Epi-on Versus Epi-off Accelerate Corneal CXL for Progressive Keratoconus: 1-Year Follow-up

Sunday, April 19, 2015: 9:00 AM
Room 5B (San Diego Convention Center)
Luis Izquierdo Jr, MD
Maria A. Henriquez, MD
Mauricio Rodriguez Diaz, MD

Purpose
To evaluate and compare the safety and efficacy of accelerate corneal collagen crosslinking (CXL) epi-on versus epi-off in progressive keratoconus.

Methods
This prospective and comparative study included 60 eyes with progressive keratoconus. 30 eyes underwent transepithelial CXL (epi-on), and 30 eyes conventional CXL removing the epithelium (epi-off); between July 2013 and July 2014.  The solution for epi-on was TE-riboflavin and for epi-off was isotonic M-riboflavin (Peschke Ltd, Germany); for both procedures the time of impregnation was 30 minutes and  Ultraviolet-A treatment was performed with CCL-VARIO (Peschke Ltd, Germany) with 5 minutes of irradiation (18mW). Scheimpflug imaging parameters where evaluated at pre and postoperatively at 1, 6 and 12 months; as the demarcation line using AS- OCT (anterior segment optical coherence tomography).

Results
Mean crosslinking depth in epi-on group using AS-OCT at the center of the cornea was 243.05 um, compared to 270.19 um in the epi-off group, with statistically significant difference between groups (p < .001). Mean maximum posterior elevation decreased from 28.14 um to 27.00 um (p = 0.009) in the epi-on group and from 24.14 um to 22.55 um in the epi-off group (p = 0.034) at 1 year, with no statistically significant difference between groups (p = 0.310). Mean decrease in the maximum keratometry was 0.71 Diopters (D) in the epi-on compared with 1.42D in the epi-off group (p =0.05).

Conclusion
Both accelerate crosslinking epi-on and epi-off procedures are safe and efficacy to stop the progression of the keratoconus. AS-OCT images showed that epi-off CXL had deeper demarcation line compared with epi-on CXL.