Vitreous and serum concentrations of vascular endothelial growth factor and platelet-derived growth factor in proliferative diabetic retinopathy

Abstract

Purpose: This study aimed to investigate the concentrations of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) in vitreous and serum samples, analyze the ratio, and compare among proliferative diabetic retinopathy (PDR) subgroups. Patients and Methods: This study included 17 eyes of patients with PDR, identified as the PDR group which was divided into three subgroups (vitreous hemorrhage [VH], VH with fibrotic tissues, and tractional retinal detachment), and five control eyes (nucleus and intraocular lens drop). Vitreous and serum samples were obtained on the same day. The VEGF-A and PDGF-AB concentrations were calculated by enzyme-linked immunosorbent assay. Results: The VEGF-A and PDGF-AB concentrations in vitreous samples were significantly higher in the PDR group (630.72 ± 342.81 pg/mL) compared with those in the control group (153.58 ± 145.85 pg/mL); however, they were not detected in serum samples. The vitreous/ serum ratio of the VEGF-A concentration in the PDR group (2.1 ± 1.8) was significantly higher compared with that in the control group (0.31 ± 0.33). The VEGF-A concentrations in vitreous samples were highest in the VH group and lowest in the VH with fibrotic tissue subgroup (mean difference 536.16 pg/mL). The vitreous VEGF-A/PDGF-AB concentration ratios were also significantly different among the PDR subgroups. Conclusion: High concentrations of VEGF and PDGF in vitreous samples of PDR eyes indicate its local related activity in PDR pathology. There is a possibility of PDGF involve-ment in the pathogenesis of PDR. The VEGF/PDGF concentration ratios possibly play a significant role in the formation of fibrotic tissue in PDR.