Abstract
Purpose: :
The study was to investigate the effects of bevacizumab on retinal function in rats. We first evaluated the safety of intravitreally injected bevacizumab using electroretinogram (ERG) recording and histologic analysis. We also assessed the effects of bevacizumab using a model of isolated retina ERG recording.
Methods: :
In a first set of experiments, Wistar rats were injected intravitreally with bevacizumab (10 or 50 µg). Full-field ERGs (0.1-1000 Hz) and oscillatory potentials (OPs, 300-500 Hz) were recorded before injection and 24 hours after. The b-wave sensitivity curves (-4 to 1 log cd.s/m2) were fitted to calculate the saturated b-wave amplitude (Vmax) and the retinal sensitivity parameter (k). Rats were then sacrificed, the eyes enucleated and prepared for histologic analysis. In a second set of experiments, retinas from rats were isolated and kept in a perfusion chamber. Every 3 minutes, ERGs were recorded to a white light stimulation. When the b-wave became stable, bevacizumab was injected into the perfusion solution at different concentrations (0.25 and 0.50 mg/ml). The amplitude of the b-waves vs. time were plotted to obtain ‘the survival curve’.
Results: :
There was no significant change in Vmax, k values and OPs parameters between pre-injections and post-injections for bevacizumab-treated or untreated groups. Moreover, no significant difference was observed between the bevacizumab-injected and uninjected groups. No histopathological change was found in any of the groups. In isolated retina models, no effect was observed on the ERG when bevacizumab was added to the perfusion liquid at the studied concentrations, and no significant difference in the survival curve of the b-wave amplitude was observed between treated and control retinas.
Conclusions: :
Our study did not show toxic effects of bevacizumab on retinal function in rats from intravitreal injection in eyes or from direct application on isolated retinas.
Keywords: retina • drug toxicity/drug effects • electroretinography: non-clinical