斜位近視を伴う成人外斜位斜視例の術後屈折値の変動

Refractive changes in an adult with exophoria-tropia and phoria myopia after strabismus surgery

（18-G402-1）　長期間放置され，偏位角の大きい35歳男性の外斜位近視に斜視手術を行った。良好な眼位が得られ，片眼視下の近視性乱視の球面度数も軽減した。斜位近視の発症機序について，輻湊を初期の急速反応とその後の緩徐な緊張性反応に分けるSchoの説を引用し，成長過程での正位化に必要な両眼の像のズレを求めて緊張性反応を自己抑制し，このために生じた外斜偏位を急速反応で打ち消そうとして輻湊性調節が惹起されて近視化すると考察し，本例では加齢による輻湊力の低下も加わってより強い近視化が生じたと考えた。

We performed strabismus surgery on a 35-year-old male with phoria myopia. After normalization of eye position, both eyes showed reduction in myopic astigmatism under monocular viewing. This case supports the theory by Schor who divided accommodation in rapid initial reaction and late chronic tonic one. Myopinization in the present longstanding case appeared to have been the consequence of self-induced tonic reaction to compensate disparity of retinal images in both eyes followed by excessive convergence accommodation to suppress the resulting exophoria by rapid initial reaction. Decrease of the power of convergence by aging appeared to be another factor for myopinization.