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Show © 1989 Raven Press, Ltd., New York Editorial Comment Retinal Causes Of The Big Blind Spot Syndrome In this issue, Wakakura ( 1) reports a young, apparently healthy woman, who complained of photophobia and temporal field defects of lO- day duration. The positive findings included enlarged blind spots and ill- defined elevation of the peripapillary retina, mild juxtapapillary hyperflourescence, and mild abnormalities of dark adaptation in both eyes. No changes were noted over a 3month period. However, 4 years later, there was evidence of slight further enlargement of the blind spots, angiographic evidence of depigmentation of the juxtapapillary pigment epithelium, greater changes in dark adaptation thresholds, and electro- oculographic abnormalities. Although they suggest that these changes may have been the result of a chronic, slowly progressive, primary pigmentary dystrophy, the clinical history of acute onset of symptoms of lO- day duration suggests otherwise. There is accumulating evidence that the acute idiopathic big blind spot syndrome described in 1988 by Fletcher et al. ( 2) is probably part of the multiple evanescent white dot syndrome ( MEWDS) first described in 1984 by Jampol et al. ( 3) in this country, and Takeda et al. ( 4) in Japan. Many of these patients develop evidence of marked blind spot enlargement, in addition to central and paracentral scotomata and photopsia associated with faintly visible white spots at the level of the pigment epithelium in the mid- peripheral fundi. These spots last only a few weeks, and may disappear before the patient is first examined. A characteristic fluorescein angiographic picture of wreath- like arrangement of tiny, hyperfluorescent spots in the peripapillary and mid- peripheral fundi is present during the acute phase, along with some light staining at the level of the outer retina and the optic disc. These changes, however, also are present only during the first few weeks of the disorder, and are easily overlookt'd. Although the original description of the multiple evanescent white dot syndrome suggests th< lt it is < l self- Iimit- ,'- ,, 1\' 11', · ., , " II.' lInt' l'VL' in women, , I!, dk.- tl'd. The pigment epithelium and retinal receptor changes, in the peripapillary may be severe, may progress, may persist, and may leave zones of pigment epithelial and retinal atrophy in the fundi of either one, or less often, both eyes ( 5,6). It is of interest that this patient presented in Japan in 1984, the same year that this apparently new, acute ocular inflammatory disease was first reported in that country. The spectrum of this disorder, which may include macular neuroretinopathy ( 5), is expanding, and I believe includes the findings in the patient reported by Wakakura. Fluorescein angiography in some patients with MEWDS may show evidence of depigmentation of the juxtapapillary pigment epithelium that may be subtle ophthalmoscopically 3 months after the onset of symptoms when this 36- year- old woman still complained of a dense temporal scotoma, blurred vision, and photopsias in the right eye. Her visual acuity was 20/ 30. A few vitreous cells were present. Visual fields revealed a dense enlargement of the blind spot and peripheral scotomata. An unusual finding was cystoid macular edema that did not stain angiographically, a feature that I have recently observed in a young woman with monocular MEWDS. Electroretinography revealed a moderate decrease in rod and cone amplitudes in the right eye. Her left eye was normal. While primary retinal and pigment epithelial dystrophies may be manifest by development of geographic areas of atrophy in the juxtapapillary region, as well as in the central macular region, ( i. e., Sorbsby's central areolar choroidal sclerosis), these dystrophies are rarely associated with absolute visual field defects prior to the development of easily detectable ophthalmoscopic and angiographic changes. The absence of such changes, together with history of acute onset in the subject of this report, speaks against her having a primary dystrophy. This report, should further alert ophthalmologists and particularly neuro- opthalmologists to this new acute inflammatory disorder affecting pri- EDITORIAL COMMENT 145 marily the pigment epithelium and outer retina which may cause dense visual field defects, including enlarged blind spots in the absence of easily detectable changes in the ocular fundus. The rapid development of scotomata, often accompanied by photopsia, and subtle angiographic changes, most often present in the juxtapapillary area, are features that should suggest this disorder. The characteristic evanescent white retinal lesions and angiographic changes mayor may not be demonstrable by the time the patient presents. Electroretinographic abnormalities may be present ( 2,7). Although it is often a self- limiting disorder, it may cause permanent visual field and ophthalmoscopic changes. J. D. M. Gass, M. D. Bascom Palmer Eye Clinic Miami, Florida REFERENCES 1. Wakakura M, Furuno K. Bilateral slowly progressive big blind spot syndrome. I Clin Neuro- OphthalmoI1989; 9: 141- 3. 2. Fletcher WA, Imes RK, Goodman D, et al. Acute idiopathic blind spot enlargement: a big blind spot syndrome without optic disc edema. Arch OphthalmoI1988; 106: 44- 9. 3. Jampol LM, Sieving PA, Pugh D, et al. Multiple evanescent white dot syndrome: I. clinical findings. Arch Ophthalmol 1984; 102: 671- 4. 4. Takeda M. Kimura S. Tamiya M. Acute disseminated retinal pigment epitheliopathy. Folia Ophthalmol Ipn 1984; 35: 2613- 20. 5. Gass JDM, Hamed LM. Acute macular neuroretinopathy and multiJe evanescent white dot syndrome occurring in the same patients. Arch Ophthalmol 1989; 107: 189. 6. Hamed L, Glaser JS, Gass JDM. Schatz NJ. Protracted enlargement of the blind spot in multiple evanescent white dot syndrome. Arch OphthalmoI1989; 107: 194- 8. 7. Siving PA, Fischamn GA, Ganpole LM., Pugh D. Multiple evidence in white dot syndrome. II. Electrophysiology of the photoreceptors during retinal pigment epithelial disease Arch Ophthalmol 1984; 102: 675. 1elill Nellro- ophthalmol. Vol. 9. No. 3. 1989 |