Changes of accommodative facility in myopia after LASIK and its relation with asthenopia

Objective To investigate the changes of accommodative facility(AF) in myopia after laser in situ keratomileusis(LASIK) and its relation with asthenopia.Methods Thirty-two myopic patients(64 eyes) who underwent standard LASIK were divided into two groups by the age,30 years and ≥30 years.AF was measured binocularly before LASIK,1 week and 1 month after LASIK.Asthenopic symptoms were surveyed by the questionaire at 1 month after LASIK.AF at pre-operation and post-operation was compared using paired t test.The effects of preoperative and postoperative AF,age and refractive spherical equivalent on asthenopic symptom were analyzed by Logistic regression.Results For the group 30 years,AF of pre-operation,postoperative 1 week and 1 month were(7.12±2.02)c·min-1,(6.22±1.73)c·min-1 and(9.46±1.97)c·min-1,respectively,there was no statistical difference between pre-operation and postoperative 1 week(P0.05),but statistical difference between pre-operation and postoperative 1 month(P0.05).For the group ≥30 years,AF of pre-operation,postoperative 1 week and 1 month were(5.68±2.51)c·min-1,(4.02±1.59)c·min-1 and(6.03±1.61)c·min-1,respectively,there was statistical difference between pre-operation and postoperative 1 week(P0.05),but no statistical difference between pre-operation and postoperative 1 month(P0.05).There were 13 cases(40.6%) with positive asthenopic symptom and 19 cases(59.4%) with negative asthenopic symptom by the questionaire.Logistic regression showed that age,preoperative spherical equivalent and AF at pre-operation and postoperative 1 week were positive related with asthenopia.Conclusion AF in myopia may decrease in the early stage after LASIK and gradually recover in about one month,which may be one of the reasons of asthenopia postoperatively.