PURPOSE To compare the postoperative astigmatism among eyes that had received femtosecond laser in situ keratomileusis(LASIK) at different optical zone diameters
METHODS 23 eyes of 23 chinese patients were underwent subject refraction before and after(at least 6 months) femtosecond LASIK. Patients were divided into three groups according to optical zone diameter:group1(n=8),optical zone diameter <6.5mm;group2(n=9), optical zone diameter =6.5mm;group 3(n=6),optical zone diameter >6.5mm.
RESULTS Mean optical zone diameters of groups 1,2 and 3 were 6mm, 6.5mm and 6.75mm,respectively. The astigmatism of groups 1,2 and 3 befor femtosecond LASIK were -1.34±0.78,-1.14±0.60 and -0.75±0.27, respectively(P=0.221). The astigmatism of groups 1,2 and 3 after femtosecond LASIK were -0.66±0.11,-0.28±0.10 and -0.25±0.13, respectively(P=0.031). The difference of astigmatism between before and after femtosecond LASIK were -0.68±0.25 in group1,-0.86±0.20 in group2 and -0.50±0.25 in group3. Compared to group 1,group 2 and 3 had significantly less astigmatism after LASIK(P=0.021,P=0.025 respectively). The difference of astigmatism between before and after femtosecond LASIK in all groups was not significant(P=0.53)
CONCLUSIONS In femtosecond LASIK treatment, a larger surgical optical zone diamert had better effect on correction of myopic astigmatism. |
