Changes of corneal high-order aberrations after femtosecond laser-assisted in situ keratomileusis

Background:Femtosecond laser-assisted in situ keratomileusis (FS-LASIK) has gained widespread popularity as a safe, effective and predictable treatment for correcting myopia and myopic astigmatism.However, complications such as biomechanical changes, structural weakness, dry eye and induction of high-order aberrations (HOAs) have been associated with FS laser excision. The induction of HOAs has been reported to reduce quality of vision, leading to increased glare, halos, starburst and deterioration of contrast function corneal HOAs play a significant role in whole-eye aberration. Thus, it is necessary to investigate the changes of corneal high-order aberrations after FS-LASIK.Methods:One hundred thirty-four eyes from 68 consecutive patients with myopia or myopic astigmatism were enrolled in this study. Corneal topography and visual acuity were measured preoperatively and at 1, 3, 6, and 12 months after FS-LASIK. Wavefront errors from the whole cornea, anterior cornea, and posterior cornea were measured by Pentacam.Results:Corneal aberrations on the posterior surface were less affected by FS-LASIK compared with those on the anterior surface and the whole cornea. The high-order aberrations (HOAs) on the whole and anterior corneal surfaces increased significantly at 1 month after surgery (P=.000, P=.000), while HOAs on the posterior surface did not significantly change (P=1.000). The spherical aberration on the whole corneal and anterior corneal surfaces were significantly increased at 1 and 3 months postoperatively (P=.000 and P=.000, respectively), along with the vertical coma on the whole and anterior corneal surfaces at 1 and 3 months (P=.000 and P=.000, respectively). There was no significant difference in horizontal coma or trefoil on the whole, anterior and posterior corneal surfaces after surgery compared with preoperatively (all P=1.000).Conclusion:After FS-LASIK changes in corneal aberration occurred mainly on the anterior surface, which may have a significant effect on visual quality.