Long-term refractive outcomes and stability after excimer laser surgery for myopia

Abstract

To evaluate the long-term refractive outcomes of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for myopia. Centre for Eye Research Australia, Melbourne, Australia. Comparative case series. Preoperative baseline refractions in eyes having PRK, LASIK, or both at 1 multisurgeon center were analyzed from patient databases. Two- to 13-year follow-up data were analyzed and compared with 1-month postoperative visual outcomes. The study evaluated 389 eyes (229 patients). In the PRK group, the mean preoperative spherical equivalent (SE) was -4.05 diopters (D) ± 1.17 (SD) in eyes with low to moderate myopia and -7.97 ± 2.00 D in eyes with high myopia (P = .009) and in the LASIK group, -3.98 ± 1.27 D and -7.64 ± 1.66 D, respectively (P = .008). At the last visit, the mean SE in the PRK group was -0.64 ± 0.83 D in eyes with low to moderate myopia and -1.06 ± 1.74 D in eyes with high myopia (P = .73) and in the LASIK group, -0.33 ± 0.59 D and -0.63 ± 0.90 D, respectively (P = .68). At the end of the study, 45.9% of eyes with low to moderate myopia and 25.0% with high myopia in the PRK group and 64.8% and 37.3%, respectively, in the LASIK group were within ± 0.50 D of the attempted correction. Laser refractive surgery effectively treated all levels of myopia. Refractive stability was achieved within 1 year postoperatively, with LASIK showing better stability than PRK for up to 6 to 9 years.