Biomechanical stiffening effect in ultra-high-fluence extracorporeal cross-linked corneal allogenic intrastromal ring segments

Purpose: To compare the biomechanical stiffening effects of a novel ultra-high fluence corneal cross-linking (CXL) protocol with conventional high-fluence CXL for extracorporeal corneal allogenic intrastromal ring segment optimization (ECO-CAIRS). Setting ELZA Institute, Zurich, Switzerland. Design: Experimental, randomized, controlled ex vivo laboratory study using porcine corneas. No mask-ing was applied. Methods: Eighty-four porcine corneas were divided 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, Groups B, C, and D were treated with 0.1% hypo-osmolar riboflavin. UV-A irradiation was delivered at fluences of 10 J/cm2 (18 mW/cm2, 9:15 min) for Group B, 30 J/cm2 (30 mW/cm2, 16:40 min) for Group C, and 60 J/cm2 (30 mW/cm2, 33:18 min) for Group D. Corneal biomechanical properties were assessed via stress-strain extensiometry. Results: Mean elastic modulus (5% strain) values were: Group A (1.39 ± 0.49 N/mm), Group B (1.83 ± 0.48 N/mm), Group C (2.25 ± 0.83 N/mm), and Group D (2.31 ± 0.88 N/mm). Ultra-high fluence groups (C and D) showed significantly greater stiffening than Group B (P = 0.041 and P = 0.015), with no significant difference between Groups C and D (P = 1.00). Group B exhibited significantly greater stiffening than Group A (P = 0.023). Conclusions: Ultra-high fluence CXL enhances biomechanical stiffening compared to conventional high-fluence CXL, supporting its use in ECO-CAIRS. In this extracorporeal context, endothelial safety and haze are irrelevant, while increased stiffness facilitates intrastromal ring insertion and re-duces corneal swelling.

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610 - Medizin und Gesundheit

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1873-4502
0886-3350

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English

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Yes

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Published

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peer-reviewed

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Closed

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Aydemir, M. E., Kollros, L., Hillen, M., Boote, C., Meek, K. M., Hayes, S., Torres-Netto, E. A., Awwad, S. T., Depczyńska, M., Hafezi, N., & Hafezi, F. (2026). Biomechanical stiffening effect in ultra-high-fluence extracorporeal cross-linked corneal allogenic intrastromal ring segments. Journal of Cataract & Refractive Surgery. https://doi.org/10.1097/j.jcrs.0000000000001981

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