Comparison Of Changes In Corneal Epithelial Thickness Profile With And Without Accelerated Corneal Crosslinking In Small Incision Lenticule Extraction.

This study aimed to compare the changes in the corneal epithelial thickness (ET) profile induced by standard small-incision lenticule extraction (SMILE) versus combined small-incision lenticule extraction and accelerated corneal collagen crosslinking (SMILE-Xtra) for the treatment of myopia.

Restrospective Case Control Study

Thirty-one myopic eyes undergoing SMILE-Xtra and 36 control myopic eyes undergoing SMILE were retrospectively analyzed. Corneal ET was measured using spectral-domain optical coherence tomography (CIRRUS™ HD-OCT 5000, ZEISS, Dublin, CA) at17 zones within the central 7-mm zone preoperatively, as well as 1, 3, and 6 months postoperatively. Postoperative ET alterations and treatment parameters were also analyzed.

There was no difference in the preoperative mean age, postoperative manifest refraction spherical equivalent, visual acuity, or ablation depth between the two groups; however, there was a significant difference in the preoperative central corneal thickness. Both groups showed the greatest increase in corneal ET in the paracentral area on the inferotemporal area for 6 months. The preoperative MRSE and ablation depth showed a significant correlation with postoperative epithelial thickening in the mid-peripheral sectors in both groups, and significant negative correlations in the paracentral sectors only in the SMILE-Xtra group.

This is the first study to compare corneal epithelial remodeling between SMILE and SMILE with accelerated corneal collagen cross-linking. SMILE-Xtra with relatively large corneal ablation did not show a significant difference in the pattern of corneal epithelial remodeling compared with the SMILE group.