Gelatinase B and A Expression After Laser In Situ Keratomileusis and Photorefractive Keratectomy

Objective To compare the expression of gelatinases in the corneal epithelium and stroma after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). Methods Rabbit eyes were treated with LASIK (n=11), PRK (n=12), or corneal flap construction (n=12); 4 eyes served as unwounded controls. Zymography was performed on the central epithelium and the stroma 1, 3, and 7 days after surgery to determine the expression of gelatinases. Results Epithelial expression of gelatinase B in the LASIK group (0%-25%) was lower than that in the PRK group at all time points (50%-100%) and was identical to the corneal flap group. Stromal expression of gelatinases A and B was similar after LASIK and PRK, but was minimal after corneal flap construction at all time points. Epithelial expression of gelatinase A was similar for the first 3 days after LASIK and PRK but not thereafter. Conclusions Gelatinase B epithelial expression was upregulated after PRK but not after LASIK. Gelatinase B stromal expression was up-regulated after both procedures. Clinical Relevance Differences in wound healing and subepithelial scarring after these 2 procedures may be related to gelatinase B.