（43）シーソー眼振の二症例

Two cases of seesaw nystagmus.

I．緒言

　詳細な眼科教科書や，眼振の綜説にはシーソー眼振に就いて必ず若干の記載がある。併し実際に本症例の報告は甚だ稀で，著者の調べた範囲内では現在までにE．E．Maddox氏（1914）^1）とC．W．Rucker氏（1946）^2）の各1例があるに過ぎない。

　著者は最近本症の2症例を経験したので，これを報告すると共に文献上の2例を加えて比較検討してみたい。

Two cases of seesaw nystagmus were presented and discusse with other two cases in the literatures. The first case was 30 yr. old male patient having no other eye disease. The frequency of nystagmus were 88/min. and its amplitude were 2.5-3.0mm. The second case was 15 yr. old boy complicating degeneration pigmentsa retinae. Its frequency were 168/min. and its amplitude 0.2-0.4mm. All of these 4 cases were not jerky but pendular. When one eye moved upward, the other eye move downward and subsequently the oppsite movement were occured. The eye-ball intorsed moving upward and extorsed when moved downward.