A HIGH-FLUENCE ACCELERATED EPITHELIUM-OFF CXL PROTOCOL PROVIDES A SIMILAR CLINICAL BIOMECHANICAL EFFECT TO DRESDEN PROTOCOL CXL: 1-YEAR FOLLOW-UP DATA

To date, the original Dresden epi-off CXL protocol remains the protocol with the strongest biomechanical effect and thus is still preferred over accelerated CXL protocols in aggressive forms of ectasia (keratoconus in children, postoperative ectasia).

The aim of the present study is to present the results of an evaluation of the clinical and biomechanical outcomes of an accelerated high-fluence epi-off CXL protocol for treating progressive keratoconus and post-refractive surgery ectasia.

The study was conducted at the ELZA Institute, Zurich, Switzerland.

Eyes with progressive ectasia underwent epi-off CXL. Each eye underwent epithelial debridement and received a 0.1% riboflavin solution application for 10 minutes (Ribo-KER, EMAGine AG, Switzerland), followed by UV irradiation at 18 mW/cm² for 9 minutes and 15 seconds (C-eye, EMAGine AG). Comprehensive corneal evaluations including topography, tomography, and biomechanical assessments using devices such as Pentacam, CorVis ST (both Oculus, Germany), and MS-39 (CSO Italia, Italy) were performed at baseline, post-procedure, and at all subsequent follow-up visits up to the 1-year mark, as well as standard slit lamp and visual acuity assessments.

Forty-two eyes of 35 patients were treated with high-fluence CXL. The average depth of the postoperative demarcation line was 257µm. The one-year outcomes of high-fluence epi-off CXL treatment in patients with progressive keratoconus showed no significant changes in thinnest corneal thickness (Δ -3.71μm [445.17 μm, 441.45 μm], p = 0.14) or thinnest epithelial thickness (Δ 1.05 μm [41.12 μm, 42.17 μm], p = 0.24) values. Endothelial cell density remained stable following high-fluence CXL treatment (Δ 4.17 [2637, 2641], p = 0.87).

This study validates in a clinical setting our previous ex vivo laboratory study (TVST 2021) that shows that an accelerated higher fluence epi-off CXL protocol with an optimized UV delivery protocol can induce corneal strengthening comparable to the Dresden protocol. This approach appears to be a viable option for patients with progressive keratoconus or post-refractive surgery ectasia, offering a shortened treatment duration while strengthening the cornea to a comparable extent to the Dresden protocol.