Correlation between Ocular Wavefront Aberrations and Contrast Visual Acuity before and after Q-LASIK

Objective To investigate the correlation between ocular high-order aberration and contrast visual acuity(CVA) in low and moderate myopice eyes before and after Q-LASIK. Methods Thirty-six low-moderate myopia patients(36 right eyes) were enrolled in this study.Some representative high-order aberration and CVA with 4 contrast concentrations(100%,25%,10%,5%) were measured by Allegro wavefront analyzer and multi-functional visual acuity tester(MFVA-1000).Multiple linear regression was used to analyze the relationships between ocular high-order aberration and CVA with dark background in dark environment before and 1,3months after surgery. Results One and 3 months after surgery,the vertical coma and total aberration decreased,while the spherical aberration,4th order aberration and total high-order aberration increased obviously(P0.05).The 4 contrast concentrations of visual acuity were higher than those of CVA before surgery(P0.05).Before surgery,the vertical coma,spherical aberration and total high order aberration were significantly correlated with the visual acuity at the contrast concentration of 10%(P0.05),the spherical aberration was significantly correlated with the visual acuity at the contrast concentration of 5%(P0.01).One month after surgery,the spherical aberration was significantly correlated with the visual acuity at each low contrast concentration(P0.05),the 4th order aberration and total high order aberration were significantly correlated with the 4 contrast concentrations of visual acuity(P0.05).Three months after surgery,the spherical aberration was significantly correlated with the visual acuity at each low contrast concentration(P0.05),4th order aberration was significantly correlated with four contrast levels of visual acuity(P0.05).Beside,the total high-order aberration was significantly correlated with the visual acuity at the contrast concentrations of 10% and 5%(P0.05).Others were not(P0.05). Conclusions Coma and spherical aberration are the important factors for visual performance.However,the main aberration factor affecting postoperation visual performance is spherical aberration under dark environment in low and moderate myopic eyes.