遮閉除去試験にみられる眼球運動の特徴

Characteristics of eye movement during uncover test

　12例の斜位症例を対象に，遮閉除去試験で生ずる眼球運動を計測した。その結果，サイクロピアン眼を固視目標に向けるむき運動（sacca-de）と融像性よせ運動（fusional vergence），さらに修正的な小さいむき運動を伴う両眼の眼球運動を認めた。症例の50％は，被検眼を変えて検査を行うと異なる大きさのむき運動を示し，症例の88％は左右非対称のよせ運動を示したが，hole in　card testで定めた優位眼との間に一定の関係は認めなかった。これらの眼球運動の特徴はPick‐wellの主張を裏付けるものであり，遮閉を除いた片眼のみに固視運動が生ずるとする従来の成書の記載とは明らかに異なるものであった。

We recorded eye movements during uncover test by infrared electrooculogram in 12 cases of hetero-phoria. The eye movement consisted of three com-ponents: a saccade which brings the cyclopean eye toward a fixation target, a fusional vergence eye movement, and some following corrective saccades. Saccades of unequal sizes were seen in 50% of the cases when the uncovered eye changed. Constantasymmetry of vergence eye movement was seen in 88 % of the cases. The laterality of eye movements did not always coincide with the ocular dominancy as determined by hole-in-card test. The character-istics of eye movements should be explained by Hering's law of equal innervation in general. That fixation eye movement was elicited in both eyes in the present study did not match the description in standard textbooks.