Comparative study of the efficacy of bevacizumab and rose bengal photodynamic therapy for treatment of corneal neovascularization

Abstract

Introduction: To compare the efficacy of bevacizumab and rose bengal photodynamic therapy (RB-PDT) in the treatment of corneal neovascularization (CNV). Material and methods: The study design included the induction of CNV by suture placement in three groups of New Zealand rabbits: (1) a group with CNV without any treatment; (2) a group treated with subconjunctival injection of bevacizumab (25 mg/eye); (3) a group treated with intravenous injection of rose bengal and exposed to 532 nm photodynamic therapy. For 4 weeks, the animals were followed up by slit-lamp to analyze the extent of CNV, evaluate the corneal protein secondary structure, and determine the oxidative stress index (OSI). Results: After 4 weeks, traces of neovascularization were observed only in the bevacizumab treated group with grade 0.5. The contents of α -helix and β -sheet were 17% and 61% in CNV, 32%, and 46% in bevacizumab and 40% and 36% in RB-PDT groups vs. 43% and 35% for the control group. Moreover, the percentage changes in the total oxidative status (TOS) for CNV, bevacizumab and RB-PDT groups were 97.1%, 14.6%, and 1.0%, respectively, with respect to the control. The total antioxidant status (TAC) showed no significant changes ( p > 0.05) for both treated groups. The percentage of changes in OSI was 15.9% and 1.3% in bevacizumab, and RB-PDT treated groups compared with the control group. Conclusions: Both modes of treatment were effective in the regression of CNV, but RB-PDT was more efficient than bevacizumab by improving the corneal protein secondary structure and the oxidative stress.