片眼の突然の網膜中層障害をきたした1症例

A case of sudden unilateral visual loss with impaired middle retinal layer

要約　目的：突然の片眼性視力低下をきたし，網膜電図（ERG）にて網膜中層の機能障害が考えられた1例を報告する。

症例：糖尿病網膜症で経過観察を行っていた75歳の男性が，急激な右視力低下を自覚して受診した。

所見：2か月前に矯正0.7であった右眼の視力は0.1まで低下していた。暗順応下のフラッシュERGで陰性型波形を認め，錐体系ERGの振幅が低下していた。ERGの結果，不全型停在性夜盲と同様の片眼性の網膜中層障害が疑われた。

結論：双極細胞を含む網膜中層障害が原因と考えられた急激な片眼の視機能障害をきたした貴重な症例を経験した。原因は不明だが，肺腺癌の病歴もあることから，腫瘍関連網膜症の可能性も考えられた。

Abstract　Purpose：To report a case of sudden unilateral visual loss with impaired middle retinal layer by analysis sof electroretinogram（ERG）.

Case：A 75-year-old male presented with sudden visual loss in the right eye since 3 weeks before. His left eye had had amblyopia since childhood. He had reportedly visual acuity of 0.7 right and 0.2 left 2 months before. He had had diabetes mellitus since 40 years before.

Findings：Best-corrected visual acuity was 0.1 right and 0.2 left. ERG showed negative waveform with bright flash stimulus under dark adaptation. Photopic ERG showed reduced amplitudes. The ERG waveform simulated those of incomplete type congenital stationary night blindness, and suggested incomplete damage in the middle retinal layer. He was later diagnosed with lung carcinoma.

Conclusion：Acute functional damage in the middle retinal layer in this patient may be related to lung adenocarcinoma as cancer-associated retinopathy.