Outcomes of Photorefractive Keratectomy Enhancement After LASIK

PURPOSE: To report the outcomes of photorefractive keratectomy (PRK) enhancement after LASIK for patients diagnosed as having hyperopic and myopic refractive errors. METHODS: In this retrospective case series at a single private practice in the United States, all patients undergoing PRK enhancement after LASIK were identified. Patients with visually significant cataract, non-plano targets, and follow-up of fewer than 226 days were excluded. The primary outcome measure was uncorrected distance visual acuity (UDVA) with secondary measures of corrected distance visual acuity (CDVA) and postoperative refractive error. Linear regression analysis was performed for actual versus targeted change in spherical equivalent. RESULTS: Mean UDVA improved from 20/39 to 20/24 for hyperopes (n = 14; P < .002) and from 20/45 to 20/22 for myopes (n = 29; P <.0000001) after enhancement. All patients had a UDVA of 20/40 or better at their most recent follow-up visit. Fifty percent of hyperopes and 65.5% of myopes were 20/20 or better. The mean refractive error for hyperopes changed from +1.10 +/- 0.71 (range: +0.13 to +2.25 diopters [D]) to +0.38 +/- 0.66 D (range: -0.75 to +1.38 D) and from -1.21 +/- 0.61 (range: -3.25 to -0.38 D) to +0.34 +/- 0.45 D (range: -0.25 to +1.75 D) for myopes. The manifest refraction cylinder decreased from 0.84 to 0.46 D in hyperopes (P = .02) and from 0.64 to 0.26 D in myopes (P < .002). CDVA was maintained in both groups, with only one patient in each worse than 20/20. There was a nonsignificant trend toward less haze in the patients receiving mitomycin C (5.1% vs 25%, P = .14). Linear regression showed a tendency toward overtreatment in the myopic group. CONCLUSIONS: PRK is safe and highly effective for patients who previously underwent LASIK and in whom the surgeon would prefer not to perform a flap-lift enhancement.