2.7. Corneal Fluorescein Staining and Imaging

The extent of corneal wound closure was examined by corneal fluorescein staining as previously described [19,20]. 24 and 48 h after corneal abrasion, mice were anesthetized with an intraperitoneal injection of the rodent combination anesthesia. A 1 μL amount of fluorescein (0.1%) was instilled on the injured corneas for 1 min, followed by rinsing with 1 mL of BSS. Images were then recorded by an SLR digital camera (Nikon Inc, Melville, NY, USA) and a stereoscopic zoom microscope (SMZ25; Nikon Instruments, Melville, NY, USA), with a fluorescence excitation at 470 nm. Three animals per group were used. Wound areas were analyzed by ImageJ software (U.S. National Institutes of Health, Bethesda, MD, USA)