Changes of higher-order aberrations after LASIK surgery for myopia.

Objective To investigate the influence of LASIK surgery on the higher-order aberrations for myopia and analyze the relationship between the higher-order aberrations after LASIK surgery and the myopic diopters before LASIK surgery.Methods The RMS value of the total higher-order aberrations and the Zernike coefficients of the 3rd and the 4th higher-order aberrations in 150 eyes were measured in small pupil(3 mm) and large pupil(6.25 mm)by WASCA aberrometer preoperatively,1 month and 3 months postoperatively.The RMS value of spherical aberration,coma,the 3rd and 4th higher-order aberrations were calculated.ANOVA,and the linear correlation were used to analyze the data. Results After LASIK,the higher-order aberrations increased significantly for both small and large pupil.The higher-order aberrations 3 months after LASIK regressed slightly compared with the higher-order aberrations 1 month after LASIK at both small and large pupil.At large pupil,the spherical aberration,the 4th order higher-order aberration and the total higher-order aberrations after LASIK had significant positive correlation with myopic diopters before LASIK when the optical zone diameter was 6.25 mm. Conclusions After LASIK,the higher-order aberrations increase significantly,especially for spherical aberration.The higher-order aberrations after LASIK surgery have positive correlation with the myopic diopters before LASIK.For wavefront-guided refractive surgery,the myopic diopters before refractive surgery should not be too high.