JUN 17, 2014
In an effort to predict differences in regression rates between LASIK and LASIK combined with corneal cross-linking (LASIK-Xtra), investigators compared postoperative 3-dimensional epithelial thickness distribution maps of patients who underwent these two procedures.
All 139 eyes had femtosecond-assisted LASIK for high myopia. Of them, 67 eyes also underwent concurrent prophylactic corneal cross-linking. Before surgery and at six months postop, AS-OCT measurements of epithelial thickness were performed over the central 2-mm zone, mid-peripheral 5-mm rim, and overall 6-mm central corneal diameter.
Within the subgroups of patients who had preoperative myopia of –8.00 to –9.00, and –7.00 to –8.00 (3.79 vs. 9.75 microns, and 3.95 vs. 7.14 microns, respectively; p<0.05) the epithelial thickness increase was less among those who had the combined procedure. Results were similar for mid-peripheral, central and overall epithelial thicknesses within these subgroups. They observed no significant thickness differences among the subgroup of patients with less than –7.00 sphere of myopia.
The authors suggest that this lessened epithelial thickness increase with LASIK-Xtra may be an indication of enhanced corneal stability and less risk of future regression.