優性遺伝性若年型視神経萎縮の一家系

A pedigree with dominantly inherited juvenile optic atrophy

　先天性第3色覚異常を診断するにあたり，その鑑別が問題とされる優性遺伝性若年型視神経萎縮の一家系，男子兄弟3人と父に色覚検査を主とする臨床一般検査を行った．

　視神経乳頭の耳側蒼白は長男のみ明瞭で，他は極めて軽度であった．色覚異常は全員，第3異常を呈したが，色相配例検査より程度が強いと判定される症例は，赤緑異常も併有していた．これら色覚異常の程度は0.1〜0.6の矯正視力とよく相関していた．一方，視神経乳頭の耳側蒼白の程度とは，蒼白が顕著な場合を除き，必ずしも相関しないと考えられた．

　螢光眼底造影施行の3症例中の2症例に腕—網膜循環時間の遅れを認めたため，中の1症例に循環器と血液凝固機能の精査を行ったが，特に著変はなかった．さらに視神経萎縮の原因として，乳頭周囲毛細血管網を含む乳頭血管の異常の存在を疑ったが，その証拠は見出せなかった．

Three male siblings, aged 19, 16 and 13 years, and their father, 49 years in age, manifested dominantly inherited juvenile optic atrophy. All the cases showed common clinical features of slightly to markedly reduced visual acuity, temporal disc pallor, defective color vision, central visual field abnormalities and reduced critical flicker fusion frequency.

A Type III blue-yellow color defect was found in all the cases with Standard Pseudoisochromatic Plates Part 2, Panel D-15 test, FM 100-hue test and New Color Test. Red-green discrimination was also affected in two severe cases. The degree of color defect was correlated with the visual acuity which ranged from 0.1 to 0.6. Fluorescein angiography was performed in 3 cases. A significantly prolonged arm-to-retina circulation time was noted in 2 cases. The angioarchitecture of the retina and the choroid appeared to be normal.

Rinsho Ganka (Jpn J Clin Ophthalmol) 40(8) : 909-915. 1986