Determination of Vascular Endothelial Growth Factor-B Concentrations in Aqueous Humor and Plasma of Neovascular Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy Patients Before and After Anti-VEGF Therapy

INTRODUCTION: Anti-vascular endothelial growth factor (anti-VEGF) injection was widely used in patients with neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV); however, the systemic and local levels of vascular endothelial growth factor (VEGF)-B were seldom detected before. This study was conducted to detect and compare the aqueous humor and plasma VEGF-B levels in nAMD and PCV before and after anti-VEGF therapy. METHODS: Concentrations of VEGF-B in aqueous humor and plasma of individuals with nAMD (n = 10), PCV (n = 22), and age-related cataract controls (n = 12) were measured by enzyme-linked immunosorbent assay. Ranibizumab was injected intravitreally in patients monthly for three consecutive months. Before each injection in patients and at the baseline of controls, blood and aqueous humor samples were collected. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were collected before each injection in patient groups. The differences of BCVA, CRT, and VEGF-B levels in aqueous humor and plasma between groups before and after anti-VEGF therapy were compared. RESULTS: VEGF-B was overexpressed in aqueous humor and plasma of nAMD and PCV groups compared with control group (P < 0.05), but no statistically significant difference existed across nAMD and PCV groups (P > 0.05). Moreover, there were no obvious difference in levels of VEGF-B in aqueous humor and plasma within the treatment groups after anti-VEGF treatment (P > 0.05). The mean CRT in the nAMD group was thinner than that in the PCV group at baseline (P < 0.01). After injections, the CRT obviously declined in both groups (P < 0.05). There was no correlation between CRT reduction and high VEGF-B expression in aqueous humor and plasma of treatment groups. CONCLUSION: Overexpression of VEGF-B locally and systemically in patients with nAMD and PCV indicated that elevated VEGF-B concentrations were relevant to the disease processes. Ranibizumab did not influence the levels of VEGF-B in the real world. CRT might help to distinguish PCV from nAMD.