Visual Outcomes of Photorefractive Keratectomy Enhancement After Primary LASIK

PURPOSE: To evaluate the safety, efficacy, and predictability of photorefractive keratectomy (PRK) at least 4 years after primary laser in situ keratomileusis (LASIK) and compare it to the United States Food and Drug Administration (FDA) criteria. METHODS: This retrospective, single-site study compared patients who underwent PRK enhancement from 2014 to 2019 after primary LASIK to those who only underwent primary LASIK without re-treatment from the same time period. Patient demographics and clinical information were compared between the two groups. Visual outcomes and postoperative complications were evaluated in the enhancement group. RESULTS: A total of 374 eyes with PRK enhancement were compared to 472 without re-treatment. Age, sex, surgical eye, and preoperative sphere, and spherical equivalent (SE) were significantly different between the enhancement and control groups (P <.05). At 12 months post-enhancement, 67% had uncorrected distance visual acuity (UDVA) of 20/20 or better, 98% had UDVA of 20/40 or better, and 0.4% of eyes lost at least two lines of corrected distance visual acuity (CDVA). A total of 83% and 98% of eyes were within +/- 0.50 and +/- 1.00 diopters of the target, respectively. Post-enhancement complications (n = 66) included dryness (6.1%), epithelial ingrowth (2.7%), and haze (2.7%). CONCLUSIONS: Older age at the time of the primary LASIK, female sex, right surgical eye, and more myopic sphere and SE were risk factors for enhancement. Although PRK enhancements are considered off-label procedures, they produce favorable outcomes at 3 and 12 months postoperatively while meeting FDA benchmarks for safety, efficacy, and predictability.