Comparison of the effect of epithelial removal by transepithelial phototherapeutic keratectomy or manual debridement on cross-linking procedures for progressive keratoconus

Abstract

PURPOSE: To compare the visual, refractive, keratomet-ric, topographic, and pachymetric outcomes of corneal collagen cross-linking (CXL) for progressive keratoconus following epithelial removal by transepithelial photother-apeutic keratectomy (PTK) or manual debridement. METHODS: In this analysis, 339 eyes (78% male, 22% female) that had undergone CXL following manual epithelial debridement (n = 180) or ablation via PTK (n = 159) were evaluated preoperatively and at 6, 12, and 24 months postoperatively for uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), maximum corneal keratometry, pachymetry, and spherical equivalent. The data were analyzed in at test to evaluate the relative efficacy of each epithelial removal procedure. RESULTS: Manual epithelial debridement and ablation via PTK produce equivalent changes for all variables at each time interval with the exception of maximum cor-neal keratometry at 6 months postoperatively, for which PTK exhibited a significantly improved (fatter) result. This difference was present but not statistically signif-cant at 12 and 24 months postoperatively. CONCLUSIONS: Prior to CXL, both manual epithelial debridement and ablation via PTK result in equivalent visual, refractive, and keratometric outcomes up to 24 months postoperatively.