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Leber's congenital amaurosis
986
AMERICAN JOURNAL OF OPHTHALMOLOGY
My observations began with the solar spectrum ex hibited in a dark room by a glass prism. Persons in general distinguish six colors, namely red, orange, yellow, green, blue and purple. I see only two dis tinctions. That part of the image which others call red appears to me little more than a shade of light; the orange, yellow and green seem one color which descends uniformly from an intense to a rare yellow. The difference between the green and blue is very striking to my eye. Purple appears blue much dark ened. It appeared possible that a number of individuals might be found whose vision agreed with my own. The family at Mayport consisted of six sons and one daughter; four of the sons were in the predica ment in question. One family consisted of three sons and one daughter, of whom two sons are circum stanced as I have described. Our vision, except as to colors, is as clear and distinct as that of other per sons. It is remarkable that I have not heard of one female subject to this peculiarity.
In 1822, Dalton was elected Fellow of the Royal Society and, in 1830, the French Academy of Sciences honored him to suc ceed Davy as foreign associate. At the age of 68 years, the self-educated Quaker was awarded an honorary LL.D. from the Uni versity of Edinburgh and in homage to his grandeur a splendid bust of Dalton domi nates the entrance hall of the Manchester Royal Institution. Though color-blindness was reported pre viously by Huddard in a letter to Joseph Priestley (1777) and by Lort (1778), Dalton's detailed account of his own experi ence instigated a permanent lively interest in the subject. The term, Daltonism, is still used by the French. In 1854, Wilson sug gested that the color-blind are unfit to be come painters, dyers, tailors, chemists, bot anists, geologists, seamen or railroad em ployees. Following a serious railway acci dent, Holmgren advised that only persons with normal color vision should be employed in the Swedish railroad service (1876), a procedure adopted since throughout the world. In 1878, Horner, Swiss ophthal mologist, noted that Daltonism is inherited by sons of daughters whose father was color-blind. Partially defective color percep tion, anomalous trichromatism, was dis covered and quantitatively measured by Lord Rayleigh (1882). Anomalous trichro-
NOVEMBER, 1966
mats may be unusually adept in interpreting differences of brightness. One such patient of mine, studying dentistry, was cited for the best matching of artificial teeth; another, in architecture, aware of his deficiency, when required to present a sketch in color, sub mitted a design in various shades of green and won special commendation for origi nality. James E. Lebensohn
CORRESPONDENCE LEBER'S CONGENITAL AMAUROSIS
Editor, American Journal of Ophthalmology: I read with interest "Congenital amauros is of Leber," by Frederick D. Gillespie, M.D., in the May edition of T H E JOURNAL
(Am. J. Ophth. 61:874, 1966). In describing the retinal histology, Dr. Gillespie stated that "the retina showed ab solutely no percipient elements" and that in the posterior pole the percipient elements (rods and cones) were replaced by a single layer of cuboidal cells. I wish to point out that electron mi croscopy of Leber's amaurosis1 has demon strated that the single layer of cells in the posterior pole, referred to by Dr. Gillespie, consists of remnants of photoreceptors, most probably cones, and that these are not new cells replacing the vanished photorecep tors. The evidence for this is ample: the cells synapse in the external plexiform layer, their cell membranes contribute to the terminal bar formation of the external lim iting membrane, and they contain a typical photoreceptor connecting cilium. The cells, however, are strikingly abnor mal in that they lack an outer segment and that the inner segment is markedly short ened. Dr. Gillespie's Figure 9 nicely shows the cone inner segments projecting through the external limiting membrane toward the pigment epithelium, and the lack of cone outer segments.
VOL. 62, NO. 5
CORRESPONDENCE
It is indeed remarkable that, 35 years ago, Dr. Verhoeff, in describing the histology of retinitis pigmentosa2 (a microscopically similar abiotrophy), spoke of this single layer of cells as remnants of cones. Arnold J. Kroll Miami, Florida REFERENCES
1. Kroll, A. J., and Kuwabara, T.: Electron microscopy of a retinal abiotrophy. Arch. Ophth. 71:683,1964. 2. Verhoeff, F. H.: Microscopic observations in a case of retinitis pigmentosa. Arch. Ophth. 5 :392, 1931.
987
in itself to be absolutely significant. An im portant omission in the statistics presented in this paper was the final visual acuity. This might well have reflected on the nature of the binocularity. This letter is not primarily a criticism, but is written with the hope that it may stimulate those who have or are able to ac cumulate statistics on a similar group of pa tients in the age group three to five years. M. S. Osher Cincinnati, Ohio *
*
*
DR. ING'S REPLY
SURGERY FOR CONGENITAL ESOTROPIA
Editor, American Journal of Ophthalmology: The article "Surgery for congenital eso tropia," by Ing, Costenbader, Parks and Al bert (Am. J. of Ophth. 61:1419, June, 1966) might seriously mislead ophthal mologists into doing strabismus surgery at the age of six to 18 months with a resulting increase in anesthetic deaths. The fusion, referred to in the article, is not foveal fu sion or binocular single vision in the ordi nary sense but merely peripheral fusion which may be obtained regardless of age when the surgical result is good. One can hardly deny that there will be more anes thetic accidents in the six to 24-month age group than in the three to five-year age group. The article might well be used as an excuse by eager young surgeons to operate at a dangerous age without the help of an accurate preoperative evaluation. A fair analysis concerning the value of surgery at an early age cannot be obtained unless one gives similar statistics on an older age group, for example between three to five years of age. Evidence that 16 pa tients in the age group of six to 18 months obtained binocular peripheral fusion as com pared with seven who did not is not enough
Editor, American Journal of Ophthalmology: As I recall, (1) we did not make any claim for any kind of fusion other than "pe ripheral" and, indeed, that was one of the major findings. (2) I am unaware of any study showing more anesthetic deaths in elective surgery in the six to 24-month age group vs the three to five-year group, al though such a study may have been made. (3) We shared a hope that a similar study would be done in the three to five-year age group and I am not sure "merely peripheral fusion (can be) obtained regardless of age when the surgical result is good." In fact, my impression is that a functional result usually does not result when the child is in the older age group. (4) The statement "that 16 patients in the age group of six to 18 months obtained binocular peripheral fu sion as compared with seven who did not is not enough in itself to be absolutely significant," does not appear to be applicable to our statistics. (5) The final visual acuity would perhaps be nice-to-know information but not essential to the study as I recall. When, finally, my papers catch up with me, I can probably find this out. Malcolm Ing Tripler General Hospital, Honolulu *
=k
♦
AMERICAN JOURNAL OF OPHTHALMOLOGY
My observations began with the solar spectrum ex hibited in a dark room by a glass prism. Persons in general distinguish six colors, namely red, orange, yellow, green, blue and purple. I see only two dis tinctions. That part of the image which others call red appears to me little more than a shade of light; the orange, yellow and green seem one color which descends uniformly from an intense to a rare yellow. The difference between the green and blue is very striking to my eye. Purple appears blue much dark ened. It appeared possible that a number of individuals might be found whose vision agreed with my own. The family at Mayport consisted of six sons and one daughter; four of the sons were in the predica ment in question. One family consisted of three sons and one daughter, of whom two sons are circum stanced as I have described. Our vision, except as to colors, is as clear and distinct as that of other per sons. It is remarkable that I have not heard of one female subject to this peculiarity.
In 1822, Dalton was elected Fellow of the Royal Society and, in 1830, the French Academy of Sciences honored him to suc ceed Davy as foreign associate. At the age of 68 years, the self-educated Quaker was awarded an honorary LL.D. from the Uni versity of Edinburgh and in homage to his grandeur a splendid bust of Dalton domi nates the entrance hall of the Manchester Royal Institution. Though color-blindness was reported pre viously by Huddard in a letter to Joseph Priestley (1777) and by Lort (1778), Dalton's detailed account of his own experi ence instigated a permanent lively interest in the subject. The term, Daltonism, is still used by the French. In 1854, Wilson sug gested that the color-blind are unfit to be come painters, dyers, tailors, chemists, bot anists, geologists, seamen or railroad em ployees. Following a serious railway acci dent, Holmgren advised that only persons with normal color vision should be employed in the Swedish railroad service (1876), a procedure adopted since throughout the world. In 1878, Horner, Swiss ophthal mologist, noted that Daltonism is inherited by sons of daughters whose father was color-blind. Partially defective color percep tion, anomalous trichromatism, was dis covered and quantitatively measured by Lord Rayleigh (1882). Anomalous trichro-
NOVEMBER, 1966
mats may be unusually adept in interpreting differences of brightness. One such patient of mine, studying dentistry, was cited for the best matching of artificial teeth; another, in architecture, aware of his deficiency, when required to present a sketch in color, sub mitted a design in various shades of green and won special commendation for origi nality. James E. Lebensohn
CORRESPONDENCE LEBER'S CONGENITAL AMAUROSIS
Editor, American Journal of Ophthalmology: I read with interest "Congenital amauros is of Leber," by Frederick D. Gillespie, M.D., in the May edition of T H E JOURNAL
(Am. J. Ophth. 61:874, 1966). In describing the retinal histology, Dr. Gillespie stated that "the retina showed ab solutely no percipient elements" and that in the posterior pole the percipient elements (rods and cones) were replaced by a single layer of cuboidal cells. I wish to point out that electron mi croscopy of Leber's amaurosis1 has demon strated that the single layer of cells in the posterior pole, referred to by Dr. Gillespie, consists of remnants of photoreceptors, most probably cones, and that these are not new cells replacing the vanished photorecep tors. The evidence for this is ample: the cells synapse in the external plexiform layer, their cell membranes contribute to the terminal bar formation of the external lim iting membrane, and they contain a typical photoreceptor connecting cilium. The cells, however, are strikingly abnor mal in that they lack an outer segment and that the inner segment is markedly short ened. Dr. Gillespie's Figure 9 nicely shows the cone inner segments projecting through the external limiting membrane toward the pigment epithelium, and the lack of cone outer segments.
VOL. 62, NO. 5
CORRESPONDENCE
It is indeed remarkable that, 35 years ago, Dr. Verhoeff, in describing the histology of retinitis pigmentosa2 (a microscopically similar abiotrophy), spoke of this single layer of cells as remnants of cones. Arnold J. Kroll Miami, Florida REFERENCES
1. Kroll, A. J., and Kuwabara, T.: Electron microscopy of a retinal abiotrophy. Arch. Ophth. 71:683,1964. 2. Verhoeff, F. H.: Microscopic observations in a case of retinitis pigmentosa. Arch. Ophth. 5 :392, 1931.
987
in itself to be absolutely significant. An im portant omission in the statistics presented in this paper was the final visual acuity. This might well have reflected on the nature of the binocularity. This letter is not primarily a criticism, but is written with the hope that it may stimulate those who have or are able to ac cumulate statistics on a similar group of pa tients in the age group three to five years. M. S. Osher Cincinnati, Ohio *
*
*
DR. ING'S REPLY
SURGERY FOR CONGENITAL ESOTROPIA
Editor, American Journal of Ophthalmology: The article "Surgery for congenital eso tropia," by Ing, Costenbader, Parks and Al bert (Am. J. of Ophth. 61:1419, June, 1966) might seriously mislead ophthal mologists into doing strabismus surgery at the age of six to 18 months with a resulting increase in anesthetic deaths. The fusion, referred to in the article, is not foveal fu sion or binocular single vision in the ordi nary sense but merely peripheral fusion which may be obtained regardless of age when the surgical result is good. One can hardly deny that there will be more anes thetic accidents in the six to 24-month age group than in the three to five-year age group. The article might well be used as an excuse by eager young surgeons to operate at a dangerous age without the help of an accurate preoperative evaluation. A fair analysis concerning the value of surgery at an early age cannot be obtained unless one gives similar statistics on an older age group, for example between three to five years of age. Evidence that 16 pa tients in the age group of six to 18 months obtained binocular peripheral fusion as com pared with seven who did not is not enough
Editor, American Journal of Ophthalmology: As I recall, (1) we did not make any claim for any kind of fusion other than "pe ripheral" and, indeed, that was one of the major findings. (2) I am unaware of any study showing more anesthetic deaths in elective surgery in the six to 24-month age group vs the three to five-year group, al though such a study may have been made. (3) We shared a hope that a similar study would be done in the three to five-year age group and I am not sure "merely peripheral fusion (can be) obtained regardless of age when the surgical result is good." In fact, my impression is that a functional result usually does not result when the child is in the older age group. (4) The statement "that 16 patients in the age group of six to 18 months obtained binocular peripheral fu sion as compared with seven who did not is not enough in itself to be absolutely significant," does not appear to be applicable to our statistics. (5) The final visual acuity would perhaps be nice-to-know information but not essential to the study as I recall. When, finally, my papers catch up with me, I can probably find this out. Malcolm Ing Tripler General Hospital, Honolulu *
=k
♦