Measurement of central corneal thickness and pre-corneal tear film thickness of rabbits using the Scheimpflug system

AIM: To compare the effect of topically administered and subconjunctivally injected bevacizumab on experimental corneal neovascularization in rats for two weeks after treatment.METHODS: Twenty-eight Sprague-Dawley rats were divided into four groups of 7 animals. Each corneal center of right eye was cauterized with silver/potassium nitrate for 8s. After corneal burning, bevacizumab (12.5mg/mL) was topically administered three times per day (TB group) for two weeks or subconjunctivally injected on days 2 and 4 after cauterization (0.02mL; SB group). As negative controls, rats received 0.9% saline topically three times per day (TS group) or subconjunctivally on days 2 and 4 (0.02mL; SS group). Digital photographs of the cornea were taken 1 and 2 weeks after treatment and analyzed to determine the area of cornea covered by neovascularization as the percentage of corneal neovascularization.RESULTS: One week after treatment, the percentage of corneal neovascularization was significantly lower in the TB and SB groups than in the TS and SS groups (all P<0.05). Two weeks after treatment, the percentage of corneal neovascularization was significantly lower in the TB group than in the TS group (P<0.05). In all groups, the percentage of neovascularization was decreasing as time passed (all P<0.05)CONCLUSION: Topically administered bevacizumab has longer standing anti-angiogenic effect than subconjunctivally injected bevacizumab in corneal neovascularization following chemical injury in rats.