Soluble Flt–1 is present in human vitreous and is upregulated in patients with rhegmatogenous retinal detachment.

Abstract

Abstract: : Purpose: Although rhegmatogenous retinal detachment (RRD) induces retinal ischemia and elevated levels of the angiogenic cytokine vascular endothelial growth factor (VEGF)–A, ocular neovascularization rarely occurs. We sought to quantify vitreous levels of soluble Flt–1 (s–Flt–1), an endogenous anti–angiogenic molecule that scavenges extracellular VEGF–A, in patients with RRD and in controls. Methods: Undiluted vitreous samples were collected from patients undergoing pars plana vitrecomy either for RRD (n=7) or epiretinal membrane (ERM) removal (n=6). VEGF–A and s–Flt–1 levels in the vitreous were quantified by ELISA. Western blotting was performed to identify the molecular species of detected s–Flt–1. Results: As expected, there was a marked increase in VEGF–A levels in the vitreous of patients with RRD. We also identified a significant increase in the level of s–Flt–1 in patients with RRD (1349.6± 303.9 pg/ml) compared with patients with ERM (623.1±195.5 pg/ml) Conclusions: This first report of the presence of s–Flt–1 in human vitreous also identified its upregulation in patients with RRD, and suggests that elevated levels of s–Flt–1 effectively prevent high levels of ischemia–induced VEGF–A from promoting ocular neovascularization.

Keywords: retinal detachment • vitreous • neovascularization