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Safety and Efficacy of Repeated Corneal Collagen Crosslinking in Progressive Keratoconus.

PURPOSE
Keratoconus is a progressive visually impairing disorder. Despite the beneficial effects of epithelial off-crosslinking (CXL) on the stabilization of keratoconus, progression may still occur. We report the efficacy and safety of a repeated CXL for significant progression of keratoconus after a single CXL procedure.


METHODS
This retrospective study includes patients diagnosed with progressive keratoconus who were previously treated with CXL and underwent repeated CXL. Demographic, clinical, and surgical data were retrieved and analyzed.


RESULTS
Ten consecutive eyes of nine patients who developed progressive keratoconus after CXL were identified. The mean age at diagnosis of keratoconus was 20.2 ± 6.0 years. The post-repeated CXL follow-up period was 2.1 ± 1.3 years. The mean best corrected visual acuity (BCVA) remained stable throughout the follow-up period. The mean Kmax at baseline was 60.4 ± 3.6 D. Before the repeated CXL, Kmax progressed significantly (P = 0.018) and was 62.2 ± 6.3 D, and at the last follow-up, the value decreased significantly (P = 0.037) and was 60.3 ± 6.4 D. The mean minimal pachymetry was 464.0 ± 27.0 µ at base line. Before the repeated CXL, minimal pachymetry was significantly lower (P = 0.018), and after the repeated CXL, the minimal pachymetry was stable (P = 0.2). No intra- or postoperative complications were noted.


CONCLUSIONS
Repeated CXL is a safe and effective treatment option when failure of the initial CXL is diagnosed, even in young patients. This procedure may prevent visual deterioration and a potential need for keratoplasty.