Evaluation of the outcomes of corneal collagen cross-linking in progressive keratoconic eyes

Abstract

BACKGROUND: Corneal collagen cross-linking (CXL) is gaining popularity as a treatment in arresting the progression of keratoconus. It is a relatively new therapy using ultraviolet-A (UVA) with a photosensitizer to increase corneal stiffness. The purpose of this study was to evaluate visual, keratometric and topographic outcomes after corneal CXL in progressive keratoconic eyes. MATERIALS AND METHODS: In this prospective nonrandomized clinical study, 140 eyes of 110 patients with progressive keratoconus were treated by combined riboflavin/UVA CXL. Mean sphere, mean cylinder uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refractive spherical equivalent, corneal topography, pachymetry, and endothelial cell morphology were examined preoperatively and 12-24 months postoperatively. RESULTS: The preoperative mean sphere was -3.33 +/- 3.13 diopter (D) and decreased to -3.09 +/- 3.09 D (P = 0.007). The preoperative mean cylinder was -4.05 +/- 2.29 D and changed to -3.79 +/- 2.23 D (P = 0.011). UDVA changed from 0.95 +/- 0.64 logarithm of the minimum angle of resolution (logMAR) to 0.85 +/- 0.59 logMAR (P = 0.003). Thirty-five eyes (25) gained one or more lines of preoperative UDVA, 87 eyes (62.1) did not change and 18 eyes (12.8) lost one or more lines of the preoperative UDVA. CDVA in 80 of the patients remained stable (no lines lost). Statistical analysis of keratometry, pachymetry, and endothelial cell count did not show the significant difference after surgery. CONCLUSION: Our study showed improvement in visual and refractive results of the corneal CXL and confirmed that CXL is the safe and effective procedure.