Purpose: To evaluate the short-term toxic effects of pegaptanib sodium on retinal function. At present, intraocular anti-vascular endothelial growth factor (VEGF) therapy is the primary choice of treatment for neovascular maculopathy. The isoform VEGF(165) is specifically inhibited by pegaptanib sodium. Therefore, since VEGF(165) has neuroprotective effects against apoptosis of neuronal cells, blockage of VEGF(165) by pegaptanib could induce retinal dysfunction. In the present study, we used an electrophysiological technique for testing retinal toxicity in order to evaluate the short-term toxic effects of pegaptanib sodium on retinal function in a model of isolated perfused vertebrate retina.
Methods: Isolated bovine retinas were perfused with an oxygenated, pre-incubated nutrient solution. Electroretinograms (ERGs) were recorded as trans-retinal potentials using Ag/AgCl electrodes. Pegaptanib sodium (0.006, 0.06, or 0.2 mg/ml) and solvent carrier were added to the nutrient solution for 45 min. ERGs were monitored before, during, and after exposure.
Results: No significant reductions of b-wave (p = 0.357, p = 0.31, and p = 0.11, respectively) or a-wave (p = 0.189, p = 0.46, and p = 0.23, respectively) amplitudes were detected during application of pegaptanib (0.006, 0.06, or 0.2 mg/ml). The solvent carrier alone had no effect on ERG b- or a-waves (p = 0.98 and p = 0.42, respectively). During washout, ERG amplitudes of all test series remained unchanged.
Conclusion: Results suggest that both pegaptanib sodium and its solvent carrier have good safety profiles. Intraocular application of 0.3 mg pegaptanib sodium induced no significant changes in ERGs in our ex vivo model and, thus, appears to be safe.