Abstract
Purpose:
Vascular endothelial growth factor 165b (VEGF165b) is a splice variant of VEGF, and it is anti-angiogenic as opposed to the pro-angiogenic forms of VEGF. The purpose of this study was to determine the level of VEGF165b in the aqueous humor of eyes with age-related macular degeneration (AMD), retinal vein occlusion (RVO), and eyes undergoing cataract surgery (controls).
Methods:
Aqueous samples were collected from 119 eyes of 119 consecutive patients (AMD, 85 eyes and RVO, 34 eyes) before an intravitreal injection of anti-VEGF bevacizumab and ranibizumab. The concentration of VEGF165b was measured by enzyme-linked immunosorbent assay (ELISA). The VEGF165b level was compared in the AMD subgroups, viz., choroidal neovascularization (CNV) and polypoidal choroidal vasculopathy (PCV). The relationships between the VEGF165b level and the central foveal thickness (CFT) and the height of the subretinal fluid (SRF) were determined in AMD cases. The aqueous humor collected during cataract surgery in 19 patients without ocular pathology was used as control.
Results:
The level of VEGF165b was higher than the lower limit of detection (15 pg/ml) in 55% of the AMD cases (median: 16.2, range: <15-151 pg/ml) and 63% of the controls (median: 20.6, range: <15-188 pg/ml). On the other hand, the percentage of eyes with VEGF165b >15 pg/ml was significantly lower in RVO cases than in the controls (37%, P=0.067, median: <15, range: <15- 47 pg/ml). There was no significant difference in the VEGF165b level between eyes with CNV and PCV (P=0.654). The VEGF165b level was not significantly correlated with the CFT or the height of the SRF (P=0.613, 0.278 respectively).
Conclusions:
The level of VEGF165b in the human aqueous humor was low in eyes with RVO which suggests that the anti-angiogenic isoform of VEGF is reduced in RVO. In addition, there was no significant difference between AMD and the controls. It is possible that the change of the VEGF165b level is too small to detect because of the subretinal location of pathology in AMD.
Keywords: 748 vascular endothelial growth factor •
427 aqueous •
412 age-related macular degeneration