DEHYDRATION AND REHYDRATION BEHAVIOUR OF ULTRA-HIGH-FLUENCE EXTRACORPOREAL CROSS-LINKED CORNEAL ALLOGENIC INTRASTROMAL RING SEGMENTS (ECO-CAIRS)

Published 2026 - 30th ESCRS Winter Meeting

Reference: PO042 | Type: Presented Poster & Poster | DOI: 10.82333/4355-q715

Authors: Farhad Hafezi** ¹ , Léonard Kollros ¹ , M. Enes Aydemir ¹ , Mark Hillen ¹ , Craig Boote ² , Keith M. Meek ² , Sally Hayes ² , Shady T. Awwad ³ , Michalina Depczyńska ¹ , Nikki Hafezi ¹ , Emilio A. Torres-Netto ¹

¹ELZA Institute,Zurich,Switzerland, ²School of Optometry and Vision Sciences,Cardiff University,Cardiff,United Kingdom, ³American University of Beirut Medical Center,Beiruit,Lebanon

Purpose

To evaluate the impact of ultra-high-fluence extracorporeal corneal cross-linking on the dehydration and rehydration dynamics of porcine corneal stromal ring segments, simulating preparation steps used for extracorporeal corneal allogenic intrastromal ring segments (ECO-CAIRS).

Setting

ELZA Institute, Zurich, Switzerland.

Methods

Corneal ring segments (two per cornea) were prepared from freshly enucleated porcine corneas (n=48) and randomly assigned to three groups: control (no CXL, “Jerky” technique), 30 J/cm², and 60 J/cm² (n=32 each). After epithelial removal, the control group was soaked in balanced salt solution (BSS), while the CXL groups were soaked in 0.1% riboflavin (Ribo-Ker, EMAGine AG, Zug, Switzerland) for 10 minutes before ultraviolet-A irradiation (365 nm) at 30 mW/cm² using the C-eye device. The total dehydration period (irradiation + passive drying) was standardized to 45 minutes, followed by a 10-minute BSS rehydration phase. Segment thickness was measured by calibrated digital imaging at baseline, after dehydration, and after rehydration.

Results

Baseline thickness did not differ between groups. Both CXL-treated groups showed significantly greater dehydration (p < 0.01) and reduced rehydration (p < 0.01) compared with controls, with no significant difference between the 30 J/cm² and 60 J/cm² groups. Median dehydration was 308 µm (control), 360 µm (30 J), and 402 µm (60 J), while median rehydration was 178 µm (control), 81 µm (30 J), and 105 µm (60 J).

Conclusion

Ultra-high-fluence extracorporeal cross-linking enhances dehydration and slows rehydration of corneal stromal ring segments, producing thinner, more dimensionally stable tissue. These effects may improve intraoperative handling, prolong the surgical window, and reduce deformation during CAIRS implantation. ECO-CAIRS, therefore, represents a promising optimization step in the preparation of allogenic corneal ring segments.