Ocular Higher-Order Aberrations and Contrast Visual Function After Laser In Situ Keratomileusis

Abstract

Abstract: : Purpose: To investigate the relationship between higher-order aberrations of the eye and contrast sensitivity after conventional laser in situ keratomileusis (LASIK) for myopia. Methods: In 200 eyes of 110 consecutive patients (age 32.7+/-8.4 years) undergoing LASIK, ocular aberrations and contrast sensitivity function were determined before and 1 month after surgery. The amount of myopic correction was 5.2+/-2.8D (1.0~13.0D). We examined higher-order aberrations for a 4-mm pupil using the wavefront analyzer (Topcon KR-9000PW), contrast sensitivity using the CSV-1000E (Vector Vision), low contrast visual acuity using the CSV-1000LanC10%, and letter contrast sensitivity using the CSV-1000LV. From the data of CSV-1000E, the area under the log contrast sensitivity function (AULCSF) was calculated. Results: LASIK significantly improved logMAR best-corrected visual acuity (paired t-test, p<0.001), but reduced AULCSF (p<0.001), low contrast visual acuity (p=0.005), and letter contrast sensitivity (p<0.001). Coma (p<0.001) and spherical (p<0.001) aberrations significantly increased by LASIK. Increases in ocular higher-order aberrations showed significant correlations with AULCSF (coma r=-0.332, p<0.001; spherical r=-0.359, p<0.001), logMAR low contrast visual acuity (r=0.462, p<0.001; r=0.339, p<0.001), and letter contrast sensitivity (r=-0.235, p=0.001; r=-0.200, p=0.006). The amount of myopic correction correlated with the degree of deterioration of these indices for contrast sensitivity function. Conclusions: The conventional LASIK increases ocular higher-order aberrations, which significantly correlate with reductions in contrast sensitivity function after LASIK.

Keywords: refractive surgery: LASIK • contrast sensitivity • cornea: clinical science