Stargardt病・黄色斑眼底群Ⅲ型に属する2症例

Two cases of Stargardt's disease and fundus flavimaculatus type Ⅲ

　Stargardt病・黄色斑眼底群Ⅲ型の2症例の臨床所見と経過の差異について報告した。症例1は初診時37歳で，黄斑部萎縮巣は比較的大きく，4年間の経過で明らかに拡大した。症例2は初診時40歳で，黄斑部萎縮巣は小さく，15年間の経過で拡大傾向が乏しかった。また症例1よりも中心暗点が小さく，周辺部視野もよく保たれていた。黄色斑は症例2のほうが多かった。赤外螢光眼底造影で，症例1には黄斑部萎縮巣の低螢光領域を取り囲む虫食い状の低螢光領域と周辺部の低螢光斑が散在していたが，症例2にはみられなかった。脈絡膜毛細血管板の萎縮の差異が両例の進行の差に関与していると考えられ，同じ病型の中の異なるsubtypeの存在が示唆された。

We report herein different clinical findings in two cases of Stargardt's disease and fundus flavimaculatus type Ⅲ. In case 1, a 37 years-old male, extensive macular atrophy had enlarged over a 4-year-follow-up period. In case 2, a 40 year-old male, limited macular atrophy had enlarged slightly over a 15-year-follow-up period. Visual field disturbance was less severe in case 2 than in case 1. The number of yellow fleeks in case 2 exceeded that in case 1. Indocyanine green fluorescein angiography (IA) of case 1 showed a band shape area of irregular hypofluorescence surrounding hypofluorescent macular atrophy and several hypofluorescent spots within peripheral background fluorescence. These findings were not present in case 2. Differences in choriocapillaris atrophy between the two, shown by IA, suggest that there are two distinct subtypes within the same type of Stargardt's disease and fundus flavimaculatus.