Risk Factors for Progression of Keratoconus and Failure Rate After Corneal Cross-linking

To assess the occurrence of risk factors for progression of keratoconus and failure rate after corneal cross-linking (CXL) in patients with progressive keratoconus.

This retrospective study observed 230 eyes of 173 patients with a minimum follow-up of 36 months after CXL. A total of 185 eyes underwent CXL once (80%) (control) and 45 (20%) underwent this treatment more than once (Re-CXL-group). Subgroup analysis included standard CXL with the Dresden protocol (S-CXL group, n = 120) and accelerated CXL with a reduced radiation time of 10 minutes and a higher radiation power of 9 mW/cm² (A-CXL group, n = 110). Risk factors of interest were age, maximum keratometry (Kmax), minimum corneal thickness (MCT), sex, and atopy (including allergic bronchial asthma, food allergy, allergic rhinitis, and neurodermatitis).

Follow-up for the control group was 76.0 ± 33.2 months. Re-CXL was performed after 46.2 ± 34.1 months overall and after 62.6 ± 41.9 months in the S-CXL subgroup and 29.2 ± 19.2 months in the A-CXL subgroup (P = .02). Kaplan-Meier analysis revealed a cumulative prediction rate of success after CXL of 92.5% (S-CXL) and 86.4% (A-CXL) after 36 months (P = .103). A high preoperative Kmax value (odds ratio = 1.056, P = .003 and odds ratio = 1.067, P = .028) in both subgroups and the presence of neurodermatitis combined with other atopic diseases in the A-CXL group (odds ratio = 11.662, P = .003) were significant risk factors for new progression of keratoconus after CXL.

Risk factors for progression of keratoconus after CXL are both high preoperative Kmax values and the presence of neurodermatitis combined with other atopic diseases. Patients with severe atopy should receive the S-CXL procedure. [.