LEVELS OF VASCULAR ENDOTHELIAL GROWTH-FACTOR ARE ELEVATED IN THE VITREOUS OF PATIENTS WITH SUBRETINAL NEOVASCULARIZATION

Background-Vascular endothelial growth factor (VEGF) has been shown to play a major role in intraocular neovascularisation in ischaemic reti nal diseases. Subretinal neovascularisation is an important cause of c entral visual loss, but little is known about the role of this growth factor in its pathogenesis. The aim of this study was to investigate t he possible role of VEGF in the development of subretinal neovasculari sation. Methods-Undiluted vitreous samples were obtained from patients undergoing vitrectomy for removal of non-age-related subfoveal neovas cular membranes (SFNM). For comparison vitreous from patients undergoi ng vitrectomy for idiopathic full thickness macular holes (FTMH) and p roliferative diabetic retinopathy (PDR) was used. Indirect enzyme link ed immunosorbent assay (ELISA), with an antibody directed against the conserved N-terminal region of human VEGF(165), was used to determine vitreous levels of VEGF. The growth factor was also localised in the v itreous of patients with SFNM by western blot analysis. Results-The me an (SE) VEGF concentration in the vitreous of patients with SFNM was 2 7 . 78 (2 . 22) ng/ml (n = 8), FTMH was 16 . 62 (0 . 9) ng/ml (n = 18) , and PDR was 37 . 77 (3 . 28) ng/ml (n = 16). The differences between the PDR group and SFNM group versus the FTMH group were both signific ant (p = 0 . 0001 and p = 0 . 0015) as analysed by the Wilcoxon rank s um test). Conclusions-Vitreous levels of VEGF are significantly elevat ed in eyes with nonage-related subretinal neovascularisation compared with eyes with FTMH but not as elevated as in PDR. This suggests that VEGF is involved in subretinal angiogenesis.