Abstract
PURPOSE: To report two cases of corneal allogenic intrastromal ring segments (CAIRS) as a rescue treatment for failed synthetic intracorneal ring segments (ICRS). OBSERVATIONS: Case 1 was a 49-year-old woman with a history of keratoconus who presented with unimproved vision in the right eye after the insertion of synthetic ICRS ten years ago at another healthcare center. Her uncorrected visual acuity (UCVA) was 20/400, and best corrected visual acuity (BCVA) was 20/60. The old synthetic ring segments were removed, and CAIRS was implanted three months later. Postoperatively, the UCVA improved to 20/30. The preoperative K max was 68.9, which decreased to 61.9 after CAIRS implantation. Case 2 was a 40-year-old woman with a history of bilateral advanced keratoconus who complained of unsatisfactory vision in the left eye after synthetic ICRS insertion eight years ago at another hospital. Her UCVA in the left eye was 20/60, with no improvement with refraction. Due to a broken proximal eyelet, and after discussing the options with the patient, CAIRS was inserted without removing the old ICRS. Postoperatively, the UCVA improved to 20/25, and BCVA improved to 20/20. Topography pre- and post-CAIRS implantation showed a decrease in K max from 51.3 to 47.9. CONCLUSION: These cases highlight the potential of CAIRS as a valuable option for restoring vision and improving the quality of life in patients with failed synthetic ICRS.