Accelerated Corneal Crosslinking to Arrest Progression of Corneal Ectasia: A Prospective Multicenter Study

Abstract

Objectives: To report the results of epithelium-off accelerated corneal collagen crosslinking (accelerated corneal crosslinking [ACXL]) in patients with progressive keratoconus. Methods: This prospective, nonrandomized, noncomparative, interventional, multicenter clinical study included all patients who underwent ACXL, either continuous (c-ACXL; 9 mW/cm2, 10′, 5.4 J/cm2) or pulsed (p-ACXL; 2″ON/1″OFF, 30 mW/cm2, 4.5′, 5.4 J/cm2) between January 2014 and May 2017. Best-corrected visual acuity, sphere, cylinder, spherical equivalent, and topographical keratometry data were collected preoperatively and at 1, 3, 6, 12, 18, and 24 months postoperatively. Results: Ninety-six eyes of 78 patients were included. The mean age was 20.8±4.4 years (14–33) for c-ACXL and 26.7±7.7 years (12–37) for p-ACXL. The mean best-corrected visual acuity was 0.4±0.4 for c-ACXL and 0.01±0.1 for p-ACXL preoperatively, and 0.3±0.3 (P=0.0014) and −0.01±0.1 (P=0.1554), respectively, at the last follow-up. The subjective sphere and spherical equivalent did not show statistically significant differences between the time points (P>0.05). The subjective cylinder showed significant differences (P=0.0013 for c-ACXL; P=0.0358 for p-ACXL). Keratometric values (Ksteep, Kflat, and SimK) remained stable, with no statistically significant differences (P>0.05). No major complications were noted. Conclusions: Both c-ACXL and p-ACXL are equally safe and effective ACXL protocols in stabilizing the progression of keratoconus and can be considered alternatives to the conventional Dresden protocol.