Corneal Allogenic Intrastromal Ring Segments (Cairs) With Accelerated Cross-Linking For Keratoconus

To evaluate the visual and topographic outcomes of Corneal Allogenic Intrastromal Ring Segments (CAIRS) combined with epithelium-off accelerated corneal cross-linking (CXL) in keratoconus patients. This study aims to assess improvements in visual acuity, refractive error, and corneal curvature.

Hashmanis Group of Hospitals, Pakistan

A total of 16 eyes from 8 patients with keratoconus underwent CAIRS implantation using preserved donor corneal tissue. Intrastromal channels were created with the WaveLight® FS200 femtosecond laser (Alcon, USA), followed by epithelium-off accelerated CXL (10 mW/cm² for 9 minutes). Pre- and three-month postoperative assessments included uncorrected and corrected visual acuity (UDVA, BCVA), refractive error, keratometry (Pentacam®), and anterior segment OCT (Spectralis®).

At three-month post-op, BCVA median improved from 0.7 to 0.4 (p=0.04). Kmax reduced significantly from 59.8D to 56.1D (p=0.001), and Km improved from 52.0D to 47.9D (p=0.001). Spherical equivalent median decreased from -8.5D to -6.2D (p=0.003), and topographic cylinder reduced from 2.7D to 2.1D (p=0.027). Corneal thickness showed no significant change.

CAIRS combined with accelerated CXL significantly improves corneal regularity, visual acuity, and keratometric values in keratoconus patients. The results suggest CAIRS as a viable treatment alternative to synthetic intracorneal ring segments, providing structural stability and improved vision.