Vitreous levels of vasohibin-1 and vascular endothelial growth factor in patients with proliferative diabetic retinopathy

Abstract

Abbreviations PDR proliferative diabetic retinopathy PEDF pigment epithelium-derived factor VEGF vascular endothelial growth factor To the Editor: Intraocular neovascularisation develops in many ischaemic retinal diseases, e.g. diabetic retinopathy, ischaemic retinal vein occlusion and retinopathy of prematurity. The new vessels are fragile and often rupture, leading to vitreous haemorrhage, tractional retinal detachment, neovascular glaucoma and subsequent vision decrease. The formation of new vessels is dependent on a local balance of stimulators and inhibitors of angiogenesis [1]. Among the stimulators, vascular endothelial growth factor (VEGF) has been shown to play a major role in mediating active neovascularisation in patients with diabetic retinopathy [2]. In addition, several studies have shown that the concentration of VEGF in the intraocular fluids was significantly elevated in eyes with proliferative diabetic retinopathy (PDR) [3–5]. On the other hand, pigment epithelium-derived factor (PEDF) is a potent inhibitor of angiogenesis, and lower levels of PEDF have been found in the vitreous of eyes with active diabetic retinopathy [4]. It has also been shown that the vitreous level of endostatin, another inhibitor of angiogenesis, is correlated with the level of VEGF and that endostatin is produced in the fibrovascular membrane of eyes with PDR [5]. Vasohibin-1, a novel angiogenesis inhibitor, is mainly produced in endothelial cells and is induced by stimulation with VEGF or fibroblast growth factor 2. Vasohibin-1 selectively affects endothelial cells and inhibits angiogenesis [6]. We therefore hypothesised that vasohibin-1 is present in the vitreous of eyes with PDR and is associated with the vitreous level of VEGF. To examine this hypothesis, we measured the vitreous levels of vasohibin-1 and VEGF in 49 samples from 46 patients. This study was conducted in accordance with the tenets of the Declaration of Helsinki as revised in 2000 and was carried out with the approval of the Institutional Review Board of Tohoku University. Informed consent was obtained from all patients Diabetologia (2009) 52:359–361 DOI 10.1007/s00125-008-1229-z