Use of corneal allogenic intrastromal ring segments (CAIRS) in high astigmatism, a case report

: Background Corneal allogenic intrastromal ring segments (CAIRS) were developed as a biologic alternative to synthetic intracorneal ring segments and are primarily reported in the management of keratoconus and corneal ectasia. Its role in high corneal astigmatism still limited. Case Report A 54-year-old male presented with decreased visual acuity in the left eye due to high regular corneal astigmatism. Preoperative best-corrected visual acuity was 0.8 (decimal scale), with a manifest refraction of: +3.5 / 9.25 × 109. CAIRS implantation was performed based on the magnitude of astigmatism, and limitations of alternative corrective options. At one year postoperatively, corneal tomography demonstrated a marked reduction in astigmatism with improved corneal regularity. Pachymetry and posterior corneal parameters remained stable, and anterior segment optical coherence tomography (OCT) confirmed appropriate intrastromal segment positioning without complications. Conclusion This case demonstrates the feasibility of CAIRS implantation in isolated high corneal astigmatism, with stable tomographic outcomes at one year. With careful patient selection, CAIRS may represent a tissue-preserving option in selected cases.