Concentrations of different isoforms of VEGF in aqueous humor in patients with neovascular age-related macular degeneration and polypoidal choroidal vasculopathy

Abstract

Background There remains some controversy over whether polypoidal choroidal vasculopathy (PCV) represents a subtype of neovascular age-related macular degeneration (nAMD).Anti-vascular endothelial growth factor (VEGF) therapies are important in the treatment of PCV and nAMD.It has been identified that VEGF-A was differentially spliced from exons 8 and formed two isoforms families:the pro-angiogenic VEGFxxx family and the anti-angiogenic VEGFxxxb family.However,the role of the two VEGF families in PCV and nAMD was still unclear.Objective This study was to measure the contents of pro-angiogenic VEGFxxx family and the anti-angiogenic VEGFxxxb family in aqueous humor of nAMD and PCV patients and explore their effect on nAMD and PCV.Methods Thirty-four nAMD patients and 26 PCV patients were enrolled in Peking University People's Hospital during March to December,2013,and 16 age-related cataract patients served as controls.The aqueous humor samples 0.1 ml was collected before the introvitreous injection of anti-VEGF drug.The contents of pro-angiogenic VEGFxxx family and the anti-angiogenic VEGFxxx b family in the aqueous humor were measured by enzyme-linked immunosorbent assay(ELISA).Results The concentrations of VEGF in the aqueous humor in the nAMD group,PCV group and control group were (4 210.00±998.40),(387.00±51.31) and (377.40 ±69.97)pg/ml,respectively,showing a significant difference among the three groups (F =12.851,P =0.000).The concentrations of VEGF165 b in the aqueous humor in the nAMD group,PCV group and control group were (205.50±12.59),(159.40±16.25) and (347.90±29.18) pg/ml,with a significant difference among them (F=23.752,P=0.000).Compared with the control group,VEGF content in the aqueous humor was elevated and the VEGF165b content was declined in the nAMD group,and VEGF165b was lowed in the PCV group,with significant differences between them(all at P=0.000).However,no significant difference was seen in the change of VEGF between the PCV group and the control group (P=0.992).The VEGF content in the aqueous humor was higher in the nAMD group than that in the PCV group (P =0.001),but VEGF165b content was insignificantly different (P =0.097).Conclusions The downregulation of VEGFxxx b may be associated with nAMD and PCV.The different role of VEGFxxx b in the development of PCV and nAMD needs to be verified in further studies. Key words: Vascular endothelial growth factor/VEGFxxx family, VEGFxxx b family; Age-related macular degeneration/neovascular; Choroidal neovascularization; Polypoidal choroidal vasculopathy