ESCRS - CR03.06 - EXTRACORPOREAL OPTIMIZATION OF CORNEAL ALLOGENIC INTRASTROMAL RING SEGMENTS (ECO-CAIRS) USING ULTRA HIGH-FLUENCE CORNEAL CROSS-LINKING

EXTRACORPOREAL OPTIMIZATION OF CORNEAL ALLOGENIC INTRASTROMAL RING SEGMENTS (ECO-CAIRS) USING ULTRA HIGH-FLUENCE CORNEAL CROSS-LINKING

Published 2025 - 29th ESCRS Winter Meeting

Reference: CR03.06 | Type: Case Report (Cornea Day) | DOI: 10.82333/yvm2-xc56

Authors: Farhad Hafezi* 1 , M. Enes Aydemir 2 , Mark Hillen 2 , Shady Awwad 3 , Léonard Kollros 2 , Fabian Müller 4 , Cosimo Mazzotta 5 , Nikki Hafezi 6 , Larissa Paulasto 2 , Emilio A. Torres-Netto 2

1ELZA Institute,Zurich,Switzerland;Faculty of Medicine,University of Geneva,Geneva,Switzerland;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;Department of Ophthalmology,Wenzhou Medical University,Wenzhou,China;National Eye Institute of Uzbekistan,Tashkent,Uzbekistan, 2ELZA Institute,Zurich,Switzerland, 3Department of Ophthalmology,American University of Beirut Medical Center,Beiruit,Lebanon, 4Ziemer Ophtalmic Systems,Port,Switzerland, 5Siena Crosslinking Center,Siena,Italy, 6ELZA Institute,Zurich,Switzerland;National Eye Institute of Uzbekistan,Tashkent,Uzbekistan

Purpose

To describe a novel technique for treating keratoconus using corneal allogenic intrastromal ring segments (CAIRS) prepared with a femtosecond laser and cross-linked extracorporeally using ultra-high fluence corneal cross-linking (ECO-CAIRS) prior to implantation, aimed at improving segment rigidity and insertion outcomes.

Setting

Four eyes (4 patients) with stable keratoconus (Kmax 58.0-69.8D) and corneal thickness ≤400µm at 5mm from the pupil center were included. CAIRS were prepared from human donor corneas using a femtosecond laser. The segments were subjected to extracorporeal UV cross-linking at fluences of 30J/cm² and 60J/cm². Outcomes included segment rigidity, thickness changes, and the ease and safety of the insertion process.

Report of case

Insertion was uneventful in all cases. Cross-linked segments maintained their rigidity throughout the entire insertion process and showed no tendency to soften during placement. The initial segment thickness decreased by up to 60% immediately after cross-linking, with a gradual increase in thickness over the days following implantation.

Conclusion / Take home message

ECO-CAIRS offers several advantages over unmodified or air-dried CAIRS, including easier insertion due to increased stiffness and reduced re-swelling during surgery. The high UV fluences applied to the allogenic ring segments likely eliminate viable keratocytes, effectively converting the segments into acellular collagen scaffolds. Additionally, the temporary reduction in thickness may enable the insertion of larger segments, potentially enhancing their impact on corneal topography. Further clinical research is needed to determine whether these topographic changes are primarily influenced by segment volume or intrinsic stiffness.