40歳以下で発症した両眼性視神経症の予後不良例の検討

Cases of bilateral optic neuropathy with poor outcome manifesting before 40 years of age

　40歳以下で発症し明らかな原因がなく，最終視力が0.1以下の両眼性視神経症25例の，性，発症年齢，家族歴，ゴールドマン定量視野につきretrospectiveに検討を行った。その結果，男性で（80％），明らかな視力低下で発症し（76％），慢性期に中心暗点を認める（72％）症例が多く含まれていた。これらすべてを満たす14例のうち少なくとも10例（71％）はレーベル視神経症であった。レーベル視神経症は全部で11例であり，うち4例は家族歴はなかったが，DNA診断により診断された。40歳以下の男性で急性または亜急性に発症し中心暗点をきたす両眼性の予後不良な視神経症をみた場合，レーベル視神経症を念頭におくべきであると思われた。

We reviewed 25 cases with severe bilateral idiopathic optic neuropathy which became manifest before 40 years of age. We paid particular attention to sex, age of onset, family history and perimetric findings. These cases were characterized by prepon-derance of males 80%, acute onset 76% and pres-ence of central scotoma during the chronic stage 72%. Fourteen patients showed these characteristic features. Leber's hereditary optic neuropathy (LHON) was diagnosed in 10 of these 14 patients, 71%. Mitochondrial DNA analysis was positive in 11 cases with LHON and in 4 with negative family history. The findings show that LHON is a liability in male patients who are under 40 years of age and who manifest severe bilateral optic neuropathy of unknown cause. DNA analysis is recommended for definitive diagnosis.