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Photorefractive keratectomy versus laser in situ keratomileusis: a control-matched study
Objective:
Photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) outcomes were compared at 1, 3, 6, and 12 months after surgery.
Design:
Retrospective, nonrandomized, comparative study.
Participants:
One hundred seven LASIK-treated eyes (58 patients) and 107 PRK-treated eyes (91 patients) having myopia between -1 and -9.50 diopters (D). All LASIK-treated eyes were analyzed retrospectively and matched with PRK-treated eyes having sphere within +/-0.25 D, +/-1 D of cylinder, and +/-7 years of age.
Intervention:
For PRK and LASIK, the refractive surgery was performed with the slit-scanning excimer laser Nidek EC-5000, (Nidek Co. Tokyo, Japan)
Main Outcome Measures:
Manifest refraction, best-spectacle and uncorrected Snellen visual acuity, haze, halos, and keratometry were evaluated before surgery and up to 12 months after surgery.
Results:
Seventy percent of eyes were evaluated at the 12-month postoperative exam. Of these eyes, 83% of LASIK cases and 86% of PRK cases had uncorrected visual acuities of 20/20 or better. Refractions within +/-0.5 D represented 78% of the LASIK eyes and 83% of the PRK eyes at that follow-up. Patients who underwent LASIK reported halos twice as often as patients who underwent PRK using a subjective scale. The odds ratio of high halos for LASIK versus PRK was 3.50 (95% confidence interval, 1.89-6.46; P<0.0001). At 1 month after surgery, 64% of the LASIK eyes were within +/-0.50 D compared with 77% of the PRK eyes. No eye lost 2 Snellen lines of best corrected visual acuity at 6 or 12 months after surgery. Ten PRK eyes (9.3%) and three LASIK eyes (2.8%) were retreated.
Conclusions:
PRK and LASIK achieved equal refractive outcomes at all postoperative follow-ups, but LASIK patients were twice as likely to experience halos.