Abstract
Abstract: :
Purpose: Although clinically acceptable results can be obtained by laser in-situ keratomileusis (LASIK) in terms of high contrast visual acuity for day vision, some patients following refractive surgery complain difficulty in night driving. It this study, we measured the mesopic vision and the association between mesopic vision and wavefront aberration was investigated to find the factors that deteriorate the mesopic vision.Methods: The subjects in the study included 66 normal eyes, 22 mild keratoconic eyes, and 32 eyes following LASIK. The best spectacles-corrected visual acuity (BSCVA) was 20/20 or better for all eyes. Mesopic vision was measured with MesotestII (Oculus, Germany). Results were recorded as correctly recognized numbers of optotypes (From 0 to 24). Wavefront sensing was performed with the Wavefront analyzer (Topcon Corp., Japan) for 6mm diameter, and total higher-order aberrations up to 6thorders (RMS error, µm) were obtained. Correlation between higher-order aberration and mesopic vision was studied.Results: Mesopic vision in normal group (20.63.7) was significantly better than that in LASIK (13.0±6.2) or in keratoconus (3.8 ± 4.1)(p<0.05, One Way ANOVA). Similarly, total higher-order aberration in normal group (0.33 0.09µm) was significantly better than that in LASIK (0.82 0.25µm) or in keratoconus (1.45 0.66µm)(p<0.05, One Way ANOVA). There was a significant correlation between mesopic vision and higher-order aberration (R= 0.63, p=0.001).Conclusion: Even if subjects had normal day vision for high-contrast visual acuity, their mesopic vision can be widely scattered. This loss of mesopic vision can be explained with higher-order aberration for large pupil measured with wavefront sensor.
Keywords: 368 contrast sensitivity • 544 refractive surgery • 450 keratoconus