ESCRS - POCOR408 - Primary Corneal Allogenic Intrastromal Ring Segment Implantation For Stable Keratoconus: A Tertiary Centre Nhs Experience

Primary Corneal Allogenic Intrastromal Ring Segment Implantation For Stable Keratoconus: A Tertiary Centre Nhs Experience

Published 2026 - 44th Congress of the ESCRS

Reference: POCOR408 | Type: Poster | DOI: 10.82333/pf7k-j770

Authors: Mr Christopher Way* 1 , Mr Hasan Naveed 1 , Ms Artemis Matsou 1 , Mr Mohamed Elalfy 1

1Corneoplastic Unit,Queen Victoria Hospital,East Grinstead,United Kingdom

Purpose

We aimed to review the first 18 months of use of Corneal Allogenic Intrastromal Ring Segments (CAIRS) in our tertiary centre NHS department. 

Setting

Keratoconus is an ectatic disease characterised by irregular astigmatism and progressive corneal thinning. Improving visual quality can be a challenge, especially in patients who cannot tolerate or become unsuitable for rigid gas permeable (RGP) contact lenses. Corneal Allogenic Intrastromal Ring Segments (CAIRS) have been reported to be a safe and effective treatment in such patients.

Methods

Retrospective chart review of 17 eyes with keratoconus who were previously crosslinked and intolerant to RGPs underwent CAIRS implantation. Visual, refractive, and topographic data was assessed pre operatively and at post operative months 1, 3, 6 and 12. Statistical analysis was performed using a paired t-test.

Results

Pre-operative mean UCVA was 0.93±0.38 logMAR, Kmean 49.3±3.5 D, spherical equivalent −7.5±3.5D, and coma 1.12±0.81µm. At 12 months (N=8): UCVA improved by −0.24±0.15 logMAR (p=0.003**); CDVA improved by −0.23±0.18 logMAR (p=0.044*, N=5). Keratometry reduced; K1 −3.4±2.1D (p=0.003**), K2 −2.9±1.6D (p=0.001**), Kmean −3.2±1.8D (p=0.001**), however Kmax reduction was non-significant (−0.9±4.2D, p=0.563). Spherical equivalent improved by +4.57 ± 2.59D (p=0.002**, N=8), demonstrating spherical myopic correction. BFS anterior increased significantly (+0.22±0.12mm, p=0.001***) whereas BFS posterior change was non-significant (+0.02D, p=0.573). Coma was noted to reduce from 1.12±0.81µm to 0.70±0.53µm (mean diff −0.29µm, p=0.028*).

Conclusions

The outcomes of our study show that CAIRS is a successful procedure for carefully selected cases. It improves the anterior curvature of the cornea, resulting in improved uncorrected and corrected visual acuity, keratometry, higher order aberrations and reduced myopia. Further work is required in this field to establish a standardised nomogram which incorporates patient findings and CAIRS segment morphology.