blindness supervened on an attack of apoplexy. Death occurred fifteen years later, and the remains of an old haemorrhage were found in the left corpus striatum. Both optic nerves and optic tracts presented grey atrophy. The connection between the two is probably indirect. CEREBRAL SOFTENING. In softening of the brain, marked ophthalmoscopic changes are rare as the result of the cerebral mischief, although occa- sionally present, as several reliable cases testify; and I believe that slight changes are more common than in cerebral haemorrhage. Most of the cases in which alterations have been found have been cases of softening from embolism, not from thrombosis secondary to vascular disease. Changes in the fundus oculi, moreover, sometimes result from the same causes as those which lead to the cerebral mischief. 1. EMBOLIC SOFTENING : (a) Associated Changes. Em- bolism of the trunk or of a branch of the central artery of the retina may occur before or after embolism of a cerebral artery ; very rarely at the same time (see p. 34.). When the two occur at the same moment, the demonstration of the nature of a cerebral lesion is brought almost to its most complete form. The only defect in the demonstration is that the plug in the artery cannot actually be seen. An instance of such coincidence is afforded by the case illustrated in PI. XII. 2. In this, however, the proof was completed 1 Galezowski : "Journal d'Ophthalmologie," Jan. 1872. CEREBRAL SOFTENING. 147 by post-mortem inspection. The plug in the retinal artery is shown in Fig. 4, p. 36. 1 (i) Consecutive Changes. When the artery plugged is the middle cerebral, marked disturbance of the circulation might be expected in the eye which derives its blood-supply from the same trunk. Any signs of such disturbance have, how- ever, hitherto escaped attention, and probably the free anastomoses of the circle of Willis carry off any excess of pressure. If the condition of the discs is carefully observed from time to time, I believe that a state of congestion may often be observed a few weeks after the onset of embolic softening, especially in those cases in which the cerebral damage is extensive and leads to mental change. PL I. Figs. 1 and 2 show such an appearance in a young man with mitral disease and left hemiplegia. 2 Actual neuritis has been observed in a few cases, distinct, moderate in intensity, coming on a few days or weeks after the cerebral lesion, running a subacute course, and slowly subsiding. One of the best marked cases of the kind has been recorded by Broadbent, 3 in a man, aged nineteen, with mitral disease, who was seized with left hemiplegia and impairment of sen- sation. Nine days after the onset of the hemiplegia the margins of the optic discs were ill-defined ; there was swelling, with an unduly vascular " woolly " appearance, the retinal veins were large, dark, and tortuous, the arteries visible, but small. By the eighteenth day the paralysis had improved considerably, but the papillitis persisted, sight being normal. Six weeks after the onset, he was walking about the ward, and the papillitis was subsiding. A fort- night later the outlines of the discs were becoming perceptible, 1 For fuller details see description of the plate. 2 The increased redness of the disc, with slightly softened outline to indirect image, developed in both eyes under observation, and was so marked that I thought neuritis was coming on. It became stationary, how- ever ; soon lessened in the left eye, and much more slowly in the right. Coincidently with it there was marked and increasing mental failure, persistence of the complete hemiplegia, and rapid development of the ankle-clonus. 3 "Cliii. Trans.," vol. ix. 1876, p. 62 148 MEDICAL OPHTHALMOSCOPY. the papillae being still red and rather prominent. He sub- sequently had some convulsive attacks and symptoms of ulcerative endocarditis, and died four months after the onset of the hemiplegia. There was softening below the posterior cornu of the right lateral ventricle, extending to the tip of the occipital lobe, and involving the tail of the corpus striatum and the fibres passing from the thalamus to the occipital lobe. The part softened was in the region of the posterior cerebral, but no obstruction of this vessel was found ; the calcarine artery could not be traced. Double neuritis, with slight changes in the contiguous retina, was seen by Stephen Mackenzie 1 in a case of left hemiplegia, no doubt the result of embolism of the right middle cerebral artery. The softening found five weeks after the onset was slight, and the middle cerebral was pervious, although thickened, the probability being that the plug had broken up and had been carried on into some of the terminal branches of the artery. Splenic infarctions were also found. Three days after the onset, the discs (previously normal) were swollen, and three weeks later the swelling persisted, but with a good deal of opacity, the vessels being " buried in exudation." One or two haemorrhages existed close to the discs. The appearance of the discs, Dr. Mackenzie has in- formed me, was precisely that often seen in cerebral tumour. A grey infiltration, incompletely veiling the disc, and extending into the adjacent retina, is figured by Bouchut from a case of hemiplegia in a child of seven years with mitral regurgitation. Most of the above cases seem to be distinct instances of the association of neuritis and softening. It is important to note that all were cases of softening from embolism, that in most the plug came from valves the seat of actual recent inflammation, and that in some the development of the optic neuritis was accompanied by evidence of wide-spiead dis- turbance of the cerebral functions. There is nothing in the mere process of necrotic softening, the mere breaking up of the nerve-elements into discontinuous particles separated 1 " Brain," Jan. 1879. CEREBRAL SOFTENING. 149 by liquid, which can cause optic neuritis, according to our present knowledge. But the process is never one of simple necrosis of the tissue-elements. Adjacent inflammation always accompanies it just as it does the suppuration of a gangrenous foot. Inflammation in parts of the body shows wide variations in its character, variations which at present are imperfectly understood but are certainly of vast importance. One of the differences in character is the tendency to spread. It is certain that emboli from an inflamed cardiac valve have a special power of exciting inflammation a power which is ascribed, with much plausi- bility, to the presence of organisms within them. The inflammation thus excited or conveyed varies in its intensity and in its tendency to spread, just as the inflammation in the heart seems to vary in its " malignancy." It is in- evitable, therefore, that in some cases the inflammation that is secondary to the process of necrosis should have its character modified by the influence of the plug ; the organisms of it, if organisms are the morbific agents, may readily find their way into the inflamed brain tissue and determine characteristics possibly more extensive than the immediate influence of the presence of the organisms them- selves. And it is thus inevitable that the cases should present such differences as we have noticed, and that in some the spread of the irritative process should lead to an optic neuritis, slight or severe, which is absent in other cases. It may be well, however, again to remark how easily the error may be made of mistaking a soft glioma for a patch of softening. 1 1 The following case has been recorded by Drs. Darby and Upham ("Boston Med. and Surg. Journal," vol. Ixxii.) as one of softening, in which, however, there was no evidence of embolism. A man aged twenty-six had a hemiplegic attack, followed by fits and double " neuro-retinitis " with haemorrhages. A necropsy some months later revealed a peculiar softening of the corpus striatum and optic thalamus, grey and white gelatinous soft tissue, to the naked eye very like a glioma, but, on microscopic examination, only the signs of degeneration were visible. It is to be remarked, however, that many parts of these tumours may contain, and even appear to consist only of, products of degeneration. A careful search may be necessary for the very delicate cells of which they consist. 150 MEDICAL OPHTHALMOSCOPY. In a case recorded by Leber of supposed neuritis from softening, the fact that the "softening" was a soft glioma was not suspected; the nature of the lesion was only dis- covered on microscopic examination. Atrophy of one optic nerve is said to succeed softening, embolic or other, just as it has been observed to succeed haemorrhage. This result is supposed to be due to the seat of the lesion being such as to damage the nutrition of some part of the brain to which the optic fibres are related. Embolism of the middle meningeal artery, which supplies the dura mater near the optic nerve, is said also to cause atrophy of the latter. 2. SOFTENING FROM THROMBOSIS. (1) Arterial This may be due to syphilitic or degenerative disease of the vessels, or to blood-changes. Syphilitic Disease. In softening from syphilitic disease of vessels, associated ophthalmoscopic changes are common, consecutive changes are very rare. The associated conditions are the various changes which are due to syphilis, and which need not be mentioned here. They come practically under the cognisance and teaching of the ophthalmic surgeon. This is because their active stage affects sight and seldom coin- cides with disease elsewhere. But the changes in the eye in inherited syphilis come very often under the notice of the physician, and in both the inherited and acquired diseases the relics of the syphilitic disease are of extreme value to the physician. Among the diseases in which their signi- ficance is of the greatest importance are those now under consideration. In cerebral softening such indications are, of course, of the greatest significance in the case of persons who have not reached the period of life at which vascular degeneration is common. In the latter condition, the recognition of con- stitutional syphilis still leaves us in some doubt, and care must be taken to avoid attaching undue weight to its signs. Causal indications are of significance, in general, in proportion to their isolation. At the same time it must not be forgotten CEREBRAL SOFTENING. 151 that syphilitic vascular disease does occur, and not rarely, in the degenerative period. Syphilitic disease and atheroma have been observed post-mortem in the same individual. In doubtful cases, the recognition of the ocular signs of syphilis should always lead to a trial of the special remedies. Although associated changes are common, consecutive alterations in the eye are very rare in softening from syphilitic disease of vessels. Only one case has yet been recorded in which congestion or inflammation of the optic papilla was apparently due to this cause. The proof can only be given by pathological demonstration of the absence of any other morbid process. The case is one described by Leyden, but it is not quite conclusive, since the inflammation of the papilla may have been a primary lesion. 1 In the few recorded cases in which such changes were observed, syphilitic growths in the brain were associated with the vascular disease, and the ocular change was due to the former, not to the latter. I have met with one case in which a fortnight after the sudden onset of hemiplegia, in a patient who had had constitutional syphilis, there was slight distinct optic neuritis ; but the absence of growths could not be excluded, and preceding pain in the head for six months rendered it probable that there was more than arterial disease. In all cases of this kind the question arises, can the coin- cident papillitis be an independent effect of the syphilitic poison ? This question we cannot at present answer with a positive negation. Syphilis probably can cause a retro-ocular neuritis ; it certainly can cause retinitis involving the pa- pilla. Isolated double papillitis may be an effect of many morbid states of the blood, varied in character, with a virus 1 "Zeitsch. f. Klin. Med.," 1882, Bd. ii. p. 173. The patient, a man aged eighteen, died from limited softening of the inner part of the right crus and adjacent part of the pons, due to syphilitic disease of the extremity of the basilar artery ; and seven days after the onset of the acute symptoms there was found " neuro-retinitis with choked disc as in cerebral tumour " (Dr. Hiller), although no other lesion than syphilitic disease of the vessels could fee found. The details from an ophthalmoscopic point of view leave much to be desired. 152 MEDICAL OPHTHALMOSCOPY. organized or inorganic, and cases are met with possibly presenting a pure syphilitic papillitis. Thus this possibility constitutes at present an unbridged break in the proof that softening from syphilitic disease of the vessels causes papillitis. The difficulty is the greater in proportion as the papillitis is intense. It then exceeds the degree met with even in softening from irritative embolism, and on the other hand resembles that of which the chief causes are tumours and blood-states. Degenerative Disease : "Atheroma" Cerebral softening from this cause is rarely associated with any similar morbid state of the retinal arteries, which are below the size in which " endarteritis deformans " is common. Occasionally, thick- ening of the wall or undue tortuosity of the retinal arteries has been observed. But it is doubtful whether the appear- ances that have been described as atheroma are really such, or if this state has ever really been met with. The malady is an affection of the inner coat, and such alterations as are depicted in PL XII. Fig. 1 are manifestly seated in the outer coat of the vessel or in its sheath. Changes in the retina in the old have been ascribed to atheroma lessening the blood-supply, but such an inference has, of course, no bearing on the question whether atheroma occurs or not. Atheroma of cerebral vessels is very common in cases of chronic kidney disease, and it is in them that these appear- ances have been chiefly seen, but this does not prove their nature. Various elements in the retina suffer in renal disease, and hence all forms of albuminuric retinitis may be associated with cerebral softening. They are also associated r in the same manner, with cerebral haemorrhages, and hence the affection of the retina and even haemorrhages in it are evidence only of probable disease of the arteries of the brain. In the case figured in PL IX. 1, for instance, although there was a retinal haemorrhage due to the effect of chronic renal disease, the cerebral symptoms pointed unmistakably to softening rather than to haemorrhage. Consecutive changes are very rare in senile arterial throm- bosis. Optic neuritis certainly due to this cause is scarcely CEREBRAL SOFTENING. ] 53 ever met with. Its occurrence would not be surprising, since the secondary inflammation about an infarcted area might be adequate to cause it, but practically it is almost unknown. A case of optic neuritis, however, with and apparently due to, atheromatous softening is recorded by Wilbrand. 1 In some cases on record it is most probable that the papillitis was nephritic a source of fallacy to be carefully borne in mind. 2 Atrophy of the discs has, in rare cases, been observed to supervene. In some cases, however, the obstruction by thrombosis of the internal carotid may give rise to alterations in the eye, which have been hitherto observed only after death, but which must be attended by marked ophthalmoscopic changes. Such a case was described long ago by Yirchow. 3 A man aged forty-six who had an attack of apoplexy, leaving right hemiplegia, died from a melanotic cancer of the liver. The internal carotid was obstructed by a thrombus, probably spontaneous, since no embolus was found, and there was fatty and calcareous degeneration of the wall of the vessel. There was a large area of softening in the left hemisphere. The ophthalmic artery was patent, evidently by a collateral circulation having been set up. The vitreous was trans- parent, the retina thickened, and around the papilla were four opaque white spots, which were, however, found to be due to the persistence of the medullary sheath of the nerve fibres. The ganglion cells were granular. The elements of the 1 "Arch, fiir Ophth.," Bd. xxxi. p. 119, PI. 3. 2 A case is recorded by Wurst, for instance (Virchow's " Jahresbericht," 1877, ii. 463, from the " Przeglad lekarski "), in which optic neuritis, " stauungs-papille," was associated with cerebral softening a spot the size of a walnut in the posterior portion of the left hemisphere, and a second, the size of a bean, in the pons Varolii. Sudden complete amaurosis had come on a few days before. There was, however, interstitial nephritis and hypertrophy of the heart, and it is most probable that the optic neuritis was due to the renal disease. In the remarkable case figured in PI. VI. 2, optic neuritis co- existed with softening from extensive arterial disease, the results of old traumatic meningitis, but inflammatory (?) growths existed beneath two old fractures of the skull. The man had had syphilis, but the lesions presented no syphilitic character. 3 "Arch, fur Path. Anat.," Bd. x. 1856, p. 189. 154 MEDICAL OPHTHALMOSCOPY. nuclear layers showed a tendency to arrange themselves in lobular cylinders. Another case of the same character which came under my observation has been before alluded to (p. 32), and in it the ophthalmoscopic changes would pro- bably have been much more striking. Although the origin of the ophthalmic artery was closed by clot, the central artery of the retina retained a channel, narrowed by clot formed upon its walls. Some retinal branches were pervious, others closed. The retina presented atrophy of all its structures, and was reduced to about two-thirds of its normal thickness. It is important, therefore, to watch the fundus continu- ously in cases of thrombosis in the region of the internal carotid. It is probable that the obstruction of the carotid would always be accompanied by a sudden diminution in the size of the retinal artery, the degree of this, and the occurrence of parenchymatous changes in the retina, depend- ing on the character of the anastomoses of the ophthalmic artery. These are usually abundant, chiefly with the facial, but also to a less extent with the middle meningeal. Softening from Arterial Thrombosis due to Blood States. In this condition, which is rare except in the puerperal state, ophthalmoscopic changes have been found only in cases of septicaemia (q. v.). Softening from Venous Thrombosis. Ophthalmoscopic changes are unknown. In thrombosis of the cavernous sinus, it is said that there may be double optic neuritis and exophthalmos. Slow obliteration of this sinus, however, may cause no ophthalmoscopic changes. 3. PRIMARY SOFTENING. Primary softening of the brain is still a region of cerebral pathology of which we know little. Apparently three forms occur, acute and subacute inflamma- tory softening, and a senile form of chronic softening. Inflammatory Softening. The acute form is only known in connection with injuries in which meningitis is never absent, and ophthalmoscopic changes must be ascribed to this rather than to the morbid process in the brain. ABSCESS OF BRAIN. 155 Subacute Softening is a possible lesion, symptoms suggest- ing it being met with especially in gouty persons, but no optic neuritis has been seen in connection with it a fact of much importance, since it is upon this and upon the occasional retrogression of the symptoms that the hypo- thetical diagnosis has chiefly rested. Chronic Softening is a certain senile lesion, but is extremely rare. A few cases have been described, but in this the nature of the malady has not been suspected during life. Apparently it is not attended with ophthalmoscopic changes. ABSCESS OF BRAIN. The only changes known are consecutive. Optic neuritis, which differs in no respect from that due to cerebral tumour, is found in many cases : the papillae are swollen, red, and opaque, the vessels concealed, and haemorrhages may be pre- sent. But the neuritis is frequently absent ; the rapidity with which the abscess develops or increases being, apparently, the chief element in the disease on which the presence of neuritis depends. This element, however, is merely the result of the intensity of the inflammation which causes the abscess, and so we trace the result to the condition which, beyond any other, seems to determine this effect of a cerebral lesion, the amount of irritation produced by the central disease. This condition, however, it should be remembered, is subject to another that of time. Several days are necessary for the development of neuritis ; sometimes, indeed, when the morbid process is in a distant part of the brain, several weeks may be required. Hence lesions in which the irrita- tive element is most intense often end the life of the patient before their effect on the eye can be produced. The changes in the optic nerves do not differ from those met with in tumours, &c. Dropsy of the sheath has not often been looked for, but was found in one case (Peipers), the abscess being in the right temporal lobe. The only conspicuous difference between the cases of 156 MEDICAL OPHTHALMOSCOPY. abscess with, and those without, optic neuritis, is that due to the course of the malady. In perhaps the larger propor- tion of the cases with neuritis the bone disease causing the abscess was the result of injury. In two instances recorded by Hughlings-Jackson this was the case. The position of the abscess has been in the temporal and posterior parts of the parietal lobes beneath the surface. In a case recorded by Benedikt it was outside the optic thalamus. Abscess in the left hemisphere of the cerebellum, in a case recorded by Pfluger, 1 caused double optic neuritis, well marked, with capillary haemorrhages on the papilla, and large extra- vasations beyond its edge. TUMOURS OF THE BRAIN. A. GROWTHS. Associated Conditions. Growths may occur in the eye, of the same nature as the growth in the brain, but such cases are not common. The disc shown in PI. III. 4 is the left disc of a boy, whose right eye was the seat of a tuber- cular growth, in whose brain there was another similar growth, of which vomiting and optic neuritis were the only signs. In such a case the ocular growth becomes an important symptom. Choroidal miliary tubercles might be expected to be found occasionally in cases in which a tubercular mass exists in the brain, but they occur rather in acute general tuberculosis, while tubercular tumours of the brain are rare in that condition. Their nature is rather that of the tubercular condition that we associate with the word " scrofula." This differs in course and associations from acute tuberculosis, although presenting the same bacilli. Thus choroidal tubercles are met with far more frequently in tubercular meningitis than in the tubercular growths. Consecutive Changes. Optic neuritis is the ocular lesion in intra-cranial growths, which are, on the other hand, its most frequent causes. It is present, in various degrees, in a large 1 "Arch. f. Ophth.," vol. xxiv. 1878, pt. 2, p. 171. TUMOURS OF THE BRAIN. 157 proportion of the cases of intra-cranial tumour ; in what proportion cannot be determined by statistics from published cases, on account of the selection for publication on special grounds. From my own experience I should say that neuritis occurs in about four-fifths of the cases. This is a much smaller proportion than has been deduced from published cases. Annuske and Reich, for instance, collected eighty-eight cases with ophthalmoscopic examination and autopsy, and found that there was no ophthalmoscopic change in only five per cent. But these cases have all been recorded during the period when ophthalmoscopic observation possessed the interest of novelty, and a far larger proportion of cases with neuritis has probably been published than of cases without neuritis. It does not seem possible at present to say on what the occurrence of optic neuritis depends ; why it is present in the majority, absent in the minority. Position of growth has apparently no direct influence on its occurrence, and only an indirect influence, insomuch as secondary meningitis near the nerves is more considerable when the tumour is not far from that part of the base. But the influences through which neuritis is caused seem to be exerted from any situation. It has been met with in tumours of every part of the cerebral hemispheres, of the pons Yarolii, the crura cerebri, the cerebellum. Tumours of the medulla below the pons usually cause death too quickly for optic neuritis to be developed ; but my colleague, Dr. T. Barlow, has met with a f ca.se of neuritis from a small tumour in the middle of the medulla oblongata. Allbutt thinks that .tumours of the anterior lobes are more uniformly attended with neuritis than those of other parts, but I have seen a large growth in the anterior hemisphere with normal discs throughout. Nor does the nature of the tumour apparently influence the development of neuritis. It occurs with every variety glioma, sarcoma, tubercle, syphiloma. The most frequent forms of tumour are those which are most usually asso- ciated with optic neuritis ; and they are also those in which 158 MEDICAL OPHTHALMOSCOPY. neuritis is most frequently absent syphilomata, tubercles, and gliomata. At the same time, growths that infiltrate and only damage the nerve elements late in time and little in comparison with the amount of the growth, seem to have less tendency to cause neuritis than those which damage readily. A like difference perhaps, indeed, related is seen from the amount of adjacent inflammation that is produced. The greater these secondary processes about the tumour, the more readily does neuritis occur. Hence the nature of a growth has an indirect, though not a direct, effect. In a case of my own, of a glioma infiltrating almost the whole of the medulla oblongata, which was under obser- vation for two months before death, there was no optic neuritis at any time. The size of the tumour also seems to have little influence in producing neuritis. I have twice seen syphilomata the size of half an egg without optic neuritis. One of the largest intra-cranial tumours I have met with was a sarcomatous growth, the size of the closed fist, growing from the dura mater, and compressing, not invading, the brain over the posterior portion of the parietal lobe, a tumour which must have increased the intra-cranial pressure as much as it is ever increased directly by a growth, and in this case the discs, repeatedly examined from soon after the onset of the symptoms until death, about six months later, were perfectly normal; and a similar case is fully described by Byrom Bramwell in his recent work on " Intra-cranial Tumours," pp. 11, 12. On the other hand, Benedikt has recorded a case of well-marked neuritis with much swelling and haemor- rhages, due to a tubercle of the pons Yarolii no larger than a cherry. There were no signs of meningitis. The chief facts at present known regarding the mechanism by which optic neuritis is produced have been already dis- cussed (p. 78). Some points having special reference to tumour may be again adverted to. It is clear from the facts stated above and a long list of similar cases might be given that encephalic tumours do not cause neuritis by the direct effect of their mass on the intra-cranial pressure. Perhaps TUMOURS OF THE BRAIN. 159 no form of cerebral tumour is attended with optic neuritis in a larger proportion of cases than glioma, which commonly does not press upon, but invades, the brain substance, and often occupies the invaded tissue almost bulk for bulk. It has been thought that the rapidity of growth of a tumour influences the occurrence of optic neuritis, but a limited experience of these cases, or a very short search among recorded cases, disposes of the hypothesis, at any rate in an absolute form. Rapidity of growth may be one factor in the production of neuritis, and an important factor in determining the rapidity or slowness of the course of the neuritis, but it certainly does not alone determine its occurrence. There is, however, one mode in which neuritis is produced which may sometimes be distinctly traced post-mortem, viz., by the mechanism of meningitis. The disc shown in PL III. 3, for instance, was in a case of tumour originating in the pineal body and invading the anterior corpora quadri- gemina. The changes in the disc were very gradual in development, and moderate in degree. There was no general meningitis, but the orbital lobules were gently adherent, and fine shreds of lymph were visible on the dura mater after their separation. The optic nerves in front of the commissure were swollen and reddened. Microscopical evidence of neuritis of the nerve-trunk was very distinct. In another case of tumour (glioma) of the anterior lobe, in which the neuritis was of the form most characteristic of tumour, greyish-red, with much swelling, the microscopic changes in the nerve-trunk, most intense behind the foramen, indicated a communicated descending neuritis, and old adhesions over the tumour showed that there had been local meningitis. It must be remembered that, in such cases, whatever mechanism leads to the occur- rence of neuritis without meningitis may influence the degree and course of that which is set up by meningitis. In most cases optic neuritis is a transient event in the history of a cerebral tumour, not a constantly-associated condition. A tumour may exist and cause symptoms for a 160 MEDICAL OPHTHALMOSCOPY. considerable time without leading to any change in the eyes, and then optic neuritis may be rapidly developed, run its course, and pass away, in many cases leaving atrophy of the discs, while the symptoms of the tumour continue or increase for months or years. It is not only that a tumour takes a certain time to cause optic neuritis, but it often exists for a considerable time before the mechanism for the production of neuritis, whatever that may be, is set in operation. A tumour may exist and cause symptoms for years before optic neuritis is produced. A striking instance of this is afforded by a case which was under the care of Dr. Hughlings- Jackson, who had examined the eyes repeatedly during nine months, and always found them normal. Then neuritis came on, but subsided, and in six weeks the discs were again normal, and continued so till death. The microscopical appearance of part of the papilla is shown in Fig. 22, p. 63. Dr. Jackson has recorded 1 a still more significant case, in which a man had had symptoms of cerebral tumour for nine years : during the last three years his discs had been repeatedly examined and found normal. Six weeks before death neuritis was discovered. In many cases in which neuritis occurs long after the symptoms of tumour have existed, its occurrence precedes death by no long interval. The appearance of the discs in intra-cranial tumour is that of neuritis in its most typical form, as described in a preceding page (p. 49). The neuritis may stop at one or another of its stages, constituting what may be termed varieties of neuritis. As already stated, until our knowledge of the relation of the appearances to their causes is much more extensive, and founded on more minute and full observation of the conditions of origin, macroscopic and microscopic, a division of neuritis into varieties according to its degree is much more useful than a separation of forms according to hypothetical modes of origin. Those varieties or stages have been already enumerated (p. 93). Each of the earlier stages may or inay'not be accompanied by obvious 1 " Med. Times and Gazette," Sept. 4, 1875. TUMOURS OF THE BRATN. 161 over-distension of veins, and each may be accompanied by extravasations. The neuritis of tumour is in most cases double, sometimes equally advanced in the two eyes, often more intense and subsiding earlier in one than in the other. Rarely the affection of the disc is unilateral, and this, although the tumour may be in the brain, where growths commonly cause double neuritis. In two cases of this character recorded by Hughlings-Jackson, 1 and in one described by Field, 2 the neuritis was on the side opposite to the tumour. In one recorded by Greenfield, 3 however, where unilateral neuritis accompanied an abscess in the top of the temporo-sphe- noidal lobe, the neuritis was on the same side as the lesion. Possibly the inflammatory process extended to the nerve as it passed to the optic foramen. Symptoms. The symptoms of the neuritis which accom- panies cerebral tumour have been already fully described (p. 69) . It must be remembered that all symptoms may be absent, the acuity of vision, the fields of vision, and colour- vision may also be unaffected, as in many of the cases figured in the plates and referred to in the description of the symptoms of neuritis. It must also be remembered that affections of sight of various kinds may co-exist with neuritis, and be due, not to the intra-ocular, but to the intra-cranial disease. Regarding the course of the neuritis in cerebral tumour, it is important to note that the neuritis often coincides at its onset with an obvious increase in the other symptoms of the cerebral tumour. This was pointed out, long ago, by Dr. Hughlings-Jackson. Instances of it are frequent, but at the same time exceptions are not rare. It is probably true, however, that the occurrence of optic neuritis indicates progress in the morbid growth and its consequences. "With regard to the course of the neuritis, it is necessary to distinguish two classes of cases. One of these is where the 1 "Ophth. Hosp. Rep.," 1871, and " Brit. Med. Journal," July 20, 1872. 2 " Brain," July, 1881, p. 247. 3 " Brit. Med. Journal," 1886, p. 317. M 162 MEDICAL OPHTHALMOSCOFY. progress of the tumour, either spontaneously, or under the influence of treatment, becomes lessened or arrested after the onset of the neuritis; the other, where the progress of the tumour to which the neuritis is due is uninterrupted. In the first event, the neuritis commonly subsides. It may pass away completely, even although it has reached the stage of considerable swelling and obscuration of disc and vessels, with distended veins and narrowed arteries, and sight may throughout be unimpaired. This occurred, for instance, in the cases shown in PL IV. 1, 2, 3, 4, Y. 3. Or, less commonly, a slight or moderate damage to sight, from the inflammatory swelling and damage to nerve fibres, may pass away. Yery frequently, however, although the neuritis subsides, amblyopia occurs or increases when the nerve fibres suffer from compression from the contracting tissue. The last is the more likely to occur the longer the neuritis has lasted, because there is then more tissue formed, incapable of removal. Instances of each course are often seen in syphilitic tumours, and not rarely where there is strong reason to believe that a scrofulous tumour exists a cerebral or cere- bellar tubercle. In cases in which the neuritis is slight and commencing, a subsidence of the neuritis may be the first sign of the improvement. It was so in the case figured in PL Y. 4, in which the neuritis passed away before there was any improvement in the symptoms, and then slowly the paralysis lessened, and improved up to a certain point, at which it became stationary, no doubt from the tumour (probably tubercular) ceasing to grow, and becoming, from partial degeneration, smaller, and thus permitting damaged tissue near it to recover, while the destruction, which had before taken place, persisted. In syphilitic tumours, arrest can be obtained much more rapidly than in tubercular growths, and a considerable neuritis may pass away without damage to vision (PL IY. 1 & 2, 3 & 4, VI. 4 & 5). In these cases, however, if a considerable neuritis exists before the treatment affects the tumour, tissue-changes too often progress in the disc to an extent which leads to loss of sight TUMOURS OF THE BRAIN. 163 even though ultimately the cerebral lesion ceases to increase and becomes quiescent (PL IV. 5, 6). Occasionally, although rarely, an analogous arrest of growth occurs in other tumours, attended with degeneration and calcification. The neuritis may, in these cases, subside with the change in the growth. In the cases in which the tumour causing the optic change continues its growth, as most tumours of other descriptions than the tubercular and syphilitic growths, the course of the neuritis differs according to the intensity of the inflammation. When this is considerable, the neuritis remains for a time at its height ; commonly the signs of strangulation are developed, and then the neuritis subsides slowly into atrophy. The inflammation, as it were, terminates itself, and its con- sequences remain. "When the neuritis does not reach so intense a grade it has a much longer duration. The lilac- grey neuritis, with little sign of strangulation, may persist for months without much change, and then slowly subside to atrophy ; sight perhaps being little damaged until the sub- sidence, when the tissue formed during the long duration of the inflammation compresses the nerve-fibres. In a still slighter degree, that of " slight neuritis," for instance (p. 93), the change may persist without alteration for a very long time. In the case represented in PL V. Figs. 1 and 2, the appearance of the discs was unchanged for a year and a half , and when the patient was again seen a year later, the neuritis was nearly in the same degree, although the least inflamed portion of the disc had become grey and sight was gone. There is at present little direct information regarding the conditions which determine the course and duration of neuritis in the cases in which the cerebral tumour continues its progress. But it has been seen that the onset of neuritis may accompany, or succeed, an increase in the symptoms due to the tumour, such as indicates an increase in the size or irritative action of the growth itself. And we have seen also that the early subsidence of neuritis may attend a diminution in the other effects of the tumour such as may 164 MEDICAL OPHTHALMOSCOPY. be taken as indicative of an arrest of growth, or even a diminution in size. These facts taken together indicate that the course of the neuritis is, to some extent at least, depend- ent on, and influenced by, the course of the tumour. This conclusion is corroborated by the fact that in some cases of tumour of very chronic nature, the course of the neuritis is equally chronic. The case mentioned above (PL V. 1 & 2) is a striking illustration of this, since the progress of the very marked symptoms was but slight during the year and a half, in which the neuritis was absolutely stationary. In rare cases, as in that recorded by Field and above referred to, in which, without retrogression of the tumour, neuritis subsides without influencing vision, the affection of the optic nerve is probably largely due to excessive secondary effects of the growth. In this case there was adjacent softening out of all proportion to the size of the growth itself. Significance. The value of optic neuritis as an indication of the existence of an intra-cranial tumour is very great. Tumour is the cause of the majority of cases of neuritis due to intra-cranial disease. On the other hand, neuritis is present, at some period, in at least four-fifths of the cases of tumour, and it may be the only unequivocal sign of the organic intra-cranial disease. It is important to remember that the neuritis is a transient condition, however long its duration, and that its effects continue a much longer time than the inflammation. The atrophy left by neuritis may constitute unequivocal evidence of the antecedent inflammation, and where actual atrophy is not left, the state of the disc and the narrowing of the vessels may show clearly that there has been previous neuritis. Unfortunately it is not always possible, in old- standing cases, to say from the aspect of the discs how the atrophy originated. If the neuritis was moderate, and the adjacent choroid undisturbed, a clean cut disc may be left, and the narrowing of the vessels may not be greater than is sometimes seen in cases of atrophy of the disc of other forms. The concealment of the lamina cribrosa is, however, usually complete. Valuable information may also be gained TUMOURS OF THE BRAIN. 165 from the circumstances under which the loss of sight came on ; the existence at the time of cerebral symptoms makes it probable that the atrophy was due to neuritis. It is not only during life that neuritis may assist the diagnosis of tumour. As an instance, I may mention the case of a man who died soon after his admission, with hemi- plegia, into University College Hospital. The autopsy re- vealed a soft area, bounded and crossed by trabeculse of firmer tissue, which was at first thought to be an area of old softening with some connective-tissue formation in and about it. It was suggested, however, that it might be a tumour. Before it was examined with the microscope, the backs of the eyes were removed, and found to present distinct evidence of neuritis swollen papillae with haemorrhages. A diagnosis of probable tumour was therefore made, and was fully confirmed by the microscope. From the facts given above it is evident that optic neuritis may, in some cases, afford not only diagnostic, but prognostic indications. A subsidence of neuritis which has not reached any considerable degree of intensity, may be taken as indicat- ing, in most cases, a retrogression of the growth, and a neuritis of very chronic course affords evidence that the progress of the tumour is equally chronic. It might be supposed, there- fore, that the absence of neuritis would indicate still greater ohronicity. This, however, cannot be inferred, since tumours of very rapid course may be unattended with neuritis, and it is only when neuritis is actually present that a prognostic inference can be drawn. It has been remarked that optic neuritis in tumour of slow growth often occurs not long before death. In such cases, also, it affords some prognostic indication. In more acute cases, or in those in which it developes early, it has not the same significance. It would appear as if the mechanism for the production of neuritis were, in the latter cases, readily excited, while in the former it is the result of changes of such a degree as to be incompatible with the long continuance of life. 166 MEDICAL OPHTHALMOSCOPY. Simple atrophy of the optic nerves also results from intra- cranial tumours, but only by the mechanism of compression of the fibres of the optic nerve where all those proceed- ing from one eye or both can be destroyed. Thus, such atrophy only occurs when there is pressure on the chiasma, or on one of the nerves in front of the chiasma. Pressure on one tract seldom causes sufficient alteration in the disc to be attended wi.th more than slight pallor and slight shrinking in both eyes. Theoretically, pressure on both tracts should cause conspicuous atrophy, but no instance is known ; perhaps life, in such a case, is not prolonged for the time necessary to permit visible alteration. The simple atrophy is thus " secondary " in nature, and due to the direct effect of the growth on the fibres of the nerves, and also to the secondary consequences of the tumour especially the pressure of ventricular effusion on the chiasma. It is doubtful whether this form of atrophy ever results from the damage to the nerve by inflammation, such as may be produced by a secondary meningitis. In tumours, the tendency for a communicated inflammation to spread down the nerve is so strong that optic neuritis seems to be invariable. But the visible inflammation is often slighter than the failure of sight, and the ultimate atrophy may be in part simple although apparently papillitic. Such atrophy has the characters of secondary atrophy of the optic nerves, the features and origin of which have been already described. Great caution is also necessary in inferring, from the appearance of discs long after the onset of the atrophy, that this was simple and not neuritic. We have already seen that the characters of the latter may ultimately resemble very closely those of the former. Moreover, not only may there be a combination of the two processes (secondary atrophy from greater damage near the chiasma, and the atrophy from papillitis), but the two may occur at different periods. The chiasma may be compressed by ventricular effusion, or even by a fresh increase in the tumour, after neuritis has gone on to partial atrophy. Sight, damaged much or little by the neuritic process, may fail rapidly at a TUMOURS OF THE BRAIN. 167 subsequent period from secondary pressure effects. This was well illustrated in the case of a man who was admitted with double optic neuritis, impairment of vision, and symp- toms pointing to a tumour of the base involving the ocular nerves. Under treatment with iodide, the neuritis quite subsided, and vision improved until it became almost normal, with perfect fields. Nine months later, however, deterioration of sight again occurred, the fields remaining normal, but nothing could be detected with the ophthalmo- scope. Six months after the relapse he had a foetid smell in the left nostril and loss of vision in the temporal half of the right field. A few months later there was failure of sight in the temporal half of the left field, and there were also indications of pressure on the right fifth and left third nerves. He was under observation for five years later, during which time most of the symptoms passed off. There was, however, atrophy of both discs, with qualitative perception of light only, and complete loss of the sense of smell. There must, in this case, have been a tumour at the base of the brain, pressing on the anterior part of the chiasma, and also involving the nerves mentioned. E.-HYDATID CYSTS. Associated Changes. A cysticercus has been occasionally observed in the vitreous humour, but the coincidence of a parasite in the eye with symptoms of cerebral tumour due to another in the brain, has not, I believe, hitherto been recorded. Consecutive Changes. Optic neuritis is frequent in cases of hydatid disease of the brain, and has all the characters of the neuritis which occurs in growths swollen papilla, obscured and tortuous vessels, haemorrhages. It has been observed with hydatid cyst of both cerebrum and cerebellum. It may go on to consecutive atrophy, life being prolonged for years. The few cases on record of neuritis associated with cysts in the brain, the nature of which was not ascertained, were probably examples of hydatid disease. 168 MEDICAL OPHTHALMOSCOPE. LABIO-GTLOSSAL PARALYSIS. In chronic bulbar paralysis, due to degeneration, ophthal- moscopic changes are extremely rare. Unilateral atrophy was once seen by Gralezowski, and Robin quotes a case from Dianaux of rapid atrophy of both nerves in the course of the affection in a man aged sixty-seven. It was accompanied by transient paralysis of one sixth nerve. Sight was lost com- pletely in two months, but considerable subsequent restoration of vision (up to T V) occurred. INTRA-CRANIAL ANEURISM. Miliary aneurisms have been spoken of in connection with cerebral haemorrhage. Intra-cranial aneurisms of larger size are not, as a rule, accompanied by any associated ocular changes: those of the central artery of the retina being too rare to be of significance. Nor do they often cause consecutive changes, unless their position is such as to press upon the optic nerve (causing unilateral amaurosis and secondary atrophy), on the chiasma (bilateral atrophy), or, very rarely, on the optic tract (causing hemianopia). An aneurism of the internal carotid may obstruct the cavernous sinus, and cause transient distension of the retinal veins, without papillary changes, but the pressure is relieved by the free communication of the ophthalmic and facial veins ; the enlarged angular vein may be conspicuous beneath the skin. In rare cases, however, an aneurism in this situation has led to optic neuritis, as in a case recorded by Michel ; x double neuritis, with evidence of obstruction, was the first sign of a cirsoid aneurism of the two internal carotids. It pressed on the optic nerves at the spot, and these showed evidence of interstitial inflamma- tion. Holmes of Chicago has recorded several cases in which optic neuritis co-existed with intra-cranial bruit, and in the only one on which a post-mortem was obtained an 1 "Arch. f. Ophth.," xxxiii. 2, p. 225. INTERNAL HYDROCEPHALTJS. 169 aneurism of the internal carotid was found ; but there was also an adjacent growth in the pituitary body. In an interesting case 1 (by Jeaffreson of Newcastle-on- Tyne), although there was no post-mortem examination, an aneurism of the internal carotid was most probable, and caused unilateral papillitis. A loud intra-cranial murmur could be arrested by compression of the carotid ; there was paralysis of the third nerve, and subsequently aphasia developed. The origin of the papillitis in these cases is probably a descending inflammation, extending to the nerve from that which always exists around an aneurism. That the papillitis is not the effect of compression of the cavernous sinus is probable from the fact that aneurisms which produce the same effect on the sinus may or may not be accompanied by papillitis. Moreover, when there is papillitis the enlarged communications with the facial vein may (as ia Jeaffreson's case) afford the same evidence of relief to mechanical ob- struction, which is supposed to prevent the papillitis (when this is absent) by those who ascribe it to the mechanical influence alone. INTERNAL HYDROCEPHALUS. Simple internal hydrocephalus, without a growth, is not at first attended by ophthalmoscopic changes unless the state is due to inherited syphilis. They may be absent through- out, even though the distension of the ventricles is such as to cause a marked increase in the size of the head. Some- times there is slight fulness of the retinal veins. Sight often fails at a later period, and in some cases early, and the signs of simple white atrophy of the optic nerve are then present. In several cases the onset of the atrophy has been watched, and the occurrence of any neuritic process excluded. In a few cases the atrophy has been preceded by signs of neuritis similar to that seen in tumour; it is usually slight in degree, but was considerable in a case recorded by Wildbrand and Binswanger. 2 1 "The Lancet," March 8, 1879. 2 "Centralbl. f. med. Wiss.," 1879, p. 923. 170 MEDICAL OFHTHALMOSCOPY. The simple atrophy of the nerves is usually due to the pressure of the distended third ventricle on the optic chiasma. In one adult case, mentioned by Forster, the distended ventricle appeared at the base of the brain as a bladder measuring ten lines by eight. It has been said by Bouchut that the ophthalmoscopic changes may serve to distinguish chronic hydrocephalus from the large head of rickets; but, owing to the lateness of the optic changes, the cases must be very rare in which the nature of the disease is not distinct long before ophthal- moscopic signs are present. DISEASES OF THE MEMBRANES OF THE BRAIN. MENINGEAL GROWTHS. Tumours springing from the pia mater always involve the cerebral substance to a greater or less extent, either by invasion or compression, and their effects have been included in the account of the cerebral tumours. Tumours springing from the dura mater differ in their effects according to two characteristics first, their tendency to invade ; secondly, their position, whether at the base of the brain or on the convexity. They commonly cause the same effects, in the brain and OD the eye, as growths in the brain itself. Growths springing from the dura mater of the base of the brain cause optic neuritis much more frequently. When in the front of the base, the inflammation around the growth may extend directly to the nerve. But when more distant, as in the posterior fossa, optic neuritis is still a frequent con- sequence and is often intense, even when the nerve centres are not invaded. Those that invade the brain have the same tendency to cause optic neuritis as tumours beginning in the brain substance. But the compressing growths have this tendency in far slighter degree, and it is less the slower the growth of the tumour. The more rapidly the MENINGITIS. 171 pressure is induced, the greater and more acute is the secondary inflammatory process in the compressed part, manifested by its softening. With very slowly growing tumours such softening may be entirely absent, and the tendency to the occurrence of optic neuritis is very much slighter. I have seen a tumour the size of the closed fist, which had compressed the hinder half of one hemisphere so as to produce a depression corresponding to the growth, in which there was no optic neuritis up to the end, and no sign that optic neuritis had ever existed. Hence the absence of optic neuritis is evidence of some value that a tumour at the surface of the brain springs from the membranes and is not invasive. Cases are on record, moreover, in which the optic neuritis was for a long time the only symptom of such a growth ; as in one case in which, after the neuritis had existed for months, hemiplegia came on, and was found to be due to a sarcoma springing from the periosteal dura mater, and which had compressed the left hemisphere of the cerebellum and the left side of the pons Yarolii. 1 In the case figured in PI. V. 5, optic neuritis, although not the earliest symptom, reached its height before any motor paralysis occurred. The tumour sprang from the dura mater, and had compressed the right side of the pons and right hemisphere of the cerebellum. In some of these cases secondary meningitis may be traced along the base of the brain. Such inflammation is produced by meningeal growths even more frequently than it is by tumours in the substance of the brain, and it may play an important part in the production of the changes in the eye. MENINGITIS. The effects of meningitis on the eye vary much according to its seat, being slight and late when the inflammation is at the convexity of the hemisphere, considerable and 1 Pagenstecher and Genth's "Atlas of the Path. Anat. of the Eyeball," PI. xxxiv. Fig. 3. 172 MEDICAL OPHTHALMOSCOPY. early when the meningitis is at the base. In some cases, especially of the former class, ophthalmoscopic changes are entirely absent, and when present they attend the stage of developed inflammation rather than the initial vascular disturbance. They thus afford, as Manz and others have pointed out, little support to the doctrine that the intra- ocular circulation shares and reveals disturbances of the encephalic vessels. It will be convenient to consider sepa- rately the changes in the several forms of meningitis. SIMPLE MENINGITIS. Acute simple meningitis of the convexity is usually unaccompanied by ophthalmoscopic changes ; only when it has lasted for a considerable time is neuritis sometimes developed. In a case of purulent meningitis, suppurative inflammation of the eye (chemosis and post-mortem infiltration of the retina with pus) was observed by Berthold, 1 but was probably coincident. Leube 2 has recorded a case of purulent meningitis of the convexity secondary to septicaemia in which there was intense inflammation of the optic nerve in front of the commissure. The only changes in the eye were distension of the retinal veins and haemorrhages. I have seen well- marked neuritis in a case of septic meningitis (post- puerperal) with grave cerebral symptoms. The patient recovered. Chronic simple meningitis of the convexity, slight in degree (such as that of which traces are often found in the brains of drunkards), is also commonly unattended by any optic change. The slight oedema and congestion of the disc, sometimes seen in chronic alcoholism, 'is probably the result of the toxaemic condition rather than of the encephalic change. Simple meningitis of the base is rare, except in association with tumour or some bone disease. Optic neuritis may occur by direct propagation, and in those cases in which the disease is chronic, the visible changes in the disc may be 1 "Arch. f. Ophth.," Bd. xvii 1874. 2 " Deut. Arch. f. klin. Med. ," 1878, xxii. 263. MENINGITIS. 173 considerable in degree and duration. Basilar meningitis is, however, in most cases tubercular or syphilitic. TUBERCULAR MENINGITIS : Associated Condition. Tubercles of the choroid may now and then be found in tubercular meningitis, and furnish valuable diagnostic information. But they are less frequent, as Cohnheim pointed out, in tubercular meningitis than in general tuberculosis without meningitis. Heinzel 1 never saw them in forty-one cases of tubercular meningitis which he examined with the ophthal- moscope, and the case figured (Fig. 49) was the sole instance in which they were found in twenty-six cases examined by Grarlick at the Hospital for Sick Children. The few recorded cases in which neuritis due to meningitis co- existed with tubercles of the choroid have been collected by Bruckner. 2 Consecutive Changes. A peculiar marbled reflection from the retina has been described by Leber and Hock, occurring especially in the neighbourhood of the veins. They have seen it in conjunction with tubercles of the choroid, and state that it is not due to neuritis occurring earlier. Nevertheless, redness of the disc is sometimes observed in association with this condition. 3 A somewhat similar reflec- tion, chiefly around the disc, has been described by Manz as the most frequent change. He associates it with oedema of the sheath of the optic nerve, and it may be due to a slight oedema of the retina (compare PI. I. 3). Changes in the optic discs of more considerable degree are, however, present in tubercular meningitis in such a proportion of the cases as to constitute a very important symptom of the disease. The frequency of the occurrence has been variously stated. The discs are often normal throughout in the rare cases in which the tubercular 1 " Jahrbuch fur Kinderheilkunde," 1875, p. 334. 2 "Arch. f. Ophthal.," vol. xxvi. pt. 3, 1880, p. 154. 3 It is doubtful whether this appearance is really pathological ; a condition very like it is met with apart from disease, often called the "watered-silk retina." For an explanation of this appearance, see Gunn, " Ophth. Hosp. Rep.," vol. xi. p. 348. 174 MKDICAL OPHTHALMOSCOPY. inflammation is confined to the convexity of the brain. In some cases of basal meningitis, also, changes are entirely absent. Grarlick, 1 of twenty-six cases carefully watched at the Children's Hospital, found the discs normal throughout in five ; distinct swelling was developed in about half the whole number, increased redness only in one quarter, and in a few others only distension of veins. In many of these cases, however, the changes were slight, and their patho- logical character was recognizable only by their development under observation. It is probable, then, that considerable changes are present in one-half the cases, and that in two-thirds of the remainder slight alterations will be found, if the discs are watched with care from day to day. The occurrence of congestion and oedema of the disc seems to be especially related to the occurrence of inflammation, and the formation of lymph, in the anterior part of the base, about the chiasma and the optic nerves. The degree of change is rarely great. The disc becomes full-coloured, and its outlines hazy. Sometimes this and distended veins constitute the only morbid appearance. More often swelling, with undue striation, becomes visible on direct examination, and the edges of the disc gradually cease to be recognizable. The disc has sometimes a reddish- grey aspect. In several recent cases I have noted that the colour of the swollen papillae was much paler, especially on examination by the indirect method, than in the early stage of the acute neuritis of cerebral tumour ; the aspect suggest- ing the idea of a subsiding neuritis rather than one that is commencing, and this in cases in which the neuritis was quite recent. The neuritis rarely passes into a more intense degree, perhaps because life is only prolonged sufficiently in cases in which the inflammation is not intense. The veins are often, though not always, over-distended from the first. In Grarlick's observations their distension was especially related to excess of subarachnoid fluid ; when the quantity of this was normal, there was no distension of the sheath a fact of much importance. Occasionally white lines along 1 "Med.-Chir. Trans," 1879, p. 441. MENINGITIS. 175 the sides of the vessels are unduly conspicuous. Haemor- rhages are rare. Sometimes white spots are seen in the neighbourhood of the swollen disc. They are in the substance of the retina, and consist of an accumulation of lymphoid corpuscles in the nuclear and molecular layers, or of degeneration of nerve-fibres. They may readily be mistaken for tubercles of the choroid. It has been thought that they are of the nature of tubercles, and they have accordingly been described as retinal tubercles, but very similar spots are seen in neuro- retinitis from other causes. Occasionally a gauze-like opacity is seen over a wide area of the retina, with scattered white points and flakes (Heinzel). Very rarely retinal haemor- rhages are associated with the papillitis. 1 The changes that occur in tubercular meningitis are always double, though often more advanced on one side than on the other. In some cases the excess was found by Garlick to be on the side of the chief cerebral change, but in a few it was on the other side. In most cases the patients die not long after its development, and sight suffers little. In the rare cases that recover the inflammation does not become intense within either the skull or the eye. In such cases the optic neuritis is of extreme diagnostic importance. As the cerebral symptoms subside, the neuritis passes away, and sight is preserved or restored. This has been pointed out by Clifford Allbutt, and two probable instances are described by Grarlick. The symptoms were headache, vomiting, constipation, irregular pulse, normal temperature, and the development of ophthalmoscopic changes under observation. In both cases recovery was complete. In another case observed by him an increase in pulmonary symp- toms was attended by a marked decrease in the cerebral symptoms, and in the optic changes, for five days before death. Cases of optic nerve atrophy of old-standing are occa- sionally seen in which sight was lost in early life with acute cerebral symptoms very like those of an attack of tuber- 1 Heinzel, loc. cit. p. 341, Cases 6, 16, 19, 26. 176 MEDICAL OPHTHALMOSCOPY. cular meningitis. Several such cases have been related by Hutchinson. 1 Incipient atrophy was noted by Heinzel in one case of long duration, and in two others he observed the initial stage of consecutive atrophy. In some of the cases of recovery from supposed tubercular meningitis with ophthal- moscopic changes, the symptoms, it must be remembered, may possibly have been due to a tubercular mass in the brain. The symptoms of such a tumour sometimes resemble closely those of tubercular meningitis, but much more frequently pass away. The neuritis which accompanies tubercular meningitis was regarded by v. Grraefe as affording the typical example of descending neuritis, the inflammation passing directly from the membranes to the optic nerves. With this my own experience accords. In some cases the existence of inflam- mation in the trunk of the nerve is obvious on naked-eye examination. The nerve is swollen, softened, and reddened. In most cases the descending neuritis may be demonstrated by microscopical examination. Besides the distension of the sheath, which sometimes, but not always, coincides (and has been supposed to be the cause of the neuritis), more pronounced lesions are often found in it. The sheath usually presents, under the microscope, evidences of inflammation and exudation, which were found by v. Ziemssen 2 to extend from the chiasma to the eye. Moreover, Michel, 3 in a case in which there was a cloudy halo around the papilla, found not only effusion into the sheath, but numerous miliary tubercles in both the dural sheath and pial tissue. In a considerable number of cases the symptoms of menin- gitis are distinct before the ocular changes are developed. In such cases the ophthalmoscope corroborates rather than assists the diagnosis. But in some cases the cerebral symp- toms are latent or dubious, and in these the examination of the eyes may afford very valuable help, and it is probable 1 " Ophth. Hosp. Rep.," v. 310 and ix. 124. 2 "Jahrb. f. Ophthalmologie," 1878, p. 242. 3 "Deutsch. Archiv. f. klin. lied.," xxxii. p. 439. MENINGITIS. 177 that it would do so in at least one-third of the cases. Of the twenty-six cases watched by Garlick, the ophthalmoscope was of real diagnostic assistance in six, and would doubtless have been so in a larger number had earlier examination been practicable. In one case, which lasted twenty-six days, the other symptoms were indefinite until the nine- teenth day, but on the fourteenth day the ophthalmo- scopic changes were so unmistakable that the diagnosis of meningitis was confidently made. In another case, ophthal- inoscopic changes were distinct on the ninth day, the symp- toms were diagnostic only on the fifteenth day, the patient dying on the twentieth day. In both cases, the changes about the optic commissure were much more marked than those elsewhere. During the course of meningitis a diminution of the cerebral symptoms may be accompanied by a diminution in the ocular changes. SYPHILITIC MENINGITIS. Syphilitic meningitis (1) may be associated with the ocular signs of syphilis, and (2) may cause optic neuritis. When at the base, the ophthalmoscopic signs are similar to those of tubercular meningitis, but more chronic in course and more considerable in degree. When localized in the convexity, ocular symptoms may be entirely absent. If the case is not subjected to proper treatment, and local chronic meningitis persists, it is probable that the disc sometimes passes into a condition of intense neuritis, similar to that which is seen in cerebral tumour. Syphilitic meningitis is a malady about which, however, we still have much to learn. Its diagnosis from gummata is only possible hy the more extensive symptoms, and a growth can never be excluded if focal symptoms are produced. Moreover, the two processes pass one into the other. H^EMORRHAGIC PACHYMENINGITIS (H^EMATOMA OF THE DURA MATER). According to Flirstner, 1 there may be mechanical congestion of the retinal veins and papillitis, '* "Arch. f. Psychiatric," vol. viii. pt. 1. 178 MEDICAL OPHTHALMOSCOPY. accompanied by distension of the optic sheath with dark- coloured fluid. CEREBRO-SPINAL MENINGITIS. In epidemic cerehro-spinal meningitis, optic neuritis may occur, but is rare. Schirmer found it in one only of twenty-seven cases examined. Von Ziemssen 1 observed slight neuritis in one case, and in another a pale fundus with broad and tortuous veins, narrow arteries, and haemorrhages beside the disc; at a later period white points appeared in the retina. Cyclitis and retinitis were found by Oeller. 2 Many of the retinal veins contained thrombi and granular plugs ; no direct connection with the intra-cranial process could be traced. A purulent irido- choroiditis is the most frequent change in this disease. In the sporadic (possibly rheumatic) form of cerebro- spinal meningitis, optic neuritis may occur, and may lead to atrophy. Thus Mr. E. Pope of Tring recently showed me a lad who, after a severe wetting, had suffered from intense headache, delirium, fever, and retraction of the head. Sight failed ten days after the onset. The symptoms subsided at the end of six weeks, but he remained blind, and when I saw him, six months later, there was slight perception of light in one eye only. The optic discs had all the appear- ance of consecutive atrophy, the centres were filled in with new tissue, the vessels narrowed, and the adjacent choroid disturbed. Such a case, however, is perhaps to be separated from most sporadic cases, since in these a conspicuous exciting cause is seldom to be traced. TRAUMATIC MENINGITIS often causes ophthalmoscopie changes, of which an instance is shown in PL III. o, a case in which fever, delirium, and convulsions succeeded a fall on the head. The neuritis subsided with the symptoms. These cases are considered in the section " Injuries to the Head." The ophthalmoscopie changes are frequent and are of the highest importance in the many cases in which other symptoms are subjective only, and when the grave 1 " Jahrb. f. Ophthalmologie," 1878, p. 243. 2 "Arch. f. Augenkrauk.," vol. viii. 1878, p. 357. DISEASES OF THE CRANIAL BONES. nature of the effects of the injury may be doubted or even denied by those whose interests are opposed. DISEASES OF THE CRANIAL BONES. CARIES. In caries of the sphenoid bone, or suppuration beneath the periosteum, the inflammation may extend to the optic nerve, damaging it, and causing secondary atrophy, or r descending the nerve, may produce intra-ocular neuritis. The disc shown in PL III. 2 is an illustration of this effect, The case was one of caries of the body of the sphenoid bone in a girl aged sixteen. There was well-marked neuritis in the left eye, but for a month afterwards the right eye was normal. Coincidently with an increase of the symptoms of meningitis, this also became inflamed, and she died a few days later. The autopsy showed caries of the sphenoid, chronic meningitis around the left sphenoidal fissure, involving the sheath of the left optic nerve. There was also general acute purulent meningitis, which had, no doubt, been the cause of the neuritis in the right eye. The damage to the nerve was just in front of the chiasma ; the neuritis coincided in onset with an increase in local symptoms, which ended in an attack of meningitis, from which the patient died. When the draw- ing was made, the neuritis was confined to the eye corre- sponding to the damaged nerve ; soon after the onset of the meningitis, a day or two later, similar neuritis made its appearance in the other eye. In this case there was no change in the sheath of the nerve. In a case recorded by Horner, of caries of the sphenoid, the sheath of the optic nerve was distended by purulent material as far as the eyeball. Caries of the bone, at a distance from the optic nerves, does not cause ophthalmoscopic changes unless it excites menin- gitis or cerebral abscess. To this, however, an exception must be made in regard to disease of the bones of the ear, which there is reason to believe may cause optic neuritis when no abscess or meningitis is to be found. It has been suggested by Mr. Arthur Barker that the papillitis in these 180 MEDICAL OPHTHALMOSCOPY. eases may be the result of a septic inflammation in the middle ear, infecting directly the adjacent carotid canal, and extending along the lymphatics of the latter to the sheath of the optic nerve. Cases such as he has observed are certainly of much clinical importance, and deserve close attention on the part of the pathologist. THICKENING OF THE CRANIAL BONES. General thicken- ing of the cranial bones may cause optic neuritis and con- secutive atrophy. Neuritis with great swelling of the papilla, was present in a case of this description in the Queen Square Hospital under the care of Dr. Buzzard. The general thickening of the bones of the skull appeared to be of a sub-inflammatory character. There was no post-mortem examination, as the patient recovered; but Michel has recorded the case of a boy who was blinded by neuritis and consecutive atrophy early in life, and who died aged fifteen. The ne- cropsy revealed great hyperostosis of the bones of the skull, by Which both optic foramina Were considerably narrowed. The optic nerves were atrophied from the chiasma to the eye, but the orbital portion was greatly thickened by hyperplasia of the cellular tissue in the subvaginal space. A similar case has been described by Manz, in which the tissue between the sheath and the nerve had a semi-gelatinous aspect. Michel explains this change, by assuming that the narrowing of the foramen leads to retention within the sheath of lymphatic fluids, which cause irritation. In other cases, similar conditions of bone, exostoses, &c., narrowing the optic foramen, have caused only simple atrophy of the optic nerve. DISEASES OF THE ORBIT. Inflammatory Processes in the OrfoY,e.<7.,cellulitis (as in facial erysipelas), inflammation at the back of the orbit, or periosteal affections in which the symptoms and their course point clearly to the seat and nature of the lesion, although the pathological inference is still as unconfirmed by post-mortem evidence as is the case with the analogous inflammation of DISEASES OF THE ORBIT. 181 the facial nerve, frequently damage the optic nerve. This damage always involves inflammation, which may or may not be seen in the papilla. The difference depends partly on its tendency to spread down the nerve, coupled with its proximity to the eye or distance from it, and partly, perhaps, on the compression of the vein. But whether there is neuritis or not, atrophy is subsequently visible, propor- tioned, in degree, to the impairment of sight. This may or may not have the aspect of " consecutive atrophy." There may be neuritis and its effects, but the affection of sight may be due chiefly, not to the visible inflammation, but to the changes behind the eye, at the spot primarily diseased. Hence care must be taken (as pointed out in the account of secondary atrophy) not to regard the papillitis as the chief cause of a failure of sight that may occur without any intra-ocular inflammation. It is of practical importance to remember that no forecast can be drawn from the visible inflammation that the absence of this affords no ground for a good prognosis. In the one case, the nerve is simply compressed by the inflammatory products, or, if inflamed, the inflammation is localized. Sight is lost sometimes very rapidly, and simple secondary atrophy of the lower portion of the nerve results, occasionally with ultimate narrowing of the vessels (Allbutt and Teale). In the other case, the inflammation is communicated to the nerve, and descends along it to the eye, or inflammatory processes in the sheath lead to a secondary papillitis. In many cases the eyeball becomes prominent, usually only in slight degree, and the absence of such prominence is of no negative significance. The exophthalmos depends on the amount of effusion and its character. The nerves may be gravely damaged when the general orbital inflammation is slight. PL II. 3 affords an example of the occurrence of simple atrophy of the nerve due to this cause. It is an illustration of a well-marked type, 1 in which loss of sight of one eye comes on simultaneously with paralysis of all the ocular 1 For example, those recorded by v. Graefe, "Arch. f. Ophth.," vol. i. pt. 1, p. 424, and Baumeister, ibid. vol. xix. pt. 2, p. 264. 182 MEDICAL OPHTHALMOSCOPY. muscles, sometimes with tenderness on pressing the eyeball back into the orbit. The symptoms have been ascribed to haemorrhage (v. Grraefe) or inflammatory mischief (Bau- meister) at the back of the orbit. In the case illustrated, the cause was almost certainly " rheumatic " inflammatory mischief, for the symptoms came on suddenly, with much pain, after exposure to cold, in an intensely rheumatic woman, who had previously had an attack of " rheumatic " paralysis of the facial nerve. The paralysis of the ocular muscles passed away, but that of the optic nerve persisted, and the disc slowly passed into atrophy without the least sign of neuritis. In such a case it is probable that the nerve suffered chiefly from pressure. A case of rapid but not permanent failure of sight, accompanied with shooting pains passing to the back of the head, in a woman who had had facial paralysis, has been recorded by Nettleship. 1 There was slight puffiness of the eyelids, but no tenderness on pressing the eyeball back, and the ophthalmoscopic appear- ances were normal. In another case, probably of syphilitic mischief at the back of the orbit, with intense pain in the eye, orbit, and head, the inflammation descended to the eye, and produced secondary .papillitis, ending in atrophy. In this case sight was lost, and the vision of the other eye also became impaired. Hence it is probable that the inflamma- tion extended from one optic nerve to the other, probably by the chiasma a danger that makes energetic, prompt treatment imperative. A very similar state of secondary atrophy of the nerve may result from a blow on the head, 2 or on the eye. Rapid exophthalmos and the appearance of the lids may show that haemorrhage has occurred into the orbit. These conditions are considered in the section on " Injuries to the Head." In rare instances, haemorrhage has occurred apart from injury, in sufficient quantity to cause prominence of the eyeball and distension of the eyelids with blood. Of two 1 " Laucet," 1881, i. p. 760. 2 Snell: " Ophth. Rev.," i. 402. INJURIES TO THE HEAD. 183 cases recorded by Ayres, 1 the exciting cause in one was a violent effort, in the other a strain during vomiting. The degree of impairment of sight appears to depend upon the amount of blood effused, and the consequent stretching of the optic nerve. Tumours in the Orbit. A tumour at the back of the orbit or of the optic nerve, may cause neuritis such as results from intra-cranial tumour, but this is at first limited to the eye in front of the growth ; the other optic papilla either escapes or presents only a slighter and later inflammation, which has been communicated to the nerve through the chiasma. There is also distinct and increasing prominence of the eyeball. INJURIES TO THE HEAD. Injuries to the head, blows, falls, &c., frequently cause ocular symptoms and often very marked ophthalmoscopic signs. The forms of ocular affection are of several varieties. 1. Impairment or loss of sight, without ophthalmoscopic changes, or with very slight alterations simple congestion of the disc, easily overlooked. Such impairment may result from blows on the anterior portion of the head. In some cases the mischief is probably direct concussion of the retina, for in slight cases an alteration of vision has been noted such as must be ascribed to disturbance of the retinal elements. For instance, in a case recorded by Gfosetti, after a blow on one angle of the orbit, near objects appeared unduly large, -and there was some colour-blindness, but no ophthalmoscopic change. 2. Optic neuritis has followed injuries to the head in many cases, at an interval of a few days or weeks. It is apparently due to secondary results of injury, especially to meningitis (PI. III. 5), less commonly to traumatic inflammatory soften- ing of the brain or hernia cerebri. In a case under my own observation, there was a compound depressed fracture of the left parietal bone. This was elevated five weeks after the 1 "Archives of Ophthalmology," vol. x. pt. 1, March, 1881, p. 42. 184 MEDICAL OPHTHALMOSCOPY. injury, but a few days later hernia cerebri occurred. The optic discs were then normal, but five days later there was acute optic neuritis, which persisted until death. The neuritis may be slight or considerable, and may entail loss of sight and consecutive atrophy. When occurring long after an injury it may be due to abscess of the brain, as was possibly the case in a patient who pre- sented double papillitis a year after a violent blow from an exploded shell, over one eyebrow, which ultimately caused necrosis of bone. 1 3. Simple atrophy of the optic nerves, unilateral or bilateral, may result from injuries which damage the optic nerves, directly or by pressure from secondary inflammation. An example of this condition was met with in a patient in whom a fall on the right side of the head and shoulder, injuring the circumflex nerve, was followed by slow grey atropjiy of the right optic disc. In such cases sight often fails some time before the ophthalmoscopic signs of atrophy are apparent. See below, " Fracture of the Skull." 4. In some cases an injury to the head may be followed by gradual failure of sight, with very slight and stationary papillitis. In such cases it is probable that a chronic interstitial neuritis has been set up in the nerve trunk. Concussion of the Brain is attended by no ophthalmoscopic change. Simple concussion of the nerve and retina may probably, as just stated, cause loss of sight and slow atrophy. Contusion and Laceration of the Brain may entail optic neuritis, commonly slight in degree, although sometimes marked with increased vascularity and redness and opacity of the adjacent retina. It is apparently due, in some cases, to a secondary meningitis, but may occur directly from the brain lesion. It may constitute a valuable indication of the occurrence of greater mischief than a mere concussion. For instance, in a case recorded by Grazet, 2 the symptoms of concussion were followed by neuritis and consecutive atrophy, and ten weeks after the injury the necropsy showed two foci 1 Recorded by Boncour : " Journ. d'Ophth.," July, 1872. 2 " I/Union Med.," 1865, ii. 3, No. 63. INJURIES TO THE HEAD. 185- of red softening in the right anterior lobe and one in the corpus callosum. Panas has found in such cases distension of the sheath of the nerve, and it is assumed, on the Schmidt - Manz theory, that thus the neuritis is produced, but this is at present unproved. Fracture of the Skull 1 not uncommonly causes loss of sight in consequence of laceration of the optic nerve. According to the statistics of Holder, quoted by Berlin, the orbital vault is involved in 90 per cent, of fractures of the base of the skull (80 out of 88 cases), and the optic canal is implicated in 54 (or 60 per cent.). In 42 of these there was haemorrhage into the sheath of the optic nerve. The most frequent causes are blows and falls on the frontal bone (especially the orbital portion), less frequently on the temporal or occipital bone. The effect of the resulting laceration of the nerve is usually immediate and permanent loss of sight. It is generally unilateral and on the side of the injury, very rarely on the opposite side, as in a case recorded by Leber and Deutsch- mann, in which the eye blinded was on the side opposite to that on which blood escaped from the ear. Both eyes are only affected when both optic canals are fractured. Some- times the haemorrhage into the orbit is evidenced by promi- nence of the eyeball and effusion of blood into the eyelids. The optic nerve may be torn, compressed, stretched, or the seat of haemorrhage. Absolute loss of sight from direct injury to the nerves is usually permanent. When the lesion, as is- commonly the case, is behind the place of entrance of the central vessels, there is at first no ophthalmoscopic change or only transient retinal hyperaemia, but atrophy' gradually sets in. The pallor has been observed to commence three weeks after the injury. The ultimate appearance of the disc is usually that of simple atrophy, the edges sharp, and the vessels of normal size. Sometimes narrowing of the 1 The statements in the text are, in part, derived from important papers by Berlin (" Heidelberg Ophth. Gesellsch.," 1879, and "Annaies d'Oculis- tique,"vol. Ixxxiii., 1880, p. 69), and by Leber and Deutschmann, "Arch. f. Ophth.," vol. xxvii. pt. 274. See also Graefe and Saemisch's "Handbuch," vol. v. p. 219. 186 MEDICAL OPHTHALMOSCOPY. vessels has been observed, and has been ascribed to the extension of inflammation to the tissue around the vessels, or to their direct compression by the injury, or by effusion of blood. Ophthalmoscopic signs of inflammation are not common, except as a result of subsequent meningitis, but, in one of my cases, oedema of the disc with retinal haemor- rhages accompanied effusion of blood into the optic sheath. If the injury to the nerve is in front of the place of entrance of the central artery, the ophthalmoscopic appearances are similar to those of embolism. When the injury to the nerve is partial, the loss of sight may be incomplete, and in such cases central scotomata and peripheral limitation of the field have been observed. When sight is impaired by effusion of blood into the sheath, the prognosis is said to be better than when the nerve is injured. Occasionally signs of direct injury to the eye have been observed in these cases, rupture of the choroid or vitreal opacities. Compression of the Brain may, it is said, be attended by changes in the fundus oculi distension of the retinal veins, congestion and oedema of the papilla. Such appearances are, however, certainly rare. Traumatic Meningitis entails, very commonly, ophthal- moscopic changes similar, for the most part, to those which are found in tubercular meningitis. Meningitis often results from fracture of the base of the skull, and may, like tuber- cular meningitis, be attended with neuritis. An instance of traumatic mischief with neuritis is afforded by the case figured in PI. III. 5. The neuritis came on with mental disturbance and convulsions, following, at an interval of a week, a fall on the head. The change was slight in degree, although very distinct, and passed away soon after the cerebral symptoms subsided, leaving no trace. When the neuritis is more intense, blindness may result. Hock l has described the case of a child who had symptoms of menin- gitis five months after a fall on the head. Optic neuritis (" descending ") was found with the ophthalmoscope, sight 1 " Oest. Jahrb. fur Padiatrik," vol. v. 1874, p. 1. " Nagel's Jahrb. f. Ophth.," vol. v. p. 427. DISEASES OF THE NOSE. 187 being little impaired. Four years later, however, the child was healthy hut blind, with atrophy of both optic nerves. In other cases of the kind actual meningitis has been found. The neuritis may be associated with the signs of mischief at the base of the brain, paralysis of ocular muscles, &c. The chronic inflammatory consequences of an injury (chronic meningitis, inflammatory " growths," &c.) may persist and progress for a long time, even for years, as in a case .in which meningeal growths, apparently the result of chronic inflammation, were found beneath two old fractures of the skull, the result of injuries received several years previously. At the base the results of chronic meningitis had damaged the arteries and caused fatal softening, but no recent change. Hernia Cerebri, resulting from fracture of the skull, with loss of bone, may be accompanied with neuritis, as in the case referred to on page 183. Necrosis of the Cranial Bones. The damage to bone by injury may cause necrosis and meningitis or abscess of the brain, both of which may entail inflammation of the optic nerve. As Hughlings-Jackson has pointed out, the relation of the symptoms to the injury may be obscure and unsus- pected by the patient or friends, so that careful attention should be paid to any sign of injury, such as puffy swelling, <&c., and the occurrence of a blow or fall should be carefully inquired for in all cases of local brain disease. DISEASES OF THE NOSE. Some curious cases have been recorded 1 in which optic neuritis coincided with persistent discharge of watery fluid from one nostril. In most cases there were chronic cerebral symptoms, and in some there were polypoid growths in the nose. The fluid is not cerebro-spinal fluid, nor is it ordinary nasal ] See Nettleship : "Oph. Rev.," 1883, and Emrys Joues : "Oph. Rev.," vii. 97. 188 MEDICAL OPHTHALMOSCOPY. secretion. The most probable explanation is that there is increased intra-cranial pressure and hydrocephalus, and that the escape of fluid relieves the pressure indirectly, and that it is conditioned by some abnormal state of the mucous membrane of the nose. In a case recorded by Baxter, 1 however, there was no disease, but the bones of the skull were abnormally thick. But in this case the cerebral symp- toms were rather those of functional than of organic- disease. To increase the mystery, some of the cases pre- sented slight symptoms of exophthalmic goitre. INSOLATION AND HEATSTROKE. The occurrence of congestion of the optic discs in cases of severe sunstroke, described by Macnamara, has been before alluded to (p. 138). In America, according to Hotz, 2 it is not uncommon to meet with cases of atrophy of the optic nerves, which are ascribed by the patients to sunstroke. Commonly the arteries are narrowed, as if from preceding inflammation, and in some recent cases he met with actual neuritis. In three the exposure had been to the sun, in three to an intense heat. Severe headache was a prominent early symptom, and it is probable that the neuritis was secondary to acute cerebral congestion or meningitis. Hotz has also seen exudative choroiditis apparently from the same cause, in degree sufficient to cause detachment of the retina. He regards it as due to the extension of inflam- mation along the sheath of the optic nerve, but the absence of choroiditis in other cases of such extension renders the explanation difficult to accept. 1 "Brain," v. 325. 2 "American Journal of Medical Science," July, 1879. INFLAMMATION. 189 DISEASES OF THE SPINAL CORD. INFLAMMATION. Spinal meningitis may be accompanied by ophthal- moscopic changes when the cerebral membranes are also affected (see " Cerebro-Spinal Meningitis," p. 178). But we must be prepared to meet with neuritis as a coincidence of any local inflammation that is produced by a blood-state, so many and various are the states of the blood in which the papilla becomes inflamed. Myelitis is an illustration of the same truth. It is also usually unattended by any changes in the eye, but to this rule several remarkable exceptions have been recorded. They show, conclusively, that the papilla is susceptible to some states of the blood that influence the spinal cord. Slight optic neuritis, veiling the edges of the discs, was seen by Clifford Allbutt in a case of chronic myelitis in the upper dorsal region. Partial grey atrophy supervened. The same observer has also met with partial atrophy after dorsal myelitis. Seguin 1 has twice seen optic neuritis coincident with subacute transverse myelitis. The affection of the optic nerves ran a favourable course and left no impairment of sight. Noyes 2 has recorded the case of a young man in whom, without cause, impairment of sight in the right eye was simultaneous with some spinal symp- toms, and a fortnight later slight optic neuritis was found. The spinal symptoms (initial retention of urine, tingling, and some anaesthesia in the legs) did not increase, but the fields of vision became changed in a peculiar and irregular manner, suggesting an affection of the chiasma or optic tracts. In a man, aged fifty-two, whose case has been recorded by 1 " Journal of Nervous and Mental Disease," April, 1880. ~ "Archives of Ophthalmology," vol. ix. 1880, pt. ii. p. 199. 190 MEDICAL OPHTHALMOSCOPY. Steffen l and by Erb, 2 loss of sight, commencing by a central scotoma, and accompanied by slight neuritis, occurred first in the left eye, and, three weeks later, in the right. Sight slowly returned, but three months later there was renewed failure in both eyes with temporal hemianopia, without marked ophthalmoscopic changes. Two months later the symptoms of a transverse dorsal myelitis came on. Very significant also are two cases of coincident neuritis and myelitis observed by Dr. Dreschfeld, of Manchester. One was a man aged forty-one, who, simultaneously with an attack of double optic neuritis going on to complete atrophy, and slight mental disturbance, presented the symptoms of acute myelitis, from which he died at the end of a month. The necropsy revealed disseminated acute inflammation of the spinal cord in the dorsal and lumbar regions. The brain appeared healthy. The other case was that of a woman, aged thirty-eight, who died from res- piratory paralysis six weeks after the onset of symptoms of acute myelitis. Soon after the paralysis came on, double optic neuritis was found to exist. After death the brain presented merely signs of congestion, but the upper part of the spinal cord was softened. It is probable that, in these cases, the optic neuritis and myelitis were both the result of a common cause. The coincidence of acute inflammation of the optic nerve and spinal cord is of considerable interest in connection with their frequent affection in chronic disease. It is probable, however, that in some cases (Noyes, Steffen) the cause of the neuritis was situated at or near the chiasma. SCLEROSIS or THE CORD. POSTERIOR SCLEROSIS I LOCOMOTOR ATAXY. Atrophy of the optic nerves is, as is well known, frequent in locomotor ataxy. In what proportion of the cases it 1 " Sitzungsbericht der Heidelberg Ophth. Gesellschaft," 1879. 2 " Archiv fur Psychiatric," vol. x. p. 146. SCLEROSIS OF THE CORD. 191 occurs is difficult to say. Ophthalmic surgeons have been impressed with its frequency. Charcot believes that almost all cases of so-called simple atrophy ultimately present spinal symptoms. Careful statistics show that the proportion of the cases of simple atrophy in which spinal symptoms of any kind can be recognized is about one-half (see p. 112). But we must not infer from this the converse proposi- tion that most cases of ataxy present optic nerve atrophy. It is probably near the truth to say that about one ataxic in six suffers from optic atrophy. Of seventy consecutive cases of ataxy which have come under my observation, only nine presented atrophy. It existed in nine out of fifty-two cases recorded by Voigt, 1 and in seven out of fifty-six cases analyzed by Erb. 2 Thus of 178 cases of ataxy, optic nerve atrophy existed in twenty-five, or 14 per cent. When it does occur, it is more frequently an early than a late symptom, occurring before rather than after the difficulty in walking has become considerable. In the nine cases above referred to, the onset of the atrophy preceded any distinct disturbance of locomotion in eight. In only one case did it develop after the inco-ordination was considerable, and in this the spinal symptoms came on very rapidly. When sight is lost, any inco-ordination which exists is greatly increased the con- dition which the physician employs as a test to exaggerate the difficulty, the withdrawal of the guiding visual sensation, being permanent. The ataxic symptoms are often so slight that, even as increased by the blindness, a careful investi- gation is necessary to discover them. Blind people often walk in a more or less hesitating and uncertain manner, and the uncertainty of slight ataxy is easily attributed to the blindness. Inquiry, however, elicits other symptoms, as pains in the limbs, especially " lightning pains," and loss of sexual power, and careful observation of the gait shows an unsteadiness in turning, and in standing with the feet bare, and toes and heels close together. It is, however, well known that the atrophy may occur before any obvious symptoms 1 " Berl. Kl. Wochenschrift, " 1881, lS T o. 39. 2 " Deut. Arch. f. Kl. Med.," 1879. 192 MEDICAL OPHTHALMOSCOPY. referable to the cord. One extreme instance of this early atrophy has come under my own observation, in which the atrophy of the discs was complete, and vision lost for twenty years before the first symptoms of ataxy showed themselves. I have seen another case in which the loss of sight preceded for sixteen years distinct spinal symptoms. But in many such cases the loss of the " knee-jerk," l an early symptom in ataxy to which Westphal first called attention, precedes other symptoms, and if looked for will often be found to co-exist with optic nerve atrophy when other symptoms of ataxy are absent. A very marked example of this relation, in which the atrophy existed for fifteen years, associated only with lightning pains and loss of the knee-jerk, has been related by Buzzard. 2 Another early symptom is the loss of the reflex action of the pupil to light, although the contraction occurs on an effort at accommodation (Argyll Robertson). The pupils are often small (" spinal my osis"). It is to be remarked, however, that this may co-exist with optic nerve atrophy without any spinal symptom, as in the case men- tioned on p. 266. When the atrophy is advanced, the optic discs are usually grey, even to indirect examination, and to direct examination very grey and mottled, the meshes of the lamina cribrosa may or may not be visible, the edges sharp and clear, the sclerotic ring distinct. Sometimes there is a peculiar gelatinous opacity of the substance of the disc. To ordi- nary daylight the tint is a greenish grey; to gaslight a bluish or iron grey. Its characters are shown in PI. II. 6. Less commonly, the discs appear white to the indirect method of examination, but a grey mottling can always be seen with the direct method. The vessels are usually of the normal size. The grey disc and normal vessels have been supposed to be peculiar to this form of atrophy, but this is 1 It must not be hastily inferred, however, from the occurrence of the jerk, that the atrophy is unconnected with disease of the cord, because lateral sclerosis, in which there is an excess of the knee-jerk, may, in rare cases, be Accompanied by optic nerve atrophy. 2 " Brain," 1878, No. 2, p. 168. SCLEROSIS OF THE CORD. 193 incorrect. The disc in atrophy from post-orbital pressure on the nerve, such as that shown in PL II. 3, may present exactly the characters of the atrophy of ataxy. A stage of hyperaemia, " chronic optic neuritis," has been described by Dr. Clifford Allbutt as sometimes preceding the atrophy, but the occurrence of this condition has not been confirmed by other observers. I have frequently looked for it, but without success. The anatomical characters of the atrophy have been already described (p. 116). The trunk of the optic nerve is commonly nearly normal in size, but is grey and semi-translucent. The grey degeneration may stop at the chiasma, but often, as Tiirck pointed out, involves also the optic tracts, and can be traced to the external corpora geniculata. The microscopical investigations (of Leber especially) have shown that the change in the nerve consists of an increase in the interstitial tissue, and sometimes the formation of translucent colloidal tissue around the vessels, as in Fig. 51, p. 117, together with a wasting of the nerve fibres. The histological resem- blance to the change in the spinal cord is not so close as has been asserted. Charcot and Abadie have suggested that the change commences in the nerve fibres, and is essentially parenchymatous, but the balance of evidence is not by any means conclusively in favour of this view. The affection is usually bilateral, although often more advanced in one eye than in the other. In rare cases, one eye may be much aifected, and the other very little. Symptoms. The affection of sight is usually characterized by a progressive peripheral defect in the field of vision, especially extensive on the outer side (Forster) . It progresses until only a small portion is left, situated to the inner side of the blind spot, and enclosing the fixing point. Central vision may be little impaired even after the peripheral defect has become very great. When the acuity of vision is thus preserved patients may, for a long time, be unaware of the affection of sight, until indeed the field is greatly reduced. Sometimes a sector-like defect occurs, an example of which is figured at p. 125. Rarely one half of a field may o 194 MEDICAL OPHTHALMOSCOPY. be lost (Fig. 56, p. 124). This has hitherto only been observed when the sight of the other eye was entirely lost. Colour-blindness is frequent, and is almost always an early symptom. The first change is commonly a loss of perception of green, then of red (see p. 120). Occasionally, as I have seen, the defect in the field may be more per- ceptible in a bright than in a dim light, and the latter be preferred by the patient. The degree of impairment of sight, both in regard to acuity and to colour-vision, may vary from day to day, just as does the degree of impair- ment of sensibility in the legs. The manner in which the atrophy often precedes the symptoms of spinal mischief points to the anatomical in- dependence of the two affections, whatever may be their relations. Pathology verifies this conclusion, for in cases in which both posterior columns and optic nerves are affected, no anatomical continuity of degeneration can be traced. The degeneration extends as far as the chiasma, but the tracts are little affected. Thus there is an apparent want of correspondence between the optic and spinal phenomena. Both are, it is true, parts of the sensory nervous system, but in the nerve the seat of the morbid process is peripheral, in the cord it is central. It is, however, asserted by Pierret 1 that this opposition is apparent only. Although the de- generation of the optic nerves can be traced only as far as the chiasma, he has frequently found, in the corpora quad- rigemina, anterior and posterior, a process of sclerosis, which thus, at the root of the optic nerve, represents the sclerosis at the roots of the spinal nerves. Further, the latter may, he says, be found changed in the same manner as the optic nerve. On examination of the terminal expansions of the nerves of the anaesthetic and painful regions he has found in two cases the evidence of lesions of these nerves perfectly comparable to that which constitutes optic nerve atrophy. The farther from the peripheral termination the nerves are 1 Quoted by Robin, op. cit. The statements in the text are partly derived from a communication M. Pierret has kindly made to me on the subject. INSULAR (DISSEMINATED) SCLEROSIS. 195 examined, the slighter do the changes become, and soon they disappear, and the nerves are healthy, until the posterior columns are reached. Thus, according to this view, in locomotor ataxy we have a combined peripheral and central change in the sensory nervous system ; and it has been merely an accident of pathological progress that attention has been primarily fixed on the central alteration in the cord and the peripheral process in the optic nerve. But, as has been pointed out by Ghinn, the optic nerve is to be regarded rather as part of the central nervous system than as an ordinary peripheral nerve, and the importance of this relationship must be borne in mind (see p. 112). The course of the optic nerve atrophy is very like that of the cord degeneration. Recovery of sight, if ever observed, is a still rarer event than recovery of co-ordination in the limbs. The interference with the function of the posterior columns of the cord may, in a recent case, be out of pro- portion to structural change, but in the eye this is rare, and the structural change is that on which our prognosis is based. At the same time an arrest of progress is sometimes obtained, as it is in the ataxy. Although ultimately almost all cases increase, yet the progress is often very slow, and many years may pass before even a small field is finally lost. The perimeter affords valuable aid in estimating changes, which/ patients are apt to regard too favourably. LATERAL SCLEROSIS. Ophthalmoscopic changes are very rare in cases which present the symptoms of primary lateral sclerosis of the cord. In one or two cases, however, I have seen grey atrophy slowly supervene, similar in character to that met with in locomotor ataxy. INSULAR (DISSEMINATED) SCLEROSIS. Amblyopia occasionally occurs in insular sclerosis of the brain or cord, but very rarely goes on to complete loss of 196 MEDICAL OPHTHALMOSCOPY. sight. It is often unattended by the ophthalmoscopic signs of atrophy ; the examination is frequently difficult on account of the associated nystagmus. In such cases the optic nerves may be found to be occupied by patches of sclerosis, similar to those which occur elsewhere. 1 The nerve fibres passing through are not destroyed, their axis cylinders persist, and retain impaired functional power, although their medullary sheath may disappear. Occasionally, however, atrophy of the optic nerves is observed in this affection quite similar in its character to that seen in ataxy, attended by a similar loss of vision, progressing to complete blindness. 2 Dr. S. H. Habershon found uniocular central scotoma, absolute for white, red and blue, in a case of this disease. The corresponding optic disc was greyish white, especially in its outer half. 3 CARIES OF THE SPINE. Caries of the spine in the dorsal region is unattended by ocular changes. Bull 4 has recorded an examination of fifty oases, but the changes he met with, confessedly rare, are of doubtful pathological character, being confined to fulness of the retinal vessels, and sometimes dilatation of the capillaries of the disc. When the caries is in the cervical region, marked congestion of the disc has been described. In one case under my own observation the discs were red, and there was much white tissue about the vessels, very conspicuous against the red disc (as in PI. I. 2), but the margins of the side were quite clear, and the pathological nature of the appearance was somewhat doubtful. Abadie 5 has recorded a case in which atrophy of the optic nerves supervened, and attributes it to meningitis ascending to the base of the brain, of which, 1 Charcot : "Le9ons sur les Maladies du Systeme Nerveux," t. i. p. 206. 2 Magnan : " Arch, de Physiologic," t. ii. p. 765. Liouville : "Memoires de la Soc. de Biologie," 1868, p. 231. 3 "Trans. Ophth. Soc.," vol. ix. 1889, p. 162. 4 " Am. Journal of Med. Science," July, 1875. 5 " Bull, de la Soc. de Chir.," Jan. 12, 1876. INJURIES TO THE SPINE. 197 however, there was no other evidence. In the case of a girl, aged fifteen, suffering from Pott's paraplegia, who was in Queen Square Hospital, under the care of Dr. Buzzard, there was well-marked optic neuritis. She had, however, frequent severe headaches, and occasional vomiting, and the neuritis did not improve as the paraplegia passed away, so that it is possible that some intra-cranial tumour (? tubercular) co-existed. INJURIES TO THE SPINE. The subject of the changes in the optic discs in spinal injuries has received a large amount of attention in conse- quence of the prominence which " railway cases " have given to this class of accident. In its scientific relations the sub- ject has not escaped the sinister influence which litigation exercises on the investigation of facts, and there is no doubt that the pathological nature of many of the appearances described in these cases has been the result of an affection of the mind of the observer, rather than of the eye observed. Still, it seems well established that in some cases of spinal injury ocular changes supervene, and the observations of Clifford Allbutt especially show that they occur with greater frequency the higher up the injury is. The changes are those of simple congestion, congestion with oedema, and slight neuritis, uniform redness of the disc, and concealment of the outlines so that the position of the disc may ultimately be recognized only by the convergence of the vessels. In one case a " daffodil colour " was described. Sight is a little, but not much affected, and the condition, which is of slow onset and course (coming on some weeks after the injury), usually passes away. A remarkable case of this kind has been described by Thorowgood. 1 A girl, aged twelve, after a blow on the lower part of the back, complained of pain and tenderness at the neck, with muscular stiffness. A week after this some dimness of sight came on and increased, 1 ' Clin. Trans.," viii. 1875, p. 80. 198 MEDICAL OPHTHALMOSCOPY. until five weeks after the blow sight was lost, and well- marked optic neuritis was found. Leeches and mercury were employed, and the discs and sight recovered completely- It has been supposed (especially by Mr. Wharton Jones) that a disturbance of the sympathetic is the cause of the ocular symptoms in spinal injury. In cases of actual disease of the sympathetic, however, no ophthalmoscopic change has been found (Hughlings- Jackson, Eiegel, and Jolly). Clifford Allbutt suggests that they may be the result of " meningeal irritation " passing up to the base of the brain, but other evidence of such irritation has not been recognized. FUNCTIONAL DISEASES OF THE NERVOUS SYSTEM. EXOPHTHALMIC GOITRE. The conspicuous ocular symptoms which form part of Graves' disease might lead to the expectation that changes in the fundus oculi would be found in that affection. As a rule, however, it is not so. The prominence of the eyeballs does not lead to any alteration in the optic nerve. The retinal arteries participate in the general arterial dilatation, which occurs so uniformly in the disease, and is ascribed to a paralysis of the sympathetic vaso-motor fibres. The arteries are larger than normal, and when their course is favourable for their comparison with the veins, the two may be observed to be nearly equal in size, clearly in consequence of arterial dilatation. The strong pulsation which occurs in the arteries of the head and neck, in consequence of their dilatation and of the excited action of the heart, may be visible in the retina as a spontaneous arterial pulsation, as Becker first pointed out. He has found it in six out of seven cases, and remarks that it varies in degree, and may at times be unrecognizable. 1 CHOREA. Embolism of the central artery of the retina is an ex- tremely rare result of the endocarditis which is generally found (post-mortem) to be associated with the disease in 1 " Kl. Monatsbl. f. Augenh.." Jan. 1880. CHOREA. 199 severe cases. Only two instances have been recorded ; the best marked case is that of Swanzy, of Dublin. 1 The embolism occurred at the time of the commencement of the chorea, and was in the left eye. The chorea was most severe on the left side. The state of the heart is not mentioned. The other case is recorded by Forster, but was not seen until some time after its occurrence. The patient, a child, had suffered from chorea for some years, and during the chorea had lost the sight of one eye. The disc was atrophied, and the arteries very small. Slight optic neuritis is not very uncommon in chorea, and now and then neuritis of considerable intensity is seen, although seldom in the degree comparable to that usually met with, for instance, in cerebral tumour. I have twice? however, seen this latter intensity attained. In each case the patient was a girl of seventeen or eighteen years, and in each the neuritis passed away completely as the chorea subsided. These cases give significance to the slighter forms. In these the edge of the disc is decidedly blurred, sometimes only on one side, sometimes all round, although not often to such an extent as to prevent its position being recognized in the indirect method of examination. To the direct method the edge of the nasal side is obscured, necessarily. The swelling is slight, the physiological cup seldom encroached upon, and haemorrhages absent. In all the cases in which I have met with it, there has been a recognizable degree of hypermetropia ; this fact would lessen the significance of the neuritis in regard to the chorea, were it not that the aspect of the disc, in every case that I have seen, has become normal when the chorea has subsided. The frequency with which such an appearance is met with is difficult to ascertain ; in a percentage probably of eight or ten this is to be seen. The slight form is seen in children chiefly the more severe in girls about puberty. It is probably, when intense, a co- incident effect of the state of the blood. Slight double optic neuritis was seen by Hughlings- Jackson in a case of hemi- chorea, right-sided. When first observed the discs were 1 "Ophth. Hosp. Rep.,"viii. 181. 200 MEDICAL OPH.THALMOSCOPY. hypersemic, badly margined, the veins large and irregular. The change was most marked in the left eye. The appear- ance increased with the chorea, and disappeared with recovery. Bouchut has figured white exudation on and about the disc in a case of a third attack of severe chorea. In one case which came under my observation there was also kidney disease, and ulcerative endocarditis, and slight retinal haemorrhages were also present, so that it is certain that the neuritis could not be ascribed wholly to the cerebral affection. NEURALGIA AND MIGRAINE. Occasionally atrophy of the optic nerve has been observed in cases of severe unilateral neuralgia of the fifth nerve. Its origin is obscure. Temporary amaurosis, supposed to be " reflex," is more common. The transient disturbances of sight, temporary amaurosis, hemianopia, &c., which accompany migraine, are well known. In a girl, aged eighteen, blindness of the left eye occurred after some days of migrainous pain. The ophthalmoscopic appearances were normal ; vision was qualitative only, and the pupil did not react to light. Treatment was without effect for fifty days ; then chloral and quinine were given, and slight improvement took place, probably not due to the treatment. The slow improvement of vision went on, and the sight became good, although the progress was interrupted by slight relapses due to changes of weather and mental excitement. Of greatest importance, however, are the attacks of loss of sight lasting for a few hours or a day or two, occasionally observed in the subjects of migraine, apart from attacks of headache, and at other times, in association with pain. This transient failure of sight sometimes remains permanent, always in one eye only. The ophthalmoscopical appearances in such cases are those of occlusion of the central artery. The state is usually ascribed to embolism, but it is more likely thrombosis. Gralezowski 1 has recorded three such 1 "Rec. d'Ophthmal. ," Jan. 1882. See also Rampoldi, "Ann. di Ottalmo.," 1882. A case recently described by Doyne was probably of this nature. There had been two attacks of transient blindness of one eye, in the last of IDIOPATHIC EPILEPSY. 201 cases without heart disease, also one in which slow atrophy occurred in one eye, and another in which failure of sight after an attack of migraine was attended by signs of neuro-retinitis, with small haemorrhages and thrombosis in some minute vessels. Now and then atrophy of the optic nerve has been observed to follow repeated attacks, and Hutchinson has associated the three symptoms of migraine, amaurosis, and xanthelasma. Glaucoma is sometimes ob- served in cases in which there has been long-standing liability to unilateral neuralgia of the fifth nerve. It has been proved that irritation of the fifth nerve may increase the intra-ocular tension. 1 IDIOPATHIC EPILEPSY. Inter-paroxysmal State. In idiopathic epilepsy the appear- ance of the fundus oculi between the paroxysms is, as a rule, normal. Some observers have described changes in the optic discs, and increased vascularity, distended retinal vessels, and the like. I have examined very carefully about a thousand epileptics, and have found that in most cases every character of the fundus was such as is presented by persons not epileptic. Now and then an unduly red disc is to be seen, but not more frequently than in persons not epileptic, and in most cases it is explicable by the ocular conditions a point too little attended to in medical ophthalmoscopy. The only deviation from the normal state of the fundus which has seemed to me frequent, is an unusual equality in size of the retinal arteries and veins. The latter are not, as a rule, larger than normal, and the arteries appear as if large from a lax state of wall. Spontaneous pulsation in the veins has been described by Kostl and Niemetschek 2 as especially frequent in epileptics : it is certainly not which the upper half of the retina was found to be cedematous. The ascend- ing arteries ultimately became narrowed on the disc, and the lower part of the field remained defective after several months. "Trans. Ophth. Soc.," vol. ix. p. 148. 1 Hippel and Griinhagen : " Arch. f. Ophth.," vols. xiv. and xvi. 2 "Prager Vierteljahreschr.," vols. cvi. and cvii. 202 MEDICAL OPHTHALMOSCOPY. more frequent in them than in individuals who are not epileptic. During the paroxysm the appearance of the fundus has been described variously by different observers. For obvious reasons, the difficulties in the examination are great, and opportunities are rare. The only change which seems well established, is that the retinal veins, during the stage of lividity, become much distended. Regarding the state of the arteries, there is considerable doubt. On theoretical grounds, because contraction of the cerebral arteries is supposed to be the immediate cause of a fit, it has been expected that contraction of the retinal arteries would also be seen, and De "Wecker has described a sensible diminution in the size of the arteries during the pallor, but Kostl and Niemetschek thought that they recognized in one case dilatation of the arteries during an attack. Observation, however, of the size of the vessels by the indirect method, is of small value. In a case of convulsions from meningeal haemorrhage, in which there was, however, no initial pallor of face, and also in a case of severe one-sided fits, I have been able to keep a retinal artery and vein under (direct) view through the whole of a severe fit, from before its commencement until after its close. In neither case did the retinal artery present the slightest change in size. During the stage of lividity, the vein became large and dark. In a case of chronic local meningitis of the motor region of the left hemisphere (Case 2), by galvanizing the region of the cervical sympa- thetic, I was able to produce the aura with which the fits commenced, and once watched the retinal vessels by the direct method during the operation, but no change in their calibre was to be observed, although the aura was so intense as almost to pass into a fit. Clifford Allbutt, during a fit, has observed pallor of the discs, and a similar con- dition has been seen by Hughlings- Jackson and Arlidge, 1 immediately after a fit, in several cases. During an attack of epileptiform amaurosis, Dr. Jackson failed to see any 1 " West Riding Asylum Reports," vol. i. 1DIOPATHIC EPILEPSY. 203 change in the fundus which he was at the time comparing with a drawing of it. After a second attack the veins appeared a little paler than before. 1 I have repeatedly examined patients immediately after fits, but without being able to satisfy myself that there was any difference from the appear- ance of the disc and vessels at other times. It is possible that, as Knies 2 has suggested, changes in the size of the vessels sometimes described, may be due to a sudden alteration in the intra-ocular pressure from changes in the accommodation. In cases of epilepsy in which the fits were frequent, Clifford Allbutt has seen hypersemia of the discs, and even some exudation into them. As a rule, my own observations have given quite negative results. In one case, however, I met with marked changes in the discs, developed under observation during a series of exceedingly severe convulsive attacks, recurring at short intervals for several days. The patient was a young man, and the convulsions were of hysteroid type paroxysms of struggling, arching of back, throwing about of head and limbs, so intense that the united strength of three or four persons was required to keep the man in bed. They were accompanied by loss of conscious- ness. Bromide and other remedies produced no effect, and the convulsions continued unabated until ice was applied to the cervical spine, when the attacks at once ceased. The optic discs, after some days of convulsion, became reddened and veiled, so that their edges were quite invisible, and there was distinct swelling. After the cessation of the fits the discs gradually resumed their normal appearance. This patient, about three months later, died, after a series of true epilepti- form convulsions beginning in the left hand. Post-mortem, no trace of disease was visible in the brain to naked-eye examination. It might be expected that the retinal vessels would often give way during the violent venous stasis of an epileptic fit, just as do those of the conjunctiva. As already stated, retinal haemorrhage is rarely observed under the circumstances, no 1 " Lancet," Feb. 17, 1874. 2 " Sitzungsbericht der Heidelberg Ophth. Gesellsch.," 1877, p. 61 204 MEDICAL OPHTHALMOSCOPY. doubt on account of the support afforded to the walls of the vessels by the intra-ocular tension. It must be remembered that many cases of apparently idiopathic epilepsy may present traces of old optic neuritis or choroiditis indicative, the former certainly, the latter probably, that the convulsions originated in organic brain disease ; the choroiditis indicating former syphilis. Traces of old optic neuritis are especially common in cases of epilepsy due to blows on the head. It must also be remembered that chronic convulsions resembling idiopathic epilepsy may occur in the subjects of lead-poisoning and chronic renal disease, in each of which optic papillitis may be present. HYSTERIA. Although functional disturbances of sight (single or double amblyopia, hemianopia, colour-blindness, often with pain on use of the eyes), occur occasionally in the hysterical, ophthal- moscopic changes are very rare. Atrophy of the optic nerve has been met with in one or two cases, but was probably an accidental coincidence; or there may have been co- existent organic disease, such as disseminated cerebro-spinal sclerosis, underlying the manifestations of hysteria. When there is extreme amblyopia, dilatation of vessels and serous transuda- tion into the retina have been seen by Landolt. The chronic perineuritis described by Gralezowski in one case must be regarded as altogether exceptional. In hystero-epilepsy also there are, as a rule, no ophthalmoscopic changes, but after extremely severe and repeated fits, slight alteration may be met with, as in the case described in the section on "Epilepsy." INSANITY. The frequency with which pathological appearances are to be recognized with the ophthalmoscope in cases of insanity has been very variously stated. The discrepancy between INSANITY. 205 observers is so great, that it seems certain undue weight has been given by some to appearances which are not uncommon in normal conditions. In fact the ophthalmoscopic appear- ances in the insane seem, for some reason, to be a favourite subject for observers whose experience of normal eyes is insufficient to enable them to estimate the significance of the appearances seen. The observations in which changes were found in a large proportion of the cases examined must therefore be received with considerable reserve. As an instance of the different conclusions which have been reached may be cited the observations of Tebaldi, 1 who found changes in three-fourths of the cases examined; and of Schmidt- Rimpler, 2 who found changes only in thirteen out of 128 cases, and some of the thirteen he considered as doubtful. An even more striking instance of this discrepancy is afforded by two observers of the appearances in general paralysis, one of whom described atrophy as existing in eight out of every nine cases examined, while the other found hypersemia in about the same proportion. It must be remembered, in estimating the significance of the considerable changes sometimes found, that the cases of " organic " brain disease, tumour, softening, chronic menin- gitis, and the like, in which mental disturbance is prominent, occasionally find their way into asylums. GENERAL PARALYSIS OF THE INSANE. This disease is more closely allied to some spinal degenerations than to other forms of mental derangement. Unequivocal changes in the eye have been found much more frequently than in any other form of insanity. Loss of sight has been known since the time of Calmeil as an occasional com- plication; but in a considerable degree it is rare. Billed noted complete blindness in only three out of 400 cases. 3 The loss of sight has been proved to depend on grey atrophy of the optic nerves, similar to that which occurs in spinal 1 Nagel's " Jahresbericht," 1870, p. 374, from the "Rivista Cliiiica," 1870. 2 "Ann. d'Oculist.," vol. Ixxiv. 1875, p. 267. 3 "Ann. Med.-Psychologiques," 1863. 206 MEDICAL OPHTHALMOSCOPY. disease. The retinal vessels have been normal in size or narrowed (Magnan). In its slighter degrees, it affects one eye more than the other, and its occurrence may easily be overlooked unless the ophthalmoscope is used. Even in slight degree it is not a very frequent symptom. Gralezowski found it in one only of forty cases examined. 1 Boy, of eighty cases very carefully examined, found commencing atrophy, with amblyopia, in four only. 2 Jehn found distinct atrophy in seven cases out of forty-seven : in four double, in three single. 3 As in locomotor ataxy, it may be an early event, and may even precede the other symptoms of the disease. Magnan has observed the affection of sight to commence two and four years before the other symptoms of general paralysis. In a case recorded by Nettleship, grey-white atrophy of the disc, in a man aged thirty-five, with slight unsteadiness of gait, was followed, nine months after the onset of the amblyopia, by mental symptoms which developed into general paralysis. 4 Mr. Nettleship has informed me that he has since seen three or four similar cases. It is said by Jehn and Boy that the amblyopia commences with defective colour- vision, just as it may do in locomotor ataxy. As another point of contact between the two diseases, it is of interest to note that Westphal has shown that sclerosis of the posterior or lateral columns of the cord is occasionally found in general paralysis. It has not yet been ascertained whether atrophy of the optic nerves is especially common in such cases. Magnan 5 has found after death the optic nerves grey in colour and sometimes reduced to a third of their volume, and the chiasma and optic tracts also atrophied. The medullary sheaths of the nerve fibres had disappeared ; the walls of the vessels were thickened and covered with nuclei. The changes 1 " I/Union Med.," vol. xxxi. 1866, pi 404. 3 "These de Paris," 1879. 3 " Allg. Zeit. f. Psych," xxx. 519. 4 "Ophth. Hosp. Rep.," vol. ix. p. 178 B Quoted by Robin: " Des Troubles Oculaires dans les Maladies de 1'Encephale," p. 330, 1880. INSANITY. 207 were most marked in the circumferential part of the nerve, giving rise to a zone of sclerosis from which thick connective- tissue septa extended into the central part of the nerve, limiting irregular spaces containing degenerated nerve fibres. Magnan found analogous changes in the motor nerves to the eyeball. He regards the process as starting from the walls of the vessels, and as part of a general change in the central nervous system, commencing in the superficial layers. The atrophy usually begins as such in the simple form, but Magnan and Clifford Allbutt have described an initial stage of hypersemia uniform redness of the optic discs, with softened edges. Leber and other observers have failed to find this. Well-marked papillitis was found by Boy in one case, and in another he observed small haemorrhages along a few of the veins. Neuritis was also seen in one case by Jehn. " Peripapillary oedema," a " brownish circle around the papilla," 1 was observed in some cases by Magnan and Grale- zowski. Uhthoff found distinct hypereemia and opacity of the papilla in a case in which sight had failed in one eye for six weeks only, and was reduced to with concentric limitation of the fields for white and colours. Voisin described an undue tortuosity and dilatation of the retinal arteries, while by Magnan and others a grey or white line along the vessels was frequently observed. Jehn described the arteries as of very small size in some cases. Bouchut has figured aneurisms of the branches of the central artery from two general paralytics. Most of the cases I have examined in various stages of the disease presented perfectly normal conditions. In one case only was there the appearance of simple congestion of the disc. MANIA. During a paroxysm, Clifford Allbutt in one case found pale discs ; in others the discs were hypersemic. Noyes 2 described hypersemia in fourteen and anaemia in six out of twenty-six cases. Dr. Savage, formerly of Bethlem 1 The nature of this appearance is questionable. (Edema usually causes a pale halo around the disc as in PI. I. 3. 2 "American Journal of Insanity," 1872. 208 MEDICAL OPHTHALMOSCOPY. Hospital, has informed me that he has noted pallor of the discs in some cases, and in others undue fulness of retinal veins, but no other change. Of several cases I have ex- amined, in one only was there a pathological appearance, undue and uniform redness of the discs, with distinctly softened edge. MELANCHOLIA. Most observers have reported the ophthal- moscopic appearances in melancholia to be normal, and with this my own observations entirely agree. Jehn, however, described hypersemia in some of forty cases examined, and in two there was actual neuritis, which he supposes to be due to meningitis. Neither in mania nor melancholia has Magnan 1 found any change worthy of note. DEMENTIA. In chronic dementia, Dr. Clifford Allbutt, classing " worn out lunatics of all sorts " in the category, found changes in twenty-three cases out of thirty-eight in some atrophy, in others hyperaemia. Noyes found hyper- semia in two-thirds of the cases examined, atrophy in none. Jehn and Klein could find no change in the discs in any cases examined. In acute dementia Clifford Allbutt found no change. " Anaemia of the fundus " with " oedema of the retina around the disc " have been described by Aldridge. 2 DISEASES OF THE URINARY SYSTEM. BRIGHT'S DISEASE. In all forms of renal disease loss of sight from uraemic poisoning may occur. 3 Its characteristics are the sudden onset, completeness, the usual absence of ophthalmoscopic changes, excepting such as may have before existed, the preservation of the reaction of the pupil, and the quick dis- 1 Quoted by Robin, loc. cit. p. 287. 2 West Riding Asylum Reports," vol. iii. 3 The association of transient amaurosis with dropsy after scarlet fever \vas noted in 1812 by Wells ("Transactions of a Society for the Improvement HEIGHT'S DISEASE. 209 appearance of the symptom when the blood-state is relieved by purgation or diaphoresis. To the almost invariable rule that the ophthalmoscopio appearances are unaffected by uraemia, a few exceptions have been recorded. . Thus, in a case of ursemic amaurosis, slight oedema of the papilla, passing away with the return of sight, in the course of a few hours, was observed by Dobro- wolsky. 1 Again, Litten 2 has recorded a case of granular kidney in which frequent uraemic attacks occurred with coma, convulsions, and vomiting. Characteristic albuminuric retinitis was present, and a considerable amount of oedema of the papilla, causing swelling and peripapillary cloudiness. During each attack of ursemic symptoms the swelling of the papilla and the adjacent opacity increased, and the veins became more tortuous. After the attack was over, the changes resumed their usual degree. In diseases of the kidney of considerable duration, the vessels of the retina may present changes which they undergo in common with the vascular system of the body generally. The tendency to haemorrhage which exists in so marked a degree in many cases of chronic Bright's disease may lead to simple retinal haemorrhage. Lastly, considerable changes are often seen in the retina, which vary greatly in different cases, and are commonly described by the general, but not very accurate, term of " retinitis albuminurica." Vessels. According to my own observations, 3 in some cases of chronic renal disease, especially of the granular form, there is to be seen a notable diminution in size of the retinal arteries, independently of the existence of any special of Medical and Chirurgical Knowledge," vol. iii.). The first observation of actual changes in the retina was made (post-mortem) by Tiirck in 1850 ("Zeitschrift der Wiener Aerzte," No. 4, 1850). The microscopical changes were first carefully studied by Zencker ("Arch, fur Ophth.," ii. 142) and Virchow ("Arch, fur Path. Anat.," x. 1856, p. 178). 1 " Klin. Monatsbl. fiir Augenheilk.," March, 1881, p. 121. 2 "Charite Annalen," 1879, p. 169. 3 " British Medical Journal," December 9, 1876. P 210 MEDICAL OPHTHALMOSCOPY. retinal disease. The veins are in such cases not larger than the normal, but the arteries are not more than one-half or even one-third the diameter of the veins (PL IX. 2), instead of being two-thirds or three-quarters the diameter. The comparison can only be made, as already stated (p. 9), between arteries and veins which run side by side and correspond in distribution. Sometimes the arteries can be seen, even by the direct examination, as lines only (PL IX. 4.) I have only observed this, however, when papillary obstruction co-existed. The size of the arteries may then be less than is ever seen in simple papillitic obstruction without Bright's disease. Very often, when slight swelling of the retina co-exists, the arteries are invisible beyond the papilla (PL IX. 3, X. 1), due in part, I believe, to their extremely small size. "When this reduction in size exists the pulse usually presents marked incompressibility. A re- duction in size, in one case of acute passing into chronic Bright's disease, was observed to coincide with a very marked increase in the tension of the pulse. The contraction is not visible, however, in all cases in which the arteries are tense. In the absence of any cause for the reduction, it must be ascribed to arteriole contraction, and constitutes evidence of some weight in support of the view of Dr. Gr. Johnson, that such contraction exists, and causes the hypertrophy of the muscular coat of the artery. It is, as just stated, to be seen, in some cases, independently of any retinal disease, but is not invariable even when the tension of the pulse is very high. This may in some cases be due to degenerative changes in the walls of the vessels, as in PL XII. 1, in which no con- traction can be perceived. According to Brailey and Edmunds, 1 the walls of the retinal arteries are constantly altered in chronic Bright's disease, even when no abnormal appearances can be seen with the ophthalmoscope. The thickening consists of a growth of tissue which is especially situated between the endothelium and the rest of the interna. It may progress even to the obliteration of vessels. 1 "Trans. Ophth. Soc.," vol. i. p. 44. BRIGHT'S DISEASE. 211 When the retina is diseased, conspicuous white lines are sometimes seen along its vessels, apparently due to a sclerosis of the outer coat. I am not aware that this con- dition has been observed in any case in which the retina was otherwise normal. The remarkable appearance shown in PI. XII. 1 presents, however, a still more extreme con- dition of perivascular change. The arteries are, in part, concealed by a white opaque sheath, ceasing in places suddenly, and presenting the normal vessel emerging from the sheath. In the same fundus one artery presented two small aneu- rismal dilatations an interesting evidence of the vascular degeneration which is a well-known consequence of chronic renal disease. In the retinal capillaries irregular dilatations may be found, especially in cases of retinal degeneration, as in Fig. 68, p. 218. In this figure an increase of the nuclei of the capillary wall is seen in places, thickening it. It is probable that the degeneration of such nuclei, and the formation of such aneurismal dilatations, are the conditions which lead to haemorrhages, which were numerous in this case (PL X. 1). Hcemorrhagcs form, as will be immediately described, a conspicuous feature of most cases of retinal disease in albu- minuria. Their common seat is the nerve-fibre layer, in which they are striated and flame-shaped, and often follow the course of the vessels. Less commonly they may occur in other layers, and are then rounded and irregular. They may detach the retina from the choroid or burst through into the vitreous. They sometimes occur, however, apart from other retinal changes, as isolated evidence of the hsemorrhagic tendency. An instance of this is shown in PL IX. 1. The retina which presented this extravasation, even up to the time of the patient's death, several months later, showed no sign of other changes. The haemorrhages are probably due to the weakening of the wall of the minute vessels (by such changes as have been just described), and to the increased intra-vascular tension, causes which are the same as those 212 MEDICAL OPHTHALMOSCOPY. which give rise to the extravasation into the brain, so common in the same cases. "ALBUMiNURicE-ETixixis." The special retinal alterations which occur in renal disease are perhaps the most frequent ocular changes to come under the notice of the physician. They are met with only in chronic forms of renal disease those which are chronic from the beginning, or which are chronic as resulting from an acute attack. They have been met with in most chronic forms of kidney disease granular kidneys, large white kidney, sequential to an acute attack, and lardaceous kidney. They are by far the most common in the granular form, and least common in the lardaceous kidney. 1 The tendency to their occur- rence is said to bear some relation to the amount of albu- men in the urine. Both eyes are almost invariably affected. Yvert, how- ever, records a case 2 in which recovery took place, where the left eye only was affected. The appearances were quite characteristic, with numerous haemorrhages. The intensity of the changes varied with the amount of the albumen. A subsequent post-mortem showed that the left kidney only existed, and that that was diseased. Yvert assumes the influence of reflex nervous impressions as well as of blood- states, and quotes several cases in which a blow on one lumbar region caused anasarca, limited to, or greater on, that side. This view receives some support from a case of Eales', 3 the sight of whose left eye failed the day after an injury to his left lumbar region. Three weeks later there were white spots near the macula, along with yellowish exudation round the disc, and slight papillitis. The albumen gradually disappeared, and the eye became perfectly normal. 1 It has been said that retinal changes do not occur with lardaceous disease of the kidney. Cases have, however, been recorded by Beckmann, Traube, Alexander, Argyll Robertson, and Bull, and one case has come under my own observation. 2 "Rec. d'Ophthal.," 1883, p. 145. 3 "Trans. Ophth. Soc.," 1885, p. 126. BRIGHT'S DISEASE. 213 The frequency of retinal changes has been variously stated. Published statistics vary between 7 and 33 per cent. Eales, 1 in 100 cases of chronic disease, found retinal changes in 28, or 1 in 3J, and this probably represents approximately the frequency with which they are met with. The variation in the estimated frequency is doubtless due mainly to the rela- tion of retinal changes to the duration of the disease. Only after the kidney disease has been exerting its influence on the system for a considerable time, do these changes occur. They commonly correspond in time with the development of cardiac hypertrophy. This led Traube to assert that the hypertrophy of the heart is the cause of the affection of the retina. But the latter may be found in rare cases, without the former. 2 It is not probable that there is any necessary connection between the retinal and the cardiac change, other than that both indicate a pronounced and prolonged effect of the renal disease upon the system. It is indeed well known that the renal disease is often first ascertained by the discovery of the existence of the ocular change, but this is not opposed to the fact just stated, since the retinal disease is only the earliest discovered symptom in those cases in which the renal affection has been insidious in its onset, and has existed for a long time, and reached an advanced stage, before its symptoms obtrude themselves upon the patient's notice. It has been suggested that the retinal changes may some- times precede the onset of the renal affection, but all observed facts concur in showing that the relation above described is the invariable one, that renal disease, usually with more or less albuminuria, precedes the retinal affection. The only cases in which the retinal changes precede the albuminuria are rare examples of granular kidney disease, in which albumen is absent from the urine until a late stage of the renal affection, as in the case of a lady, aged fifty-seven, suffering from hemiplegia, who came to me with perfectly characteristic degenerative albuminuric retinitis in each eye. She had hypertrophy of the heart, with strong aortic second sound 1 "Birmingham Medical Review," Jan. 1880, p. 34. 2 Cf. Litten, loc. cit. 214 MEDICAL OPHTHALMOSCOPY. and high-tension pulse. Repeated careful examination of the urine, however, failed to reveal a trace of albumen, and the specific gravity was not low. There was a family history of rheumatic (?) gout, and of apoplexy. Two cases are also recorded by Abadie. In one of them there was polyuria. 1 The retinal changes, as a rule, occur only in cases of organic disease of the kidney. In forms of functional albu- minuria they have not been observed, with the exception of some cases recorded by Eales. 2 Of 14 cases of young men between eleven and twenty-eight suffering from what was believed to be temporary functional albuminuria, he found retinal changes in 5, white specks in 4, white patches in 1. This observation affords support, as he points out, to the view that, in ordinary Bright's disease, the retinal changes are due to the morbid state of the blood. The retinal disease presents certain elements which are variously combined in different cases. These are (1) diffuse slight opacity and swelling of the retina, due to oedema of its substance ; (2) white spots and patches of various size and distribution, due for the most part to degenerative processes ; (3) haemorrhages ; (4) inflammation of the intra-ocular end of the optic nerve ; (5) the subsidence of inflammatory changes may be attended with signs of atrophy of the retina and nerve. In most cases one or other of these changes predominates, especially in the early stage of the affection, and, according to the element most conspicuous, four types of disease may be distinguished. These are the degenerative, the haemor- rhagic, the inflammatory, and the neuritic, according as white spots of degeneration, extravasations of blood, parenchyma- tous retinal inflammation, or inflammation limited to the optic nerve, predominate. It is, however, to be observed that degeneration and haemorrhage commonly accompany or succeed the inflammatory changes, and that forms are often seen combining the characters of these varieties. In the typical degenerative and haemorrhagic forms the signs of inflammation are inconspicuous or subordinate. 1 "La Union Medicale," 1882, p. 627. 2 Loc. cit. The nature of the cases is open to some question. BRIGHT 8 DISEASE. 215 The degenerative form (PL IX. 2) is the most common. It commences usually without signs of inflammation, by the appearance of small whitish spots on the substance of the retina, sometimes near the optic nerve entrance, sometimes at a distance. They are commonly at first soft-edged and rounded, and as they get larger become irregular. Grene- rally, small very white spots, often punctiform or elongated, make their appearance around the macula lutea, arranged in a radiating manner, although frequently not forming a complete circle. These are sometimes so minute as to be only visible on careful direct examination ; sometimes they are large and very conspicuous, and are often arranged irregularly, end to end, so as to form radiating streaks, beyond which dots may be scattered (Fig. 67). Often a less intense and diffuse opacity is visible in tracts here and there. Sometimes the larger spots coalesce into white areas, which may surround the disc. FIG. 67 THE RETINAL CHANGES IN ALBUMINUKIA. A fan-shaped group of white spots radiating from the macula lutea ; small arteries ; slight papillitis. 216 MEDICAL OPHTHALMOSCOPY. Haemorrhages, almost constant in all varieties, are slightest in the most chronic degenerative forms. They often are adjacent to the white spots due to the changes in the nerve fibres, and, lying for the most part in the nerve-fibre layer, they have a more or less striated arrange- ment, determined by the nerve fibres, the direction of which the striae follow. Sometimes linear haemorrhages are seen. When larger, the extravasations are more or less flame-shaped. When small, they often lie adjacent and parallel to vessels, but it is not often that the vessel from which they originate can be traced. When large they may be irregular in shape and occupy the deeper layers of the retina. The diffuse opacity already described is sometimes con- siderable and accompanied by a little swelling here and there. Such a change is, however, rarely well marked in the form which begins with simple degeneration. The retinal changes in this form may be considerable without any alteration in the optic disc. Often, however, its edges become blurred, the physiological cup indistinct, and the tint abnormal, reddish-grey. In two patients suffering from lardaceous degeneration Bull 1 observed the whole retina to present a uniform whitish infiltration, with numerous haemorrhages. He suggests that the appearance may have been due to lardaceous degenera- tion of the retina. In the fmmorrhagic form, the conspicuous change is the occurrence of a large number of haemorrhages, with but little degenerative change and but slight signs of inflammation of disc or retina. Commonly, especially after a time, there is more or less degeneration adjacent to the haemorrhages, and traces of the halo of spots around the macula are rarely absent. The haemorrhages, for the most part, resemble those just described, differing only in their number, size, and predominance. In the inflammatory form (PL X. 1) there is a general parenchymatous swelling of the retina with complete obscu- 1 " American Journal of Med. Science," Oct. 1879. BRIGHT'S DISEASE. 217 ration of the disc. The vessels are concealed, the arteries especially. The veins are distended, and sometimes have an extremely irregular and tortuous course over the fundus ; the -arteries are narrow. Haemorrhages invariably occur in con- siderable number, and are often large and striated. White spots are commonly numerous, and more or less uniform in character, especially in the acute cases, in which they are large, rounded (as in the figure), and soft-edged. In these cases there is rapid degeneration of the tissue elements, and abundant infiltration with lymphoid cells. If the inflamma- tion subsides, the signs of degeneration may become more predominant, and the optic nerve may present evidence of secondary atrophy. I believe, however, that it is rare for any subsidence of this form to occur, because it is confined to cases in which the effect of the renal disease on the system is intense, and usually soon leads to death. Neuritic Form (PL IX. 2, 3, 4). In some cases the inflam- mation of the optic nerve predominates over the other retinal changes to such an extent that it may appear to be the only alteration, 'and may present nearly the aspect which is common in intra-cranial disease. The edges of the disc are veiled under a greyish-red swelling, of moderate prominence, which may extend a little distance beyond the normal edges of the disc. The prominence may be slight, or such that the veins form conspicuous curves over the sides. The arteries are usually narrow, and often concealed in the swelling ; even the veins may be concealed. On direct examination it is generally conspicuously striated. Fre- quently, on the surface of the swelling, or apparently beneath its surface, there is a conspicuous white reflection in certain spots (PL IX. 2), most distinct on oblique illumination. Occasionally on the surface of the swollen papilla may be very minute white dots (just recognizable in PL IX. 3). A careful examination will show, in almost all cases, signs of slight retinal degeneration, sometimes so slight as to require close attention and careful focussing by the direct method to detect them. Sometimes, as in PL IX. 2, there 218 MEDICAL OPHTHALMOSCOPY. FIG. 68. SECTION THROUGH RE- TINA IN A CASE OF ACUTE ALBUM INURIC RETINITIS. The section passes through one of the white spots near the disc, shown in PL X. 1. The retina is greatly thickened, mainly from changes in the nerve-fibre layer (a a'), where numerous granular bodies are seen (such as are shown more magnified in Fig. 69). Capil- laries are dilated, with con- spicuous alterations in their walls ; one of them (near right edge of figure) presents a series of aneurismal dilatations ( x 180). are one or two white spots in the retina, near the neuritic swelling. At others, as in PL IX. 3, 4, minute white spots are to be detected near the macula lutea. Frequently small haemorrhages are to be seen somewhere about the fundus (PI. IX. 4). It is remarkable that there is little tendency FIG. 69. PRODUCTS OF DEGENERATION FROM A WHITE PATCH IN A CASE OF ALBUMINURIC RETINITIS. (x 250.) FIG. 70. DEGENERATED FIBRES OF MULLEK FROM A CASE OF ALBUMINURIC RETINITIS. Swelling of the ends of the fibres, and rows of fatty granules due to- degeneration. ( x 250. ) BRIGHT S DISEASE. 219 for haemorrhages to occur in the swollen papilla in this form. If the neuritis subsides, a condition of consecutive atrophy may be left a filled-in disc, greyish, with paler lines along the vessels, and often extremely small arteries. Such a con- dition is shown in PI. IX. 4. Anatomical Changes. The scattered white spots depend commonly on degeneration of the layer of nerve fibres, which are found to be greatly thickened. The fibres often present varicosities, which may attain a large size and become crammed with fat-like globules. These ultimately become isolated as large fat-containing spheres, which, with free globules of fatty matters, are found abundantly on micro- scopical examination of recent specimens (Figs. 69, 70), and are very conspicuous in a surface view (Fig. 71). The degeneration occurs also, and sometimes chiefly, in the deeper layers, which may also be infiltrated FIG. 71. SURFACE VIEW OF A WHITE SPOT ON THE RETINA IN ALBUMINURIC RETINITIS. The transverse lines indicate the nerve fibres. Among these are large and small oil globules and spherules consisting of similar still smaller globules. (After Pagenstecher and Genth.) 220 MEDICAL OPHTHALMOSCOPY. with the " compound granule cells." Degeneration of other retinal elements, round corpuscles, and vertical fibres of Muller may sometimes be found. The latter are swollen and contain minute oil globules (Fig. 70). When swollen they have an undue refraction, and have been said, rather unnecessarily, to be " sclerosed." It is to the position of these that the stellate zone of spots around the macula is mainly due. The fibres here have a less vertical direction, radiating from the fovea centralis, and the degeneration of these fibres and the grouping by them of the degeneration of other retinal elements produces the radiating group of spots, most conspicuous near the margin of the fovea, where the fibres become placed more closely together. The diffuse opacity of the retina is in part due to oedema. The elements of the nerve- fibre layer may be separated by clear spaces, and similar spaces may form in the ganglion-cell layer, in the molecular and even in the nuclear layers. In this con- dition the ganglion cells often fall out of the section (Fig. 72). The diffuse opacity is also partly due to an infiltration of the retinal interspaces with a coagulable fluid, which, after hardening processes, presents an appearance of interlacing fibrillee with granules at their points of intersection. This may occupy large areas, as in Fig. 68, especially in the FIG, 72. SECTION THROUGH THE RETINA, SOME DISTANCE FROM THE Disc, IN A CASE OF ALBUMINURIC RETINITIS, SHOWING (EDEMA. The nerve-fibre layer (a) is normal, but in the nerve-cell layer (b) the gang- lion-cells have fallen out, owing to the formation of spaces round them in consequence of the cedema. The other layers show a tendency to dissociation of their constituents, and to the formation of spaces here and there. ( x 150.) BRIGHT'S DISEASE. 221 outer molecular layer, where cavities, containing this sub- stance and separated by the remains of the vertical fibres, may alone be perceptible. A similar effusion may also separate the " membrana limitans interna " and bases of Miiller's fibres from the rest of the nerve-fibre layer. Occasionally the layer of rods and cones presents remarkable thickening, such as is shown in Fig, 68, and is sometimes seen in other morbid states of the retina. Liebreich has called attention to the occurrence of small angular grey spots of pigment, often arranged in groups, and appearing first in the periphery. They are due to changes in the pigment- epithelium, and are seen especially in cases in which a parenchymatous inflammation has passed away. Choroidal Changes. Occasionally, although rarely, choroidal haemorrhage may occur in Bright's disease, and may lead to circumscribed atrophy of the choroid with adjacent pig- mentary disturbance. A peculiar " colloid " degeneration of the vessels of the choroid in old cases of albuminuric retinitis has been figured by Poncet. It leads to a thickening of the tissue of the choroid. Symptoms. In the slighter forms of the degenerative, hsemorrhagic, and neuritic varieties, vision may be unaffected. More considerable alteration, and even slight parenchy- matous inflammation, commonly entails amblyopia, without limitation of the field or changes in colour- vision. In rare cases colour-vision may be affected. As the changes pro- gress, the interference with vision increases. When the macula lutea is damaged, central vision is lost, but this is not common. Degenerative changes rarely reach the centre of the macula, no doubt because the structures in which the degeneration occurs do not extend to the f ovea centralis itself. Haemorrhages, from the paucity of large vessels, are also rare- in this situation. The haemorrhage may, however, encircle the macula, and cause an annular defect in the field. With a central loss of sight, some adjacent colour-blindness was found by Gralezowski. Sight is rarely altogether lost. Attacks of uraemic amaurosis often accompany and compli- cate the amblyopia due to the retinal disease. 222 MEDICAL OPHTHALMOSCOPY. Pathology. We know little of the relation between the renal and the retinal affection. The degenerative changes have been ascribed to the tendency to fatty degeneration which renal disease entails ; but this scarcely explains their localization in the retina. Some facts, however, seem to show that a careful recent microscopic examination of the nervous tissues elsewhere may reveal the occurrence of similar changes in them. We know, especially through the researches of Grull and Sutton, that an extensive increase in the supporting tissue of the nerve centres may be found in chronic Bright's disease, and the thickening in the supporting tissue of the retina may be part of this change. Knob-like degenerations of the nerve fibres have also been found elsewhere in the nervous centres. The facts stated on p. 214 render it probable that the mechanism by which renal disease excites the retinal changes is the altered state of the blood. The haemorrhages have been ascribed, with reason, to the double effect of the degeneration in the minute vessels and the increased arterial pressure from the cardiac hypertrophy. It has been speculated that the neuritis may be due to the effusion of serum into the sheath of the optic nerve, but the view rests on no post-mortem evidence. In several cases in which I have found neuritis predomi- nating, symptoms of cerebral disturbances were conspicuous, intense headache, delirium, convulsions, due apparently to the effects of the blood-state. It seems probable that in these oases there is much cerebral disturbance, and that this may determine the occurrence of the excessive change in the optic nerve. Complications. Detachment of the retina is an occasional, although not frequent, accident. It may be double and extensive, as in one case under my own observation. The whole retina was detached in a case recorded by Davidson. 1 It is apparently due to serous effusion between the retina and 1 "Trans. Ophth. Soc.," vol. i. p. 57; see also vol. viii. p. 141, where Dr. Anderson relates a case in which very extensive retinal detachment occurred in both eyes of a child with chronic interstitial nephritis BRIGHT'S DISEASE. 223 horoid. An example of it in slight degree is figured in Fig. 68, which shows that the pigment-epithelium may be detached with the retina. Hcemorrhage into the vitreous occasionally occurs from the rupture of an extensive extravasation in the superficial layers of the retina. It is always single, and may occur, as in a case under my observation, without the patient's knowledge. One day the f undus was distinct, and vision good ; the next nothing but a black reflection from the interior of the eyeball could be seen, and sight was lost. It is hardly necessary to say that damage to vision may be permanent. It may probably occasionally determine glaucoma. Embolism is said to be an occasional complication of albu- minuric retinitis (Yoelcker). But this statement must be accepted with considerable reserve. Embolism elsewhere is extremely rare. Thrombosis sometimes occurs in the cerebral arteries, and the signs of embolism may have been due to that cause, and on the other hand the contraction of the retinal arteries may simulate that in embolism ; but there is no corresponding defect of the field of vision in these cases, such as would certainly have been present if embolism or thrombosis existed. As I have suggested, the explanation of these appearances which seems most probable is that the tendency to arterial contraction, which is often traceable in normal arteries in this disease, leads to an extreme degree of narrowing when the changes in the disc lessen the flow of blood into the arteries. Course. In most cases the retinal changes persist, some lessening, others increasing, until the patient's death. Not rarely, however, they diminish notably, and the retrogression may proceed until the changes almost or quite disappear. This is especially the case when the affection comes on in the course of the chronic kidney disease which results from an acute attack, in which considerable improvement in the renal affection is often obtained, and in other chronic cases when prompt treatment soon after the onset of the retinal disease can improve the action of the kidneys. The effect of purgation in lessening the retinal affections has been often observed, and 224 MEDICAL OPHTHAI.MOSCOPY. Eales has remarked that constipation appears to increase the tendency to their recurrence or relapse. Improvement is often noted in the albuminuria of pregnancy, a form very prone to lead to retinal changes, which commonly improve or even disappear when the pregnancy is over. The greatest improvement is obtained in the cases of slight papillitis. Haemorrhages constantly disappear, and, if the formation of fresh ones can be prevented, considerable improvement in the retinal state may result. Even the degenerative changes may pass away, especially those which depend on the presence of the granular bodies in the layer of nerve fibres. Most of the white spots shown in PI. X. 2 disappeared. The most persistent changes are those which result from the degeneration (or sclerosis ?) of the fibres of Miiller. The white specks around the macula lutea, which result from this cause, rarely disappear. Occasionally re- missions in the retinal affection are observed, although the kidney disease progresses. Thus in Litten's case, referred to on p. 209, there was repeated subsidence of the retinal change, in spite of rapid progress of the renal affection. There was not only resorption of extravasation, but also disappearance of white patches. Diagnosis. The recognition of the degenerative changes in the retina is only a matter of difficulty when the changes are slight and limited to the region of the macula. The strong contraction of the pupil, when this part is examined, very often renders the use of homatropine indispensable for a thorough exploration. The aspect of the degenerative form is most closely simu- lated by the retinal degeneration which results from a neuro- retinitis of wide extent (PL VIII. 2). It is probable, indeed, that the changes are, to a considerable extent, identical. The damage to and between the radiating fibres around the macula lutea may leave a stellate group of shining spots quite indistinguishable from those which occur in renal disease, and the diffuse white areas nearer the disc may also resemble those seen in the latter form. If the patient have come under observation during the acute period of the inflamma- BRIGHT S DISEASE. 225 tion, there will be no question as to the nature of the retinitic change. It will be seen that, as in PL VIII. 1, the neuritic swelling reaches as far as the neighbourhood of the macula, and that the development of the white spots around the latter is part of the changes in the retina occurring near to, and evidently excited by, the inflammation. If, however, the patient come under observation at a later stage, the distinc- tion may be less easy. This is especially the case when a neuritis from a cerebral tumour has been unnoticed till the loss of sight which accompanies its subsidence. The signs of one or the other classes of disease encephalic affection or renal disease are usually, however, sufficiently clear to leave little doubt, after a general survey of the symptoms. But this does not always afford so clear a guide as might be expected. A cerebral tumour may be accom- panied by a trace of albumen in the urine. This was the case in a child whom I saw some years ago with the late Dr. Anstie. The only symptoms were headache, the retinal changes, and the trace of albumen. On the other hand there may be no symptoms of intra-cranial disease, except J FIG. 73. PAPILLO-RETINITIS. From case of cerebral tumour, with appearances at macula closely reseni bling those common in albuminuric retinitis. (After Edmunds.) 1 1 See "Trans. Ophth. Soc.," vol. iv. p. 291 and pi. 7. 226 MEDICAL OPHTHALMOSCOPY. headache, which can, alone, hardly be regarded as such, and may accompany the neuritis of albuminuria, as in the case of the patient whose eye is shown in PL IX. 3. Lastly, a neuritis, primary in the eye, may occur after diseases, as scarlet fever, which are liable to be attended with albuminuria. But attention to the following points will, in most cases I think in all cases enable a correct diagnosis to be made by the ophthalmoscopic signs alone, or in conjunction with the other symptoms. In the first place, there are always present the signs of a considerable preceding neuritis. Commonly, at the time the failure of sight calls attention to the eye, and the white spots are discovered, there is a prominent pale swelling over the disc, as in PI. VI. 3. It is very rare for albuminuric neuritis to leave a swelling of this prominence and pallor. If atrophy results from an albuminuric neuritis, the disc, by the time it becomes pale, is very little above the retinal level, as in PI. IX. 4. More- over, the neuritic form never occurs, at least as far a& recorded facts and my own observation have gone, except in cases of advanced chronic renal disease, commonly of con- tracting kidney, 1 in which the signs of Bright's disease are always obvious enough. (Regarding these distinctions, see also pp. 96 98.) In the degenerative changes of neuro-retinitis, of such an extent as to simulate closely the appearance of the albumi- uuric form, as in PI. VIII. 2, all the features of the change are those of past, retrogressive mischief. The disc is atro- phied, the arteries evidently compressed, and there are, as a rule, no hemorrhages. In the renal form, of corresponding extent, there are always signs somewhere of active progress. The disc is commonly still inflamed, and there are usually haemorrhages. Lastly, when the retinal degeneration is present as a consequence of neuritis, at the time any diffi- culty in diagnosis might arise, sight is almost always lost. Whereas complete loss of sight is an event of great rarity in the albuminuric form. 1 In one case I have seen it in the late stage of the large pale kidney, in which induration was commencing. DIABETES. 227 The form in which haemorrhages and spots of degeneration are combined, may resemble closely the changes in the retina in pernicious anaemia. But in the latter the perimacular circle is commonly not recognizable, and the degeneration is for the most part connected with, and secondary to, the retinal haemorrhages. The degeneration does not attain the same extent, and the disc is usually unaffected. The same- remarks apply, in the main, also to leucocythsemic retinitis. In the latter, the white spots are much more common in the peripheral portions of the retina than they are in the renal form, and in the latter it is very rare to see the circular spots,, surrounded by a halo of haemorrhage, which are so frequent in leucocythaemia. In the latter the tint of the fundus is- commonly very different from that in albuminuria. In both pernicious anaemia and leucocythaemia the independent symptoms of the malady usually leave little room for doubt as to the nature of the retinal changes, but it must be- remembered that, in the latter especially, renal degeneration is often present. Prognosis. Considerable attention has recently been drawn to the unfavourable prognosis as regards life in cases of chronic renal disease with retinal changes. Such patients seldom live two years, and a large percentage of them die within a few months, 1 after the retinal affection is observed. Treatment. Local treatment is of doubtful value, (rood can only be effected by improvement in the blood-state, especially that which is produced by purgation and dia- phoresis. By this means considerable improvement may often be effected in the retinal disease. In several cases,, however, the albuminuric spots have entirely disappeared while under observation, although the patient died from the renal affection. DIABETES. DIABETES MELLITUS. Defects of sight are common in diabetes (as Bouchardat pointed out many years ago), but changes in the fundus oculi are rare. The most frequent 1 See Miles Miley, " Trans. Ophth. Soc.," vol. viii. p. 132. 228 MEDICAL OPHTHALMOSCOPY. cause for the defect is cataract, which is apt to occur in these cases. Occasionally, considerable amblyopia occurs without ophthalmoscopic changes, probably due to the blood- state and comparable to uraemic amaurosis, although pro- bably the result of a different condition of blood. Simple atrophy of the optic nerve has been observed in some cases. In a few cases a central scotoma for white and colours has been observed, peripheral vision being normal. The symptom thus closely resembles that which results from tobacco, but in some of the cases this cause could be with certainty excluded. Examples of this affection have been recorded by Bresgen, 1 Samelsohn, 2 and by Nettleship and Edmunds. 3 The latter, in one of their cases (in which the loss was chiefly for red) found atrophy of nerve -fibres, with increase of nuclei and connective tissue, in a tract which, at the back of the orbit, occupied the axis of the nerve, and near the eye, the outer portion. They attribute the changes in this case, however, to the fact that the patient was a smoker. Occasionally retinal changes are visible, first observed by Ed. Jager 4 and afterwards by Desmarres and Gralezowski. A careful study of them has been made by Leber, 5 by James Anderson 6 and by Nettleship 7 (Fig. 74). They axe only seen when the disease is advanced. In such cases of diabetes, albumen is often present in the urine as well as sugar, but the occurrence of these retinal changes is not related to the albuminuria, since they have been observed in many cases in which not a trace of albumen was present. The changes in the retina bear considerable resemblance to those of albiiminuria, and still greater resemblance to those seen in some cases of pernicious anaemia. Hiemorrhages 1 'Centralbl. fiir prakt. Augenheilk.," Feb. 1881, p. 33. 2 'Cent. f. prakt. Augenh.," 1882, p. 202. 3 'Trans. Ophthalmological Society," vol. i. p. 124. 4 ' Beitrage zur Pathol. des Auges." "\Vien, 1855, taf. xii. 5 'Arch. f. Ophth.," xxi. 306. 6 'Ophth. Rev.," viii. 1. 7 'Trans. Ophth. Soc.," vi. 331. DIABETES. 229 are conspicuous in many of the cases, but may be entirely absent, as in the case drawn in Fig. 74. They are often situated behind the vessels, and are sometimes of considerable size. They may exist alone or may lead to a secondary parenchymatous retinitis. In one case, figured by Jager, a condition of parenchymatous retinitis existed in the posterior segment of the eyeball, with obscuration of the disc, concealment of the veins in places, a few large whitish spots, and a few striated haemorrhages, the arteries being unconcealed. White spots of degeneration are frequently present, commonly of moderate size, scattered over the fundus. They are situated in the deeper layers of the retina. They differ from the patches of the albuminuric retinitis in shape, having less tendency to assume a circular form ; in colour, having a more dingy shade of white ; and in grouping, the star round the macula being seldom seen, although there is a tendency for the spots to be arranged in the form of incomplete rings. Sometimes, however, although rarely, there may be a perimacular circle of spots, and this in cases, as those described by Noyes, FIG. 74. OPHTHALMOSCOPIC APPEARANCE IN A CASE OF RETINITIS IN DIABETES. (Nettleship. ) The disc is free from swelling. Scattered aboxit the fundus, especially in yellow spot region, are numerous ill-defined whitish patches (see text). In this case there were no haemorrhages. 230 MEDICAL OPHTHALMOSCOPY. Desmarres, Eales, and Culbertson, in which there is no albumen in the urine. Occasionally a preponderant papillitis may be present, as in the case related by Culbertson, 1 in which consecutive atrophy resulted and caused permanent amblyopia, although the neuritis was apparently cured. The simple atrophy of the optic nerve, which occasionally exists alone, may, in rare cases, accompany the retinal changes (Gralezowski). A marked difference from the forms of retinitis which it most resembles is afforded by the frequent association, in diabetes, of opacities in the vitreous. They appear to be produced by the escape of blood in small quantities from the retinal haemorrhages. Leber has traced the development of a complete opacity of the vitreous by this mechanism of repeated haemorrhagic infiltration. Occasionally, hsemor- rhagic glaucoma is the result. In one curious case recorded by Nettleship 2 there were, in several parts of the fundus, capillary loops, apparently from the choroid, perforating the retina, and projecting for several millimetres into the vitreous. In another case he found by the ophthalmoscope numerous small dilatations on a large vein near the disc. 3 Few microscopical examinations have been made. One by Nettleship is recorded by S. Mackenzie. 4 The chief change, beyond oedema, was a peculiar hyaloid degenera- tion of the interna of the arteries, and numerous capillary aneurisms, some of which are shown in Fig. 75. These vascular changes afford an explanation of the tendency to haemorrhage. In this case the vessels of the brain (and of the kidneys and spleen) were similarly affected, and a small cerebral haemorrhage had occurred. Both eyes are commonly affected in diabetes. The dis- turbance of sight may be slight or considerable. Blindness is usually the result of the extravasations, or of secondary changes in the vitreous. In Mackenzie's case, just described, 1 "Detroit Lancet," April, 1880. 2 " Trans. Ophth. Soc.," vol. viii. p. 159. 3 "Trans. Ophth. Soc.," vol. viii. p. 161. 4 "Ophth. Hosp. Rep.,"ix. p. 150. DIABETES. 231 the disease was discovered by Waren Tay in consequence of the result of the ophthalmoscopic examination. There is nothing absolutely pathognomonic in the characters of the affection, since they closely resemble the albu- minuric form. In addition to the distinctions already described, the most suggestive indications are, as Leber points out, the combination of the retinal change with opacity of the vitreous, and also with atrophy of the optic nerve having the characters of a simple atrophy. In albuminuria, atrophy is very rare, except as the result of neuritis. The retinal affection is apt to relapse, even though temporary improvement be obtained under the influence of dietetic treatment. The advanced stage of the disease at which it occurs also renders the prognosis unfavourable. The treatment is, in the main, that for the general disease. Carbolic acid is suggested by Leber, but is more likely to be useful in the diabetic amblyopia, without retinal changes, than in the latter. In very rare cases optic neuritis and glycosuria may both be consequences of an organic cerebral disease. The two TIG. 75. CAPILLARY ANEURISMS, AND VARICOSE CAPILLARIES FROM RETINA, IN A CASE OF DIABETES WITH RETINAL HEMORRHAGES. They are seen in the course of the vessels (c) at their bifurcation (d), and also situated laterally (b). (x 150.) 232 MEDICAL OPHTHALMOSCOPY. symptoms, for instance, existed in a case recorded by Gross- mann, 1 and the optic neuritis was thought to be due to the diabetes, until other indications of a cerebral tumour de- veloped. After death a tumour was found in the anterior part of the base of the brain, and the fourth ventricle was distended by a pseudo-membranous mass. DIABETES INSIPIDUS. In a very few cases of diabetes insipidus, ophthalmoscopic changes have been observed, which have not, however, much analogy with those observed in diabetes mellitus. Atrophy of one optic nerve was observed by Laycock, 2 and double optic neuritis was present in a case described by Van der Heyden. 3 The connection of these changes is probably with the cause, rather than with the condition, of polyuria. It must also be remembered that the polyuria of contracted kidney is sometimes mistaken for diabetes insipidus. DISEASES OF THE CIRCULATOEY SYSTEM. DISEASES OF THE HEART. The veins and arteries of the retina participate in any general changes in the circulation which result from diseases of the valves and walls of the heart, although the changes in them are commonly less marked than those in other vessels. For this there are two reasons (1) Their size is far below that of the other vessels accessible to physical exami- nation ; (2) the conditions of the intra-ocular. tension keep the circulation more uniform in the eye than in other parts. The over-filling of the venous system, from over-distension and dilatation of the right heart, consequent on congenital disease of the pulmonary orifice, on emphysema, and other causes of pulmonary obstruction, and on disease of the mitral orifice, may be revealed by an over-distension of the retinal veins, the chief trunks being large, and the smaller 1 " Berl. Klin. Wochenschrift," 1879, p. 138. 2 " Lancet," 1875, ii. 242. 3 " Leyden Thesis," 1875. DISEASES OF THE HEART. 233 veins unduly visible, and therefore apparently more numerous. It is commonly unattended with visual disturbance, although a case in which it was accompanied with transient attacks of amblyopia has been described by Galezowski. This condition is most marked in congenital cyanosis. In that disease the retinal veins may be enormously dilated (as in a case figured in the first edition of Liebreich's Atlas), and they afford proof of the degree to which the distension of the venous radicles contributes to the cyanotic tint. Retinal hsemor- rhages occurred shortly before death in a case of congenital cyanosis recorded by Stangloneier. 1 In acute venous over- distension, such as occurs during effort, during severe cough, or during an epileptic fit, the venous congestion may also be very marked. Under-filling of the arterial system, if chronic, such a& occurs in aortic obstruction and in mitral disease, is rarely evidenced by a corresponding state of the retinal vessels, na doubt on account of the second local influence just mentioned. Nor is chronic over-action of the left ventricle, if sustained,, evidenced, as a rule, in the retinal arteries, probably because the cause of such over-action commonly lies between these- minute vessels and the heart. Exceptions are, however,, met with. In exophthalmic goitre, in which the over-action of the heart depends on a primary nervous disturbance, and not on an obstruction to be overcome, distension (and even pulsation) of the arteries may be visible. The former is probably in part due to dilatation of the vessels from vaso- motor paralysis. (See p. 198.) Sudden over-action of the heart, as from emotion or violent exertion, may also show itself in visible pulsation of the retinal vessels ; rarely in the arteries, more frequently in the- veins, to which it is transmitted from the arteries. In aortic regurgitation pulsation in the veins is common, and pulsation in the arteries is not rare. This depends on the fact that the force of the pulse-wave becomes increased out of proportion to the actual movement of the blood, and 1 "Inaug. Dissert. Wurzburg, 1878; Nagel's "Jahrbuch fur Ophth.," 1878, p. 261. 234 MEDICAL OPHTHALMOSCOPY. the conditions which obtain in the larger arteries pass on, so to speak, into the smaller vessels, and even overcome the regulating influences of the eye (see p. 20). In one case described, the existence of the valvular lesion was first suspected from this pulsation. For the above-mentioned reasons, neither simple dilatation nor simple hypertrophy of the left side of the heart usually affects the size of, or circulation within, the retinal vessels. Dilatation only acts when it involves the right side of the heart in an extreme degree, and then may cause some venous congestion. But hypertrophy, when its cause is such as per- mits it to act on the smaller vessels, may produce, although rarely, retinal haemorrhages. It is doubtful whether it is <3apable of doing this unless rupture be permitted by vascular degeneration. The haemorrhages which result may lead to degenerative white spots, which may persist after the dis- appearance of the effused blood. Thrombosis of the central vein occurs in rare cases of heart disease, mitral and aortic (see p. 30). Embolism of the central artery of the retina is an occasional consequence of valvular disease of the heart, and is probably the most common cause of amaurosis associated with cardiac disease a coincidence which was first noted by Seidl and Kanka in 1846. 1 Its occurrence is governed by the same conditions as those which determine it elsewhere. It is most common in mitral disease, especially, like cerebral embolism, in mitral constriction. Its signs have been already described iii. pt. 2, p. 396 ; Roosa : "Archives of Ophthalmology," vol. iii. p. 3, and ix. pt. 1 ; Gruening : ibid. vol. x. pt. 1, p. 81 ; Vorhies : " Trans. American Med. Assoc.," 1879; Michel: "Archives of Ophthalmology," x. pt. 1, p. 102 ; and Knapp : ibid. x. pt. 2, p. 220. The last paper contains a very full discussion of the subject. See also papers by Browne, "Trans. Ophth. Soc.," vol. vii. p. 193 (with references to previously recorded cases), and. Nettleship, in same volume, pp. 218, 219. 278 MEDICAL OPHTHALMOSCOPY. tinned for a longer time, which varied according to the dose. Central vision returned to the normal in a few days, weeks, or months, but the peripheral vision continued lost for a very long time. This contraction of the visual field after the return of central vision seems to be invariable, and the restricted field is usually transversely oval. Colour- vision is also impaired. The pupils are dilated, and during total blindness are irresponsive to light, but act to accommodation (Gruening). The ophthalmoscope has shown pallor of the disc, and in all cases a remarkable diminution in size of the retinal vessels, which may be reduced to threads, and emptied by the slightest pressure on the eye. A cherry-red spot at the macula has been noticed (Gruening). Yorhies found the choroidal vessels also empty. In the case of Giacomini, where three drachms were taken at a single dose, there was loss of consciousness at the onset. In all cases a considerable degree of recovery has ultimately occurred. In the most severe case (Michel), in which seven drachms of quinine were taken, there was no improvement for several months, and it was thought that sight was permanently lost ; nevertheless, fifteen months afterwards acuity of vision was nearly normal, although the fields were much restricted. The vessels had increased in size, but were still much below the normal. Recovery in six weeks has followed a dose of five drachms. Whilst the symptoms are passing off, relapses may be produced by insignificant doses of quinine. BISULPHIDE OF CARBON. Bisulphide of carbon was the apparent cause of a " peri- neuritis," ending in partial atrophy, in a case recorded by Galezowski. 1 Atrophy of the optic nerves is also seen, not very rarely, among the workers in india-rubber factories, in which bisulphide of carbon is used. A special committee of the Ophthalmological Society (consisting of Messrs. Frost, Gunn, and Nettleship) was appointed to investigate this form of toxic amblyopia, and in their very valuable i Galezowski : " Des Amblyopies et Amauroses Toxiques," p. 141. ACUTE GENERAL DISEASES. 279 report 1 on the whole subject they tabulate twenty-four cases of amblyopia coming on after the development of other symptoms indicating great depression of the whole nervous system. In most cases examined there was a distinct central colour-scotoma, and the ophthalmoscope showed pallor and blurring of the edge of the optic disc, with loss of trans- parency of the retina for some distance from the disc. OTHER POISONS. Silver poisoning is said to be accompanied by amblyopia, in addition to the other symptoms of argyria. No ophthal- moscopic changes have, however, been recorded, but silver has been found in the eyeball (sclerotic sheath of the optic nerve, &c.), by Reimer, deposited in small round granules. The effect of silver is closely analogous to that of lead. It may, as I have seen, lead to wrist-drop, gout, and albumi- nuria, and it is therefore highly probable that the same ocular changes may, in some cases, result. In mercurial poisoning amblyopia has been observed ; in one case optic neuritis existed, 2 and in another optic nerve atrophy. 3 Of ocular changes in copper and phosphorus poisoning nothing is known. Salicylic acid may cause amblyopia, but without changes in the fundus oculi. The same effect has been observed from salicylate of soda. 4 ACUTE GENERAL DISEASES. TYPHUS FEVER. Loss of sight has been many times observed during con- valescence from typhus fever, 5 and subsequently atrophy of 1 "Trans. Ophth. Soc.," vol. v. 1885, p. 157. - Square: "Ophth. Hosp. Rep.," vi. p. 54. s Galezowski : " Des Amblyopies et Amauroses Toxiques, p. 141. 4 Gatli : " Gaz. degl. Ospital," 1880, i. 4. 5 In a considerable number of the cases recorded abroad it is doubtful whether the disease was typhus or typhoid fever. The cases on which the .statements in the text are founded appear to have been true typhus. 280 MEDICAL OPHTHALMOSCOPY. one or both optic nerves has been found. In some of these cases there have also been cerebral symptoms, as in a case recorded by Benedikt, in which left hemiplegia was accom- panied by atrophy of the right optic nerve. In such cases, probably, the atrophy was the result of a cerebral lesion. In other cases there were no symptoms except those in the eye, and a primary affection of the" optic nerve appeared to have occurred. In some cases these ophthalmoscopic changes have been those of simple atrophy, but in others, where the affection of sight was first noticed during convalescence, optic neuritis has been found. 1 In a case at Great Ormond Street Hospital, marked papillitis was found by Penrose and Gunn during the height of the fever. Of the origin of the neuritis nothing is known. TYPHOID FEVER. The occurrence of amblyopia and amaurosis during conva- lescence from typhoid is well established, 2 although rare. It may or may not be attended with ophthalmoscopic changes. In the latter case the prognosis is favourable ; the affection usually passes away in the course of two to eight weeks. The form of amblyopia varies ; anaesthesia of the retina has been observed by Leber, and an annular defect in the field by Hersing. When ophthalmoscopic changes have been observed, there has been simple atrophy, single or double, without preceding- inflammation ; or double neuritis may be present, ending in atrophy, partial or complete, or less commonly in recovery. Hutchinson has, for instance, recorded 3 the case of a boy whose sight failed at three years and a half, two to four weeks after a fever with diarrhoea and headache, a sister having suffered from similar symptoms at the same time. Symmetrical neuritis was found, and ten years later white 1 Teale : " Med. Times and Gazette," May 11, 1867. Chisholm : " Ophth. Hosp. Rep.," vol. vi. p. 214. - Nothnagel : " Deut. Arch, fur Kl. Med.," 1872, ix. p. 480. 3 "Ophth. Hosp. Rep.," ix. p. 125. RELAPSING FEVER. 281 atrophy with small vessels. The neuritis is so rare that Leber suggests, as Stellwag v. Carion had suggested long before, 1 that the cases in which it is found may really have been cases of meningitis which have been mistaken for typhoid fever an error not very rare. It must be remembered, however, that neuritis does occasionally follow other acute specific diseases. It has been thought that the cases accompanied by hypersemia of the discs are cases complicated by meningitis; but meningitis, except as secondary to suppuration in the ear, is exceedingly rare in typhoid fever. Sir William Jenner has informed me that he has never seen it. It does not appear from Dr. Murchison's work on Fevers, that he had ever met with a case. To infer meningitis in consequence of extreme delirium or coma is certainly not warranted by pathological facts. Extreme narrowing of the retinal arteries, on both sides, with pallor of the disc and loss of sight, was found by Heddaens 2 in a case of great emaciation after typhoid. On good food the arteries regained their normal size, but the disc remained pale, and sight did not improve beyond -^. Gralezowski 3 and Snell 4 have observed embolism of the central artery of the retina during convalescence from typhoid. RELAPSING FEVER. . It is well known that extensive intra-ocular inflammation is apt to follow relapsing fever. Trompetter 5 found it in 21 out of 325 cases, or six per cent. There was inflammation of the choroid and ciliary body with hypopyon, but without iritis. There were also opacities in the vitreous, amblyopia, and limitation of the field. Its origin is doubtful. Throm- 1 ' Ophthalmologie," Bd. ii. Abt. I. 1855, p. 662. 2 'Monatsbl. fur Augenheilk.," Aug. 1865. 3 'Traite Iconographique, " p. 188. 4 ' Ophth. Rev.," i. p. 403. 5 'Klin. Monatsbl.," April, 1880, p. 123. 282 MEDICAL OPHTHALMOSCOPY. bosis in vessels or embolism from the spleen has been assumed as its cause (Blessig, quoted by Trompetter). MEASLES. Amblyopia, without ophthalmoscopic changes and ulti- mately improving to the normal, has been seen, as a sequel to measles, by v. Graef e and Xagel ; in some cases accom- panied by cerebral symptoms, convulsions, and sopor. Nagel has also met with three cases of optic neuritis after measles, but in the epidemic in which they occurred there were many cases of meningitis. In three other cases lately recorded by Wadsworth l there were also symptoms of meningitis. Dr. Stephenson 2 has recently reported a well-marked case of optic neuritis after measles, without any symptoms indicative of meningitis. The observation is valuable, since the eyes were examined shortly before the attack, and the f undi found normal. The discs have become paler than formerly, Dr. Stephenson writes, but are not completely atrophied, and there is still good vision. As Forster remarks, the common- ness of the disease, and the rarity of affections of sight in it, show that the connection between the two cannot be a very close one. SCARLET FEVER. The frequency with which renal disease accompanies and succeeds scarlet fever renders affections of sight not very rare consequences of the disease. Occasionally, however, they arise independently of any renal disturbance. UraBmic amaurosis is common in scarlatinal dropsy. It comes on suddenly, when the renal disease is at its height, is commonly complete, double, unattended by ophthalmoscopic changes, and passes away. Occasionally, cerebral symptoms accompany it convulsions, and, in rare cases, hemiplegia, from a cerebral thrombosis or embolism, which persists after the cessation of the convulsions, and the return of sight. 1 " Boston Med. and Surg. Journal," vol. ciii. p. 636. 2 "Trans. Ophth. Soc.," vol. viii. 1888, p. 250. SCARLET FEVER. 283 Neuro-retinitis has, however, been observed to succeed scarlet fever when there has been no renal disease or albumen in the urine. Betke 1 has recorded a case in which there was great dimness of sight seventeen days after desquamation. There was no albuminuria, but a marked neuro-retinitis was found on ophthalmoscopic examination, less developed in the right eye than in the left. There was no sign of meningitis, past or present. The neuritis entirely disappeared, and sight was restored in eight weeks. A similar case has been recorded by Pfluger. 2 A child, ten years old, became blind three weeks after an attack of scarlet fever, the loss of sight being complete at the end of three or four days. During the fever there had been considerable headache. When sight was lost, double papillo-retinitis was found to exist. The arteries were narrow and tortuous, with slight pulsation ; the veins were dilated ; there was considerable swelling, and some haemorrhages existed. A month later sight had much improved, but four months after it was not quite normal, and the neuritis had not entirely subsided. The urine through- out was free from albumen. In a case recorded by Hodges 3 the loss of vision was due to embolism or thrombosis of one retinal artery. The amaurosis was complete and permanent in the affected eye. It is not uncommon to meet with atrophy of the optic nerve after scarlet fever, and the atrophy may have all the aspects of a consecutive atrophy. It has been observed in association with the symptoms of a local cerebral lesion, hemiplegia, &c. (Loet) , but in some cases has occurred alone. Two remarkable cases have been recorded by Bayley, 4 in which, in two sisters, sight gradually failed some months after an attack of scarlet fever, without albuminuria or dropsy. One became blind and idiotic, and the other epileptic. The tint of the optic discs was " pale but not the bluish- white of atrophy," and the fundus in each case showed accumulation of pigment. 1 "MoDatsbl. fur Augenheilkunde," Bd. viii. 1869, p. 201. 2 " Arch. f. Ophth.," xxiv., pt. 2, p. 180. 3 c ' Ophth. Rev.," iv. p. 296. 4 "Lancet," Sept. 15, 1877. 284 MEDICAL OPHTHALMOSCOPY. It must be remembered that an intense albuimnuric inflammation may leave partial atrophy of the optic nerve. YARIOLA. Leber has observed diffuse neuro-retinitis in variola during the stage of drying of the eruption. In a case which came under my own observation, atrophy of one optic nerve appeared to have succeeded small-pox. (See Case 60 in previous editions.) ACUTE RHEUMATISM. Acute rheumatism is not usually associated with any changes in the fundus oculi. Embolism of the cerebral arteries sometimes, though rarely, occurs during the course of an attack, but embolism of the retinal arteries has not, I believe, been observed except as a late sequel of the resulting endocarditis. Schmidt once observed irido-choroiditis (such as is common in relapsing fever) after an attack of acute articular rheumatism without endocardial complication. 1 MALARIAL FEVERS. Changes in the fundus oculi are present in some cases of malarial fever; rarely in the intermittent of this country, but not uncommonly in the severer forms of malarial fever, especially in tropical climates. Poncet, 2 for instance, found changes in ten per cent, of the cases of malarial cachexia in Algeria. The changes which have been observed consist of retinal haemorrhages, neuro-retinitis, and atrophy of the optic nerve. Haemorrhages may occur without other change, sometimes in the posterior segment of the eyeball, sometimes chiefly in the ciliary region (Poncet). Three instances of retinal haemorrhages in ague have been recorded by Stephen Mackenzie. 3 One was a young man, aged twenty, who had 1 "Arch. f. Ophth.," Bd. xviii. 2 "Ann. d'Oculistique," May, 1878. 3 In a paper on " Retinal Haemorrhages and Melaiiaemia as Symptoms of Ague," "Med. Times and Gaz.," 1877. I am much indebted to Dr Mackenzie for the woodcuts from his paper. MALARIAL FEVERS. 285 one attack of ague on his way home from India, and a severe paroxysm immediately after his arrival. The attacks recurred daily for a fortnight, when he came under treatment, and numerous retinal haemorrhages were found, most numerous near the disc, chiefly along the course of the larger vessels, especially arteries, which they in places obscured (Fig. 80). Sprinkled about the fundus, and most numerous near the disc, were many small round bright spots, resembling pin- holes pricked in a piece of paper held up against the light. FIG. 80. RETINAL HEMORRHAGES IN AGUE (MACKENZIE). The retinal vessels were of normal size, and their sheaths did not appear thickened. These haemorrhages were carefully observed day by day, and were seen to fade away gradually ; and, as each died away, it left, to mark its former situation, one of the shiny white spots of which mention has been made above. There was no albuminuria or other symptom of Bright's disease. The spleen was large. The blood at first contained much pigment, but after the first few days no more could be found. 286 MEDICAL OPHTHALMOSCOPY. In two cases, at the Seamen's Hospital a man, aged twenty-nine, with quotidian ague, and another, aged eighteen, with tertian ague haemorrhages were found ; in the former case, numerous, large, and superficial, leaving white patches. One was paler in the centre than in the periphery (Fig. 81). They quickly disappeared. Neither of these patients had melansemia. In several cases subsequently examined, no haemorrhages were found. Hsemorrhagic retinitis has also been met with by von FIG. 81. RETINAL HEMORRHAGES IN AGUE (MACKENZIE). Kries. 1 One patient, who had suffered from ague for a week only, had an extensive haemorrhage into the vitreous. The intermission had been arrested by quinine, and the first freedom on the day of periodical recurrence was accompanied by the haemorrhage. Poncet observed, in Algeria, besides haemorrhages, peri- papillary oedema and even considerable neuro-retinitis. He also found, in the retinal and choroidal vessels, large cells Arch, f. Ophth.," vol. xxiv. pt. 1, p. 159. MALARIAL FEVERS. 287 containing leucocytes and pigment. Neuritis has also been seen in one case by Gralezowski, 1 and in two by HammoDd,' 2 unilateral, with stellate deposits of pigment in the retina following the course of the vessels. Atrophy of the optic nerve has also been observed to succeed malarial fever. It is very rare, however, as a consequence of the intermittents of temperate climates, although a few cases are on record. After the severe malarial fever of hot climates it is not infrequent. Several cases are narrated by Gralezowski 3 and by Bull. 4 The disc is white, the vessels are small, and the field of vision is greatly restricted. The pathology of the retinal changes is still obscure. The retinal haemorrhages have been ascribed to pigmentary embolism, but they are, as Mackenzie has shown, to be found when there is no melansemia. Poncet attributes them to the blockade of minute vessels by leucocytes. The atrophy was ascribed by Gralezowski to pigmentary embolism. It seems possible that the atrophy may be the result of such neuro-retinitis as is described above, and which, damaging sight only during the stage of atrophy, attracted no attention during its acute stage. Two remarkable cases which have been recorded by Eamorius, 5 suggest that spasm of the retinal vessels may be a consequence of malarial poisoning. The chief symptom was periodical amblyopia, and during one of the attacks the optic discs were pale, the retinal arteries were filiform and almost bloodless, and the veins were scarcely perceptible. At the same time there was great congestion of the face and ears, and a sensation of heaviness in the head. Each attack was attended with a sensation of coloured circles moving from the periphery of the field towards the centre. In the intervals between the paroxysms the appearance of the fundus oculi was normal. Bromide of potassium had no effect, but quinine quickly cured each case. i " Traite Iconographique," p. 190. 2 "Trans. American Neurological Society," 1875. 3 Loc. cit. 4 "American Journ. of Med. Science," 1877, p. 403. 5 "Annali di Ottalmologia, " 1877, pt 1, and "Ann. d'Oculist," vol. Ixxxii. p. 200. MEDICAL OPHTHALMOSCOPY. Purulent affections of the eye (choroiditis, 1 iritis, &c.) such as are seen in pyaemia, have been described in intermittent fever, but are extremely rare, and some doubt may be felt regarding the diagnosis of the original disease when it is remembered how closely some cases of pyaemia simulate intermittent fever. Even the influence of quinine, on which diagnostic weight is often laid, is not entirely conclusive. 2 ERYSIPELAS. Erysipelas of the face is sometimes followed by loss of sight and by the signs of atrophy of the optic nerve (v. Grraefe, H. Pagenstecher, Hutchinson, and others). It is produced by the extension of the cellulitis into the orbit, and the resulting damage to the trunk of the optic nerve by invasion or pressure. V. Grraefe has pointed out that there is com- monly some exophthalmos, but this may be very slight, and may bear no proportion to the subsequent damage to sight. In most recorded cases any symptoms suggestive of orbital cellulitis have escaped notice, probably from the difficulty of the examination. In one, however (that of Story 3 ), there was permanent limitation of the ocular movements. The loss of sight often comes on rapidly. In one of Pagenstecher's cases amaurosis was complete at the end of fourteen days. Early observations of neuritis or neuro-retinitis have been recorded by Vossius and Lubinski, 4 and slight opacity of the retina has been seen by many observers. It rapidly passed into atrophy. Usually, how- ever, as soon as the examination could be made, there has been pallor of the disc and remarkable narrowing of the vessels, the arteries especially. Jager has recorded, for instance, a case in which an adhesion of the eyelids 1 Peunoff : "CentralbL fur Augenk.," 1879, p. 120. 2 For example, in a case of this kind described by Landesberg, in which, although quinine cut short the affection, abscesses formed during con- valescence, in one toe and the forearm. 3 "Brit. Med. Journal," March 16, 1878. 4 Lubinski : " Klin. Monatsbl.," April, 1878, p. 168 ; Pfliiger of Berne : ' ' Augenklinik Bericht" for 1877; and Yirchow's " Jahresbericht," 1878, vol. ii. p. 438. DIPHTHERIA. 289 required division with the knife five weeks after the ery- sipelas ; the optic disc was grey and atrophied ; one branch of the central artery and its corresponding vein were normal, the others reduced to lines with white borders. In Story's case some arteries were bloodless, and occluded veins were represented by dark radiating lines. It is probable that thrombosis in the central artery is not infrequently the mechanism by which the effect is produced. Thus, August 1 found the ophthalmoscopic appearances similar to those in embolism (arteries either invisible, or, in places, transformed into white lines), in a case in which the erysipelas caused orbital cellulitis, and in addition visible clotting in supra-orbital and frontal vessels ; he believes that the organism penetrates the walls and causes inflammation and clotting. Knapp, 2 however, urges that the mechanism is compression of vessels in the orbit. In an early case he found the veins distended with stagnant blood. He quotes Panas, who found obliteration of the retinal artery. In a case observed by Nettleship, although the arteries were small they pulsated on pressure. It seems to me probable that the mechanism in these cases is not always the same. In one of Pagenstecher's cases there was a central scotoma and also peripheral limitation of the field. Necrosis of the nerve, less complete at the lamina cribrosa than farther back, was found by Nettleship. 3 Opacity of the vitreous and glaucoma have also been seen after erysipelas. DIPHTHERIA. The defect of sight which so often follows diphtheria, and is due to a paralysis of accommodation, is not attended with any ophthalmoscopic change. In rare cases, however, vision is defective, apart from the paralysis of accommodation, and in such cases one or two observers (e.g. Bouchut) have found congestion of the disc, simple or with oedema sufficient to veil the edges and even, in part, the vessels, and in very rare 1 " Klin. Monatsbl.," 1884, 43. 2 "Arch. f. Augenkr.," 1884, i. 83. s "Trans. Path. Soc.," vol. xxxi. 1880, p. 254. 290 MEDICAL OPHTHALMOSCOPY. cases an actual neuritis which may go on to atrophy. The atrophy may be unilateral, as in one case figured by Bouchut. This case, however, was accompanied with partial right hemiplegia and defect of speech. The congestion and oedema are . usually bilateral, but may be more intense on one side than on the other. I have also seen one definite case of primary atrophy after diphtheria. The patient was a woman, aged forty-one, with a family history of epilepsy. Shortly after the diphtheria she suffered from numbness of the arms, from paralysis of the palate and of accommodation, and from double vision. With the exception of the diplopia these symptoms passed off ; but, a little later, slight weakness of the right side developed and became permanent. Along with this there occurred progressive failure of sight, and two years later there was well-marked primary atrophy of the optic nerves, with considerable amblyopia. The pupils did not react to light in the least, and but slightly to accommodation. There was nystagmus on looking to the left, and the upward movement of the eyes was completely lost. There were no other signs of tabes, and the knee-jerks were perfect. PAROTITIS. Transient dimness of sight may succeed mumps, and a coincident congestion of the optic nerve has been described by Hating. TONSILLITIS. In a case of tonsillitis v. Graefe once saw signs of diminished blood-supply to the retina accompanying sudden loss of sight. The known relation of tonsillitis to rheumatism suggests the probability of embolism in this singular case. WHOOPING-COUGH. Blindness has been observed to come on during the progress of whooping-cough, and in one case Knapp 1 found the discs white, and the retinal arteries invisible in one eye and mere i "Arch, of Ophthalm. and Otol.," vol. iv. Xos. 3 and 4, p. 448. PYJEMIA AND SEPTICAEMIA. 291 lines in the other. The patient was very weak, and Knapp suggests as explanations, anaemia from cardiac weakness, or haemorrhage into the nerve-sheaths. Landesberg 1 also observed in one case symptoms of partial embolism, serous infiltration into the retina, slight swelling of the papilla, a red macula, thin arteries, engorged and tortuous veins. Two upper arterial branches were found to be permanently obstructed. In another case he observed ecchymoses in the retina. According to Loomis (quoted by Knapp), loss of sight generally occurs, in this disease, in children who are much prostrated, and who commonly die from lobular pneumonia. CHOLERA. In cholera v. Grraef e found that, during the state of collapse and cyanosis, the circulation in the smaller, and even in the middle-sized, arteries may apparently cease. When the weakness of the heart was moderate, the artery pulsated on slight pressure with the finger on the eyeball ; but when the heart was strong this could not be well produced. If the heart was so weak that the radial pulse could not be felt, and the second sound of the heart was inaudible, slight pressure on the eye caused emptying of the arteries without pulsation. The veins were large and dark, visible in the finest divisions. The papilla was of a pale lilac tint. PYJEMIA AND SEPTICAEMIA. The occurrence of a general inflammation of the eye in cases of septicaemia of various kinds, " metastatic panophthal- mitis," has long been known, but it is only during the last few years that the use of the ophthalmoscope in medical and surgical practice has revealed the fact that slighter retinal changes are present in a large proportion of the severer forms of these affections, and constitute a symptom of considerable diagnostic and prognostic importance, as well as of great pathological interest. The knowledge of their character is 1 "Med. and Surg. Reporter," Sept. 8, 1880. 292 MEDICAL OPHTHALMOSCOPY. largely due to the labours of Heiberg, 1 Both, 2 and especially of Litten. 3 All forms of affection are most common in the intense septicaemia of puerperal women, but are also met with in other cases. Panophthalmitis. The general inflammation of the eye, " pysemic or metastatic ophthalmia," is usually attended with suppuration in the various structures iris, ohoroid, retina, vitreous with rapid destruction of the eyeball. It was shown by Virchow 4 to depend upon septic embolism, and later researches have fully confirmed the fact. Plugs in the vessels have been found by Virchow, Eoth, and Heiberg. The latter found micrococci in the emboli. It is usually associated with the endocarditis which is so common in septicaemia. Virchow found yellowish granular masses in the capillaries of the retina, similar to those which were present in the cardiac valves, and he, with most subsequent observers, regarded the cardiac valves as the source of the emboli. The condition may, however, occur independently of any endocarditis. 5 Even in such cases, however, the presence of infarcts in other organs, and of suppurating thrombi in the source of the septicaemia, demonstrated the probability of embolism, although not directly from the heart. It is well known that pyaemic emboli may pass through the lungs and lodge in the general system. The septic inflammation excited in the eye may start from the choroid or the retina, as is demonstrated by two cases of Litten's, in which the process commenced a short time before death, and he found plugging in the one case of choroidal and in the other of retinal vessels. A case in which the mischief apparently commenced in the retina has also been described by Eoth. When the retinal vessels are plugged, haemorrhages in the retina are invariable, as Virchow demonstrated, and the commencement of the process i "Med. Centralblatt," 1874, No. 36. a"Deut. Zeitschrift fur Chirurgie," 1872, p. 471; Nagel's "Jahres- bericht," 1872, p. 349. 3 "Charite Annalen " for 1876, p. 160. 4 "Arch. f. Path. Anat.," Bd. x. 1856. 5 Litten: loc. cit. Case 8 ; Meckel : " Charite Annalen," Bd. v. ; Virchow: "Ges. Abhand.," p. 539 ; Schmidt: "Arch. f. Ophth.," xviii. p. 1. PIVEMIA AND SEPTiC^MIA. 293 in retinal haemorrhages, with opacity of the retina and vitreous, may be watched with the ophthalmoscope. 1 The opacity of the retina depends apparently in most cases on acute degeneration. It was found by Both to be merely softened, and containing granule cells, although the other structures of the eye were infiltrated with pus. A layer of pus has, however, been seen on the surface of the retina, and pus is said to have been found in some cases in the nerve- fibre layer. Rarely, the changes have been found limited to a small area of the retina and the adjacent choroid. It is probable that this severe ocular inflammation is always produced by the agency of septic organisms circula- ting in the blood. These, in the form of bacterial or micrococcal masses, have been found in the vessels of the eye in many cases. 2 The affection is usually single, but in many cases both eyes are affected, it may be unequally. It occurs only in intense forms of septicaemia, commonly not long before death. In rare cases it may occur when the general symptoms of the disease are hot advanced, as in a case mentioned by Litten, in which a woman came to the hospital with one eye in a state of complete suppuration, but with so little subjective symptom of the considerable fever which was found to exist, that she was unwilling to remain. Death occurred some weeks after the eye was lost. Ophthalmoscopic examination of the sound eye revealed no change for some time after admission. One day choroiditis and infiltration of the vitreous was discovered ; the same day rigors and joint- inflammation occurred, and in three days later the patient was dead. Retinitis Septica. Roth has described a peculiar form of retinitis in cases of pyaemia, characterized by the appearance of small white flecks in the neighbourhood of the papilla and macula lutea, varying in number, and occurring in most 1 Litten : Case 8. "Kahler: "Prag. Zeitsch. f. Heilkunde," 1879, iii., and "Centralbl. f. Med. Wiss.," 1880, p. 728; Pousson : "Arch. d'Ophth. Fran^aise," No. 2, Jan. 1881 ; Hosch : "Arch. f. Opkth.," vol. xxvi. pt. i, p. 177. 294 MEDICAL OPHTHALMOSCOPY. cases in both eyes. Sometimes small haemorrhages were present. The white spots were found to consist of groups of swollen nerve-fibres, among which were granule cells, fattily- degenerated capillaries, and pigment granules. The affected spots were of small size, and showed little tendency to extension, or to the involvement of the vitreous or choroid. In no case observed by Both was any plugging of vessels discovered, or any deposits on the cardiac valves, and he therefore believes that the change is due to the chemical alteration of the blood, but Kahler found micrococcal plugs. The affection was met with especially in cases in which decomposition was occurring in inflamed parts, such as exten- sive sloughing with secondary suppuration, and especially in pronounced septicaemia. It was found also in one case of putrid bronchitis. Retinal hcemorrhayes constitute, however, by far the most common and most important change in the f undus in cases of septicaemia. They usually accompany the suppurative panoph- thalmitis, especially when the process commences in the retina. They may also occur in the form described by Roth. But they may exist alone, without any sign of retinal inflamma- tion, and as such constitute the most common ophthalmoscopic change in these cases. They have been very carefully studied by Litten, in cases of puerperal septicaemia, in which they almost invariably occur during the last two or three days of life. They are always bilateral, round, or irregular in form, and of variable size, sometimes very large. They are com- monly adjacent to vessels, especially veins, but occasionally are situated apart from visible vessels. Most of the round extravasations present pale or white centres, which are often distinct as soon as the haemorrhage appears. They are recog- nized without difficulty, some being always in the posterior portion of the fundus. In some of the cases in which these haemorrhages were seen, there was endocarditis, but in several cases recorded by Both and Litten the heart was healthy. There is thus no necessary connection between the cardiac and the ocular condition. Moreover, the retinal change appears comparatively innocent ; PYJEMIA AND SEPTICAEMIA. 295 no adjacent inflammation is excited. In no case could Litten find any plugging of the retinal vessels, and from these facts, he concludes with Both, that embolism is not the cause of these extravasations, but that they are to be ascribed to the chemical change in the blood. This view is also supported by a case described by Leube, 1 but the same observer has recorded another case of septic pyaemia, secondary to Y FIG. 82. RETINAL HAEMORRHAGES IN A CASE OF ACTTDB ULCERATIVE ENDOCARDITIS. Some are striated in the nerve-fibre layer, others rounded in the deeper layers many have white spots in the centre. double caseating epididymitis, in which retinal haemorrhages existed, and, post-mortem, bacterial plugs were found in many other organs. The retinae apparently were not examined. Rosenbach, 2 however, found a similar condition of multiple haemorrhages in the retinae of dogs, in which a septic endocarditis had resulted from experimental lesions of the valves, and he found micrococcal plugs in the retinal vessels 1 "Deut. Arch, fur Klin. Med.," xxii. 1878, p. 235. 2 "Arch, fur Exp. Path, und Pharmak.," 1878. 296 MEDICAL OPHTHALMOSCOPY. after death. From these facts we may conclude that, although simple haemorrhages usually arise independently of embolism, they may sometimes he due to the plugging of vessels. In connection with the remark, that adjacent in- flammation is often not excited, it may be noted that of six cases with endocarditis observed by Litten, in only three did the cardiac change present the aspect of malignant ulcerating endocarditis ; in the other three the valves presented only innocent-looking vegetations. It is probable that the endo- carditis varies in its degree of septic character in different FIG. 83. RETINAL HJEMOKKHAGES IN A CASE or ACUTE ULCEKATIVE ENDOCARDITIS AND CHOIIEA. The rounded hemorrhage at the lower part of the figure has a white centre. cases of blood poisoning. In several cases of pyaemia similar haemorrhages have been noted on the mucous membrane of the conjunctiva or mouth (Litten, Leube). From the fact that the retinal haemorrhages usually pre- cede death by a few days only, they afford important and very grave prognostic information. Now and then they are useful also in diagnosis, since they are apparently not found in acute specific diseases, even in those severe cases in which cutaneous haemorrhages are present. Litten mentions two THE OPHTHALMOSCOPIC SIGNS OF DEATH. 297 cases of women admitted with high fever, cutaneous extrava- sations, and cardiac murmurs. One had been recently con- fined. They had the aspect of cases of septicaemia rather than of typhoid, but the absence of retinal extravasations led to a diagnosis of typhoid fever, which, in each case, was confirmed by a post-mortem examination. I have seen one case in which the presence of retinal haemorrhages was of considerable assistance in establishing the fact that a post-puerperal illness, supposed to be typhoid, was really septicaemia. The effect of the retinal haemorrhages on vision can rarely be ascertained with exactness, on account of the general state of the patients, but they appear to cause little impairment. Purulent meningitis sometimes occurs in cases of septi- caemia. In one such case, recorded by Leube, 1 there were retinal extravasations, but after death intense inflammation of the optic nerves adjacent to the inflamed membranes was found. THE OPHTHALMOSCOPIC SIGNS OF DEATH. The stoppage of the heart's action and the consequent arrest of the circulation of the blood, which constitute the chief events in the cessation of systemic life, lead to striking changes in the fundus oculi, changes which are among the most unequivocal signs of death. Attention was first called to them by Bouchut in 1863, 2 and they have since been studied by many observers, especially by Poncet, 3 Arlidge, 4 and Grayet. 5 As the heart's action is failing, the arteries may be observed to diminish in size (Arlidge). On the cessation of its con- tractions, the diminution in their size becomes more marked. A few minutes after death the capillary redness of the disc disappears, and its surface becomes of papery whiteness, in 1 "Deut. Arch, fur Kliii. Med.," Bd. xxii. 1878, p. 263. " Traite des Signes de la Alort," 1863. 3 "Arch. Gen. de Med.," 1870, p. 408. 4 "West Riding Asylum Reports/' i. 1871, p. 73. 3 "Ann. d'Oculistique," t. Ixxiii. 1875, p. 5. 298 MEDICAL OPHTHALMOSCOPY. which, however, the central cup, if present, may appear of still more brilliant whiteness. The arteries quickly cease to be recognizable upon the disc, appearing to commence at its edge. On the fundus they are at first distinct, and usually narrow but otherwise of normal appearance. The veins may present normal characters, or may, like the arteries, quickly become indistinct upon the disc, appearing to start from its edge. Commonly the columns of blood within them soon become interrupted and broken up into segments, which give the vessels a beaded appearance. The indistinctness of the arteries, which is due to their contraction emptying them of blood, quickly extends towards the periphery, and in the course of half an hour, sometimes in ten minutes, they are unrecognizable. The veins remain distinct, but in most cases the beaded appearance increases. The choroid, during the first few minutes, presents nearly its normal tint, but this quickly lessens in intensity, and the colour which is pre- sented depends on the amount of pigmentation. In dark eyes it acquires a yellow-brown colour, in lightly pigmented eyes it gradually assumes a pale, reddish-yellowish, sometimes a greyish, tint. Commencing opacity of the retina may some- times be distinguished, and may be accompanied by a red spot at the macula lutea (Gayet) , due to its freedom from opacity, and similar to that seen in embolism of the central artery. These appearances persist until, generally after five or six hours, the progressive opacity of the media prevents further observation. APPENDIX. HOW TO SKETCH THE FUNDUS OCULI. NOTHING gives dexterity in the use of the ophthalmoscope so quickly and so effectively as an attempt to draw what is seen, and nothing gives ability to recognize details with accuracy and perceive every feature presented, as a habit of drawing does. Yet ophthalmoscopic drawing is hardly ever practised. It is supposed to be difficult, but it is neither difficult nor does it need any ability or facility for ordinary drawing. The process is within the reach of every student, and it may be well therefore to describe the method which is most useful. It is indeed sufficiently simple as scarcely to need even descriptive instruction, but it may be well not to assume that it can be discovered by each student for himself. A pencil drawing should be first made, and from that either a more perfect pencil drawing on any paper that has a grain ; or, what is better, a coloured drawing, which re- quires, however, a skill a pencil drawing does not need. The disc should be drawn from f inch to 1 inch in vertical diameter. The fundus should be observed first by the indirect method, and the outline of the disc made on a piece of paper by a faint pencil line, and other simple pencil lines should indicate the position of the chief vessels that can be seen by this method, the veins being made darker than the arteries. This being done, the observer should continue and complete the drawing by the direct method. If he is drawing the patient's left eye, his pencil and materials should be on a small table to his right ; if he is drawing the patient's right 300 APPENDIX. eye, this may be on his left or immediately in front of him, he sitting to the side of the patient. To continue the drawing he must turn his paper upside down. This brings the disc, as drawn from the indirect image, into the position in which it appears in the direct image. Both arteries and veins must now be represented, as they are seen, with a double contour. After indicating more precisely the position and outline of the physiological cup, some one large vein should be selected, and its position at the edge of the cup and edge of the disc noted, compared with the first drawing, and, if necessary, corrected. Then its double contour should be marked by a broad pencil line on each side, with a very slight pencil tint between them, where the reflection is seen. This must be darkened wherever the reflection is lost in consequence of the vein being in some other plane than that at right angles to the line of vision, e.g., when passing over some prominence, or receding into the physiological cup. The branches of this vein and the artery accompanying it should then be drawn in like manner, the artery being repre- sented by paler pencil lines and its central reflection being left white. Great care must be taken to depict accurately the relative width of each vessel, both on the surface of the disc and beyond its edge. The width of the vein first drawn, must also be compared with the size of the cup and the disc generally, and this vein taken as a standard with which to compare the others ; in this manner the pre- cise representation of the size of the various vessels a very important point is much facilitated. Each of the other vessels should then be drawn in the same way ; as a rule, each different vein first and then its artery. It is necessary to indicate many features by some arbitrary signs, or by reference-indications to words written on the margin. Among the points to which attention should be given, is the presence of white lines along the vessels, due to the tissue of the wall. It will be remembered that, when we speak of the vessels we are drawing, we mean only the columns of blood within them ; we cannot see the vessels themselves except in the appearance now referred to. APPENDIX. 301 These white lines may be indicated conveniently by dotted lines outside the darker ones. Where the vessel becomes indistinct, there should be, of course, a corresponding indis- tinctness of the lines representing it ; but often this is not enough to indicate the degree of concealment, and then lines may be drawn across the vessel. The shape of the central cup should be carefully attended to, as well as its depth, and the course of the vessels down its side. The latter, together with the change in their aspect, represents the steepness of the side, and shows it at once to one who is used to ophthalmoscopic examination. The manner in which the vessels disappear at the bottom of the cup varies, and must be carefully indicated in the sketch. Often they gradually pass from view as they penetrate the tissue, which at length conceals them ; then they not only become fainter but also narrower, because at the edge of the column the depth of blood is less and its tint is less deep ; hence the margin becomes first concealed, and the vessel seems to lose in width as it loses colour. In normal discs it is common to have a little softening of the edge where the chief vessels cross above and below, striated in character, and due to the large number of nerve- fibres which cross the edge there. This may be indicated by faint lines across the edge. In general it is convenient to indicate all features that are white by dotted lines. Thus the outline of a white spot or patch should be made with dots instead of by a continuous line. If there is a difference in the intensity of the whiteness in different parts of the area, it must be drawn black with the pencil, the intensity of the white tint being inversely indicated by the intensity of the pencil shading, and the fact that it is white indicated by a dotted line around it (not then indicating the position of the edge, which should be the edge of the shading), or else by a written indication adjacent to the spot or in the margin. So, too, the sclerotic ring should be shown by dotted lines, and also the outline of a posterior staphyloma. White spots of albuminuric retinitis may be made dark, without the risk APPENDIX. of error, if as should always be the case the more finished drawing is made without any delay to permit the nature of the case being forgotten. This lessens the practical difficulty that we have to contend with the difficulty that we have only the lead pencil to indicate the white, the black, the red, and the grey. We must indicate the grey in a large cup or on an atrophied disc as we indicate the red tint, marking the difference by words or letters on the rough drawing, and in a descriptive note on the more finished one. Some remarks on the production of coloured drawings may be acceptable to those who have no knowledge of water- colour work. I offer the following suggestions because they embody the results of an attempt to make such drawings without any knowledge of the art. Colour is necessary for a perfect representation of the aspect of the fundus, but care must be taken not to lose sight of form, even in its minutiae. The knowledge of pigments that is requisite is best gained by experiment, and it is wise to obtain pigments of the proper tints, if possible, and to mix as little as possible. The " wash " is the chief thing that is needed, and this is easily acquired with a little practice. Details only need patient care. Fortunately, in the features that can only be represented in colour, the exact shade of colour is comparatively unimportant. The precise tint of the choroid varies so much, that correspondence with nature, so far as relates to the individual eye, is not appreciated, indeed is not observed by most persons, and hence a divergence from nature is equally unobserved. Of course the limits of the variations that are met with in the tint of the choroid must not be exceeded, and in the cases in which there is a choroidal change to be depicted the amount of pigment in the choroid must be carefully observed. The chief difficulties with the colour are to obtain a natural appearance as regards texture, and to obtain even- ness of the tint. The beginner may take comfort in the fact that any defects will be concealed to a large extent by details afterwards added. The conspicuous forms of APPENDIX. 303 the vessels prevent even a considerable unevenness from being noticed. Professional artists use Bristol board for the coloured drawings, and the surface of this, after having been well washed, is not so bad as might be imagined. I prefer, myself, a thin hot-pressed paper, damped and stretched. The grain thus obtained is finer than that of a paper which has not been hot-pressed, and yet it takes the colour perfectly well. All the sepia drawings in this work were done upon such paper. Hollingsworth's I found distinctly better than any other I tried. The difficulties with the colour arising from these two causes (1) getting the proper tint of red ; (2) putting the colour evenly on the paper may thus be overcome : (1) Do not use vermilion. Any colounnan will give you a choice of reds sufficiently large to represent every possible tint the human blood can assume. A little light red, added to carmine, answers very well ; but if the tint of any drawing which seems near nature, is taken and compared with sample tints, no difficulty will be experienced in selecting one that corresponds sufficiently closely. (2) Even- ness of surface is best obtained by washing the coat of colour with water, when it is quite dry, and then placing blotting paper on it, This, of course, takes off a good deal of colour ; but by laying on another coat (before the surface is quite dry), and repeating the process three or four times, a very even tint is obtained without difficulty. If any inequalities are seen they may be removed by " stippling " with the point of a brush. Some professional artists get the ground almost entirely in this manner, and it was the method adopted by the late Mr. Streatfeild, who, in his early days, made admirable ophthalmoscopic drawings. Genera] stip- pling may be necessary when there are peculiarities of the choroid, for the distribution of its pigment can only thus be represented. For neuritis it is not necessary. The method of successive coats has an advantage in the softness of the edge of an inflamed disc that can be obtained. It is better to take out, from each wash, the area of the disc, by the end of a small roll of blotting paper, 304 APPENDIX. than to leave it, on account of the hardness of the edge which the latter method involves (except in the hands of a skilful artist, for whom these directions are not intended). By softening the edge of the colour with a wet brush, how- ever, then pressing blotting paper firmly on it, and repeating the process several times, any part may be made as soft in its gradation as can be desired. Sharp-edged, perfectly white spots may be produced with a penknife. PIRATE I. DESCRIPTION OF PLATES. THE ophthalmoscopic illustrations contained in the following plates are from drawings of the erect image, with the exception of PI. I. Figs. 1, 3, & o ; PL VI. Fig. 1, and PL XII. Fig, 2, which are of the inverted image. In some of the other figures, however, the draw- ings, although of the erect image and made on a large scale, have been reduced in the photographic reproduction nearly to the dimen- sions of the inverted image. PLATE 1. FIGS. 1 & 2. Simple congestion of the optic disc in a case of embolic softening in right cerebral hemisphere, causing left hemiplegia. Right optic disc five weeks after onset. Man, aged thirty, had rheumatic fever at thirteen. The con- gestion of the discs came on a fortnight or so subsequently to the occurrence of hemiplegia, and then remained unchanged for about six weeks. Both discs ultimately became much less congested, the left clearing first. The paralysis remained absolute, and there was rapid wasting of limbs. Later, blood and albumen appeared in the urine, and rounded haemorrhages with white centres were found over both retinae ; soon afterwards distinct optic neuritis developed in the right eye only. Three weeks later patient died. Right middle cerebral artery plugged ; corpus striatum softened throughout ; traces of slight old meningitis over both hemispheres ; infarcts in spleen and in kidneys, the latter being "large white;" aortic and mitral disease. The late retinal hemorrhages were probably due to the blood-state. Note occurrence of neuritis on same side as cerebral lesion. FIG. 1 represents the disc as seen by the indirect method of examination. The tint is nearly that of the adjacent fundus, and is uniformly dis- tributed over the disc. The edge is dimly seen as a pale zone, most distinct on the right (temporal) side. The veins are large, especially one which passes apparently upwards (really downwards). Several small vessels passing from the disc are unduly visible. FIG. 2. The same disc as seen by the direct method (upright image) X 306 MEDICAL OPHTHALMOSCOPY. reduced. The uniform red tint is as conspicuous as by the indirect method. The sclerotic ring is visible on the left (temporal) side, but nowhere else is the boundary of the disc recognizable. The large size of the veins is very conspicuous, and there is white tissue about the vessels, arteries especially, in the centre of the disc, very con- spicuous against the red surface. The left disc presented nearly, but not quite, the same appearance, and after a few weeks its congestion lessened much more than that of the right. FIGS. 3 & 4. Commencinff optic neuritis ; "congestion with oedema ; " probable cerebral syphiloma. Left eye. The patient, aged twenty-five, had had a hard chancre at twenty ; subsequently cranial nodes ; an attack of right hemiplegia at twenty- three, and headache and convulsions for six months. Right optic disc full coloured, but otherwise normal. The appearance of the left is shown in the figures. FIG. 3. Appearance on an indirect examination. The edge of the disc is fairly distinct, but its surface is uniformly red a deeper and more carmine red than the adjacent choroid. Around it is a pale halo, and this can be traced upwards and downwards along the course of the larger vessels, in the situation in which the nerve fibres are most numerous. The retinal vessels are of nearly normal size, clear to their emergence in the middle of the disc. (The arteries in the figure are rather too small.) FIG. 4. Appearance of the same disc on examination by the direct method (reduced). The edge of the disc can nowhere be seen ; the pale halo is seen as a striated, reddish-grey, slightly prominent opacity, completely veiling all behind it. The increased redness in the centre is the only indication of the position of the optic disc. The opacity ceases abruptly, except above and below, where a fine striation accompanies the vessels the pale reflection recognized in the inverted image. The veins are a little larger than normal ; they curve down the sides of the swelling, but the prominence being slight, the change of plane causes only a slight diminution of the central reflection. The edge of the swelling is steepest on the tem- poral side (to the right), and there a small vein forms a conspicuous curve down the side. Vision j|. Field and colour-vision normal. FIGS, o & 6. Optic neuritis. Right optic disc of a patient suffering probably from a cerebral tumour, causing fits beginning in the right side of the face. Man aged thirty. FIG. 5 represents the papilla as seen by the indirect method. The outlines of the disc cannot be seen ; its position is occupied by a roundish prominent swelling, the centre of which is red, the outer part pale, and the sloping side greyish. The veins present con- spicuous curves as they course down the sides of the swelling. They cannot be traced to the middle of the swelling, their terminations PLATE IT. DESCRIPTION OF PLATES. 307 being concealed in the red centre. The arteries cannot be recognized on the swelling, being visible only beyond its edge, where they have a normal course. (In the figure they are rather too narrow.) FIG. 6. The same disc as seen by the direct method of examination {reduced). Its prominence is less conspicuous, but is indicated by the curves of the veins, and so great was it that, although the fundus was distinct without a correcting lens, the top of the swelling could only be seen with -J- 2 D. The centre is red, and presents a fine stippling; the outer part reddish-grey, striated. The veins are larger than normal, and being numerous, are no doubt considerably enlarged. Over the prominence of the swelling their reflection is bright; but it is lost, and the vessels, appear dark, as they pass down the sides of the swelling. Beyond its edge several of them are par- tially concealed as they dip into the substance of the retina before assuming a normal course upon the fundus. Towards the slightly- depressed centre they are lost in the tissue, some, as the lower veins, gradually, others suddenly after a slight curve, in which their central reflection is again lost. One or two arteries can be traced over the outer part of the swelling, and present there a bright reflection. Others are concealed completely by the tissue, and only appear beyond its edge. Near the centre of the disc is a small oval white spot. On the right (tenfporal or macular) side of the disc the red of the choroid is varied by a series of paler lines, most being concentric with and adjacent to the edge of the swelling. They depend on the folds into which the retina (perhaps only its nuclear layers) is thrown, in consequence of its displacement from the edge of the choroid partial detachment. (Compare PL VII. 1, Fig. 9, p. 58, and Fig. 17, p. 61.) Vision f, but considerable concentric limitation of the field. The condition of the discs remained the same when last seen, several months after the drawings were made. PLATE II. FIG. 1. Subsiding neuritis ; commencing consecutive atrophy. From . 315 PLATE VI. FIG. 1. Intense optic neuritis, with retinal haemorrhages, in a case of cerebral tumour. Right eye. Man aged thirty-six. The region of the optic disc is occupied by a large swelling, in width about four times the diameter of the disc. It is irregular in outline, with very steep sides, and is bounded in every direction by extravasa- tions. Some of these are more or less striated, others have a sharp convex edge, due to their position in the overhanging edge of the swelling. The surface of the prominence is of about the same tint as the fundus. The vessels are concealed in the substance of the swell- ing, except one or two, the position of which is dimly seen. Most of them appear first beyond its edge, and are then of about normal size, but at first they form conspicuous curves, the deeper portions of which are concealed. They then assume a nearly normal course. The arteries are narrow, some being scarcely visible. Numerous haemorrhages, small and striated, are scattered over the retina in the posterior half of the eyeball, except on the temporal side (to the left). In this direction the swelling reaches almost to the position of the macula lutea, in the neighbourhood of which are many minute white dots adjacent to the edge of the swelling. Vision 0. The patient died, but no post-mortem examination was permitted. FIG. 2. Optic neuritis in a case of old fractures of the skull; inflam- matory growths beneath them ; at the base the results of previous menin- gitis. Man aged forty-nine. The position of the disc could be recognized by the indirect method of examination, but the edge was softened. The area of the disc was bright red, and beyond the edge was a pale halo. In the upright image the edge is completely concealed under a greyish -red swelling, of nearly three times the diameter of the disc, striated. Upon it are many white spots and lines (due to granule corpuscles, &c.), some of which correspond to the course of the arteries. One, above, is sur- rounded by a narrow zone of haemorrhage. The vessels are concealed in the middle of the swelling ; the veins more completely than some of the arteries. The course of the veins is very tortuous. Vision T L. (The microscopical appearances are shown in Figs. 13, 23, 24, 33.) FIG. 3. Neuritis subsiding into atrophy; slight retinal changes; tubercle of cerebellum. J^eft eye. Soy aged eleven. The disc is invisible beneath a pale, almost white swelling, depressed in the centre. Over this the veins curve. After sloping down its sides, they are concealed by the adjacent opacity of the retina for a short distance. One artery, which passes downwards, is visible on the surface of the swelling, but is also concealed beyond its edge. The other arteries appear only some distance from the edge. Midway between the retina and the macula lutea is a group of small white granular-looking spots, apparently just behind the level of a 316 MEDICAL OPHTHALMOSCOPY. retinal vessel which passes among them. (They slowly lessened under observation. The swelling gradually subsided, the edges of the disc reappearing and its aspect becoming that of " consecutive atrophy." Its appearance is shown in section in Figs. 49, 50.) Vision 0. He died from meningitis, probably tubercular. At the necropsy tubercles were found in the cerebellum and medulla oblongata. FIGS. 4 & 5. Subsiding neuritis, recent haemorrhages, and same disc after recovery. The patient had been in the London Hospital, under the care of Dr. Hughlings-Jackson, suffering from the symptoms of cerebral tumour, and presenting intense optic neuritis. Under treatment the symp- toms subsided and the neuritis gradually lessened, but during sub- sidence several fresh haemorrhages appeared. He died some years later, and the brain presented softening of one anterior lobe, with the remains of an absorbed syphilitic gumma. Cicatrices were also found in the liver. FIG. 4. Subsiding neuritis. The outline of the disc can be seen, but is not clear ; its surface is reddish in tint, and the swelling of the papilla is still considerable, as evidenced by the curves formed by the veins in passing over its edge. Several large extravasations are seen. One of these, below, follows the course of an artery. Another above and to the left is round, not striated, and therefore probably situated in the deeper layers and not in the nerve-fibre layer. Vision f ; fields normal. FIG. 5. The same, tico months later. The haemorrhages have entirely disappeared. The disc is clear, and its swelling has almost subsided. But the tortuosity of the vessels has increased, probably on account of their permanent extension by the long-continued swelling. PLATE VII. FIGS. 1 & 2. Unilateral optic neuritis; probably cerebral x Man aged forty-four. FIG. 1. Left optic disc concealed by a swelling reddish, striated, depressed in the centre. The veins, a little larger than normal, curve over it, and some are concealed beyond the edge. In the central depression the veins pass behind the arteries and are unduly concealed by the swollen tissue. The artery which passes upwards is visible throughout ; those which pass downwards are distinct at their emergence in the depressed centre, but are concealed by the swelling, to reappear at its edge. No haemorrhages. Just beyond the edge of the papilla is a series of pale concentric lines parallel to the edge, due to the folds in the displaced retina ; they are limited above and below by a small vein. Vision : counts fingers only. PLATE VII. DESCRIPTION OF PLATES. 317 FIG. -2. Right optic disc presenting normal characters. A small deposit of pigment lies across a vein. The right disc never became inflamed, but both discs eventually became atrophied, doubtless from an intracranial cause. It is possible that both nerves were damaged in front of the commissure, and that in one only did the inflammation descend to the eye. FIGS. 3 & 4. Very chronic optic neuritis, in a case of epileptoid con- vulsions. Girl aged fifteen. FIG. S.Left disc. Outline obscured by neuritic swelling of slight prominence : the centre stippled red, the periphery only slightly lighter in tint than the fundus. Veins, of nearly normal size, concealed in centre by whitish tissue, which accompanies the larger trunks of both arteries and veins for a short distance. The double contour of the veins is lost on the sides of the swelling. Vision : No. 2 Jager, spells No. 1. Appearances unchanged during four months' observation. FIG. 4. -The same disc two years later. All swelling is now gone. The outline is clear on the outer (temporal), indistinct on the inner (nasal) side. Veins large ; at their junction in the disc they are even more concealed than before, and the white tissue about them is still very conspicuous. Vision, same. FIG. 5. Optic neuritis in anaemia. Girl aged seventeen. The outline of the disc is lost under a pale, reddish-grey swelling, of slight prominence, a little larger than the disc. The veins, of normal size, lose their reflection as they curve down the sides of the swelling, and some are obscured beyond its edge as they dip into the substance of the retina. Some of the arteries-are concealed ; others distinguishable with difficulty. There is a small white spot near the centre of the swelling. Vision (uncorrected) . Eyes hypermetropic. Both discs cleared and vision became normal. A few months later there was a temporary return of the anaemia and of the papillitis, but vision remained normal. (See p. 243.) FIG. 6. Optic neuritis in a case of lead poisoning, with cerebral symptoms. Man aged forty-five. The disc is concealed by a swelling of moderate prominence, bordered by a fringe of striated haemorrhage, and of a colour nearly that of the fundus. Veins a little larger than normal. Arteries concealed by the swelling, and most of them very narrow on the retina. His vision was considerably impaired, but could not be accurately tested, owing to his mental state. (Sec p. 272.) 318 MEDICAL OPHTHALMOSCOPY. PLATE VIII. FIGS 1 & '2. Intense ncuro-retinitis, probably idiopathic, in a chlorotic girl, leaving changes simulating albuminuric retinitis. FIG. 1. Right fundus oculi during the heiffkt of the neuritis. The papilla presents a very large pale red swelling, five times the transverse and six times the vertical diameter of the disc. The peripheral portions are paler than the central. Its sides are steep, and marked by scattered striated haemorrhages. Even the tortuous veins are almost completely concealed by the swelling, the highest parts of their curves alone being seen. At the edge all reappear, are greatly distended, and form conspicuous curves, most of them being again lost for a short space in the retina. The arteries are all concealed. Many extravasations fringe the swelling. The largest lies over a vein which passes downwards : it is striated, and has a paler centre. The pale edge of the swelling is irregular, presenting several projections, and beyond it are many pale spots in the retina. The swelling on the temporal (left) side reaches as far as the macula, and just beyond it is a group of white, rod-shaped spots, arranged in a fan-like manner, and evidently situated on the temporal side of the macula. There are a few small haemorrhages here and there in the fundus beyond the limits of the swelling. Vision: No. 19 Jager ; considerable limitation of field, especially upwards and inwards. Loss of colour-vision except for red. FIG. 2. The same fundus three months afterwards. All the swelling has disappeared. The disc is clear, but has a " filled-in " look, the vessels being partly concealed at their emergence. Both arteries and veins are very narrow. The extravasations have disappeared ; the white spots in the retina persist, but have a more granular aspect. Some extend along the vessels, and one or two have an irregular linear course as if corresponding to the position of ehoroidal vessels. Many white areas lie in the part of the retina around the disc which was formerly occupied by the swelling. The fan-like group of spots, adjacent to the macula, has become still more conspicuous, and others appear adjacent to them, and of similar arrangement; so that the aspect of albuminuric change is very closely simulated. Vision : quantitative perception of light only. (See p. 244.) PLATE Vlli PLATE IX DESCRIPTION OF PLATES. '319 PLATE IX. FIG. 1 . Haemorrhage on optic disc in a case of renal disease, arterial disease, and acute cerebral lesion. Right eye. The optic disc is otherwise normal ; the central cup distinct, narrow but deep ; the arteries and veins of normal size. On the temporal side of the disc is a small extravasation, striated, extending on the retina about a disc's breadth. It has apparently arisen from the rupture of a small vessel, which can be traced to, but not beyond, the haemorrhage. It had given rise to no symptoms. FIG. 2. Neuritis albuminurica. Right optic disc of a man suffering from chronic renal disease, convulsions, and mental derangement. The disc presents the signs of slight but distinct neuritis. Its outline can be nowhere seen; there is slight swelling; the tint of the papilla is red, and the redness is striated. Many small vessels radiate from it on to the retina more than is common in neuritis. The veins are rather large. The arteries are very narrow not more than one-half the diameter of the veins. One small haemorrhage exists on the temporal (left) edge of the disc. On the surface of the papilla are several white spots, irregular in shape. One is situated over an artery, another near the middle of the disc, and one near the lower edge. One small soft whitish spot can be seen on the retina near a vessel above the disc, but this is the only trace of retinal affection. (There were no spots near the macula lutea.) Vision : No. 12 Jager. FIG. 3. Albuminuric neuritis in a man suffering from chronic renal disease (granular kidney), intense headache, and who died shortly after- wards of uraemia. Right eye. The disc is concealed by a considerable greyish-red swelling, stippled and striated. The veins are concealed at their point of emergence, curve over the prominence, and are again concealed at its edge. Beyond, they have a normal course and size upon the retina. The arteries, where visible upon the papilla, are a little below the normal size ; but beyond, upon the retina, they are much smaller than normal, some being scarcely visible as mere lines, and two cannot be detected beyond the edge of the papilla. There are a few very minute shining white spots upon the centre of the swelling ; between it and the macula are several white flecks, and close to the macula a few radiating dots and lines are arranged in a fan-like form. Vision : reads Xo. 6 Jager. (See p. 98.) FIG. 4. Subsiding albuminuric neuritis. The fundus of a patient suffering from chronic Brighfs disease (probably granular kidney), with a pulse of very high tension. The papilla is slightly prominent, greyish-white, the edges of the disc being concealed by it. The veins are narrow and the arteries extremely small, recognizable only in narrow lines. One or two small extra- vasations are seen near the disc, and farther off are several small col- lections of pigment, probably the remains of former extravasations. 320 MEDICAL OPHTHALMOSCOPY. PLATE X. FIG. 1. Acute nephritic retinitis, in a patient suffering from chronic renal disease, consecutive to an acute attack twelve years previously. Man ayed twenty-one. The disc is veiled by a pale opacity, not prominent, which extends on to the adjacent retina. Many soft white areas and striated haemorrhages are scattered over the posterior segment of the retina. The veins are a little larger than normal. Many of them are much concealed at the edge of the papilla. The arteries are large and conspicuous over the disc, but cannot be traced beyond (probably because they become contracted in size, and are concealed by the retinal opacity). Vision 7 ' 7 . For the microscopical appearances see Figs. 68, 69, 70, 72. FIG. 2. Chronic retinal changes in albuminuria, from a case of acute renal disease passing into the chronic form. Right eye. Woman aged twenty-four. The disc and its central cup are normal. The vessels have a normal course. Many irregular white spots lie around the disc, especially between it and the macula, around which is a halo of small spots, for the most part very minute ; one or two larger and very white. The other spots are soft-edged: some of them are superficial to the veins. There are a few small haemorrhages, most of them adjacent to white spots. A small vessel which passes upwards is accompanied by extravasation, as if into its perivascular sheath. Vision : reads No. 12 Jager. PLATE XI. FIG. 1. Retinal changes in a case of progressive pernicious anaemia. Right eye. Man aged forty-seven. The general tint of the fundus is paler than normal. The disc is clear and the vessels distinct almost to their origin in the centre. The veins are very broad and pale, scarcely darker than the arteries. Their central reflection is broad and indistinct. The arteries are rather narrower than normal, and very narrow in proportion to the veins. A large number of striated haemorrhages lie around the papilla. Many of these are adjacent to vessels, in front of or beside them, but the course of the vessels is not disturbed. Some white spots are seen, most of which are adjacent to extravasations, one or two being surrounded by a halo of haemorrhage. One large white spot above the disc has an irregular extravasation below it, but only a few small spots of blood above it. (See p. 245.) FIG. 2. Retinal changes in leucocyth&mia. Right eye. Man aged tiventy-seren. The optic disc is clear. The course of the vessels is normal. The retinal veins are very broad at least twice their normal width. Their central reflection is in some veins narrow and indistinct, in PLATE X PLATE Xi 1 V PLATE XM. DESCRIPTION OF PLATES. 321 others it is broad. The disproportion in size between the arteries and veins is thus very great. The veins are exceedingly pale, scarcely darker than the arteries. An annular zone of haemorrhage surrounds the macula lutea, broader on the temporal than on the nasal side. On the latter, adjacent to it, the retina presents a grey reflection. Between this and the disc is a striated hemorrhage in which are one or two white spots. On the outer side of the annular extravasation is a small, soft, white spot surrounded by a halo of haemorrhage. The extravasation had caused a corresponding central defect in the field of vision. (Subsequently the veins became still larger and more tortuous as in Fig. 2, p. 11.) PLATE XII. FIG. 1. Retinal changes (perimscular disease, aneurisms, $c.) in a case of chronic renal disease. Right eye. Woman aged thirty-six. The outline of the optic disc can be seen on the nasal (right) side, but is not very distinct. Its temporal portion is concealed by a white opacity, which extends on the adjacent retina towards the macula lutea. Near the latter are a few minute white spots. Several small extravasations are seen : one, rounded in form, near the macula, and another below, which extends for a long distance along the course of a small vessel, wider at parts than at others, and in one place interrupted. Another extends, as a linear extravasation, along the course of a vein which passes directly downwards. Three arteries which pass upwards present a peculiar appearance, being concealed more or less completely by white bands, corresponding in width to the vessels. One, which passes upwards and to the right (in the drawing), is masked for a considerable distance by such a band, which ceases suddenly, and, before its termination, presents two interruptions. The vessel beyond this sheath, and in the inter- ruptions, is seen to present perfectly normal characters. Another artery, which passes upwards and to the left, is free at its origin, but just beyond the edge of the disc is concealed by a similar band. It pursues a somewhat wavy course, the lower parts of the curves being indistinct. Like the other, the band ends abruptly, and the vessel beyond presents a normal appearance. Another artery, which arises in the disc from that last described, has a similar white sheath from its commencement to its disappearance behind a vein. It emerges some distance beyond, free. A vein passing upwards presents peculiar corkscrew-like curves. The vein which passes downwards is invisible for a short distance, beyond the extravasation just described, together with its accompanying artery. The arteries are, for the most part, otherwise normal, but one, which passes directly downwards, presents, some distance from the disc, several at least four distinct dilatations, evidently minute aneurisms. The central reflection from the vessel broadens out in these dila- 322 MEDICAL OPHTHALMOSCOPY. tations. The last one is globular, and appears at first sight to terminate the vessel, but closer inspection reveals a narrow white band passing from it, which farther on broadens, and gives origin to a branch of an artery of normal appearance. Here and there in the retina are small collections of pigment. Vision : counts fingers only. FIG. 2. Embolism of the central artery of the retina, occurring simultaneously with an embolism of the middle cerebral artery. Left eye, indirect image. Man aged thirty. The drawing was made about a fortnight after the occurrence of the embolism. The disc (previously veiled by opacity) is clear and pale (not quite pale enough in the figure), the peripheral part almost, but not quite so clear as the central cup. Its edges are sharp. The veins have a normal size and course. Several of them, however, disappear at the edge of the disc. The arteries are filiform on the disc and for some distance beyond. Some remain, as far as they can be seen, narrow (even to the periphery of the retina) ; others become wider at a distance from the disc which varies in the case of different branches. From the upper part of the disc a white opacity extends a short distance on to the retina. A similar but narrower white area extends from the lower part of the disc, being evidently situated behind the level of an artery ; it gradually widens and becomes less intense, and is continuous with a mottled opacity which occupies the region of the macula, and is the remnant of a large white area which at first occupied this region. A branch of an artery which courses across the upper part of this area is evi- dently dilated, and the minute branches which come from it are abnormally distinct. Vision 0. For the microscopical appearance of the embolus in the retinal artery, see Fig. 4, p. 36. FIG. 3. Partial embolism of the central artery of the retina. Rii/ht eye, direct image. Woman aged twenty. The disc is clear ; the central cup and sclerotic ring distinct. The veins are of normal course and character. One division of the central artery, comprising the branches which course downwards and to the right (in the figure), is perfectly normal. The branches of the other division emerge from the upper part of the disc. Of these, two which pass upwards and outwards (to the left) are completely obliterated, visible only for a short distance as white threads. Two others which pass upwards are very narrow, but the central reflection can just be distinguished. One of them is accompanied for a short distance by fine white lines along its sides. Both vessels, some distance from the disc, become wider and resume their normal appearance ; a branch of one which passes to the right remains filiform throughout. No changes visible in the neighbourhood of the macula. Vision : the field presented a defect corresponding to the area supplied by the obstructed vessels. (See Fig. 5, p. 39.) INDEX. The Index does not contain references to the Description of the Plates. The subjects of these arc enumerated in the Table of Contents. Abscess of bi'ain, 155 Ague, 284 Albuminuria, 208 Albuminuric retinitis, 212 Alcoholism, chronic, 273 acute, 275 Amaurosis, epileptiform, 22 saturnine, 269 unemic, 209 Amblyopia in alcoholism, 273 diabetes, 228 mercury poisoning, 279 silver poisoning, 279 tobacco poisoning, 275 Anastomoses of retinal artery, 37 Ansemia, acute, 236 chronic, 11, 242 of brain, 137 pernicious, 244 scorbutic, 246 of retinal vessels, 22 Aneurism, intra-cranial, 168 of internal carotid, 169 of retinal arteries, 15 capillary, 16 miliary, 16 in Bright's disease, 211 cerebral hfemorrhage, 142 diabetes, 230 Aortic regurgitation, 19, 233 Artery, internal carotid, aneurism, 168 j thrombosis, 32, 153 Artery, ophthalmic, 32 Arteries, retinal, 7 aneurism, 15 dilatation, 12 embolism, 33 narrowing of, 11 thrombosis, 32 variations in size, 8, 22 (See also "Vessels, retinal.") Argyria, 279 Ataxy, locomotor, 190 Atrophy of optic nerve, 102 causes, 110 characters, 103 choroiditic, 110 congestion preceding, 107 consecutive, 57, 102 characters, 108 pathological anatomy, 118 prognosis, 130 symptoms, 127 diagnosis, 128 from damage to retina, 115 pathological anatomy, 116 primary, 111 prognosis, 130 retinitic, 115 secondary, 113 simple, 102 spinal, 111 symptoms, 119 in relation to form, 123 324 MEDICAL OPHTHALMOSCOPY. Atrophy of optic nerve, treatment, 131 in alcoholism, 273 in cerebral haemorrhage, 146 softening, 150, 153 tumour, 166 cerebro-spinal meningitis, 178 chronic alcoholism, 273 hydrocephalus, 169 diabetes mellitus, 228 insipidus, 232 diphtheria, 290 erysipelas, 288 gastro-intestinal disorders, 255 general paralysis, 205 hydrocephalus, 169 hysteria, 204 injuries to the head, 184 insular sclerosis, 196 labio-glossal paralysis, 168 lateral sclerosis, 195 lead poisoning, 270 locomotor ataxy, 190 anatomical characters, 193 symptoms, 193 loss of blood, 239 malarial fevers, 287 neuralgia, 200 scarlet fever, 283 small-pox, 284 syphilis, 264 tobacco poisoning, 277 tubercular meningitis, 175 typhoid fever, 280 typhus fever, 279 Atropine, use and dangers of, 2 Axial neuritis, 123 in diabetes, 228 spinal disease, 125 Bed, examination of patients in, 3 Bisulphide of carbon, poisoning by, 278 Blind spot, in neuritis, 70 Blood, diseases of the, 236 loss of, effect on retinal vessels, 19 amaurosis from, 237 Bones, cranial, diseases of, 179 caries, 179 necrosis, 187 Bones, cranial, thickening, 180 Brain, abscess of, 155 anaemia of, 139 compression of, 186 diseases of, 137 hydatid disease of, 167 hyperfemia of, 138 inflammation of, 140 injuries to, 184 softening of, 146 (See "Softening.") tumours of, 156 Bright's disease, 208 arteries in, 12, 209 optic neuritis in, 96, 217 retinal changes in, 212 (See " Retinitis.") Bronchitis, 254 putrid, 294 Bulbar paralysis, 168 Capillaries, retinal, aneurisms of, 17 in Bright's disease, 211 in diabetes, 230 varicose, 17 Capillary pulsation, 20 Carbon, bisulphide of, poisoning by, 278 Cavernous sinus, thrombosis in, 154 pressure on, 79 Cerebellum, abscess of, 156 Cerebral ansemia, 139 circulation, relation of retinal to, 18, 137 congestion, 138 haemorrhage, 142 softening, 146 from atheroma, 152 embolism, 146 syphilitic disease, 150 (See also " Brain.") Cerebritis, chronic, 140 Chiasma, optic, effects of pressure on, 72 a cause of atrophy, 114 Chlorosis, 242 Choked disc, 48, 79, 89 Cholera, 23, 291 Chorea, 198 Choroid, morbid states of, 135 INDEX. 325 Choroid, morbid states of, in Bright's disease, 221 in leucocythtemia, 253 tubercles in, 258 Choroidal arteries, degeneration, 136 embolism, 136 haemorrhage, 30 in endocarditis, 235 purpura, 253 Choroiditic atrophy, 115 Choroiditis, syphilitic, 264 Circulation, retinal, 18 obstruction to, 24 Colour-vision, affection of, in atrophy, 120 diabetes, 228 chronic alcoholism, 273 lead poisoning, 270 neuritis, 71 tobacco poisoning, 276 Congestion of brain, 138 of optic disc, 44 in alcoholism, 274 caries of spine, 196 cerebral softening, 147 chronic alcoholism, 274 diphtheria, 289 general paralysis, 207 lead poisoning, 270 mania, 207 parotitis, 290 tobacco poisoning, 277 with oadema, 46 Constipation and retinal haemorrhage, 255 Cough, effect on retinal circulation, 29 Cranial bones, diseases of, 179 caries, 179 thickening, 180 Cyanosis, 233 Cysts in brain, 167 Daylight, examination in, 4 Death, ophthalmoscopic signs of, 297 Dementia, 208 Diabetes mellitus, 227 insipidus, 232 Diarrhoea, 255 Digestive organs, diseases of, 255 Diphtheria, 289 Disc, optic, appearance of, 41 congestion, 44 causes, 46 with oedema, 46 inflammation, 48 structure, 41 variations in colour, 4, 44 vessels of, 4 (See also "Nerve, optic.") Electricity, sensitiveness of retina to, in neuritis, 72 treatment of atrophy, 132 Embolism of cerebral arteries, 34, 146 of middle meningeal, a cause of atrophy, 114, 150 of retinal artery, 33 appearances, 34 symptoms, 39 in Bright's disease, 223 cerebral embolism, 146 chorea, 198 heart disease, 234 typhoid fever, 281 capillary, of retina, in pyaemia, 292 Emphysema of lungs, 254 Encephalitis, chronic, 140 Endocarditis, malignant, 234 septic, 295 Epilepsy, 201 Erysipelas, 288 Eserine, use of, 2 Examination, methods of, 2 Excavation of optic disc, normal, 41 in atrophy, 105 Exophthalmic goitre, 198 Fever (see "Relapsing," " Typhoid, "Typhus," "Scarlet.") Field of vision in anremic amaurosis, 238 alcoholism, 273 atrophy, 119, 123 quinine poisoning, 278 neuritis, 69 326 MEDICAL OPHTHALMOSCOPY. Field of vision, in tobacco poisoning, 276 for colours, 120 Films over vessels, 6 Foramen, optic, narrowing of, 180 Fundus, how to sketch, 299 General paralysis of the insane, 205 Glaucoma, haemorrhagic, in albumi- nuria, 223 in diabetes, 230 leucocythaemia, 252 neuralgia, 201 Glioma, mistaken for cerebral haemor- rhage, 145 for softening, 149 Goitre, exophthalmic, 198 Gout, 267 Growths in the brain, 156 in the eye, 156 (See also " Tumours.") Haematoma of dura mater, 177 Hemorrhage, general, 236 cerebral, 142 indication of, how transmitted, 152 in optic nerve, 50 into optic nerve-sheath, 145 meningeal, 145 retinal, 25 symptoms, 27 causes, 28 in ague, 284 Bright's disease, 211 bronchitis, 254 cerebral haemorrhage, 142 softening, 148 endocarditis, 234 gout, 267 leucocythaemia, 249 malarial fevers, 284 meningeal haemorrhage, 145 meningitis, purulent, 172 tubercular, 175 pernicious anaemia, 245 purpura, 253 optic neuritis, 52 scurvy, 254 Haemorrhage, retinal, in septicaemia, 294 into vitreous in Bright's disease, 223 Htemorrhagic pachy meningitis, 177 Haller, circle of, 41 Head, injuries to, 183 Heart, diseases of, 232 Heatstroke, 188 Hemianaesthesia in lead poisoning, 269 Hemianopia from cerebral disease, 72 pressure on chiasma, 72 state of optic nerve in, 114 Hemi-neuritis, 50 Hernia cerebri, 187 Hydatid cysts in brain, 167 Hydrocephalus, chronic, 170 atrophy in, 169 Hyperajmia of retinal vessels, 24 Hypermetropia, neuritis in, 99 recognition of, 3 Hysteria, 204 Hystero-epilepsy, 204 Injuries to head, 183 to spine, 197 Insane, general paralysis of, 205 Insanity, 204 Insolation, 138, 188 Isohaemia, retinal, 22 Jaundice, 255 Kidneys, diseases of, 208 Knee-jerk, absence with optic nerve atrophy, 192 Labio-glossal paralysis, 168 Lardaceous kidney, retinitis with. 212 Lead-poisoning, 269 Leucocythaemia, 247 retinal veins in, 11, 248 Locomotor ataxy, 190 Lungs, diseases of, 254 Malarial fevers, 284 Mania, 207 Measles, 282 Melancholia, 208 Meninges, haemorrhage into, 145 INDEX. 327 Meninges, growths in, 170 Meningitis, 171 cerebro-spinal, epidemic, 178 simple, 172 chronic, 172 in cerebral tumour, 159 meningeal growths, 171 septicaemia, 297 purulent, 172 simple, 172 syphilitic, 177 traumatic, 178, 186 tubercular, 173 Menstrual disorders, 256 Mercurial poisoning, 279 Migraine, 200 Miliary abscesses in optic tracts, 67 aneurisms in retina, 16 Mumps, 290 Myelitis, 189 Nerve fibres, opaque, 5 Nerve, optic, atrophy of, 102 (See " Atrophy.") changes in, 42 congestion, 44 inflammation, 48 (See "Neuritis.") injuries of, 185 morbid states of, 43 trunk of, changes in, 66 sheath of, 42 (See "Sheath.") Nervous system, diseases of, 137 functional, 198 Neuralgia, 200 Neuritis, optic, 48 descending, 48, 78, 83 frequency, 89 in cerebral tumour, 156 tubercular meningitis, 173 intra-ocular (papillitis), 48 causes, 75 recognition of, 96 diagnosis, 94 duration, 76 pathological anatomy, 57 prognosis, 100 Neuritis, intra-ocular, primary, 82 relation to encephalic disease, 78 second attacks, 57 stages, 49 subsidence, 54 anatomical change during, 67 symptoms, 67 treatment, 100 unilateral, 161 varieties, 92 in alcoholism, 274 anaemia, acute, 239 chronic, 243 pernicious, 245 aneurism of internal carotid, 168 Bright's disease, 98, 217 caries of sphenoid bone, 179 cerebral abscess, 155 haemorrhage, 144 softening, 147 tumour, 75, 156 cerebritis, 141 chorea, 199 general paralysis, 207 heatstroke, 188 hydatid disease of brain, 167 hydrocephalus, 169 injuries to the head, 183 spine, 197 lead poisoning, 99, 271 loss of blood, 239 malarial fever, 287 measles, 282 meningeal haemorrhage, 145 tumours, 170 meningitis, 172 tubercular, 174 menstrual disorders, 256 myelitis, 189 nasal disease, 187 orbital disease, 181 scarlet fever, 283 syphilis, 264 tumour of brain, 156 course, 161 significance, 164 typhoid fever, 280 typhus fever, 280 328 MEDICAL OPHTHALMOSCOPY. Neuritis, retro-ocular, 93 axial, 94 (See "Axial.") from orbital disease, 115 Neuro-retinitis, (See "Neuritis.") Nose, diseases of, 187 (Edema of optic papilla, 46 in tubercular meningitis, 174 of retina in Bright's disease, 220 in alcoholism, 274 in leucocythsemia, 250 Opaque nerve fibres, 5 Ophthalmia, pyjemic, 292 Ophthalmic artery, thrombosis in, 32, 154 Ophthalmoscope, use of, in medicine, 1 Ophthalmoscopy, medical, objects, 1 Orbit, diseases of, 180 haemorrhage into, 182 inflammation, 180 injuries, 185 tumours, 183 Pachymeningitis, hremorrhagic, 177 Pallor of optic disc in anaemia, 242 in atrophy, 103 Papilla, optic, 42 estimation of prominence, 95 (See "Nerve, optic.") Papillitis, 43, 48 (See also " Neuritis.") (See "Atrophy, consecutive.") Papillitic atrophy, 55, 108 Paralysis, general, of the insane, 205 Parotitis, 290 Perineuritis, 51 retro-ocular, 94 Perivascular changes in retina, 15 in Bright's disease, 211 Pernicious anaemia, 244 Phlegtnasia dolens, 236 Phthisis, 254 Plethora, 236 Plumbism, 269 Pregnancy, affections of sight in, 256 Pressure, intra-cranial, relation to optic neuritis, 8-'? Pressure, intra-ocular, influence on circulation, 18 on apparent size of vessels, 11 Pulsation of retinal vessels arterial, 18 in exophthalmic goitre, 198 neuritis, 50 capillary, 20 veins, 20 rhythmical, 22 Purpura. 253 Pyaemia, 291 Quinine poisoning, 277 Reflex theory of optic neuritis, 81, 91 Refraction, estimation of, 3 Relapsing fever, 281 Retina, affection in neuritis, 56 tubercular meningitis, 173, 175 aneurisms in, 16 detachment of, in Bright's disease, 222 growths in, 132 haemorrhage in, 25 morbid states of, 132 vessels of, 7 (See " Vessels.") white spots in, 133 Retinitis, albuminuric, 212 anatomical changes, 219 complications, 222 course, 223 degenerative form, 215 diagnosis, 224 forms, 214 hiemorrhagic, 216 inflammatory, 216 neuritic, 217 pathology, 222 , prognosis, 227 symptoms, 221 treatment, 227 diabetic, 229 from loss of blood, 239 haemorrhagic, 28 leucocythoemic, 248 pigtnentosa, 135, 266 INDEX. 329 Retinitis, septic, 293 syphilitic, 264 Rheumatism, acute, 284 chronic, 267 Salicylic acid poisoning, 279 Scarlet, fever, 282 Sclerosis of cord, insular, 195 lateral. 195 posterior, 190 of optic nerve, 195 Scotoma, central, 125 in alcoholism, 274 diabetes, 228 tobacco poisoning, 276 Scurvy, 254 Septicaemia, 291 Sexual organs, diseases of, 256 Sheath of optic nerve, 42 communication, 80 distension of, 66, 80 effect on veins, 10 relation to neuritis, 80, 86 to excess of sub-arachnoid fluid, 86 tubercles in, 176, 262 haemorrhage into, in meningeal haemorrhage, 145 Sight, how affected -in atrophy, 119 in neuritis, 68 intra-cranial disease, 69, 72 Silver poisoning, 279 Sinus, cavernous, effects of pressure on, 78 Skin, diseases of the, 257 Skull, fracture of the, 185 Small-pox, 284 Softening of brain, 146 chronic, 155 embolic, 146 inflammatory, 154 primary, 154 thrombotic, 150 Spinal cord, connection of ocular changes with, 112 diseases of, 189 (See also "Sclerosis" and " Myelitis.") Spine, caries of, 196 injuries to, 197 Staphyloma, posterior, 5 Stauungs-papille, 48, 79 Stomach, diseases of, 255 Strangulation in optic neuritis, 52 in descending form, 83 mechanism, 84 Sunstroke, 188 Syncope, retinal vessels in, 23, 139 Syphilis, 263 inherited, 265 Syphilitic diseases of cerebral vessels, 150 Tension, intra-ocular, influence on circulation, 18 Thrombosis in cerebral vessels, 150 internal carotid, 32, 153 ophthalmic artery, 32, 154 retinal vein, 30 retinal artery, 32 Tissue, white, in front of disc, 6 Tobacco poisoning, 275 Tonsillitis, 290 Tracts, optic, changes in atrophy, 118 in neuritis, 67 Tubercles of choroid, 258 in tubercular meningitis, 173 of optic nerve, 261 retina, 262 Tubercular meningitis, 173 Tuberculosis, 257 Tumour of brain, 156 associated growth in eye, 156 atrophy in, 166 neuritis in, 75, 156 of meninges, 170 Typhoid fever, 280 diagnosis from septicaemia, 297 Typhus fever, 279 Uremia, 208 Urinary system, diseases of, 208 Variola, 284 Vaso-motor theory of neuritis, SI, 91 330 MEDICAL OPHTHALMOSCOPE. Vein, central, thrombosis in, 30 orbital, communication with facial, 79 Veins, retinal, atony of. 10 dilatation of, 10 diminution in size of, 1 1 increased width of, 9 in anaemia, 11, 242 cyanosis, 233 death, 298 leucocytheemia, 11, 248 neuritis, 51, 52 pulsation in, 20 thrombosis in, 30 varicose, 10 Venesection, effect on blood, 23 Vessels, diseases of, 235 Vessels, retinal, anaemia of, 22 arrangement, 12 atheroma, 15 calcification, 15 congestion, passive, 24 course, 13 degeneration, 15 hypersemia of, 24 in atrophy, 107 Bright's disease, 209 Vessels, retinal, in convulsions, 22, 201 malarial fever, 286 neuritis, 52 quinine poisoning, 278 pulsation ia, 18 rupture, 25 sclerosis of, 14 size, 8 variations in, 9 structural changes, 13 tissue around, 14 wall of, thickened, 14 visibility, 7 (Sec also " Arteries.' ) Vision (see "Sight," "Field"). colour (see " Colour vision "). Vitreous, haemorrhage into, 26 in Bright's disease, 211, 223 diabetes, 230 opacity of, in diabetes, 230 in pyaemia, 292 White spots near disc, 5 Whooping-cough, 290 Xanthelasma, 201 OTHER WORKS BY DR. GO WEES, F.R.S. EPILEPSY AND OTHER CHRONIC CONVULSIVE DISEASES: THEIR CAUSES, SYMPTOMS, AND TREATMENT. Svo. PSEUDO-HYPERTROPHIC MUSCULAR PARALYSIS. A Clinical Lecture. With Engravings. Svo. DIAGNOSIS OF DISEASES OF THE SPINAL CORD. With Engravings. Third Edition. Svo. DIAGNOSIS OF DISEASES OF THE BRAIN. Lectures delivered at University College Hospital. Second Edition. With Engravings. Svo. A MANUAL OF DISEASES OF THE NERVOUS SYSTEM. Vol. I. DISEASES OF THE SPINAL CORD AND NERVES. With Engravings. Royal Svo. Vol. II. DISEASES OF THE BRAIX AND CRANIAL NERVES; GENERAL AKD FUNCTIONAL DISEASES. With Engravings. Svo. UNIVERSITY OF CALIFORNIA LIBRARY Los Angeles This book is DUE on the last date stamped below. 9 '79 ^OCT171979 L& BIQ&IED Form L9-Series 444 3 1158 00443 2281