Postoperative Corneal Epithelial Remodeling After Intracorneal Ring Segment Procedures for Keratoconus: An Optical Coherence Tomography Study

PURPOSE: To assess epithelial corneal remodeling by anterior segment optical coherence tomography (AS-OCT) after sntracorneat ring segments (ICRS) implantation in keratoconic eyes. METHODS: This prospective observational study included patients with keratoconus receiving ICRS of different arc lengths according to their tomographic pattern. AS-OCT and corneal. topography (Scheimpflug camera) were performed before and 1, 3, and 6 months after surgery. Corneal pachymetry mapping was performed and total corneal and epithelial thicknesses (3-mm central and 16 points on 6-mm zone) were measured over the pupil center using AS-OCT. Topographic parameters were also assessed. RESULTS: A total of 68 keratoconic eyes were analyzed (Amster-Krumesch stages 1 to 4) in four groups of 17 eyes 210 degrees ICRS, 320 degrees ICRS, double 160 degrees ICRS, and single 160 degrees ICRS. Corneal pachymetry mapping revealed that epithelial thickness increased significantly in the internal zones juxtaposed to the ICRS without smoothing during the postoperative period (P < .05). Mean maximum epithelial thickness increased from 67 +/- 6 to 79 +/- 7 mu m for 210 degrees ICRS, 66 +/- 9 to 82 +/- 4 mu m for 320 degrees ICRS, 63 +/- 6 to 78 +/- 7 mu m for double 160 degrees ICRS, and 62 +/- 5 to 77 +/- 5 mu m for single 160 degrees ICRS (P < .00011. Significant epithelial thickening at the apex of the cone was observed in all groups (P < .05). CONCLUSIONS: Significant epithelial thickening occurs after ICRS implantation adjacent to the ICRS to compensate for the ridge created with a thickening of epithelium over the cone due to regularization of the stromal surface.

Automated summary

After ICRS implantation, significant epithelial thickening occurs, especially near the implanted ICRS, to compensate for the thickening of the epithelium over the cone due to regularization of the stromal surface.