近视与眼调节反应时间关系的研究

目的　探索不同注视时间后近视的调节反应时间。　方法　 2台显示器 ,分别用于视远 (5m )和视近 (0 .3m)。一台显示器上的注视视标消失时 ,另一台显示器上的视标立刻出现并持续一定时间。受试者先注视一台显示器上的视标 ,该视标消失时努力看清另一台显示器上视标需要的时间为调节反应时间。　结果　正视眼与早发性近视眼的远调节反应时间 (4 77、488ms)比近调节反应时间 (3 76、3 71ms)长 (P <0 .0 1)。注视近视标 60s后 ,早发性近视眼远调节反应时间 (691ms)的延长与正视眼的远调节时间 (678ms)的延长相比没有显著性差异 (P >0 .0 5 )。　结论　远调节比近调节慢 ,远调节反应时间延长与早发性近视可能没有明显相关性。

A Study of Relationship between Myopia and Accommodation Reflex Time

Objective To explore the accommodation reflex time after two prior fixation periods in early-onset myopes. Method There are two monitors used for near vision (0.3 m ) and distant vision (5 m) . When the optotype on the one monitor was cleared away, the optotype on the other monitor was presented at once and lasted a few hundred of milliseconds. The subject first looked at an optotype on one monitor till it disappeared from sight and then looked at another optotype on the other monitor. Result The time of near accommodation are 376 ms and 371 ms, and far accommodation 477 ms and 488 ms in emmetropes and early-onset myopes respectively. There are significant differences of time quantities between near accommodation and far accommodation(P<0.01). The far accommodation reflex time after 60 seconds of sustained near vision were prolonged in early-onset myopes (691 ms)and emmetropes (678 ms), but there was no significant differences between group results (P>0.05) Conclusion The far accommodation was slower than near accommodation. Even though early-onset myopes showed extended far accommodation reflex times after a sustained near vision task, the results suggest that early-onset myopia appeared to be incorrelated with extended far accommodation reflex times.