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 per formed 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.