Customized Transepithelial Photorefractive Keratectomy Without Mitomycin-C Combined With Accelerated Corneal Cross-Linking Following Corneal Allogenic Intrastromal Ring Segment (Cairs) Insertion

To present 1-year outcomes of eyes treated with wavefront-guided transepithelial photorefractive keratectomy (PRK) and cross-linking (CXL) 3 months following corneal allogenic segment (CAIRS) insertion

American University of Beirut Medical Center

17 eyes of 17 patients with moderate to severe progressive keratoconus were included. Three months following CAIRS insertion combined ocular or corneal wavefront-guided (WG) transepithelial PRK and CXL was performed. The aim was to target the higher-order aberrations (HOAs) and only the lower-order aberrations that are embedded in the HOAs treatment profile. This methodology allows for the least amount of tissue ablation. Pyramidal aberrometry, topography data, and epithelial maps derived from optical coherence tomography were used to guide the ablation. No Mitomycin C was used after WG-PRK.

Mean patients’ age was 28±12.8 years. Kmax decreased from 57.0±7.06D to 53.7 ± 6.11D 3 months post-CAIRS to 50.9±5.62D 12 months following WG-PRK and CXL (P<0.01). MRSE decreased from -7.0±4.37D to -3.3±3.86D 3 months post CAIRS, and remained stable at -3.9±2.81D 12 months post WG-PRK and CXL. Total HOA and total coma decreased from 1.83±0.86 and 1.67±0.65 preoperatively to 1.66±0.60 and 1.01±0.45 3 months post CAIRS decreasing further to 1.14±0.44 (P<0.01) and 0.62±0.36 (P<0.001) 1 month post WG-PRK after which they remained stable until 12 months. 93.75% gained >=3  CDVA lines from pre-CAIRS baseline. No eye lost any line of CDVA, but 1 eye developed a partial corneal melt which stabilized and the segment was not explanted.

Combined wavefront-guided transepithelial PRK and CXL 3 months following CAIRS and targeting HOAs showed promising outcomes. The sequential nature of this methodology allows for tissue-sparing debulking of HOAs by allogenic segments followed by controlled fine-tuning of the residual aberrations by excimer laser and CXL.