特発性血小板減少性紫斑病に合併した急性網膜壊死の1例

Acute retinal necrosis in a case of idiopathic thrombocytopenic purpura

　50歳女性が右眼視野狭窄で受診した。16年前に全身性紅斑性狼瘡（SLE），4か月前に特発性血小板減少性紫斑病と診断され，以後，副腎皮質ステロイド薬の投与を受けている。初診時の右眼矯正視力は1.0で，虹彩毛様体炎，眼底に融合性の滲出斑，網膜血管炎があった。前房水から水痘・帯状ヘルペスウイルスDNAが検出され，急性網膜壊死と診断した。診断が確定するまでの3週間に滲出斑は急速に消退し，網膜壊死病巣は萎縮化して治癒した。免疫低下状態にあったにもかかわらず炎症が沈静化し，良好な経過をとった症例である。

A 50-year-old female presented with visual field constriction in her right eye. She had been diagnosed with systemic lupus erythematosus 16 years before. She had been receiving systemic corticosteroid for idiopathic thrombocytopenic purpura during the past 4 months. Her corrected visual acuity was 1.0 right. Her right eye showed iridocyclitis, confluent exudates and retinal vasculitis. Varicella-zoster virus was detected in the aqueous by poly-merase chain reaction, leading to the diagnosis of acute retinal necrosis. Retinal exudates started to spontaneously re-gress 3 weeks after her initial visit. Foci of retinal necrosis became atropic ones. This case illustrates that retinal ne-crosis may run a benign self-limited course in spite of immunosuppressed state as the underlying cause.