Activated C3 (C3a) and its receptor (C3aR) and activated C5 (C5a) and its receptor (C5aR) have been shown to induce vascular endothelial growth factor (VEGF) expression in vitro and in vivo. Compositions and methods for inhibiting C3a, C3aR, C5a and C5aR for the treatment and/or prevention of neovascular disease are provided. Also provided are Novel therapeutic targets and diagnostic markers for choroidal neovascularization.