PHOTOCOAGULATION IN T H E DIAGNOSIS O F S E N I L E RETINOSCHISIS M A U R I C E B. L A N D E R S III, M.D.,
AND C H A R L E S H. R O B I N S O N ,
M.D.
Durham, North Carolina
Senile retinoschisis is a common and generally benign condition characterized by a localized splitting of the sensory layers of the retina, usually in the outer plexiform layer. 1 Byer 2 studied 1,500 con secutive patients, 10 years of age and older, and found an overall incidence of 3.7% for the total group and 7% for the group 40 years of age and older. He pointed out that few patients had reti noschisis leading to retinal detachment. Nevertheless, senile retinoschisis can mimic a retinal detachment and initiate rhegmatogenous retinal detachment in certain cases. The differential diagnosis between retinoschisis and atrophic retinal detachments usually can be made on the basis of the clinical examination. For those cases in which senile retinoschisis and retinal detachment cannot be differ entiated by clinical examination, photocoagulation has been proposed as a de finitive test. Duke-Elder and Dobree 3 stated:
"Photocoagulation of schisis unlike a ret inal detachment will produce a white area of retinal reaction because there is a por tion of the retina in contact with the heated pigment epithelium." Hagler and Woldoff6 stated: In instances where the diagnosis of retinos chisis cannot be made from ophthalmoscopy or visual field examination alone, xenon arc or laser coagulation can be used to absolutely determine the presence or absence of retinoschisis. If reti noschisis without detachment is present, a white coagulation burn will be produced in the external layer; whereas if the elevation represented a fullthickness retinal detachment, such a burn will not occur.
The purposes of this study are to point out: (1) that a photocoagulation procedure does not invariably differentiate between senile retinoschisis and a retinal detach ment; (2) that the white reaction to photo coagulation in areas of senile retinos chisis also can be seen in certain cases of rhegmatogenous retinal detachment; and (3) that the white reaction to photocoagu lation can be produced when the photoreceptor layer is not in contact with the retinal pigment epithelium.
It is interesting that on photocoagulation of a detached retina the detached portion shows no blanching effect, but in a schisis, while the inner layer of the retina is similarly immune, the outer layer becomes blanched and easily visible.
S U B J E C T S AND M E T H O D S
We treated seven patients with the argon laser (Coherent Radiation Model 800). In five patients, photocoagulation lesions were made around symptomatic retinal breaks. Additional lesions were made in the center of the breaks directly on the exposed pigment epithelium. In a sixth patient, photocoagulation lesions were placed through an area of atrophic detached retina on the bare pigment epi thelium. In a seventh patient, photocoag ulation lesions were placed in the center of a large outer wall hole in an area of senile retinoschisis, directly on the bare pigment epithelium.
Okun and Cibis 4 stated: If still in doubt after ophthalmoscopic exami nation, it is our practice to place a photocoagu lation lesion within the area of suspected schisis. If a "take" occurs deep to the transpar ent blood vessel layer, the diagnosis of schisis is confirmed.
Ballentyne
and
Michelson 5
stated:
From the Duke Eye Center, Duke University Medical Center, Durham, North Carolina. This study was supported in part by an unrestricted grant from Research to PreventBlindness, Inc., New York, and Public Health Service training grant EY 0002616. Reprint requests to Maurice B. Landers III, M.D., Box 3802, Duke Eye Center, Durham, NC 27710. 18
VOL. 84, NO. 1
PHOTOCOAGULATION IN SENILE RETINOSCHISIS
19
CASE REPORTS Case 1—A 50-year-old myopic white man com plained of flashing lights in his left eye. Indirect ophthalmoscopie examination revealed a retinal break in the left upper nasal quadrant associated with an elevated retinal flap (Fig. 1). We placed 54 argon laser photocoagulation lesions around the retinal break in the full-thickness retina with laser settings of 0.2 seconds, 500-n. spot size, and 115 mW power. We placed 4 photocoagulation exposures in the center of the retinal break directly on the bare pigment epithelium. A white lesion was produced in the center of the retinal break at the same intensity as was required to burn the surrounding flat retina. Case 2—A 14-year-old white girl had been struck in the left eye with a baseball. On indirect ophthalmoscopy, we noted an inferotemporal dialysis ex tending from 3 to 6 o'clock at the ora serrata. A retinal detachment extended to the macula (Fig. 2, top). The retina was reattached with a scleral buck ling procedure. Two days after surgery, additional argon laser lesions were placed in the area of the flat retina immediately behind the buckle (Fig. 2, bot tom). We placed 117 photocoagulation lesions in the full-thickness retina widi laser settings of 0.2 sec onds and 500-(i spot size. A power of 103 mW was required to produce a white lesion in the fullthickness retina. We placed 15 photocoagulation lesions on the bare pigment epithelium through the open mouth of the dialysis. With laser settings of 0.2 seconds and 500-|A spot size, we needed 105 mW of power to produce white photocoagulation lesions on the bare pigment epithelium similar to the lesions in the full-thickness retina.
Fig. 2 (Landers and Robinson). Case 2, left eye. Top, An inferior temporal dialysis. Bottom, Argon laser photocoagulation lesions placed on flat at tached retina and through the open mouth of the dialysis on the bare pigment epithelium.
Fig. 1 (Landers and Robinson). Case 1, left eye. Argon laser lesions surround a retinal break and were placed in the center of the break on the bare pigment epithelium.
Case 3—A 54-year-old white woman complained of floaters in her right eye. Indirect ophthalmoscopie examination revealed a retinal break in the upper temporal quadrant. An operculum floated in the vitreous cavity over the break. We placed 61 argon laser photocoagulation lesions around the retinal break with laser settings of 0.2 seconds and 500-p. spot size. Five lesions were made through the retinal hole directly on the retinal pigment epithelium (Fig. 3). White lesions were produced in the fullthickness retina at 144 mW, while lesions in the
20
AMERICAN JOURNAL OF OPHTHALMOLOGY
Fig. 3 (Landers and Robinson). Case 3, right eye. Argon laser lesions surround a retinal break and were placed through the retinal hole directly on the retinal pigment epithelium. center of the retinal break on the pigment epithe lium required 156 mW. The lesions in the center of the retinal break were not as intense as those in the full-thickness retina. Case 4—A 67-year-old white man complained of decreased vision and floaters in his right eye. Indi rect ophthalmoscopic examination revealed a retinal tear in the superonasal quadrant. We placed 108 argon laser photocoagulation lesions with laser set tings of 0.2 seconds and 500-|x spot size in the full-thickness retina around the retinal tear and eight lesions of the same duration and spot size were placed in the center of the retina (Fig. 4). A white lesion was produced in the full-thickness retina at 50 mW. We produced a similar lesion at 50 mW on the pigment epithelium in the center of the tear. Case 5—A 75-year-old white man with a history of vitreous hemorrhage of six months' duration in his right eye had floaters and flashes in his left eye. Indirect ophthalmoscopic examination revealed a retinal flap tear in the superotemporal quadrant of the left eye. We placed 193 argon laser photocoagu lation lesions with laser settings of 0.2 seconds and a 200- to 500-u, spot size around the retinal tear in the full-thickness retina; ten exposures were made with in the tear directly on the pigment epithelium (Fig. 5). By using the 200-ji spot size and 81 mW, we produced a white lesion in the full-thickness retina; 88 mW produced similar lesions within the center of the retinal break. Case 6—A 53-year-old white man with visual acuity of 6/6 (20/20) was referred here with a diag nosis of senile retinoschisis and associated retinal detachment. Indirect ophthalmoscopic examination revealed an area of senile retinoschisis in the super otemporal quadrant with a large outer wall hole and
JULY, 1977
Fig. 4 (Landers and Robinson). Case 4, right eye. Argon laser lesions surround a retinal break in the full-thickness retina and were placed in the center of the break on the retinal pigment epithelium. an area of retinal detachment confined to the area of retinoschisis. First, we placed ten argon laser lesions only in the area of senile retinoschisis (at 95 mW with a 200-u, spot size for 0.2 seconds ) producing a white lesion in this region. Then, we placed ten laser lesion in the center of the outer wall hole through the layers of the inner retina. These lesions were made directly on the bare pigment epithelium (Fig.
Fig. 5 (Landers and Robinson). Case 5, left eye. Argon laser lesions surround a retinal break and were placed on the bare pigment epithelium in the center of the retinal break.
VOL. 84, NO. 1
PHOTOCOAGULATION IN SENILE RETINOSCHISIS
21
differentiation between senile retinos chisis and rhegmatogenous retinal de tachment. In cases of central serous chorioretinopathy, when the retina is separated from the retinal pigment epithelium by a layer of serous fluid, according to Gass,7 white reactions to photocoagulation can be produced in the retinal pigment epi thelium alone with both the xenon arc and the argon laser. Thus, the outer layers of the retina need not be immediately adjacent to the pigment epithelium to produce a white reaction to photocoagu lation.1 Although we treated our patients exclu sively with the argon laser, it seems likely Fig. 6 (Landers and Robinson). Case 6, right eye. that a xenon arc photocoagulator might Senile retinoschisis is associated with retinal de have produced the same results. The tachment beneath the schisis. Argon laser lesions xenon arc photocoagulator produces some were placed in the area of schisis and also through the schisis into the center of the outer wall hole on of its energy at longer wavelengths than the bare pigment epithelium. the argon laser photocoagulator, even ex tending into the infrared region. Never theless, both photocoagulators produce 6) (for 0.2 seconds with a 200-u. spot size at 103 mW) their effects by generating heat at the level producing a white retinal lesion similar to that seen of the absorbing pigment epithelium. in the area of retinoschisis. Case 7—A 32-year-old white man had a retinal Bresnick and associates8 have shown that detachment of three years' duration in his left eye argon laser radiation in rhesus monkeys is that occurred shortly after blunt trauma. Reattachment surgery attempted shortly after the original absorbed primarily by the retinal pigment injury failed. The patient had a refractive error of epithelium, and that damage to the sen R.E.: -7.00 -1.00 x 175, and L.E.: -7.50 -1.25 x sory layers of the retina is not seen in the 165. Indirect ophthalmoscopy and contact lens ex amination revealed a complete retinal detachment in absence of pathologic changes in the pig the left eye with an area of diathermy scarring in the ment epithelium. Rosan and associates9 superotemporal quadrant and a small retinal break have shown that pigment epithelial dam immediately posterior to this area. With the patient's permission, we placed argon laser lesions in an area age in rhesus monkeys is the primary temporal to the macula between the macula and the response to argon laser exposure. In both area of diathermy scarring. A cross-shaped area was humans and rhesus monkeys, argon laser made with argon laser lesions (for 0.2 seconds with a 200-u. spot size at 75 mW) with 25 exposures in each photocoagulation produces a lesion at the arm of the cross (Fig. 7, top). A white lesion was level of the pigment epithelium at dis immediately visible at the level of the retinal pig ment epithelium (Fig. 7, center). We performed tances greater than two degrees from the retinal reattachment surgery the next day. We placed center of the fovea. Only within two de a silicone sponge behind the area of previous dia grees of the center of the fovea is there thermy, and flattened the retina uneventfully. Three months later the area of argon laser photocoagula significant absorption of the argon laser tion looked like an old photocoagulation scar (Fig. 7, wavelengths in the human and monkey bottom). retinas. 10,11 Because the argon laser has smaller DISCUSSION spot sizes and potentially higher energy Based on this series of cases, photoco densities than the xenon arc laser, it may agulation is not a definitive test for the produce white lesions through detached
22
AMERICAN JOURNAL OF OPHTHALMOLOGY
JULY, 1977
retinas and subretinal fluid that are suffi ciently opaque to prevent the xenon arc photocoagulator from producing a lesion. The presence or absence of a lesion after photocoagulation in cases of rhegmatogenous retinal detachment depends pri marily on the transparency of the retina adjacent to the retinal pigment epithe lium. Thus, photocoagulation, although helpful in the differentiation between se nile retinoschisis and rhegmatogenous retinal detachment, is not a definitive test and must be evaluated with other clinical findings. SUMMARY
In five of seven patients treated with argon laser photocoagulation, lesions were placed around retinal breaks and in the center of the breaks directly on ex posed pigment epithelium. In a sixth pa tient, the lesions were placed through an area of atrophic detached retina on the bare pigment epithelium. In the last pa tient, the lesions were placed in the center of a large outer wall hole in an area of senile retinoschisis directly on bare pig ment epithelium. The white reaction to photocoagulation, previously thought to differentiate between retinoschisis and retinal detachment, was produced in the eye with a rhegmatogenous retinal de tachment. The white reaction also was produced in the center of retinal breaks where the photoreceptor layer was not in contact with the retinal pigment epithe lium. Photocoagulation was not a defini tive test, and must be evaluated with other clinical findings.
Fig. 7 (Landers and Robinson). Case 7, left eye. Top, Chronic retinal detachment. Argon laser le sions placed through the detached retina onto the pigment epithelium. Center, Appearance of the photocoagulation area immediately after laser le sions were placed through the detached retina on the pigment epithelium, Bottom, Appearance of photo coagulation area three months later.
VOL. 84, NO. 1
PHOTOCOAGULATION IN SENILE RETINOSCHISIS
REFERENCES 1. Zimmerman, L. E., and Spencer, W. H.: The pathologic anatomy of retinoschisis. Arch. Ophthal mol. 63:10, 1960. 2. Byer, N.E.: Clinical study of senile retinos chisis. Arch. Ophthalmol. 79:36, 1968. 3. Duke-Elder, S., and Dobree, J. H.: Diseases of the Retina. In Duke-Elder, S. (ed.): System of Oph thalmology, vol. 10. St. Louis, C. V. Mosby, 1967, p. 564. 4. Okun, E., and Cibis, P. A.: The role of photocoagulation in the management of retirioschisis. Arch. Ophthalmol. 72:309, 1964. 5. Ballentyne, A., and Michelson, I.: Textbook of the Fundus of the Eye, 2nd ed. Baltimore, Williams and Wilkins, 1970, p. 391. 6. Hagler, W. S., and Woldoff, H. S.: Retinal detachment in relation to senile retinoschisis.
23
Trans. Am. Acad. Ophthalmol. Otolaryngol. 77:104, 1973. 7. Gass, J. D. M.: Stereoscopic Atlas of Macular Diseases. St. Louis, C. V. Mosby, 1970, p. 21. 8. Bresnick, G. H., Frisch, G. D., Powell, J. O., Landers, M. B., Hoist, G. C , and Dallas, A. G.: Ocular effects of argon laser radiation. Invest. Oph thalmol. 9:909, 1970. 9. Rosan, R. C , Flocks, M., Vassiliadis, A., Rose, H. W., Peabody, R. R., and Hammond, A.: Pathology of monkey retina following irradiation with an argon laser. Arch. Ophthalmol. 81:87, 1969. 10. Marshall, J., Hamilton, A. M., and Byrd, A. C : Histopathology of ruby and argon laser lesions in monkey and human retina. Br. J. Ophthalmol. 59: 611,1975. 11. Landers, M. B., Wolbarsht, M. L., and Shaw, H. E.: Current status of laser usage in ophthalmolo gy. Ann. N. Y. Acad. Sci. 67:236, 1976.
OPHTHALMIC MINIATURE
Skew sight, or sight askew, is a condition of our vision only accurate when the object is placed obliquely, in consequence of some partial obfuscation of the cornea, frequently from slight scars, scarcely, if at all, observable. In this lateral vision the axis of the eye affected usually coincides with that of the sound eye. In squinting, on the contrary, the two axes do not coincide. J. G. Millingen, Curiosities of Medical Experience London, Richard Bentley, 1839
AND C H A R L E S H. R O B I N S O N ,
M.D.
Durham, North Carolina
Senile retinoschisis is a common and generally benign condition characterized by a localized splitting of the sensory layers of the retina, usually in the outer plexiform layer. 1 Byer 2 studied 1,500 con secutive patients, 10 years of age and older, and found an overall incidence of 3.7% for the total group and 7% for the group 40 years of age and older. He pointed out that few patients had reti noschisis leading to retinal detachment. Nevertheless, senile retinoschisis can mimic a retinal detachment and initiate rhegmatogenous retinal detachment in certain cases. The differential diagnosis between retinoschisis and atrophic retinal detachments usually can be made on the basis of the clinical examination. For those cases in which senile retinoschisis and retinal detachment cannot be differ entiated by clinical examination, photocoagulation has been proposed as a de finitive test. Duke-Elder and Dobree 3 stated:
"Photocoagulation of schisis unlike a ret inal detachment will produce a white area of retinal reaction because there is a por tion of the retina in contact with the heated pigment epithelium." Hagler and Woldoff6 stated: In instances where the diagnosis of retinos chisis cannot be made from ophthalmoscopy or visual field examination alone, xenon arc or laser coagulation can be used to absolutely determine the presence or absence of retinoschisis. If reti noschisis without detachment is present, a white coagulation burn will be produced in the external layer; whereas if the elevation represented a fullthickness retinal detachment, such a burn will not occur.
The purposes of this study are to point out: (1) that a photocoagulation procedure does not invariably differentiate between senile retinoschisis and a retinal detach ment; (2) that the white reaction to photo coagulation in areas of senile retinos chisis also can be seen in certain cases of rhegmatogenous retinal detachment; and (3) that the white reaction to photocoagu lation can be produced when the photoreceptor layer is not in contact with the retinal pigment epithelium.
It is interesting that on photocoagulation of a detached retina the detached portion shows no blanching effect, but in a schisis, while the inner layer of the retina is similarly immune, the outer layer becomes blanched and easily visible.
S U B J E C T S AND M E T H O D S
We treated seven patients with the argon laser (Coherent Radiation Model 800). In five patients, photocoagulation lesions were made around symptomatic retinal breaks. Additional lesions were made in the center of the breaks directly on the exposed pigment epithelium. In a sixth patient, photocoagulation lesions were placed through an area of atrophic detached retina on the bare pigment epi thelium. In a seventh patient, photocoag ulation lesions were placed in the center of a large outer wall hole in an area of senile retinoschisis, directly on the bare pigment epithelium.
Okun and Cibis 4 stated: If still in doubt after ophthalmoscopic exami nation, it is our practice to place a photocoagu lation lesion within the area of suspected schisis. If a "take" occurs deep to the transpar ent blood vessel layer, the diagnosis of schisis is confirmed.
Ballentyne
and
Michelson 5
stated:
From the Duke Eye Center, Duke University Medical Center, Durham, North Carolina. This study was supported in part by an unrestricted grant from Research to PreventBlindness, Inc., New York, and Public Health Service training grant EY 0002616. Reprint requests to Maurice B. Landers III, M.D., Box 3802, Duke Eye Center, Durham, NC 27710. 18
VOL. 84, NO. 1
PHOTOCOAGULATION IN SENILE RETINOSCHISIS
19
CASE REPORTS Case 1—A 50-year-old myopic white man com plained of flashing lights in his left eye. Indirect ophthalmoscopie examination revealed a retinal break in the left upper nasal quadrant associated with an elevated retinal flap (Fig. 1). We placed 54 argon laser photocoagulation lesions around the retinal break in the full-thickness retina with laser settings of 0.2 seconds, 500-n. spot size, and 115 mW power. We placed 4 photocoagulation exposures in the center of the retinal break directly on the bare pigment epithelium. A white lesion was produced in the center of the retinal break at the same intensity as was required to burn the surrounding flat retina. Case 2—A 14-year-old white girl had been struck in the left eye with a baseball. On indirect ophthalmoscopy, we noted an inferotemporal dialysis ex tending from 3 to 6 o'clock at the ora serrata. A retinal detachment extended to the macula (Fig. 2, top). The retina was reattached with a scleral buck ling procedure. Two days after surgery, additional argon laser lesions were placed in the area of the flat retina immediately behind the buckle (Fig. 2, bot tom). We placed 117 photocoagulation lesions in the full-thickness retina widi laser settings of 0.2 sec onds and 500-(i spot size. A power of 103 mW was required to produce a white lesion in the fullthickness retina. We placed 15 photocoagulation lesions on the bare pigment epithelium through the open mouth of the dialysis. With laser settings of 0.2 seconds and 500-|A spot size, we needed 105 mW of power to produce white photocoagulation lesions on the bare pigment epithelium similar to the lesions in the full-thickness retina.
Fig. 2 (Landers and Robinson). Case 2, left eye. Top, An inferior temporal dialysis. Bottom, Argon laser photocoagulation lesions placed on flat at tached retina and through the open mouth of the dialysis on the bare pigment epithelium.
Fig. 1 (Landers and Robinson). Case 1, left eye. Argon laser lesions surround a retinal break and were placed in the center of the break on the bare pigment epithelium.
Case 3—A 54-year-old white woman complained of floaters in her right eye. Indirect ophthalmoscopie examination revealed a retinal break in the upper temporal quadrant. An operculum floated in the vitreous cavity over the break. We placed 61 argon laser photocoagulation lesions around the retinal break with laser settings of 0.2 seconds and 500-p. spot size. Five lesions were made through the retinal hole directly on the retinal pigment epithelium (Fig. 3). White lesions were produced in the fullthickness retina at 144 mW, while lesions in the
20
AMERICAN JOURNAL OF OPHTHALMOLOGY
Fig. 3 (Landers and Robinson). Case 3, right eye. Argon laser lesions surround a retinal break and were placed through the retinal hole directly on the retinal pigment epithelium. center of the retinal break on the pigment epithe lium required 156 mW. The lesions in the center of the retinal break were not as intense as those in the full-thickness retina. Case 4—A 67-year-old white man complained of decreased vision and floaters in his right eye. Indi rect ophthalmoscopic examination revealed a retinal tear in the superonasal quadrant. We placed 108 argon laser photocoagulation lesions with laser set tings of 0.2 seconds and 500-|x spot size in the full-thickness retina around the retinal tear and eight lesions of the same duration and spot size were placed in the center of the retina (Fig. 4). A white lesion was produced in the full-thickness retina at 50 mW. We produced a similar lesion at 50 mW on the pigment epithelium in the center of the tear. Case 5—A 75-year-old white man with a history of vitreous hemorrhage of six months' duration in his right eye had floaters and flashes in his left eye. Indirect ophthalmoscopic examination revealed a retinal flap tear in the superotemporal quadrant of the left eye. We placed 193 argon laser photocoagu lation lesions with laser settings of 0.2 seconds and a 200- to 500-u, spot size around the retinal tear in the full-thickness retina; ten exposures were made with in the tear directly on the pigment epithelium (Fig. 5). By using the 200-ji spot size and 81 mW, we produced a white lesion in the full-thickness retina; 88 mW produced similar lesions within the center of the retinal break. Case 6—A 53-year-old white man with visual acuity of 6/6 (20/20) was referred here with a diag nosis of senile retinoschisis and associated retinal detachment. Indirect ophthalmoscopic examination revealed an area of senile retinoschisis in the super otemporal quadrant with a large outer wall hole and
JULY, 1977
Fig. 4 (Landers and Robinson). Case 4, right eye. Argon laser lesions surround a retinal break in the full-thickness retina and were placed in the center of the break on the retinal pigment epithelium. an area of retinal detachment confined to the area of retinoschisis. First, we placed ten argon laser lesions only in the area of senile retinoschisis (at 95 mW with a 200-u, spot size for 0.2 seconds ) producing a white lesion in this region. Then, we placed ten laser lesion in the center of the outer wall hole through the layers of the inner retina. These lesions were made directly on the bare pigment epithelium (Fig.
Fig. 5 (Landers and Robinson). Case 5, left eye. Argon laser lesions surround a retinal break and were placed on the bare pigment epithelium in the center of the retinal break.
VOL. 84, NO. 1
PHOTOCOAGULATION IN SENILE RETINOSCHISIS
21
differentiation between senile retinos chisis and rhegmatogenous retinal de tachment. In cases of central serous chorioretinopathy, when the retina is separated from the retinal pigment epithelium by a layer of serous fluid, according to Gass,7 white reactions to photocoagulation can be produced in the retinal pigment epi thelium alone with both the xenon arc and the argon laser. Thus, the outer layers of the retina need not be immediately adjacent to the pigment epithelium to produce a white reaction to photocoagu lation.1 Although we treated our patients exclu sively with the argon laser, it seems likely Fig. 6 (Landers and Robinson). Case 6, right eye. that a xenon arc photocoagulator might Senile retinoschisis is associated with retinal de have produced the same results. The tachment beneath the schisis. Argon laser lesions xenon arc photocoagulator produces some were placed in the area of schisis and also through the schisis into the center of the outer wall hole on of its energy at longer wavelengths than the bare pigment epithelium. the argon laser photocoagulator, even ex tending into the infrared region. Never theless, both photocoagulators produce 6) (for 0.2 seconds with a 200-u. spot size at 103 mW) their effects by generating heat at the level producing a white retinal lesion similar to that seen of the absorbing pigment epithelium. in the area of retinoschisis. Case 7—A 32-year-old white man had a retinal Bresnick and associates8 have shown that detachment of three years' duration in his left eye argon laser radiation in rhesus monkeys is that occurred shortly after blunt trauma. Reattachment surgery attempted shortly after the original absorbed primarily by the retinal pigment injury failed. The patient had a refractive error of epithelium, and that damage to the sen R.E.: -7.00 -1.00 x 175, and L.E.: -7.50 -1.25 x sory layers of the retina is not seen in the 165. Indirect ophthalmoscopy and contact lens ex amination revealed a complete retinal detachment in absence of pathologic changes in the pig the left eye with an area of diathermy scarring in the ment epithelium. Rosan and associates9 superotemporal quadrant and a small retinal break have shown that pigment epithelial dam immediately posterior to this area. With the patient's permission, we placed argon laser lesions in an area age in rhesus monkeys is the primary temporal to the macula between the macula and the response to argon laser exposure. In both area of diathermy scarring. A cross-shaped area was humans and rhesus monkeys, argon laser made with argon laser lesions (for 0.2 seconds with a 200-u. spot size at 75 mW) with 25 exposures in each photocoagulation produces a lesion at the arm of the cross (Fig. 7, top). A white lesion was level of the pigment epithelium at dis immediately visible at the level of the retinal pig ment epithelium (Fig. 7, center). We performed tances greater than two degrees from the retinal reattachment surgery the next day. We placed center of the fovea. Only within two de a silicone sponge behind the area of previous dia grees of the center of the fovea is there thermy, and flattened the retina uneventfully. Three months later the area of argon laser photocoagula significant absorption of the argon laser tion looked like an old photocoagulation scar (Fig. 7, wavelengths in the human and monkey bottom). retinas. 10,11 Because the argon laser has smaller DISCUSSION spot sizes and potentially higher energy Based on this series of cases, photoco densities than the xenon arc laser, it may agulation is not a definitive test for the produce white lesions through detached
22
AMERICAN JOURNAL OF OPHTHALMOLOGY
JULY, 1977
retinas and subretinal fluid that are suffi ciently opaque to prevent the xenon arc photocoagulator from producing a lesion. The presence or absence of a lesion after photocoagulation in cases of rhegmatogenous retinal detachment depends pri marily on the transparency of the retina adjacent to the retinal pigment epithe lium. Thus, photocoagulation, although helpful in the differentiation between se nile retinoschisis and rhegmatogenous retinal detachment, is not a definitive test and must be evaluated with other clinical findings. SUMMARY
In five of seven patients treated with argon laser photocoagulation, lesions were placed around retinal breaks and in the center of the breaks directly on ex posed pigment epithelium. In a sixth pa tient, the lesions were placed through an area of atrophic detached retina on the bare pigment epithelium. In the last pa tient, the lesions were placed in the center of a large outer wall hole in an area of senile retinoschisis directly on bare pig ment epithelium. The white reaction to photocoagulation, previously thought to differentiate between retinoschisis and retinal detachment, was produced in the eye with a rhegmatogenous retinal de tachment. The white reaction also was produced in the center of retinal breaks where the photoreceptor layer was not in contact with the retinal pigment epithe lium. Photocoagulation was not a defini tive test, and must be evaluated with other clinical findings.
Fig. 7 (Landers and Robinson). Case 7, left eye. Top, Chronic retinal detachment. Argon laser le sions placed through the detached retina onto the pigment epithelium. Center, Appearance of the photocoagulation area immediately after laser le sions were placed through the detached retina on the pigment epithelium, Bottom, Appearance of photo coagulation area three months later.
VOL. 84, NO. 1
PHOTOCOAGULATION IN SENILE RETINOSCHISIS
REFERENCES 1. Zimmerman, L. E., and Spencer, W. H.: The pathologic anatomy of retinoschisis. Arch. Ophthal mol. 63:10, 1960. 2. Byer, N.E.: Clinical study of senile retinos chisis. Arch. Ophthalmol. 79:36, 1968. 3. Duke-Elder, S., and Dobree, J. H.: Diseases of the Retina. In Duke-Elder, S. (ed.): System of Oph thalmology, vol. 10. St. Louis, C. V. Mosby, 1967, p. 564. 4. Okun, E., and Cibis, P. A.: The role of photocoagulation in the management of retirioschisis. Arch. Ophthalmol. 72:309, 1964. 5. Ballentyne, A., and Michelson, I.: Textbook of the Fundus of the Eye, 2nd ed. Baltimore, Williams and Wilkins, 1970, p. 391. 6. Hagler, W. S., and Woldoff, H. S.: Retinal detachment in relation to senile retinoschisis.
23
Trans. Am. Acad. Ophthalmol. Otolaryngol. 77:104, 1973. 7. Gass, J. D. M.: Stereoscopic Atlas of Macular Diseases. St. Louis, C. V. Mosby, 1970, p. 21. 8. Bresnick, G. H., Frisch, G. D., Powell, J. O., Landers, M. B., Hoist, G. C , and Dallas, A. G.: Ocular effects of argon laser radiation. Invest. Oph thalmol. 9:909, 1970. 9. Rosan, R. C , Flocks, M., Vassiliadis, A., Rose, H. W., Peabody, R. R., and Hammond, A.: Pathology of monkey retina following irradiation with an argon laser. Arch. Ophthalmol. 81:87, 1969. 10. Marshall, J., Hamilton, A. M., and Byrd, A. C : Histopathology of ruby and argon laser lesions in monkey and human retina. Br. J. Ophthalmol. 59: 611,1975. 11. Landers, M. B., Wolbarsht, M. L., and Shaw, H. E.: Current status of laser usage in ophthalmolo gy. Ann. N. Y. Acad. Sci. 67:236, 1976.
OPHTHALMIC MINIATURE
Skew sight, or sight askew, is a condition of our vision only accurate when the object is placed obliquely, in consequence of some partial obfuscation of the cornea, frequently from slight scars, scarcely, if at all, observable. In this lateral vision the axis of the eye affected usually coincides with that of the sound eye. In squinting, on the contrary, the two axes do not coincide. J. G. Millingen, Curiosities of Medical Experience London, Richard Bentley, 1839
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