Standard cross‐linking protocol versus accelerated and transepithelial cross‐linking protocols for treatment of paediatric keratoconus: a 2‐year comparative study

Purpose To compare the efficacy, safety and stability of standard epithelium‐off cross‐linking (SCXL) versus accelerated epithelium‐off cross‐linking (ACXL) and transepithelial epithelium‐on cross‐linking (TCXL) in the treatment of progressive keratoconus (KC) in children. Methods This prospective multicentre controlled trial included 271 eyes (136 children) with grade 1–3 progressive KC who were randomized to undergo SCXL (n = 91, as a control group), ACXL (n = 92) or TCXL (n = 88). Uncorrected and corrected distance visual acuity, subjective refraction, pachymetry, keratometry and corneal topography measurements were recorded preoperatively and 6, 12 and 24 months postoperatively. Results At 1 year, there was no significant difference in uncorrected distance visual acuity, refractive sphere, cylinder, spherical equivalent or Kmax between the ACXL and SCXL groups; however, during year 2, ACXL regressed while SCXL continued to improve. After 2 years, there were significant differences in all visual, refractive and keratometric components between SCXL and both ACXL and TCXL (p