Evaluation of Clinical Profile and Management Modalities in Eyes With Progressive Keratoconus After Primary Collagen Cross-Linking.

Purpose: To assess the risk factors, topographic and intraoperative parameters, and outcomes of patients presenting with progression after primary collagen cross-linking (CXL) for keratoconus (KC).

Methods: Data of patients who underwent repeat procedures after primary CXL were collected from the electronic medical records system. Demographic details, risk factors for progression, duration between primary and secondary procedure, topographic data, and data pertaining to CXL protocols were noted among these cases and compared against a group of stable eyes as controls. Progression was noted as an increase in maximum keratometry (Kmax) of 1 dioptre(D) in 1 year.

Results: Thirty-one eyes of 30 patients were included in the study of which 19 were male and 11 were female patients (M:F = 1.72). Control group included 40 eyes of 32 patients (21 male, 11 female patients) that underwent CXL and remained stable for 5 years. The mean age at the time of primary CXL was 17 ± 4.75 years among cases and 17.32 ± 5.18 years (P > 0.05) in the controls. A comparison of the 2 groups revealed a higher pre-CXL Kmax of 68.47 ± 12.05 D in the cases as compared with 62.94 ± 8.48D (P = 0.021) among controls. The mean time to diagnose progression after primary CXL was 74.77 ± 56.75 months (median = 60 months). Among the cases, 20 eyes underwent repeat CXL, while 4 eyes underwent deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PKP) was performed in 7 eyes.

Conclusions: Patients presenting with steeper Kmax are likely to progression despite CXL. All the eyes that underwent repeat CXL were stable until the last follow-up. When keratoplasty was planned, macroperforation leading to conversion of DALK to PKP must be anticipated in post CXL eyes.