Vitreous Levels of Placenta Growth Factor and Vascular Endothelial Growth Factor in Patients With Proliferative Diabetic Retinopathy

Placenta growth factor (PlGF) is a close homolog of vascular endothelial growth factor (VEGF), shares receptors with VEGF, and stimulates angiogenesis (1). Intravitreous PlGF levels are elevated in proliferative diabetic retinopathy (PDR) (2), but the relationship between PlGF levels and VEGF levels or clinical activity remains unclear. We attempted to ascertain whether intravitreous PlGF levels correlate with VEGF levels or clinical activity in PDR. We assayed PlGF and VEGF levels in vitreous samples from 50 consecutive patients with PDR (31 patients) and macular hole (nondiabetic control subjects, 19 patients) who underwent pars plana vitrectomy. The PDR stage was classified as active …