Intravitreal bevacizumab in pigmented rabbit eyes: histological analysis 90 days after injection.

PURPOSE To evaluate bevacizumab toxicity in neurosensorial retina and retinal pigment epithelium in pigmented rabbit eyes by means of histological studies. METHODS Thirty eyes of fifteen rabbits were distributed into three groups: sham group (S), that received a 0.1 ml balanced saline solution (BSS) intravitreal injection (10 eyes); group 1, that received a 1.25 mg (0.1 ml) bevacizumab intravitreal injection (10 eyes); and group 2, that received a 2.5 mg (0.1 ml) bevacizumab intravitreal injection (10 eyes). Rabbits were sacrificed 90 days after the procedure and both eyes of each rabbit were enucleated. A histological examination of neurosensorial retina and retinal pigmented epithelium (RPE) was performed. Its morphological features and layer thickness were also analyzed. RESULTS No histological differences in neurosensorial retina or in retinal pigmented epithelium were found and layer thickness did not differ significantly between balanced saline solution-injected eyes and bevacizumab-injected eyes. CONCLUSION After a 90-day follow-up period, a single 1.25 or 2.5 mg bevacizumab intravitreal injection did not lead to toxic damage in the neurosensorial retina and retinal pigment epithelium of pigmented rabbit eyes, and it appears to be a safe procedure for retinal neovascular diseases.