Repeated Corneal Cross-Linking For Progressive Ectasia Following Primary Corneal Cross-Linking Failure

This study was conducted at the ELZA Institute, Dietikon, Switzerland.

Retrospective analysis of 21 eyes (19 keratoconus, 2 post-LASIK ectasia) from 18 patients undergoing Re-CXL was conducted. All received epithelium-off CXL with riboflavin soaking and UVA irradiation, averaging 10.95 ± 2.3 J/cm² total fluence. Treatment protocols were individualized. Corneal parameters (Kmax, K1, K2, thinnest pachymetry, and ARC in a 3 mm zone) were measured preoperatively, at 6 months, and at a final 1 year follow-up using Scheimpflug imaging (Pentacam HR). Paired t-tests and Wilcoxon signed-rank tests assessed changes (p < 0.05), and Kendall’s Tau correlations evaluated the relationship between fluence and keratometric outcomes.

Significant improvements in Kmax, K1, and K2 were observed following Re-CXL (p < 0.05), indicating effective corneal stabilization. Although the correlation analyses did not achieve statistical significance at α = 0.05, a trend was observed suggesting that higher total fluence may be associated with a more pronounced keratometric flattening effect. Pachymetric measurements remained within safe limits, and no cases of corneal decompensation were observed.

The findings suggest that repeated CXL is effective in stabilizing progressive ectasia after primary CXL failure with significant reductions in keratometric values. While the correlation between total fluence and keratometric outcomes did not reach statistical significance, the observed trend indicates that higher fluence levels may contribute to greater corneal flattening. Re-CXL may therefore be considered a viable option in the broader treatment algorithm for managing ectatic disorders. Nonetheless, the retrospective nature of the study and the relatively small sample size underscore the need for larger, prospective studies to further optimize treatment protocols and clarify the role of fluence in achieving desired keratometric outcomes.