Ten-Year Outcomes Of Epithelium-Off Dresden Protocol Corneal Cross-Linking For Progressive Keratoconus

Published 2026 - 44th Congress of the ESCRS

Reference: FP02.01 | Type: Free paper | DOI: 10.82333/1ctz-ar88

Authors: Ms Michalina Ludwika Depczyńska* ¹ , Emilio A. Torres-Netto ² , Mark Hillen ³ , Léonard Kollros ⁴ , Theo G. Seiler ⁵ , Farhad Hafezi ⁶

¹ELZA Institute,Zürich,Switzerland;Faculty of Medicine, University of Geneva,Geneva,Switzerland, ²ELZA Institute,Zürich,Switzerland;Ocular Cell Biology Group, Center for Applied Biotechnology and Molecular Medicine, University of Zurich,Zürich,Switzerland, ³ELZA Institute,Zürich,Switzerland, ⁴ELZA Institute,Zürich,Switzerland;FHNW Institute for Optometry,Olten,Switzerland, ⁵Institut für Refraktive und Ophthalmo-Chirurgie,Zürich,Switzerland;USC Roski Eye Institute, University of Southern California,Los Angeles,United States, ⁶ELZA Institute,Zürich,Switzerland;Ocular Cell Biology Group, Center for Applied Biotechnology and Molecular Medicine, University of Zurich,Zürich,Switzerland;Faculty of Medicine, University of Geneva,Geneva,Switzerland;USC Roski Eye Institute, University of Southern California,Los Angeles,United States;Department of Ophthalmology, Wenzhou University,Wenzhou,United States;Department of Ophthalmology, New York University,New York,United States

Purpose

To evaluate the 10-year clinical, refractive, and tomographic outcomes of epithelium-off corneal cross-linking (CXL) using the original Dresden protocol in eyes with progressive keratoconus treated during the early clinical implementation phase in Zurich.

Setting

Retrospective interventional case series conducted at the IROC Institute and ELZA Institute, Zurich, Switzerland. Patients were treated between 2004 and 2010 and followed for a minimum of 10 years.

Methods

Progressive keratoconus, defined as ≥1.0 D increase in maximum keratometry (Kmax) within one year, was treated using standard epithelium-off CXL (riboflavin 0.1% with dextran; UV-A irradiation 3 mW/cm² for 30 minutes; total fluence 5.4 J/cm²). Only corneas ≥400 µm after epithelial removal were included. Preoperative and 10-year follow-up assessments included corrected distance visual acuity (CDVA), manifest refraction, and Scheimpflug-derived keratometric parameters (K1, K2, Kmean, Kmax), anterior surface asphericity, and thinnest pachymetry. Paired statistical analysis was performed, with p<0.05 considered statistically significant.

Results

Of 418 treated eyes, 51 had complete 10-year data; after excluding eyes that underwent additional procedures, 38 eyes (mean follow-up 10.9±1.0 years) were analysed. Kmax decreased by 1.30±3.20 D (p=0.004), K2 by 0.97±1.81 D (p=0.002), and Kmean by 0.62±1.49 D (p=0.014). CDVA improved by 0.15 logMAR (p=0.023). Pachymetry and refractive parameters remained stable. Fifty-three percent of eyes demonstrated >1 D Kmax flattening, 39% remained stable within ±1 D, and 8% showed progression ≥1 D. The overall long-term stabilization rate was 90%. One eye required repeat CXL, and two eyes underwent keratoplasty. No late infectious complications, limbal stem cell insufficiency, or visually significant scarring were observed.

Conclusions

Epithelium-off Dresden protocol CXL provides durable long-term stabilization of progressive keratoconus over 10 years, with sustained keratometric flattening, preserved or improved visual acuity, and a low retreatment rate. These findings confirm the long-term safety and biomechanical efficacy of the original protocol and support its role as the clinical reference standard against which modified CXL techniques should be evaluated.