Level of vascular endothelial growth factor 165b in human aqueous humor

Abstract

Purpose: Vascular endothelial growth factor 165b (VEGF165b) is a splice variant of VEGF-A and is an anti-angiogenic form as opposed to a pro-angiogenic form of VEGF. We compared the level of VEGF165b in the aqueous humor of 77 eyes with exudative age-related macular degeneration (AMD) and 38 eyes with retinal vein occlusion (RVO).

Design: A prospective, interventional case series.

Methods: The concentration of aqueous VEGF165b was measured by enzyme-linked immunosorbent assay (ELISA), and its level in the subgroups of AMD, classic and occult choroidal neovascularization (CNV) and polypoidal choroidal vasculopathy (PCV), was compared. The relationships between the VEGF165b level and the greatest linear dimension (GLD), central foveal thickness (CFT), and the height of the subretinal fluid (SRF) were determined for the AMD and RVO cases.

Results: The level of VEGF165b was higher than the lower limit of detection (15 pg/ml) in 57% of the AMD cases (median, 16.4; range, <15-98 pg/ml) and 63% of the controls (median, 20.6; range, <15-46 pg/ml). The percentage of eyes with >15 pg/ml of VEGF165b was significantly lower in eyes with RVO (32%, p = 0.038). The VEGF165b level was not significantly different among the AMD subtypes, and it was not significantly correlated with the GLD, CFT, and SRF. In the RVO cases, the CFT and SRF thickness were greater in eyes with a VEGF level <15 pg/ml (p = 0.006, 0.048 respectively).

Conclusions: The anti-angiogenic VEGF165b was low in eyes with RVO. Therapy based on balancing the pro- and anti-angiogenic factors might be a new approach to treat ocular vascular disorders.

Keywords: Age-related macular degeneration; Vascular Endothelial Growth Factor 165b; aqueous humor; retinal vein occlusion.