Abstract
Purpose: :
Intraocular ranibizumab (Lucentis®, Novartis, Basel Switzerland) is the primary choice in the treatment of neovascular age-related macular degeneration (AMD). Vascular endothelial growth factor (VEGF) is known to be a survival factor for neuronal cells. Therefore, blockage of all VEGF isoforms by ranibizumab could induce retinal dysfunction especially in the case of an accidental injection of more than 0.5 mg ranibizumab.
Methods: :
Using isolated bovine retinas the electroretinogram (ERG) was recorded as a transretinal potential using Ag/AgCl electrodes while the retinas were perfused with an oxygen pre-incubated nutrient solution. For 45 min ranibizumab was applied to the nutrient solution at a concentration of 0.2 mg/mL. This concentration accords to an injected dose of 1 mg ranibizumab considering the volume of the vitreous humor of about 5 mL. We tested the effects of ranibizumab on the a-wave amplitude as well as on the b-wave amplitude derived from isolated bovine retinas. The solvent carrier without the active agent was used as a control. The ERG was monitored before, during and after exposure.
Results: :
The concentration of 0.2 mg/mL ranibizumab only induced a not significant b-wave reduction of 22.32 % after exposure (p = 0.13). For the a-wave amplitude only a slight reduction of 4 % was detected (p = 0.18). The solvent carrier induced no significant reduction of the a- and b-wave amplitudes (p = 0.30 and p = 0.979, respectively).
Conclusions: :
The aim of our study was to investigate the safety profile of ranibizumab. Stability of the ERG-amplitudes rule out a considerable retinal dysfunction also in the case of an accidental injection of more than 0.5 mg ranibizumab. As higher doses of ranibizumab have not yet tested in our model, no reliable conclusion can be made on the retinal biocompatibility of doses higher than 1 mg.
Keywords: drug toxicity/drug effects • electroretinography: non-clinical • age-related macular degeneration