Comparison of photorefractive keratectomy with excimer laser in situ keratomileusis in correcting low myopia (from -2.00 to -5.50 diopters) - A randomized study

Objective: To compare laser in situ keratomileusis (LASIK) with photorefrac tive keratectomy (PRK) in the correction of myopia from -2.00 to -5.50 diop ters. Design: Prospective, randomized, paired clinical trial. Participants: Fifty-two eyes of 26 myopic patients were enrolled in the stu dy. Intervention: Each patient received PRK on one eye (PRK eye) and LASIK on t he other (LASIK eye); the procedure assigned to each eye, and the sequence of surgeries for each patient was randomized. Main Outcome Measures: Slit-lamp microscopy, manifest refraction, uncorrect ed and spectacle-corrected visual acuity, and videokeratography were done b efore operation, and 2 weeks, 6 weeks, 3 months, 6 months, and 12 months af ter operation, Patient satisfaction and preference were assessed by a subje ctive questionnaire. Results: All LASIK eyes had fast, painless recovery. At 1 year, 24 patients (92.3%) were examined, the mean spherical equivalent refraction was -0.08 +/- 0.38 diopter in the PRK eyes and -0.14 +/- 0.31 diopter in the LASIK ey es, and the uncorrected visual acuity was 20/20 or better in 15 PRK eyes (6 2.5%) and 19 LASIK eyes (79.2%); no eye lost 2 or more Snellen lines of spe ctacle-corrected visual acuity. Both procedures were stable throughout the first year. One PRK eye developed dense subepithelial corneal haze. The str ongest correlate to spectacle-corrected visual acuity after the two procedu res was the coefficient of variation of corneal power over the pupil. Ninet een patients (79.2%) preferred the LASIK procedure because of the fast, pai nless recovery. Conclusions: In the current study, PRK and LASIK were found to be similarly effective, predictable, stable, and reasonably safe for the correction of myopia between -2.00 and -5.50 diopters. Laser in situ keratomileusis has t he advantage of fast, painless recovery. Patients prefer LASIK.