The Effect of Intravitreal Bevacizumab on Apoptosis of Rat Retina Cells

Purpose: To investigate the apoptotic effects of intravitreal bevacizumab on rat retinal cells. Material and Method: Thirty-six male adult Swiss albino rats were randomly divided into two groups. The first group was applied 0.25 mg bevacizumab in 0.01 ml saline, and the second group received the same amount of saline intravitreally. Each group was divided into 3 subgroups. The animals were sacrificed and their globes were enucleated at the 3rd, 24th, and 72nd hours of the experiment. Enucleated eyes were preserved for histological analysis, immunohistochemical analysis of caspase-3, caspase-8, caspase-9, Fas/Fas L, VEGF and VEGF receptors (Flt-1, Flk-1), and TUNEL staining. Results: Histological evaluation showed no sign of retinal toxicity in both groups. In TUNEL staining, TUNEL(+) cells were detected in all subgroups, but the number of positive cells was relatively lower in bevacizumab treatment group that reached statistically significant level at 24 and 72 hours of treatment (p<0.001). Immunohistochemical analysis revealed that in saline-treated subgroups, immunoreactivity was more pronounced for all apoptosis-inducing proteins compared to bevacizumab-treated group. Also immunoreactivity of VEGF was prominent in saline treated group. For VEGF receptors, staining was only positive for Flt-1 at the 3rd hour in the control group. Discussion: Bevacizumab did not have apoptosis-inducing potential compared to saline solution in short term, which was documented with TUNEL and immunohistochemical staining.