Customized Corneal Allogeneic Intrastromal Ring Segments (CAIRS) With Corneal Cross-linking for Post-LASIK Ectasia

To evaluate the results of patients with post-laser in situ keratomileusis (LASIK) ectasia who were treated with corneal allogeneic intrastromal ring segments (CAIRS) and corneal cross-linking (CXL).

Patients with post-LASIK ectasia who had undergone CAIRS and CXL were included in this retrospective series. Preoperative, postoperative, and surgical parameters of all patients were recorded. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity, spherical equivalent, flat keratometry (K1), step keratometry (K2), mean keratometry (Kmean), maximum keratometry (Kmax), maximum flattening, Q-value, root mean square (RMS) lower (LOA) and higher (HOA) order aberrations, vertical coma, spherical aberration, and intraoperative surgical parameters used were studied.

Eight eyes with post-LASIK ectasia treated with CAIRS combined with CXL or CACXL were included. UDVA improved from 0.2 ± 0.1 to 0.4 ± 0.16 (decimal equivalent). CDVA improved from 0.63 ± 0.17 to 0.73 ± 0.17 (decimal equivalent). Spherical equivalent decreased from -3.90 ± 2.70 to -1.50 ± 1.90 diopters (D). K1, K2, Kmean, Kmax, and Q-value decreased from 47.65 ± 4.10, 51.40 ± 4.60, 49.40 ± 4.20, 60.90 ± 7.70 D and -0.96 ± 0.60 to 43.40 ± 3.70, 46.00 ± 4.00, 44.70 ± 3.80, 54.60 ± 6.90, and -0.21 ± 0.60 D, respectively. RMS LOA and HOA, vertical coma, and spherical aberration decreased from 13 ± 3.3 to 8.8 ± 2.7, 4.2 ± 1.7 to 3.3 ± 1.1, -3.5 ± 1.5 to -1.9 ± 1.4, and -0.4 ± 0.5 to 0.07 ± 0.9 µm, respectively. Average maximum flattening was 12.10 ± 1.70 D. Average thinnest pachymetry was 440 ± 54 µm preoperatively and postoperatively this was 431 ± 56 µm postoperatively. Although the postoperative mean pachymetry was lower than the preoperative pachymetry, this was not statistically significant (P > .05). Average follow-up was 12.9 ± 4 months (range: 6 to 18 months). No postoperative complications were encountered except grade 1 and 2 haze in 5 and 3 patients, respectively. This did not affect vision and no patient complained of glare or halos.

CAIRS combined with CXL can be used as a safe and effective treatment for post-LASIK ectasia. It aids in improving quantitative and qualitative vision while avoiding disadvantages of synthetic intracorneal ring segments and deep anterior lamellar keratoplasty. [J Refract Surg. 2025;41(7):e709-e714.].