Correlation between concentration of vitreous angiogenic cytokines (VEGF-B and PIGF) with central retinal thickness and macular volume in diabetic retinopathy patients

Abstract

Purpose : Placental growth factor (PlGF) and vascular endothelial growth factor B (VEGF-B) are members of the vascular endothelial growth factor family, binding to VEGF-R1. PIGF inhibition suppresses pathological angiogenesis in inflammatory disorders and diabetic retinas. PIGF levels are overexpressed in the vitreous of diabetic retinopathy (DR) patients and levels may increase with the severity of the disease. VEGF-B is a vascular survival factor, safeguarding the balance between blood vessel growth and degeneration. Under degenerative conditions VEGF-B is a survival factor to protect cells from apoptosis; during certain pathologies can act as antiangiogenic factor to prevent overgrowth of blood vessels. Angiogenic VEGF-B activity during ocular neovascularization may be due to its survival effect, rescuing neovessels from apoptosis. Vitreous VEGF-B levels are significantly increased in DR patients. The purpose of this study was to correlate vitreous angiogenic cytokines (VEGF-B and PIGF) levels in DR measured by ELISA and demonstrate its correlation with quantitative measurements of central retinal thickness (CRT) and macular volume (MV) by optical coherence tomography (OCT).

Methods : Vitreous samples were obtained from 42 DR patients undergoing vitrectomy. ELISA was used to quantify vitreous VEGF-B (pg/ml) (n=24) and vitreous PIGF (pg/ml) (n=18). OCT scans were evaluated to measured CRT (μm) and MV (mm³). Results obtained of VEGF-B (pg/ml) and PIGF (pg/ml) were correlated with CRT (μm) and MV (mm³). All patients included in this study, which adhered to the tenets of the Declaration of Helsinki, gave their informed consent to surgical treatment.

Results : Correlation between vitreous VEGF-B and CRT was statistically significant, positive and moderate: 0.441 (p ≤ 0,05). Correlation between vitreous VEGF-B and MV was statistically significant, positive and robust: 0.716 (p ≤ 0,01). Correlation between vitreous PIGF and CRT or vitreous PIGF and MV, was not statistically significant.

Conclusions : These results suggest that CRT and MV observed in OCT increase with increased levels of VEGF-B. This study shows that overexpression of VEGF-B may have an impact on CRT and MV of DR patients, thus targeting VEGF-B inhibition may have therapeutic beneficial implications.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.