Factors associated with corneal high-order aberrations before and after femtosecond laser-assisted in situ keratomileusis

Background: Corneal high-order aberrations (HOAs) are related to visual quality. However, the factors associated with corneal HOAs before and after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) have not yet been elucidated. The aim of this study is to observe the factors related to corneal HOAs before and after FS-LASIK. Methods: Prospective observational study was designed to measure corneal HOAs in 149 eyes of 75 patients before and 6 months after FS- LASIK. The relationship between spherical diopter and corneal parameters, including K1 and K2 (horizontal and vertical refractive power of the cornea, respectively), the aspheric characteristics of the cornea (Q), mean radius of the curvature of the cornea (Rm), and central corneal thickness (CCT), with corneal HOAs were analyzed. Results: The spherical diopter was correlated with trefoil at 30 degrees before surgery and with vertical coma, four-order astigmatism at 0 degrees, trefoil at 30 degrees, spherical aberration, and six-order spherical aberration after surgery (P<0.05). CCT was correlated with vertical coma, four-order astigmatism at 0 degrees, trefoil at 30 degrees, and six-order spherical aberration after surgery (P<0.05). K1 was correlated with spherical aberration and six-order astigmatism at 0 degrees before surgery (P<0.05). K2 was correlated with spherical aberration, six-order astigmatism at 45 degrees, astigmatism at 0 degrees, six-order astigmatism at 0 degrees before surgery, and trefoil at 30 degrees after surgery (P<0.05). Q was correlated with spherical aberration, six-order spherical aberration, and six-order astigmatism at 45 degrees (P<0.05). Rm was correlated with six-order astigmatism at 0 degrees, spherical aberration, six-order astigmatism at 45 degrees before surgery, and astigmatism at 0 degrees after surgery (P<0.05) Conclusions: Corneal parameters and spherical diopter are related to the HOAs of the cornea before and after FS-LASIK.