Aim: To evaluate implications of intravitreal bevacizumab on proangiogenic vascular endothelial growth factor (VEGF) with regard to the endogenous angiogenesis inhibitor endostatin in human choroidal neovascularization (CNV) secondary to age-related macular degeneration.
Methods: Retrospective review of an interventional case series of forty-eight patients who underwent full macular translocation surgery with removal of CNV. Twenty five patients were treated with intravitreal bevacizumab injection 1 to 154 days prior to surgery (bevacizumab CNV). Twenty-three CNV without any kind of previous treatment were used as controls (control CNV). CNV were stained for CD34, cytokeratin18, VEGF, endostatin and E-selectin. "Predominance score of VEGF over endostatinâ" (PS) was defined by the difference between VEGF and endostatin staining scores.
Results: Bevacizumab CNV disclosed weaker VEGF expression in endothelial cells (p=0.0245) but significantly more intense endostatin in retina pigment epithelium (RPE) (p=0.0001) and stroma (p<0.0001). Consequently, PS was significantly lower in RPE (p=0.02), vessels (p=0.03) and stroma (p=0.0004) in bevacizumab CNV. Intensity of E-selectin expression in bevacizumab CNV was comparable to that in control CNV.
Conclusions: A shift within the angiogenic balance in terms of decreased VEGF predominance over endostatin is detected in human CNV treated with bevacizumab.