A comparison of the effects of different cap thicknesses on corneal nerve destruction after small incision lenticule extraction.

Abstract

To evaluate the features of corneal nerve destruction after small incision lenticule extraction (SMILE) with different cap thicknesses (100 and 120μm). Nine consecutive patients (18 eyes) received SMILE with a 120-μm cap thickness and nine patients (18 eyes) with a 100-μm cap thickness were recruited. Confocal microscopy was used to evaluate the density and microscopic morphological changes of central corneal subbasal nerves preoperatively and at postoperative week 1. The postoperative corneal subbasal nerve densities decreased significantly in both 120μm and 100μm groups. No statistical difference was detected in reduction of subbasal nerve density between two groups (P = 0.299). The number of subbasal nerve fibers significantly decreased in both groups. The reductions were not significantly different between two groups (P = 0.293). Using a 120-μm cap thickness during SMILE preserves no more central corneal subbasal nerve fibers compared to a 100-μm cap thickness.