Long-term follow-up results of corneal collagen cross-linking in keratoconus

Objective: To evaluate the changes in corneal parameters (keratometry, corneal thickness, topography indices) after corneal collagen cross-linking in keratoconus. Methods: The medical records of 6 patients who underwent corneal collagen cross-linking treatment for keratoconus and have been followed-up for a minimum of 24 months were recruited. Best corrected visual acuity (BCVA), maximum keratometry (Kmax), central corneal thickness (CCT) values and corneal topography indices: index of surface variance (ISV), index of vertical asymmetry (IVA), keratoconus index (KI), central keratoconus index (CKI), minimum radius of curvature (Rmin), index of height asymmetry (IHA), and index of height decentralisation (IHD) were recorded. Results: The mean preoperative Kmax value was 46.67±4.15 (43.30-57.10) D and the mean Kmax value at the final postoperative visit was 45.41±2.95 (43.00-53.20) D. Mean preoperative CCT was 494.70±33.69 (438-537) µm and final postoperative mean CCT was 495.60±34.99 (433-539) µm. The deterioration in corneal topography indices stopped during the follow-up period of each case. Conclusion: Stopping the deterioration of corneal parameters in keratoconus is the desired outcome after cross-linking treatment. Our results found an improvement or at least stabilization in all topography indices in keratoconus patients.