[Extracted from the American Journal of the Medical Sciences for July, 1879.] NOTES ON INTRA-OCULAR LESIONS PRODUCED BY SUNSTROKE. By F. C. HOTZ, OPHTHALMIC SURGEON TO THE ILLINOIS CHL EEYE AND EAR INFIRMARY, CHICAGO. Among a great number of cases of atrophy of the optic nerve we oc- casionally meet with a patient who traces the beginning of liis eye trouble back to an attack of sunstroke. He is positive in his assertion that pre- vious to that accident his sight was perfect, but began to fail sooner or later after it. The ophthalmoscope reveals a white or bluish-white papilla, with thin arteries and often pigmented outlines. The etiological connection between sunstroke and atrophy of the optic nerve in such cases is unquestionable; and the appearance of the atrophic disk would indicate that the atrophy was the result of optic neuritis. It is therefore remarkable that the ophthalmological literature has given so little attention to defects of sight induced by sunstroke ; it is strange that we can scarcely find an allusion to sunstroke as a remote cause of neuro-retinitis, atrophy of the optic nerve, and other intra-ocular lesions. Most of the text-books on diseases of the eye (Wells, Carter, Mackenzie, Walton, Arlt, Stellwag, Schweigger, etc.) give us no information whatever about the possible effects of sunstroke upon the eye. In that excellent and carefully compiled Handbuch der Gesammten Augenheilkunde, I could find only this vague allusion d " Cases are also reported in which similar defects of sight are said to have been induced by the effect of the scorching heat of the tropical sun." Macnamara2 is the only writer who speaks more positively on the sub- ject " It is not an uncommon thing to meet with people in India suffering from headache induced by over-exposure to the sun; the papilla will often be found intensely congested under these circumstances, the capillaries of the retina being somewhat hyperamiic also. The glare of the tropical sun seems to overstimulate the retina, and it becomes congested and swollen; if the exciting cause continues in operation, the irritation is propagated to the brain, and headache and irritative fever ensues. "It seems to me that irritation, under these circumstances, begins in the re- tina, because I have frequently found in my own case, that a pair of coloured glasses has saved me, when exposed to a tropical sun, from the distress produced by the glare, and subsequently headache, which one so frequently experiences unless the eyes are thus guarded." 1 Leber, on Retrobulbar Neuritis resulting in Partial Atrophy, vol. v., p. 837. 3 Manual of Diseases of the Eye, 3d ed., 1878, p. 437. 2 This view does not seem to me to give a satisfactory explanation of the causative relation between sunstroke and eye trouble. And, certainly, the following observations which I gathered during the past year do not sup- port it. Case I. Heatstroke followed by Partial Paralysis of Left Arm and Optic Neuritis of Right Eye-Mr. Adolf St., aged 29, manufacturer, was prostrated by the excessive heat in July, 1878. Though he was not exposed to the direct rays of the sun, he became dizzy, and fell down. When he recovered he had lost the use of his left arm, and suffered from violent frontal headache. To his right eye the air seemed to be in a wavering motion. Two months later the headache ceased, but sight of right eye became very dim. Examination on August 22d, 1878. L. E., V= emmetropic ; fundus normal. R. E., fingers at six feet; hemianopsia, the temporal half of visual field being completely obscured. Media clear; the nasal half of disk swollen and red, so much so that its boundary cannot be discovered. Around the still distinct temporal outline a narrow crescent of choroidal atrophy. Treatment: Heurteloup ; and infusion of fol. jaborandi. 28th. The jaborandi produced profuse perspiration, beginning about fifteen minutes after he took the infusion, and lasting over one hour. Optic disk is paler. V the same. Ordered iodide of potassium, 1.5 pro die. Sept. 11. Retina and optic disk appeared normal in colour. Percep- tion restored in the temporal half of the field of vision. V = fingers at fifteen feet. 24^. Crescent round the outer side of optic disk seems broader. V = 20 with is 20 Oct. 6. V = 2 0, with -40 2 0. The same result was obtained two months later. Case II. Heatstroke ; Optic Neuritis of Right Eye Mrs. Maria M-, aged 41 years, housemaid, of Oak Park. In July, while ironing in a hot kitchen, she was overpowered by the heat, and afterwards suffered from the most violent headache, attended with fever, lasting about three weeks. Since then she noticed a mist before her right eye. Sight of both eyes had always been perfect. Examination September 13, 1878. L. E. normal; V = |§. R. E., V = ; media transparent; papilla opaque, and so red that it cannot be distinguished from the surrounding retina. Two leeches were applied to right temple ; patient ordered to remain in a darkened room for one week, and to take tinctura rhamnus frangulae. 20th. Papilla is paler; its boundary visible ; V = Oct. 2. Papilla clear, vessels normal; its outlines well defined ; V = Case III. Slight Attack of Sunstroke ; Optic Neuritis of Right Eye.- Mr. John L-, aged 35 years, travelling agent, has always been in good health, never had syphilis, and had never noticed any difference in the sight of his eyes. On one of the hottest days in July, while going about to visit his customers in town, he was overcome by the heat, became dizzy and faint, and fell down on the street. He was taken home in a carriage, and was confined to his bed for three days with severe headache. On the 29th of July he observed the eclipse without protecting his eyes by smoked glasses. Three days after, he noticed that all objects to his right side ap- 3 peared as though they were wrapped in a mist. He consulted me on the evening of the 29th of September. As I expected to see the patient again on the following day at my office, where I could better test his sight, I deferred the further examination of the disturbance of vision, and only ascertained that on closing the left eye and looking with the right at my fingers he could see the thumb, index, and middle fingers distinctly, while the ring and little fingers appeared very dim. The ophthalmoscope re- vealed transparent media, a hyperaamic swollen papilla, with indistinct outlines, and a grayish mist cast over a large portion of the nasal half of the retina. I regret to give the history of this case as incomplete as it is; but the patient did not return. Case IV. Sunstroke followed by Neuro-retinitis in both Eyes Thomas Murphy, aged 48 years, labourer, of Jacksonville, HL, was admitted to the Illinois Charitable Eye and Ear Infirmary on the 7th of November, 1878. In July, after working in the sun and drinking freely, he suddenly became dizzy, and lost the sight in the lower halves of fields of vision. He says he could see distinctly straight ahead or above him, but could hardly see the steps when going down stairs. Gradually his sight im- proved to a certain extent. On examination R. E. V = f®, L. E. V^; slight epithelial opacities in both corneas, of which patient could give no information. Pupils very small, but active. Optic disks very red, slightly swollen ; boundaries quite indistinct; veins very full; arteries about normal. The treatment was begun with cathartic pills, and then potassic iodide and bromide was given. Under this treatment the sight improved so that on December 9th we found R. E. V = L. E. V = f g; disks more distinct and less red; and, when the patient was discharged, March 3, 1879, the vision of right eye was that of the left eye To these cases I will add one which was observed in 1873, and another one which was under the care of Dr. W. T. Montgomery, of this city, who kindly furnished me the notes of his case. Case V. Optic Neuritis of Left Eye; History of Sunstroke Mr. Thomas S. IL, aged 32, merchant. Examined on August 24, 1873. Was sunstruck in July of previous year; since then he was troubled with the perception of an apparent wavering motion of the air, and the sight of left eye gradually grew very dim. R. E. V emmetropic and normal fundus. L. E. fingers at 10 feet; disk very red, streaked, and swollen ; its outlines indistinct; surrounding retina cloudy. Heurteloup to left temple. Bichloride of mercury 0.006 three times daily. Aug. 31. L. E. V = Another Heurteloup. Sept. 15. L. E. V = |£. Retina clear ; disk slightly flushed, but its boundary well defined. Case VI. Neuro-retinitis following Heatstroke Mary J. B., aged 34, farmer's wife, consulted Dr. Montgomery on account of eye trouble Sep- tember 17, 1878. Patient stated that she had weak eyes for ten years, and had been troubled with motes floating before them. Vision good until about six weeks ago. The weather at that time was very hot, and she was very busy cooking for harvest labourers, and became overheated. Did not become unconscious from the heat, but was very much oppressed by it, and this oppression was soon followed by severe headache, and the sight 4 of left eye began to fail. Patient's general condition fair. Still com- plains of headache. R. E. V = L. E. V = perception of light. Ophthalmoscope, right eye, general hypersemia of fundus; left eye, papilla swollen, outline of disk very indistinct; general cloudiness of whole fun- dus, but most marked in region of disk and outer portion of field. The patient could not remain in city for treatment, and was only ex- amined once. Prescribed potassium and sodium bromide aa gr. x three times daily. A succession of blisters to temple and behind ear, rest in a dark room, and bowels to be kept lax. Husband wrote November 1st that the treatment had been faithfully followed, and that patient had improved very much. Heard nothing more from her. These observations show a most significant similarity. The patients were exposed to excessive heat until they succumbed to its noxious effect. After recovery from the immediate shock, they suffered from a violent head- ache for several weeks, and sooner or latter their eyesight began to fail; and in all cases optic neuritis and peri-neuritis was found as the patholo- gical condition of the eyes so affected. These clinical facts, I think, show pretty conclusively that the neuritis is a secondary affection, resulting from a primary lesion produced by the heat within the cranial cavity. And I believe, with our present knowledge of the anatomy of the optic nerve, it is not difficult to indicate the way by which the intra-cranial affection is propagated to the intra-ocular por- tion of the optic nerve. Among the few things pathologists agree upon in regard to the morbid changes which sun or heat strokes induce in the human body, are the facts that we generally find a marked congestion of the sinuses and nerves ; sometimes a sanguineous effusion between dura mater and cranium ; a cer- tain quantity of serum at the base of the brain ; and the gray substance more or less hypertemic. On the other hand, Schwalbe has established the fact (confirmed by other investigators) that the sheaths which envelop the intra-orbital por- tion of the optic nerve must anatomically be considered as direct continu- ations of the meninges. The external neurilemma of the optic nerve is a part of the dura mater and arachnoid, the internal neurilemma a part of the pia mater, and the space between these two sheaths-the intervaginal space-is in open communication with the arachnoidal space of the brain. Ever since these anatomical facts have been clearly understood, it has been pretty generally conceded that they afford a satisfactory explanation for clinical observations, which associate optic neuritis frequently with intracranial diseases. It was thought that disturbances of the circulation in the meninges could be communicated to the sheaths of the optic nerve on account of their contiguity. Upon this basis, I think, we can found a correct interpretation of the clinical features of the above cases. We may presume the excessive heat 5 caused hypersemia of the meninges, congestion of the sinuses; in some cases, perhaps, also a serous exudation at the base of the brain. The severe headache that most of the patients were suffering from, a headache lasting from two to three weeks, is an evident sign of a disturbed circulation in the cranial cavity. This irritation was communicated to the sheaths of the optic nerve, and produced ultimately the ophthalmo- scopic symptoms of peri-neuritis and neuritis. It does not militate against this view that in the majority of cases the head symptoms had ceased before the patient noticed any disturbance of sight. For it does not prove that during the period of headache the optic nerves were not affected. We know that a certain degree of congestion of the optic nerve may exist without any appreciable impairment of vision; we know that peri-neuritis interferes but slightly with the nutrition and func- tion of nerves ; while in neuritis the nerve-substance suffers material changes in structure and function. In two of the cases on record (Nos. 4 and 5) the sight was impaired directly after a severe sunstroke; in the other four cases (Nos. 1, 2, 3, and 6) the visual defect supervened after a period of headache. Patients 1, 2, and 6 had an attack of heat-stroke, and No. 3 a slight attack of sunstroke, while Nos. 4 and 5 had a severe attack of sunstroke. It will be noticed that the severity of the attack had an evident bearing upon the earlier or later occurrence of the eye trouble. The severer the sunstroke the sooner vision was disturbed. I am therefore inclined to think that in the severe cases the graver dis- turbance in the brain at once propagated the graver form of disturbance, neuritis, to the optic nerve, while the lighter attacks first gave rise to a peri- neuritis, which lasted a few weeks without disturbing the functions of the optic nerves ; but ultimately the inflammation extended into the substance of the nerve, developing optic neuritis, which all the cases presented at the time of examination. If the limited number of my observations would permit me to form an opinion in regard to the prognosis of this solar optic neuritis, I would say, judging from the good results obtained in all cases which were under treatment, that the disease is quite amenable to treat- ment. It will be manifest that my opinion of the relation between the optic nerve affection and the head trouble is essentially different from the view advanced by Macnamara. I may say with Dr. Allbutt 4 " Macnamara supposes that the cerebral irritation is due to advance of the solar irrita- tion from the retina upwards; my view would be rather the reverse." My observations certainly do not sustain Macnamara's view. The strongest argument against him is the fact that heatstroke and sunstroke produced identical symptoms. It so happened that among the six cases of neuro-retinitis three were the result of sunstroke and three were due to 1 Use of Ophthalmoscope in Diseases of Nervous System, 1871, p. 99. 6 heatstroke. Inasmuch as these latter cases were not exposed to the glare of the sun, the retina could not be the primary seat of solar irritation. Again, the effect of glaring light upon the retina shows itself most par- ticularly at the most sensitive part of this tunic ; the overstimulation causes a dulness of the perceptive power of the whole 'retina, but the im- pairment is especially marked in the region of the yellow spot. Such patients complain of scotomata ; but none of our patients noticed anything of this sort.1 It will be remembered that the pathological changes ob- served in the fundus oculi have been limited to the area of the papilla, or, where they extended beyond it, the disturbance of the retinal tissue was very slight compared with the change of the optic disk. We can under- stand this, if we consider the ocular trouble as being propagated from the brain to the optic nerve. But it is very improbable that an irritation of the retina strong enough to produce secondary disturbances in the optic nerve and brain should cause scarcely any change in the structure and appearance of the primary seat of irritation. Optic neuritis, however, does not seem to be the only secondary affec- tion of the eye induced by sunstroke. The severest attacks may be fol- lowed by a high degree qf choroiditis exudativa, with subsequent detach- ment of the retina, as the following observation will show. Case VII. Insolation followed by Severe Headache; Detachment of Retina in Left Eye-Mr. John W., aged 32 years, native of Holland, labourer, was admitted to the Illinois Charitable Eye and Ear Infirmary, on July 16, 1878, with the following history. On July 8th, while work- ing in the hot sun on the roof of a building, he was seized with severe fron- tal headache, which continued until in the night of July 12th ; then it ceased. Upon rising in the morning of next day, he, for the first time, dis- covered that he had almost entirely lost the sight of his left eye, only a little perception remaining in the upper region of the visual field; but this also left him by noon of the same day. Ophthalmoscopic examination: Cornea, iris and lens were normal. Vit- reous humour somewhat cloudy; upper half of retina detached in three bladder-like folds, one above and one on either side. Lower half of retina still attached, but quite opaque T. Patient was given iodide and bromide of potassium, 0.5 grams of each ; and pressure bandage was ap- plied to the eye. 17th. Eye is painful and very sensitive to pressure; slight perception of light. Pupil is dilated by atropia; the nasal fold of the detached retina is much smaller. 18^/z. Pupil still dilated; iris markedly discoloured, of a greenish cast (right iris being light blue). Vitreous humour is more clouded, and filled with numerous small black and floating bodies like coal-dust. 23tZ. Ilas had no pain . since last date. Iris less discoloured ; vitreous 1 The only patient who exhibited anything like a scotoma is the one (Case III.) who exposed his eyes to the glare of the sunlight, in observing the eclipse with the unpro- tected eye. The extensive obscuration of his visual field was due to the effect of the glare; and in this case alone we find the retina more extensively affected than in all other cases. 7 clearer; retina re-attached, except at the lower nasal portion ; can count fingers at a distance of eight feet. 30^/?. Vitreous clear; but detachments of retina more extensive again, involving the whole lower half. Remarks-The unusual severity of the headache, attended by fever, makes it very probable that the insolation has caused an inflammation of the meninges, and a serous exudation over some portion of the left half of the brain. Through the intervaginal space of the optic nerve the inflam- matory process reached the eyeball, involving its uveal tract. The cloudi- ness of the vitreous humour, the tenderness of the globe, the subsequent discoloration of the iris, are evident symptoms of a choroiditis exudativa which led to the detachment of the retina. This explanation is founded upon the clinical experience that if, in the- course of acute inflammation of the meninges, the eyeball becomes involved, the inflammation is usually propagated to the uveal tract, and not to the retina. That this propaga- tion takes place through the agency of the intervaginal space is very plau- sible, if we consider the anatomical relation of its ocular terminus to the choroid. Schwalbe gives the following description of it- " The fibres of the external sheath simply pass over into the external two-thirds of the sclerotica; external neurilemma of the optic nerve and sclerotica are con- tinuous. The inner neurilemma, or pial sheath, becomes firmly attached to the surface of the optic nerve, which it accompanies to the vicinity of the choroid ; here the larger portion of its fibres is blended with the inner third of the sclero- tica ; only a few of them can be traced into the texture of the choroid, which at this place is firmly united with the sclerotica. The intervaginal space gradually tapering off, advances between both sheaths to the closest proximity of the cho- roid, from which it is separated only by the thin layer of sclerotica, which is iden- tical with the pial sheath of the optic nerve." From the close proximity of the terminus of the inter-vaginal space to the choroid, we can well understand that this highly vascular tunic readily responds to the irritating influence of inflammatory products in the inter- vaginal space ; and therefore I infer that in this way the inflammation was started in the choroid, which resulted in a serous transudation betw een it and the retina. In support of this view I may be permitted to record another case o detachment of the retina, in which the intra-ocular affection must be attributed to a primary lesion of the meninges. Case VIII. Fall upon Head; Detachment of Retina two weeks after- wards Mr. J. H., aged 60 years, had had intermittent fever. For several years past his sight had been slightly impaired. In January he fell down a stairway, striking the ground with his left parietal bone. lie did not become unconscious, but the blow stunned him to such a degree that he was obliged to sit still for some time before he was able to get up and walk. For three or four days he had a violent pain over the left side of his head ; but he is positive that the sight of the left eye was still as good as before the accident. After one week, however, he noticed that per- pendicular lines (such as the edges of door-posts) appeared as if they were 1 Graefe & Saemisch, Handbuch der Ges. Augenheilkunde, vol. i. p. 330. 8 broken in three pieces, the middle piece being markedly displaced to the left. During the second week the sight of the left eye began to fail, and its visual field became contracted. The obscuration began in the inferior nasal section of the field, gradually extending upwards, until after three or four weeks (latter part of February) the visual field was abolished with the exception of a very narrow segment in the lower temporal section. I examined his eyes on March 23d. R. E. V = ; emmetropia; in- cipient cataract; several of the opaque spokes reaching into the central part of the lens ; fundus normal. L. E. No central vision ; only a very limited area of peripheric vision in lower temporal quadrant. Incipient cataract; whole upper half of retina detached, hanging down in a large oscillating curtain, its lower edge run- ning obliquely from above downwards and outwards. Papilla red, but well defined : vessels normal. Tension not noticeably diminished, but eye slightly sensitive to pres- sure. Remarks The facts in this case are clear. An old man, whose sight has been slightly impaired by incipient cataract, receives an injury of his head, which was followed by a certain degree of traumatic meningitis of the left side. The sight of the left eye was not disturbed immediately after the injury. After the first w^eek he noticed metamorphopsia, and two weeks later the obscuration characteristic of detachment of the retina began slowly to creep over the left eye. From these facts we can infer that the fall upon the head certainly had not injured the eye ; for the disturbance of its functions came on neither immediately nor suddenly, as it should had there been a direct traumatic lesion of the eye. The slow and gradual growth of the detachment points to a gradual accumulation of serous fluid between retina and choroid, due to the gradual rise of an inflammatory action in the choroid. The late development of this choroiditis, the serous character of its products speak decidedly against the supposition of its being traumatic inflammation. And all the symp- toms explain themselves as soon as we suppose that the choroiditis was a secondary affection, propagated from the brain through the inter-vaginal space of the optic nerve in the manner described above in connection with the other case.