Long-term outcomes after high-energy accelerated pulsed corneal cross-linking (15 mW/cm2; 7.2 J/cm2) for keratoconus: a 6 years retrospective analysis.

PURPOSE: To assess the safety and efficacy of treatment and determine topographic changes, visual outcomes, and demarcation line (DL) depth after high-energy pulsed light accelerated cross-linking (pl-ACXL) in patients with progressive keratoconus (KC).

METHODS: This retrospective analysis included 33 eyes (22 patients) with progressive KC treated with high-energy epi-off pulsed accelerated corneal Cross-linking (7.2 J/cm2, 15 mW/cm2, 12 min, 2 s ON /1 s OFF). Corrected distance visual acuity (CDVA), Scheimpflug tomography, and anterior OCT measurements were recorded preoperatively and 1, 2, 3, 4, 5, and 6 years postoperatively.

RESULTS: Significant CDVA improvement + 0.03logMAR (p=0.03) and reduction in pachymetry -14.8 μm (p=0.0006) were observed over the six years. Kmax reduction - 1.14D (p=0.003) with statistical significance was observed at all follow-up times except the third year. Astigmatism showed mild worsening < 0.5D, with statistical significance (p=0.01) only at 1 and 2 years. Total aberration (CTA) showed a mild significant improvement of - 0.16 (p=0.04) only at 6 years. Coma aberration (CCA) had a slight improvement of - 0.24 (p=0.0008) with statistical significance at all time points, except in the first year. The DL depth was 261 ± 24 µm. Two patients developed mild haze without visual acuity loss. None of the patients required a second crosslinking procedure.

CONCLUSION: High-energy pl-ACXL appears to be an effective procedure for halting the progression of keratoconus and slightly improving the CDVA and keratometric values.