Vitreous levels of vascular endothelial growth factor and stromal-derived factor 1 in patients with diabetic retinopathy and cystoid macular edema before and after intraocular injection of triamcinolone

Diffuse macular edema (DME) and/or aberrant neovascularization (NV) can cause vision loss in diabetic retinopathy (DR) and may be modulated by growth factors and chemokines. The chemokine stromal-derived factor 1 (SDF-1) is a potent stimulator of vascular endothelial growth factor (VEGF) expression, the main effector of NV, and the key inducer of vascular permeability associated with DME. Circulating endothelial cell precursors migrating in response to SDF-1 participate in NV. To investigate the relationship between SDF-1 and (VEGF) in vitreous of patients with varying degrees of DR and DME before and after intraocular injection of triamcinolone acetonide, used to treat refractory DME. In this prospective study, 36 patients were included and observed for 6 months. Vitreous VEGF and SDF-1 levels were measured by enzyme-linked immunosorbent assay in samples obtained immediately before and 1 month after injection of triamcinolone. Both VEGF and SDF-1 were significantly higher (P