Abstract:AIM: To evaluate the outcome of astigmatism correction after epipolis laser in situ keratomileusis(Epi-LASIK)by standardized vector analysis, and to investigate the relationship between the result of analysis and the change in contrast sensitivity function(CSF).
METHODS: Totally 68 myopic astigmatism eyes treated with Epi-LASIK. The myopic diopter was range from -5.00D to -9.00D, and the astigmatic diopter was range from -1.00D to -3.00D. The following-up period was for 6 months. The outcome of astigmatism correction was evaluated by the standardized vector analysis which was recommended by the American National Standards Institute. The photopic without glare CSF with best spectacle-corrected visual acuity was examined by CSV-1000E.
RESULTS: The CSF of all spatial frequency in 1 month postoperatively were significant lower than that preoperatively(P<0.01). The CSF of spatial frequency 12c/d(cycles per degree)and 18c/d in 6 months postoperatively were significant lower than that preoperatively(P<0.05). The CSF of 3c/d, 6c/d and 12c/d in 1 month were significant lower than that in 6 months postoperatively(P<0.05). The |SIRC|(absolute surgically induced refractive correction)in 1 month, 6 months were positively correlated with the decrease of 18c/d CSF postoperatively(r=0.537, 0.674, P<0.01). The error of magnitude(EM)in 1 month was -0.21±0.29 and -0.12±0.31 in 6 months postoperatively.
CONCLUSION: There was decrease in high spatial frequency contrast sensitivity under photopic without glare of myopic and astigmatic eyes with midrange and high diopter within 6 months after Epi-LASIK. The SIRC might have correlation with the decrease in contrast sensitivity.
