高齢になって視力低下が進行した乳頭周囲脈絡膜ジストロフィの1例

A case of peripapillary choroidal dystrophy with rapid loss of vision after reaching advanced age

要約　目的：70歳になるまでの4年間に急速に視力が低下したらせん型乳頭周囲脈絡膜ジストロフィと考えられる1例の報告

症例：70歳男性が両眼の視力不良で紹介受診した。4年前に両眼の耳側視野狭窄を自覚し，矯正視力は右1.0，左0.2であったという。

所見と経過：矯正視力は右0.2，左0.1で，両眼に乳頭周囲から広がる眼底の色調異常と脈絡膜萎縮があった。光干渉断層計で中心窩囊胞形成があった。フルオレセイン蛍光眼底造影とインドシアニングリーン蛍光眼底造影で，網膜色素上皮と脈絡膜毛細血管板の萎縮があった。乳頭周囲脈絡膜ジストロフィと診断した。以後7年間の経過観察で，格別の悪化はない。

結論：本症例での乳頭周囲脈絡膜ジストロフィは，70歳になるまでの数年間に急速に視力が低下したと推定される。

Abstract　Purpose: To report a case of presumed peripapillary choroidal dystrophy that showed rapid loss of vision during 4 years before reaching 70 years of age.

Case: A70-year-old male was referred to us for poor vision in botheyes. He had noticed restriction of temporal visual field in both eyes 4 years before. His corrected visual acuity was reportedly 1.0 right and 0.2 left.

Findings and Clinical Course: Corrected visual acuity was 0.2 right and 0.1 left. Both eyes showed extensive choroidal atrophy extending from the disc towards the periphery. Optical coherence tomography（OCT）showed foveal cysts. Fluorescein and ICG angiography showed atrophy of retinal pigment epithelium and choriocapillaris. He was diagnosed with peripapillary choroidal dystrophy. There has been no remarkable changes in the findings during the follow-up for 7 years.

Conclusion: Visual acuity in the present case of peripapillary choroidal dystrophy appears to have deteriorated during the few years before reaching 70 years of age.