Prospective two-year study of clinical outcomes following epithelium-off pulsed versus continuous accelerated corneal crosslinking for keratoconus.

Objective: Keratoconus is a debilitating condition with a disproportionately high impact on health resources and vision-specific quality of life.

Background: This study aimed to compare 2-year outcomes of epithelium-off pulsed (p-ACXL) and epithelium-off continuous (c-ACXL) accelerated corneal crosslinking in progressive keratoconus.

Methods: Prospective, interventional case series. Methods: Eighty eyes of 80 patients were included. Methods: The visual, refractive and tomographic results of the two crosslinking protocols were compared. Methods: Uncorrected distance visual acuity, corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE) and maximum keratometry (KMAX ) on corneal tomography assessment.

Results: The mean patient age was 22.51 ± 6.12 years (SD) and 22.08 ± 5.72 years in the p-ACXL and c-ACXL groups, respectively. The mean CDVA significantly improved from 0.30 ± 0.16 logMAR at baseline to 0.23 ± 0.17 logMAR at 24 months (P = .04) in the p-ACXL group and from 0.36 ± 0.22 logMAR to 0.26 ± 0.27 logMAR (P = .02) in the c-ACXL group. The mean induced change in MRSE (+1.79 ± 2.30 D vs +0.27 ± 3.19 D, P = .04) and KMAX (-1.75 ± 1.80 D vs -0.39 ± 1.95 D, P = .04) were superior in the c-ACXL group compared to the p-ACXL group at 24 months. No complications were encountered.

Conclusions: In this prospective study, both p-ACXL and c-ACXL treatments were safe methods to halt the progression of keratoconus within a follow-up period of 24 months. c-ACXL appeared to offer superior refractive and tomographic outcomes when compared to p-ACXL but this did not translate into better visual outcomes.