Photorefractive Keratectomy in Keratoconus

PURPOSE To assess the efficacy and safety of topography-guided photorefractive keratectomy (PRK) for keratoconus and to estimate the subsequent risk of progression. METHODS This is a retrospective follow-up study. Between 1998 and 2013, 28 eyes of 23 patients (age 17-60) with grade 1-3 keratoconus received topography-guided PRK. Corrected-distance visual acuity (CDVA), keratometry, pachymetry, and corneal topography were assessed before, after 3 months, and at a late follow-up of a median of 7 years after the procedure. Postoperative complications including subsequent keratoplasty were noted. RESULTS Of the 28 eyes, 5 (18%percnt;) had undergone corneal transplantation at a median of 7 years (range 3-10) after PRK. Four eyes were not available for follow-up. In the remaining 19 eyes, CDVA was improved in 16 eyes (84.3%percnt;), reduced in 2 eyes (10.5%percnt;), and unchanged in 1 eye (5.2%percnt;). Thus, average CDVA had improved from 0.49 logMAR before PRK to 0.27 logMAR at 3 months, and to 0.24 at the long-term follow-up. The mean spherical equivalent was reduced from - 6.2 to -3.7 dpt after 3 months and to -2.1 dpt at the late follow-up. Similarly, the mean cylinder was reduced from -4.2 to -3.0 dpt after 3 months and at the late follow-up. CONCLUSION Topography-guided PRK in keratoconus may be effective for reducing myopia and astigmatism and may offer a temporary or permanent alternative to keratoplasty in contact lens-intolerant keratoconus. In the present study, we found a low risk of keratoconus progression after PRK.