視野闘争による眼優位性と眼位の評価

Evaluation of ocular dominance using binocular rivalry as related to eye position

要約　目的：視野闘争を用いて眼優位性を定量評価し，眼位との関連の検討。対象と方法：外斜視13例，間欠性外斜視14例，外斜位16例にっき，各眼の優位時間を測定し，優位時間差を求めた。測定には北里式眼優位性定量装置を用いた。結果：優位時間差は，外斜視8.9±4.1秒，間欠性外斜視5.1±4.2秒，外斜位2.3±1.6秒であった。外斜視と間欠性外斜視の値には有意差があった（p＜0.05）。外斜視と外斜位の値には有意差があった（p＜0.01）。結論：通常の検査では検出されにくい一眼の抑制を優位時間差として定量できた。眼位異常で両眼単一視が妨げられるほど優位時間差が延長し，眼優位性が強い傾向があるので，眼優位性は眼位に影響される。

Abstract.　Purpose：To evaluate eye position and ocular dominance. Cases and Method：Binocular rivalry,or ocular dominance,was measured in 43 patients. The series comprised exotropia 13 cases,intermittent exotropia 14 cases,and exophoria 16 cases. A new apparatus was used to measure ocular dominance. Result：Difference of exclusive visibility between dominant and nondominant eye averaged 8.9±4.1sec in exotropia,5.1±4.2sec in intermittent exotropia,and 2.3±1.6sec in exophoria. Difference in the value for exotropia and intermittent exotropia,and that for exotropia and exophoria were significant（p＜0.05,p＜0.01）. Conclusion：It was possible to quantitatively evaluate suppression of one eye using the concept of difference of exclusive visibility with the new apparatus. Inhibited binocular vision due to anomalous eye position results in difference of exclusive visibility between both eyes. Eye dominance therefore is dependent on eye position.