AIM:To observe effect of the iris location to femtosecond-combined wavefront guided LASIK for myopia and astigmatism.

METHODS:The patients with astigmatism >1.0D during the same time and followed up for 1a were selected. A total of 129 eyes in 67 patients were treated under iris location with femtosecond-combined wavefront guided LASIK(experimental group)and 161 eyes in 82 cases with femtosecond-combined wavefront guided LASIK(control group). Laser cutting went with the same laser machine. The uncorrected visual acuity(UCVA), best corrected visual acuity(BCVA), and wavefront aberration between the two groups were compared at 1, 3, 6mo and 1a after surgery.

RESULTS:At 1 and 3mo after surgery, the number of patients with better postoperative UCVA than preoperative BCVA between the two group showed a statistically significant difference(χ²=6.423, P=0.011,χ²=14.431, P=0.01); at 1d and 1mo after surgery, the residual astigmatism showed a statistically significant difference between two groups(t=1.98, P<0.05; t=2.23, P<0.05). At 3, 6mo and 1a after surgery, the differences on the change of residual astigmatism between the two groups weren't significant(P>0.05). At 6mo and 1a after surgery, the differences on UCVA between the two groups weren't significant(P>0.05). Until 1a after surgery, the root mean square(RMS)of high order wavefront aberration of the two groups, spherical aberration and coma aberration(COMA)were all enhanced compared to before surgery(P<0.05). At 1, 3mo after surgery, the RMS showed a statistically significant difference between two groups(P<0.05). At 1, 3, 6mo, 1a after surgery, the increase of COMA in experimental group was significantly lower than that in control group(P<0.05).

CONCLUSION:Iris location technology applied in femtosecond-combined wavefront guided LASIK for myopia and astigmatism, can make the vision recovery faster, the RMS of high order and COMA increase less, the residual astigmatism less, show better and more stable treatment effect.