A larger corneal epithelial wound closes at a faster rate

In order to evaluate relationships between healing rates and initial wound area, epithelial wounds were made on rabbit corneas by scraping the epithelium within a 4-, 6.5-, or 8-mm trephine mark. The wounds were stained with fluorescein and photographed during healing. The wounded areas were measured by planimetry. Although larger wounds closed later than smaller wounds, all of the healing curves appeared to be linear. The mean healing rate of the 8-mm diameter wounds (0.91 mm2/hr) was significantly greater than that of the 6.5-mm diameter wounds (0.80 mm2/hr). The 4-mm diameter wounds healed at a significantly slower rate (0.37 mm2/hr) when compared to the 6.5-mm diameter wounds. The authors found a strong positive correlation between the healing rates and the initial wound areas. By comparison, regardless of the initial wound area, the wound diameter decreased at a rate of approximately 0.1 mm/hr, which may explain the dependency of the healing rate on the initial wound area. The healing rate varied considerably between animals with the same diameter wounds, but both eyes of each animal showed a similar healing rate.