先天白内障に後天的に発症した膜白内障の1例

A case of congenital cataract resulting in membranous cataract

要約　目的：両眼に先天白内障があり，4歳時に膜白内障になった症例の報告。症例：出生直後から白色瞳孔が左眼にある男児を生後2か月で診察し，両眼を先天白内障と診断した。混濁が強い左眼は生後3か月で水晶体を摘出した。生後2年目から右眼の水晶体が扁平化し，強度遠視になった。右眼に内斜視と眼振が生じ，膜白内障になったため，4歳時に水晶体を摘出した。7歳になった現在の矯正視力は右0.3，左1.0である。結論：出生時に先天白内障があり，混濁が軽度で水晶体の形態異常がなくても，稀に膜白内障になることがある。

Abstract.　Purpose：To report a case who had congenital cataract at birth that turned into membranous cataract at the age of 4 years. Case and Findings：A male infant showed leukocoria in the left eye at birth. He was diagnosed with bilateral congenital cataract when seen 2 months later. The left eye received lens extraction at the age of 3 months. The lens in the right eye became flat resulting in high hyperopia after 2 years of age. The right eye received lens extraction due to esotropia and nystagmus at the age of 4 years. The patient is now 7 years old with corrected visual acuity of 0.3 right and 1.0 left. Conclusion：This case illustrates that membranous cataract may result from congenital cataract even when,the lens is initially of normal shape with moderate opacity.