ULTRA HIGH-FLUENCE CORNEAL CROSS-LINKING (CXL) FOR EXTRACORPOREAL OPTIMIZATION OF CORNEAL ALLOGENIC INTRASTROMAL RING SEGMENTS (ECO-CAIRS): AN EX VIVO COMPARISON WITH CONVENTIONAL HIGH-FLUENCE CXL
Published 2025 - 29th ESCRS Winter Meeting
Reference: FP04.04 | Type: Free Paper | DOI: 10.82333/93k7-ba68
Authors: Farhad Hafezi* 1 , Emilio A. Torres-Netto 2 , Shady Awwad 3 , Mark Hillen 2 , M. Enes Aydemir 2
1ELZA Institute,Zurich,Switzerland;Faculty of Medicine,University of Geneva,Geneva,Switzerland;Department of Ophthalmology,Wenzhou Medical University,Wenzhou,China;National Eye Institute of Uzbekistan,Tashkent,Uzbekistan;Department of Ophthalmology,New York University Grossman School of Medicine,New York,United States;Department of Ophthalmology,University of Southern California,Los Angeles,United States, 2ELZA Institute,Zurich,Switzerland, 3Department of Ophthalmology,American University of Beirut Medical Center,Beiruit,Lebanon
Purpose
To assess the biomechanical strengthening effect of a novel ultra-high fluence CXL protocol and compare it with conventional high-fluence CXL in the context of extracorporeal optimization of corneal allogenic intrastromal ring segments (ECO-CAIRS).
Setting
ELZA Institute, Zurich, Switzerland.
Methods
This study utilized 84 porcine corneas, divided equally into four groups: Group A (control), Group B (10 J/cm²), Group C (30 J/cm²), and Group D (60 J/cm²). Following epithelial debridement, the intervention groups (B, C, and D) were treated with 0.1% hypo-osmolar riboflavin solution. UV-A irradiation at 365 nm was applied at different fluences: Group B received 10 J/cm² (18 mW/cm² for 9 minutes 15 seconds), Group C received 30 J/cm² (30 mW/cm² for 16 minutes 40 seconds), and Group D received 60 J/cm² (30 mW/cm² for 33 minutes 18 seconds). Corneal biomechanical properties were measured using stress-strain extensiometry, focusing on the elastic modulus.
Results
The mean elastic modulus (5%) values were as follows: Group A (control) 1.39 ± 0.49 N/mm, Group B (10 J/cm²) 1.83 ± 0.48 N/mm, Group C (30 J/cm²) 2.25 ± 0.83 N/mm, and Group D (60 J/cm²) 2.31 ± 0.88 N/mm. No significant difference in elastic modulus was observed between the two ultra-high fluence groups (C and D) (P = 1.00). However, both ultra-high fluence groups (C and D) exhibited significantly greater biomechanical stiffening compared to the conventional high-fluence group (B) (P = 0.041 and P = 0.015, respectively). A significant difference was also observed between Group B (conventional high-fluence) and the control Group A (P = 0.023).
Conclusion
Ultra-high fluence CXL provides superior biomechanical stiffening compared to conventional high-fluence CXL, making it an effective option for extracorporeal optimization of corneal allogenic intrastromal ring segments (ECO-CAIRS). In this extracorporeal setting, endothelial safety and haze are not concerns, and the increased stiffness promotes easier insertion and greater resistance to corneal swelling during the procedure.