IgA腎症に合併した網膜色素変性の1例

A case of retinitis pigmentosa with IgA nephropathy

　症例は18歳の女性で13歳の時にネフローゼ症候群が認められ，腎生検実施後，IgA腎症と診断された。その後腎機能が悪化し，腹膜透析導入となった。この頃より夜盲，求心性視野狭窄を自覚し，当科にて網膜色素変性の合併が確認された。眼底は骨小体様色素沈着を伴う定型的網膜色素変性で，scotopic ERGとsingle flash ERGは消失，flicker ERGは著明に減弱していた。視野も中心視野を約5度残すのみで視機能の低下が著しかった。これまで網膜色素変性とIgA腎症の関連を述べた報告はなく，本症例ではIgA腎症を伴っていることが視機能の悪化に関与していることが疑われた。

A 18-year-old female had been diagnosed as nephrose syndrome 5 years before. IgA nephropath-y was identified by renal biopsy. Deterioration of renal functions necessitated peritoneal dialysis 3 months before. Since then she noted night blindness and constriction of visual field in both eyes. Typical funduscopic features led to diagnosis of retinitis pigmentosa. Both scotopic and single flash ERGs were nonrecordable. Flicker ERG was extremely reduced. The central visual field had constricted to 5 degrees from the fixating point. Visual acuity was 0.7 in either eye. It appeared that IgA nephropathy had precipitated retinal lesions of retinitis pigmentosa. This is the first report of association of the two conditions.