Clinical efficacy of corneal collagen cross-linking with hypo-osmolar riboflavin solution in keratoconic corneas

Objective To evaluate the efficacy of corneal collagen cross-linking (CXL) with a hypo-osmolar riboflavin in keratoconic corneas (corneal thickness less than 400 μm). Methods This retrospective study collected a total of eight eyes of eight keratoconic patients. All patients underwent CXL used a hypo-osmolar riboflavin solution after epithelial removal. The best corrected visual acuity (BCVA), manifest refraction, the thinnest corneal thickness (TCT), and the endothelial cell density (ECD) were evaluated at before and 6, 12 months after CXL. Results The TCT was 418.0 μm before treatment and reduced to 383.5 μm after the removal of the epithelium. After CXL, the thickness decreased to 414.0 μm at the last follow up. Before treatment, the K-value of the apex of the keratoconus corneas was 58.2 D, and was 58.9 D at 12-month. The BCVA was 0.52 logarithm of the minimal angle of resolution before treatment, and increased to 0.46 logarithm at the last follow up. The ECD was 2 698.5 cells/mm2 before treatment, and was 2 685.9 cells/mm2 at 12-month after treatment. Conclusion CXL with a hypo-osmolar riboflavin is one of safe and effective treatment in keratoconic eyes with thin corneas (corneal thickness less than 400 μm). Key words: Corneal collagen cross-linking; Keratoconus; Riboflavin, hypo-osmolar; Therapy outcome