Abstract
Abstract: :
Purpose: To examine the kinetics and mechanisms of inflammatory response during corneal epithelial wound healing in the mouse. Methods: The central corneal epithelium (2 mm diameter) was demarcated and removed in both C57Bl/6 wild type and CD18–/– mice. Epithelial healing was digitally analyzed every 6 hours. Neutrophils and macrophages were quantified under deconvolution microscopy. Enzyme–linked immunosorbent assay (EILSA) was used to measure IL–1, IL–6, IL–8, MCP–1, MIP–2, and LIX in corneal extracts. Results: In wild type mice, neutrophil infiltration in the corneas exhibited two distinct peaks at 12 and 30 hours after wounding; macrophages peaked at 24 and 42 hours. In contrast, CD18–/– mice exhibited profoundly low leukocyte infiltration during the period of the wild type first peak, but elevated leukocytes at 30 hours (neutrophils) and 36 hours (macrophages) after wounding. Similarly, all cytokines and chemokines exhibited biphasic and monophasic patterns in wild type and CD18–/– mice, respectively. Re–epithelialization was significantly delayed by 6–12 hours in CD18–/– mice. Conclusions: The corneal inflammatory response to corneal epithelial scraping is biphasic within 48 hours for both neutrophils and macrophages. The first wave is apparently CD18 dependent, the second wave CD18 independent. Absence of first phase significantly delays re–epithelization.
Keywords: cornea: epithelium • inflammation • cytokines/chemokines