Investigation Of Correlations Between Vascular Endothelial Growth Factor (VEGF) And Proliferative Diabetic Retinopathy

AbstractDiabetes Mellitus(DM) is characterized by glucose metabolism disorders and may affect almost all the organs and tissues of the body.Diabetic retinapathy(DR) is a major ocular complication of diabetes mellitus.The most important causes ofblindness are repeated vitreous hemorrhage induced by neovascularization, tractionretinal detachment and other complications.Now the research of DR has been developed from clinical manifestation and pathogenesis to molecular biological fields.The results of these study identify that several growth factors,especially vascular endothelial growth factor(VEGF),play roles in neovascularization. Generally VEGF may promote endothelial cell proliferation,increase blood vascular permeability and induce neovascularization.And VEGF stimulates an excessive neovascularizationunder abnormal circumstances.Lots of experiments suggested that VEGF in vitreous and retina of patients with proliferative diabetic retinopathy(PDR) played a great role in the development of PDR. This study is trying to fnd if the changes of VEGF in plasma is associated with the development of PDR,and further to find the relations of VEGF concentration in plasma,aqueous humor and vitreous in patients with PDR.ObjectiveTo investigate the relations between the concentration of VEGF in plasma and the development of DR;to determine the relations between the changes of VEGF concentration in plasma,aqueous humor and vitreous of patients with DR and PDR,as well as to find if the condition of metabolism control of patients with DR may affect the VEGF level. MethodDouble antibody sandwich enzyme-linked immunosorbent assay was used to measure the levels of VEGF concentration in plasma of non-diabetic retinopathy (NDR) patients group,background diabetic retinopathy(BDR) patients group,and proliferative diabetic retinopathy(PDR) patients group.The level of HbAlc in plasma of patients in above three groups were measured at the same time.The VEGF concentration in aqueous humor,vitreous of PDR patients group and normal group was also measured for further comprehensive analysis.Human VEGF immunoassay Quantikine with high sensibility and quality was imported from R＆D Co.LTD.,USA.Result1.VEGF concentration in plasma of DM patients group was obviously lower than that of normal group(p＜0.01).(1)There was no significant difference in VEGF concentration of plasma between NDR and DR patients groups.(2)There was no significant difference in VEGF concentration of plasma between BDR and PDR patients groups.2.There was an increasing tendency in the VEGF concentration in aqueous humor of PDR patients group.There was no significant statistic difference as it was compared with normal group(p＞0.05).3.The VEGF concentration in vitreous of PDR patients group was obviously increased,there was significant difference as it was compared with normal group (P＜0.01)4.It showed an increasing tendency of VEGF concentration in turn in plasma, aqueous humor and vitreous of the 3 PDR patients selves.5.It showed that there was significant difference among VEGF concentration in plasma,aqueous humor and vitreous of all the PDR patients(p＜0.01).In normal group there was no significant difference among VEGF concentration in plasma,aqueous humor and vitreous(p＞0.05).In normal group the VEGF concentration in plasma was the highest,but in PDR patients group the VEGF concentration in vitreous was the highest. Conclusion1.It was clear that VEGF concentration in plasma of DM patients was obviously lower than that of normal group.It may be associated with metabolism disorders. This result suggested that the VEGF biological effect in plasma of DM patients was decreased.2.The VEGF concentration in plasma of DM patients did not change regularly as the development of DR which suggested that it was impossible to forecast the deterioration of DR through the changing of VEGF concentration in plasma.3.The significantly increased VEGF concentration in eyes,especially in vitreous of PDR patients may play an important role in development and deterioration of DR.4.It was clear that VEGF played its normal biological functions mainly in plasma in normal human.In severeDR patients,abnormal high may come from ischemic and VEGF concentration in vitreous suggested that it hypoxic retina and there was a tendency to diffuse towards the front of eyes.