Excimer laser treatment of spherical hyperopia: PRK or LASIK?

Purpose: To compare the efficacy and safety of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) in the treatment of spherical hyperopia with use of the VISX STAR S2™ excimer laser. Methods: A review of 15 consecutive patients (22 eyes) receiving PRK and 22 consecutive patients (26 eyes) receiving LASIK (median follow-up, 12 months). Results: Mean age was 52 ± 7 years for patients receiving PRK and 55 ± 9 years for patients receiving LASIK. Mean preoperative spherical equivalent was +2.25 ± 1.16 D for PRK patients and +1.81 ± 0.92 D for LASIK patients. Mean deviation from intended correction was -0.82 ± 0.89 D after PRK and +0.19 ± 0.47 D after LASIK at 1 month (P <.01); +0.16 D ± 0.37 D after PRK and +0.29 ± 0.51 D after LASIK at 6 months (P = .906); +0.20 ± 0.35 D after PRK and +0.37 ± 0.44 D after LASIK at 1 year (P = .301). At 1 year, 83.3% of PRK eyes and 61.5% of hyperopic LASIK eyes were within ± 0.50 D of intended correction (P = 1.0). At 1 year, all eyes in both groups had acuity of 20/40 or better uncorrected, and 47.1% of PRK eyes and 54.5% of LASIK eyes had acuity of 20/20 or better uncorrected (P = 1.0). At last follow-up (minimum, 6 months), 2 eyes in each group had lost 2 lines of best spectacle-correct visual acuity, but none had lost more than 2 lines. All PRK patients experienced significant postoperative pain that required systemic medication. LASIK patients had only minor, transient discomfort. Conclusion: LASIK and PRK are of comparable efficacy and safety. However, PRK was associated with significant postoperative pain, an initial and temporary myopic overshoot peaking at 1 month, and stability not occurring before 6 months. LASIK was less painful and was associated with more rapid stability (at 1 month) and a trend toward better uncorrected visual acuity, although not statistically significant.