Customized epithelial island corneal collagen cross-linking for progressive keratoconus

Abstract

Objective To evaluate the efficacy of epithelial island collagen cross-linking (CXL) for progressive keratoconus with thin cornea. Methods A prospective study, forty-two eyes of 42 cases with keratoconus with thickness less than 450 μm were enrolled. They received epithelial island CXL. The follow-up time was 12 months. Results One month postoperatively, the keratocytes apoptosis associated with nerve fibers loss in the 160 μm deep deeassociated under the epithelial island were observed with confocal microscope. The keratocytes apoptosis in the paracentral 250 μm deep epithelialized ring was recorded. Preoperative endothelial cell density was (2 455±73) cells/mm2. At the end of follow-up, final endothelial cells density was (2 459±69) cells/mm2. The difference was not statistically significant (t=1.68, P=0.21). Simulated K values at 12 months after surgery decreased 0.7±0.6 diopters, the difference was statistically significant (t=8.71, P=0.04). Coma values at 12 months after surgery decreased (0.7±0.1)μm, the difference was not statistically significant (t=7.43, P=0.06). Optical pachymetry demonstrated a slight decline at 3 months after surgery and the thickness resembled the baseline at 6 and 12 months follow-up. According to the VAS pain scale, the average value early postoperatively was 2(range 1-3), a mild pain could be tolerated. Conclusion Customized epithelial island cross-linking treatment(CXL) is a safe and effective method for progressive keratoconus with thin cornea. Key words: Cross-linking, collagen, cornea, epithelium island, customized; Keratoconus