LAUSR

PURPOSE To report the intra-operative changes in corneal pachymetry, efficacy and safety of accelerated corneal crosslinking (A-CXL) treatment using only hypo-osmolar riboflavin (HO-RF) solution in progressive keratoconus patients with thin corneas. SETTING University of Health Sciences, Prof. Dr. Cemil Tascioglu City Hospital, Istanbul, Turkey. STUDY DESIGN Retrospective study. METHODS Thirty-one eyes of 25 patients (mean age: 24.17±3.07 years) with thin keratoconic corneas (<400 µm without epithelium) who had A-CXL (9 mW/cm2-10 minutes) with HO-RF solution application were enrolled in the study. Peroperative corneal pachymetric changes and uncorrected-corrected distance visual acuities (UCVA-CDVA), refraction power values, topographic values and endothelial cell density (ECD) measurements were recorded pre-operatively and at 1st, 3rd, 6th and 12th month follow-up after surgery. RESULTS The mean thinnest corneal pachymetry (TCP) was 423 µm preoperatively and the thickness was reduced to a mean value of 375 µm after removing the epithelium. The mean thickness increased to 438 µm (p=0.001) after the application of HO-RF solution, and it was reduced to 424 µm (p=0.001) after ultraviolet irradiation. At all postoperative visits after month 1, there was a significant increase in both UCVA (p<0.05) and CDVA (p<0.01) values, and a significant decrease in both Kmax (p<0.05) and ECD (p<0.01) values. CONCLUSION Accelerated corneal CXL with only hypo-osmolar riboflavin solution application throughout the procedure in thin corneas is effective, but seems to result in a significant endothelial cell density decrease postoperatively.