マリオット盲点拡大症候群の2例

Two cases of big blind spot syndrome without optic disc edema

　われわれは視野測定で片眼性にマリオット盲点拡大以外の異常がみられず，検眼鏡的に乳頭浮腫のない，いわゆるbig blind spot syndromewithout optic disc edemaの2症例を経験した。何れも軽度の視力低下と色覚異常を認めるほか，検眼鏡的にも，螢光眼底造影にても盲点拡大を説明できる異常は認めなかった。網膜電位図（ERG），視覚誘発脳波（VEP），CTスキヤン等の検査では異常は捕えられず，photostress recov-ery testで患眼の回復時間の延長を認めた。瞳孔入力障害がみられたこと，経過中に傍中心暗点が見られたこと，ステロイドの効果がみられたことなどにより視神経障害である可能性が高いと考えられた。

　Big blind spot syndromeの本態は不明だが，これまでの症例報告から視野変化として盲点拡大のみが見られる疾患群として捉らえ，その原因別分類が必要と思われた。

We observed the syndrome of acute symptomatic monocular enlargement of blind spot without disc edema in 2 healthy subjects aged 16 and 31 each. Both cases noted blind area with photopsia in the temporal visual field of the affected eye. The enlar-ged blind spot measured more than 10 degrees by Goldmann and automated perimetry. Visual acuity and color vision was slightly affected. Funduscopic and fluorescein angiographic findings were almost normal. Pupillary reaction was slightly affected inone case. Electroretinogram, visual evoked poten-tial and CT findings were normal. Photostress recovery time was prolonged in the affected eye in both cases. Spontaneous recovery set in one case. Complete cure resulted in the other after systemic corticosteroid treatment. The present findings seemed to suggest disturbed optic nerve functions as underlying the big blind spot syndrome.