METHODS:Retrospective case-control study. Totally 42 patients(84 eyes)with high myopia underwent FS-LASIK Xtra and FS-LASIK in our hospital from April 2019 to April 2020 were followed up for 3mo, including 21 patients in each group(42 eyes). The uncorrected visual acuity(UCVA), spherical equivalent(SE), astigmatism and corneal high-order aberration of the two groups were analyzed and compared.

RESULTS: The UCVA of the FS-LASIK Xtra group was significantly lower than that of the FS-LASIK group at 1d after surgery(P<0.01), there was no statistical difference in UCVA at the other time points after surgery between the two groups(P>0.05). The postoperative SE of the two groups was significantly lower than that before surgery, at 3mo after surgery, 38 eyes(90%)in the FS-LASIK Xtra group and 41 eyes(98%)in the FS-LASIK group had SE within ±1.00D. In both groups, 35 eyes(83%)had residual astigmatism within 0.50D after surgery. The total corneal high-order aberrations, spherical aberrations, coma and clover aberrations in the two groups were increased at 3mo after surgery, the total high-order aberration and clover aberration in the FS-LASIK Xtra group were greater than those in the FS-LASIK group(all P<0.05).

CONCLUSION:FS-LASIK and FS-LASIK Xtra have good effectiveness and predictability in correcting high myopia in the early postoperative period, the total high-order aberrations of the cornea both increased in the early postoperative period, and the patients who underwent FS-LASIK Xtra were increased significantly.