Long-term course of contrast sensitivity in eyes after laser-assisted in-situ keratomileusis for myopia.

Purpose To evaluate the long-term contrast sensitivity (CS) after laser in-situ keratomileusis (LASIK) for myopia. Methods This retrospective, single-center, cohort study involved 190 eyes of 95 patients who underwent bilateral LASIK between January 2001 and October 2007. This study includes patients who underwent CS and higher-order aberration (HOA) measurements in a five-year postoperative period. For all enrolled patients, visual acuity, refractive error (RE) in diopters (D), CS at 3-, 6-, 12-, and 18-cycles per degree (cpd), and HOA in a 4 mm area of the dilated pupil were measured before surgery and 6 months, 1 year, and 5 years after it. Results The mean RE measured before the surgery and after 6 months, 1 year, and 5 years after was -6.08 ± 2.50D, -0.26 ± 0.65D, -0.28 ± 0.65D, and -0.48 ± 0.80D, respectively. There were no clinically significant changes between preoperative results and the measures taken 6 months, 1 year, and 5 years after surgery. The slight increase in HOA had little effect on CS over the mid to long-term postoperative period. Conclusion Our findings show that CS does not clinically change post LASIK. Although we were unable to identify the specific mechanism, we theorize that after LASIK there is a possibility for the compensation of HOA.