TIIREE CASES OF CONICAL CORNEA CORRECTED BY SIUITABLE GLASSES. By WM. THOMSON, M.D., of Plhiladelphia. THESE cases might more accurately be classified under the head of acquired astigmatism, since their histories demonstrate that the optical defects were induced in eyes that were probably eminetropic, by prolonged strain of Ilie eyes in reading with insuifficient illumination, when the individuals were rendered vulnerable by causes which produced a general debility of their systems. On inspection, the first presented slight evidence of the conical condition, the second was more mnarked,-whilst the third would be recognized at once as a cllaracteristic case of conical cornea, with sight so imperfect that the patient, who lhad been nsing - i spherical for several years, could only read at hiis far point, with his glass, viz., six inches, type of a large size; and whose correction would have been considered by me impossible by glasses buit for the experience obtained from the stuidy of the preceding ones. The high degree of acuity of vision, and the increased working power and conifort which has been gained by the correction in these cases, would enIcourage me to persevere in the analysis of any future ones that might present themselves, before proceeding to aiiy operatioin; although it would be impossible in the limits of this paper to give a truie picture of the difficulties erncountered in the hours of prolonged and wearisome examination into the refraction of these eyes. Mrs. W., age forty-eight, in good health, states that her distant sight was perfect until she was twenty-five years of age, when, after the birth of a child, she was confined to bed for
133 many weeks by a prolonged illness, and amused herself by reading in a dimly-lighted room. She founid when she reco-vered her health that her sight was imperfect. No change has since taken place, her eyes present no sign of disease, her distant sight is imperfect, but she can read at-nine inches by nipping her lids together inito a stenopaic slit, although the prolonged uise of her eyes in this way gives her severe headache; with either eye alone V.= 1 ; with botlh together V.= ; witl both she reads 3 Snellen at ten inches, but with either alone the far point is five inchec. No spherical, glasses materially assist, and this anomaly is accounted for after hours of examination, by the diagnosis of mixed astigmatism in eitlher eye, at such angles as to enable one eye to partially compensate for the defect in the other. In the R. E. she has hypermetropia for line at 300, and myopia for 1200, whilst in L. E. there is myopia for 300, and hypermetropia for 1200, so that she sees the two parts of a circle, or other object, in these angles best with both eyes togetlher, imperfectly with either alone, by the binocuilar fusion of the two indistinct images. She has a binocular far point of 10 iinches, and a monocular one of 5 inches, which also results from the degree of defect, which is hy. -1- combined witl mn. -1 in either eye, which enables her to read with both eyes at 10 inches with suppressed accommodation, but which develops an apparenlt myopia of * when she uses the accommodation to assist the hypermetropic meridian in eithier eye wlhen it is employed alone. The reflex of the window from the cornea was small in size at its centre in comparison with that from the periphery. With the ophthalmoscope in the upriglit method the refraction of -parts of the periphery of the corniea was hypermnetropic, whilst the centre was Inyopic; and whilst the astigmatism was of course readily perceived by this means, its degree was very difficult to determine. That there was slight conical cornea was shown by the difficulty in the use of all the usual means of diagnosis, including the stenopaic slit with test letters, tllc test lines of Greene, and my method with the two perforations in a screen combined with spherical and cylindrical glasses, and the use of the ophthalmoscope in the upright method. As the resuilt witlh
134
atropia, the following formula gave the-high.est acuity of vision: Rt. +-cy ax. 300 ^ cY ax. 1200. y ax. 300. Lt. +cy ax. 1200 ^ wllich increased V. from I ° to 1xvi0 . Case 2. M. P., age thirty-eight: seen first, December, 1870. Until eighteen years of age had perfect sight for distance, since he was a surveyor anld could see the signals at half a mile distant. He then changed his occupation for that of a conveyancer, and in addition to his daily duties attempted to study law, by a poor light at night, keeping himself awake by walking the floor with his book in his hand. His general health broke down, and he then found his distant sight very imperfect, but improved by concave glasses. Two years previously he had been examined and provided with a v sph. on .the Right, and -i s _ ey on Left, which gave but little satisfaction for distant vision, and is interesting as showing'the opinion of a clever surgeon. It was found that in the Left tllese glasses gave an induced hypermetropia = 1 , and a yet greater defect in the Right. Inspection, and the ophthalmoscope, revealed marked conical cornea, whilst the most patient efforts with test objects, spherical and cylindrical glasses, and stenopiic slits, with paralyzed accommodation, were needed to obtain a diagnosis. By the upright method it was found that the periphery of the cornea at soine parts was hypermetropic, whilst the centre was highly myopic; and after hours of effort the following result was obtained: Rt. + s. - lcy., axis 500, V. = -1 Lt. As._ey.,axis115, V.=20 -1 On the right this was a compromise, and was attended by a singular double vision, arising from the uncorrectable apex of the cone. When he regarded a gaslight, for example, there was at the side and below the sharp image a second large, indistinct blur of light. It was found that'this second image could be sharpened in definition by a -, at the expense, however, of the first and best one. The ghost of the main object was far enough away, and vague enough to interfere but little with the appearance of the true light, and the patient soon became indifferent to its presence. I have not seen this perc
15 son for tllree years, buit I have recently been informed that he uses his correction with entire satisfaction. The etiology of this case is lnot less interesting tllan its correction with glasses. Case 3. D. Al. P., age forty-twvo: When a boy, he couild tell the time of the clock on a distant tower, and had perfect distant vision until sixteen years of age, when he wenit as clerk into a store, and for some montlhs read from badly printed books for hours late into the night, by a very poor light. His sight became imperfect, and his geineral health also becamle impaired. At twenty he was using the glasses which he wore when first examined by me: on the Rt. - 1 which gives for distanice V. 1=0 buit with which he is able to read at six incihes fromn tlle eye; on Lt.-, wllicji gives so little aid that lie uses the right 'for all purposes. The reflex from the cornea, very small at centre, and rapidly increasing in size at the periphery, the deep anterior chamber, anid the marked cone on lateral inspection left no doubt as to tlle diagnosis. This was confiriped by the play of light from the apex of the cone with the ophthalmoscope, and by fiinding, the inverted image of tlle retinial vessels visible about 1 inch in front of tlle cornea; he could read large print at three inches, and with - s. at 6 inches, which was then his far point; With paralyzed accommodation and dilated pupil, the most contradictory results were obtailned by stenopaic slits and circles. A circular opening of 1 min. for example, and - s. gave V. ° at the conical centre, but nowhere else. With my test of double perforations, and one covered with crimson glass, the double light point would indicate either myopic or hypermetropic refraction as the patient moved his head, nor was it possible to ascertain by this method, any more than the refraction of two peripheral points of a conical cornea. A stenopaic slit with spherical glasses was likewise unavaililin, since it included in its analysis peripheral and central corneal portions; and for the same reason the radiating, astigmatic lines of Greene only served to put the patient and the observer farther apart in their efforts to extract some truth fromn the conflicting experiences. The upright examination with ophthalmoscope gave the most
136 precise preliminary knowledge, and enabled the surgeon to at least form some definite idea of the refractioin; the apex of the cone demanded the highest concave glasses, whilst there were parts of the periphery of the cornea through which retinal vessels were seen with convex ones.; one fixed point after the other was thus obtained, the patient's poNver of definite stateineint being gradually cultivated until the following result was reached, giving hypermetropia and myopia combined, and affording in Right V. = x with + 1 cy., ax. 180°, ^ - cy., s., ax. 90°. With tlle Left, the far point was 21 inches, and a-2 s gave V. °; the appearances were the same as in the right, but there was greater distortion in light points and other test objects. With the ophtlhalmoscope in the upright method, I found when he wore his -- s, that the lhorizontal retinal vessels were seen above it, avoiding its use, with + i2, and throuigh it the vertical vessels were seen with + 4, and after wearisome examinations witlh the ophthalnioscope, and every otlher possible method, the best correction was obtained with the following remarkable combination: --Xi cyld., axis 90°Q + 1 cyld., axis 180' V. - 2 0. These glasses.were construieted and properly mouinted, and after the accoinmodation had returned, he had no insuifficiency, there was binoctular vision, he had an A 8, and could read with either eye 1 S at 12 inches flulentlv. Witlh eitlher eye there was a ghost of the object regarded, which was dimly seen soine distance below the real one. When he looked through his correction at a circle of lighlt one-half inch in diameter, at twenty feet distant, it was clearly perceived, buit beloow it there was seein a pear-shaped, hazy spectre of the same light, with its long axis perpendicular, and commencing, just below the true light, and seemiig to be six inches in. len-gth by two and one-half in. width. The double vision was tested also by a disc of blue paper for an object, which was sharply defined, and recognized at twenty feet, wllilst below it the patient observed a hazy, much larger, and ill--defined blue image of the disc. From tlle study of this case and the one previously related, it. would appear tllat by patienlt experimenitation it miglht be
137 possible to correct the greater portion of a misslhapen conical cornea, and to overpower by the brillianicy of its definition the remaining uncorrectable apex of the cone. This theorylhas been fairlv successftul in practice in these two instances.; anid either by the skilfli arrangemiient of his head, or by happy accident, each patient can receive the slharp imnag,es of objects, tllrough his glasses, on the maciula, whilst the hazy images from the small corneal apAex fall above it on a less sensitive portion of hlis retina. Dr. Norris, who saw case 3d after the correction, pointed ont to me that the axis of the cone was directed downiwards. I fouind that the double images, below the true ones, could be obliterated, arii vision a little imnproved, by lifting upwards, to the horizontal line in fronit of the eye, a screen, or other opaque body, thlus cutting off the light that would pass through the lower portio-n of the cornea. It is wortlhy of remark that in this last case, with such high degree of myopia, and the use for years of glasses so unsuited, there was Ilot the slightest appearance of a crescent at the optic disc, posterior staphyloma, or choroiditis in eitlher eye; and this could be definiitely ascertained, by observing the funIdus throtughli hiis correction, by either the erect or inverted metlhod of usin]g the ophthialmoscope. NOTE-Whilst revising the proofs of these histories, a fourth case has been treated, which will be briefly described. M. W., aged 35, in 1861 had a tumor removed from upper lid of left eye; and in 1869 she used. the eyes for hours at night, whilst nursing a sick relative, in reading and writing by a dim light. She now suffers from headache on the near use of the eyes for half an hour, which continues for hours afterwards. not improved by + There is Hy. of in right, with V. {. In left, V. = or - spherical glasses. With the accommodation paralyzed, the V. in left is reduced for distance, but she can read at 3", No. 2, Snellen, proving the existence of myopic refraction. By the ophthalmoscope aerial images of the retinal vessels are seen a short distance in front of a limited portion of the cornea, and by the erect image the refraction is there found myopic, whilst above this point convex glasses are needed to see vessels which pass from north-east to south-west; a careful examination with lines and letters gave proof of Hy. astigmatism and a + X cy., ax. at 100 gave V. = 20 With no glass a point of light is a streak, but with 1 cy. it becomes a point,
138 but there extends from it downwards a luminous haze, which at 20 feet is 6 inches long by 3 wide, pear-shaped and having a point of brightness at its lower extremity; this can be entirely cut off by placing a card over the lower half of the cornea. After the atropia had passed away, and the accommodation had returned, she could read No. 2 fluently at 12 inches with the cylinder, or at 3" without it, which she did by using, in the latter experiment, the conical part of the comea.
133 many weeks by a prolonged illness, and amused herself by reading in a dimly-lighted room. She founid when she reco-vered her health that her sight was imperfect. No change has since taken place, her eyes present no sign of disease, her distant sight is imperfect, but she can read at-nine inches by nipping her lids together inito a stenopaic slit, although the prolonged uise of her eyes in this way gives her severe headache; with either eye alone V.= 1 ; with botlh together V.= ; witl both she reads 3 Snellen at ten inches, but with either alone the far point is five inchec. No spherical, glasses materially assist, and this anomaly is accounted for after hours of examination, by the diagnosis of mixed astigmatism in eitlher eye, at such angles as to enable one eye to partially compensate for the defect in the other. In the R. E. she has hypermetropia for line at 300, and myopia for 1200, whilst in L. E. there is myopia for 300, and hypermetropia for 1200, so that she sees the two parts of a circle, or other object, in these angles best with both eyes togetlher, imperfectly with either alone, by the binocuilar fusion of the two indistinct images. She has a binocular far point of 10 iinches, and a monocular one of 5 inches, which also results from the degree of defect, which is hy. -1- combined witl mn. -1 in either eye, which enables her to read with both eyes at 10 inches with suppressed accommodation, but which develops an apparenlt myopia of * when she uses the accommodation to assist the hypermetropic meridian in eithier eye wlhen it is employed alone. The reflex of the window from the cornea was small in size at its centre in comparison with that from the periphery. With the ophthalmoscope in the upriglit method the refraction of -parts of the periphery of the corniea was hypermnetropic, whilst the centre was Inyopic; and whilst the astigmatism was of course readily perceived by this means, its degree was very difficult to determine. That there was slight conical cornea was shown by the difficulty in the use of all the usual means of diagnosis, including the stenopaic slit with test letters, tllc test lines of Greene, and my method with the two perforations in a screen combined with spherical and cylindrical glasses, and the use of the ophthalmoscope in the upright method. As the resuilt witlh
134
atropia, the following formula gave the-high.est acuity of vision: Rt. +-cy ax. 300 ^ cY ax. 1200. y ax. 300. Lt. +cy ax. 1200 ^ wllich increased V. from I ° to 1xvi0 . Case 2. M. P., age thirty-eight: seen first, December, 1870. Until eighteen years of age had perfect sight for distance, since he was a surveyor anld could see the signals at half a mile distant. He then changed his occupation for that of a conveyancer, and in addition to his daily duties attempted to study law, by a poor light at night, keeping himself awake by walking the floor with his book in his hand. His general health broke down, and he then found his distant sight very imperfect, but improved by concave glasses. Two years previously he had been examined and provided with a v sph. on .the Right, and -i s _ ey on Left, which gave but little satisfaction for distant vision, and is interesting as showing'the opinion of a clever surgeon. It was found that in the Left tllese glasses gave an induced hypermetropia = 1 , and a yet greater defect in the Right. Inspection, and the ophthalmoscope, revealed marked conical cornea, whilst the most patient efforts with test objects, spherical and cylindrical glasses, and stenopiic slits, with paralyzed accommodation, were needed to obtain a diagnosis. By the upright method it was found that the periphery of the cornea at soine parts was hypermetropic, whilst the centre was highly myopic; and after hours of effort the following result was obtained: Rt. + s. - lcy., axis 500, V. = -1 Lt. As._ey.,axis115, V.=20 -1 On the right this was a compromise, and was attended by a singular double vision, arising from the uncorrectable apex of the cone. When he regarded a gaslight, for example, there was at the side and below the sharp image a second large, indistinct blur of light. It was found that'this second image could be sharpened in definition by a -, at the expense, however, of the first and best one. The ghost of the main object was far enough away, and vague enough to interfere but little with the appearance of the true light, and the patient soon became indifferent to its presence. I have not seen this perc
15 son for tllree years, buit I have recently been informed that he uses his correction with entire satisfaction. The etiology of this case is lnot less interesting tllan its correction with glasses. Case 3. D. Al. P., age forty-twvo: When a boy, he couild tell the time of the clock on a distant tower, and had perfect distant vision until sixteen years of age, when he wenit as clerk into a store, and for some montlhs read from badly printed books for hours late into the night, by a very poor light. His sight became imperfect, and his geineral health also becamle impaired. At twenty he was using the glasses which he wore when first examined by me: on the Rt. - 1 which gives for distanice V. 1=0 buit with which he is able to read at six incihes fromn tlle eye; on Lt.-, wllicji gives so little aid that lie uses the right 'for all purposes. The reflex from the cornea, very small at centre, and rapidly increasing in size at the periphery, the deep anterior chamber, anid the marked cone on lateral inspection left no doubt as to tlle diagnosis. This was confiriped by the play of light from the apex of the cone with the ophthalmoscope, and by fiinding, the inverted image of tlle retinial vessels visible about 1 inch in front of tlle cornea; he could read large print at three inches, and with - s. at 6 inches, which was then his far point; With paralyzed accommodation and dilated pupil, the most contradictory results were obtailned by stenopaic slits and circles. A circular opening of 1 min. for example, and - s. gave V. ° at the conical centre, but nowhere else. With my test of double perforations, and one covered with crimson glass, the double light point would indicate either myopic or hypermetropic refraction as the patient moved his head, nor was it possible to ascertain by this method, any more than the refraction of two peripheral points of a conical cornea. A stenopaic slit with spherical glasses was likewise unavaililin, since it included in its analysis peripheral and central corneal portions; and for the same reason the radiating, astigmatic lines of Greene only served to put the patient and the observer farther apart in their efforts to extract some truth fromn the conflicting experiences. The upright examination with ophthalmoscope gave the most
136 precise preliminary knowledge, and enabled the surgeon to at least form some definite idea of the refractioin; the apex of the cone demanded the highest concave glasses, whilst there were parts of the periphery of the cornea through which retinal vessels were seen with convex ones.; one fixed point after the other was thus obtained, the patient's poNver of definite stateineint being gradually cultivated until the following result was reached, giving hypermetropia and myopia combined, and affording in Right V. = x with + 1 cy., ax. 180°, ^ - cy., s., ax. 90°. With tlle Left, the far point was 21 inches, and a-2 s gave V. °; the appearances were the same as in the right, but there was greater distortion in light points and other test objects. With the ophtlhalmoscope in the upright method, I found when he wore his -- s, that the lhorizontal retinal vessels were seen above it, avoiding its use, with + i2, and throuigh it the vertical vessels were seen with + 4, and after wearisome examinations witlh the ophthalnioscope, and every otlher possible method, the best correction was obtained with the following remarkable combination: --Xi cyld., axis 90°Q + 1 cyld., axis 180' V. - 2 0. These glasses.were construieted and properly mouinted, and after the accoinmodation had returned, he had no insuifficiency, there was binoctular vision, he had an A 8, and could read with either eye 1 S at 12 inches flulentlv. Witlh eitlher eye there was a ghost of the object regarded, which was dimly seen soine distance below the real one. When he looked through his correction at a circle of lighlt one-half inch in diameter, at twenty feet distant, it was clearly perceived, buit beloow it there was seein a pear-shaped, hazy spectre of the same light, with its long axis perpendicular, and commencing, just below the true light, and seemiig to be six inches in. len-gth by two and one-half in. width. The double vision was tested also by a disc of blue paper for an object, which was sharply defined, and recognized at twenty feet, wllilst below it the patient observed a hazy, much larger, and ill--defined blue image of the disc. From tlle study of this case and the one previously related, it. would appear tllat by patienlt experimenitation it miglht be
137 possible to correct the greater portion of a misslhapen conical cornea, and to overpower by the brillianicy of its definition the remaining uncorrectable apex of the cone. This theorylhas been fairlv successftul in practice in these two instances.; anid either by the skilfli arrangemiient of his head, or by happy accident, each patient can receive the slharp imnag,es of objects, tllrough his glasses, on the maciula, whilst the hazy images from the small corneal apAex fall above it on a less sensitive portion of hlis retina. Dr. Norris, who saw case 3d after the correction, pointed ont to me that the axis of the cone was directed downiwards. I fouind that the double images, below the true ones, could be obliterated, arii vision a little imnproved, by lifting upwards, to the horizontal line in fronit of the eye, a screen, or other opaque body, thlus cutting off the light that would pass through the lower portio-n of the cornea. It is wortlhy of remark that in this last case, with such high degree of myopia, and the use for years of glasses so unsuited, there was Ilot the slightest appearance of a crescent at the optic disc, posterior staphyloma, or choroiditis in eitlher eye; and this could be definiitely ascertained, by observing the funIdus throtughli hiis correction, by either the erect or inverted metlhod of usin]g the ophthialmoscope. NOTE-Whilst revising the proofs of these histories, a fourth case has been treated, which will be briefly described. M. W., aged 35, in 1861 had a tumor removed from upper lid of left eye; and in 1869 she used. the eyes for hours at night, whilst nursing a sick relative, in reading and writing by a dim light. She now suffers from headache on the near use of the eyes for half an hour, which continues for hours afterwards. not improved by + There is Hy. of in right, with V. {. In left, V. = or - spherical glasses. With the accommodation paralyzed, the V. in left is reduced for distance, but she can read at 3", No. 2, Snellen, proving the existence of myopic refraction. By the ophthalmoscope aerial images of the retinal vessels are seen a short distance in front of a limited portion of the cornea, and by the erect image the refraction is there found myopic, whilst above this point convex glasses are needed to see vessels which pass from north-east to south-west; a careful examination with lines and letters gave proof of Hy. astigmatism and a + X cy., ax. at 100 gave V. = 20 With no glass a point of light is a streak, but with 1 cy. it becomes a point,
138 but there extends from it downwards a luminous haze, which at 20 feet is 6 inches long by 3 wide, pear-shaped and having a point of brightness at its lower extremity; this can be entirely cut off by placing a card over the lower half of the cornea. After the atropia had passed away, and the accommodation had returned, she could read No. 2 fluently at 12 inches with the cylinder, or at 3" without it, which she did by using, in the latter experiment, the conical part of the comea.
