罹患側上斜筋に萎縮があった片眼の先天性上斜筋麻痺の1例

A case of congenital superior oblique palsy with atrophy of the affected muscle

　MRIで上斜筋筋腹の左右差がみられた片眼の先天性上斜筋麻痺の1症例を報告した。患者は9歳女児で，正面位で2△外斜位8△左上斜位を示し，9方向向き眼位ではKnapp II型を示した。MRIでは麻痺眼の上斜筋の断面積が健眼に比べ著明に減少していた。他の外眼筋の断面積には左右差がなかった。

A-9-year-old girl was diagnosed as left congenital superior oblique muscle palsy. Exophoria by 2 prism diopters and left hypertropia by 8 prism diopters were present in the primary gaze position. The left hypertropia increased to 35 prism diopters on down and right gaze. On T1-weighted magnetic resonance imaging, the left superior oblique muscle appeared grossly attenuated in coronary section than the right one. Other extraocular muscles appeared intact.