虹彩部分異色に脈絡膜色素異常を伴った1例

A case of sectorial heterochromia iridis with abnormal choroidal pigmentation

　片眼性に扇状の虹彩異色と脈絡膜色素異常を呈した5歳女児を経験した。右眼上方の虹彩異色と右眼眼底の脱色素および色素沈着を認めた。外傷やぶどう膜炎など眼疾患の既往はなく，先天異常であると思われた。螢光眼底造影で網膜血管および網膜色素上皮が正常なことから，眼底所見は脈絡膜の色素異常と考えられた。虹彩の実質・色素細胞，脈絡膜の色素細胞は神経堤細胞由来であり，本症例の右眼の所見は神経堤細胞の異常の結果と考えた。

A 5-year-old girl presented with sectorial heterochromia iridis in the right eye. She had not suffered from trauma or uveitis before. Funduscopy showed irregular pigment deposits along the vascular arcades and diffuse hypopigmentation in the nasal hemisphere in the same eye. Fluorescein angiography showed the retinal pigment epithelium to be intact, suggesting the pigment abnormalities to be located in the choroid. It appeared that the iris and choroidal abnormalities resulted from maldevelopment of neural crest cells during differentiation into iris and choroidal pigment cells.