Quantitative Analysis Of Vascular Endothelial Growth Factor And Pigment Epithelium-derived Factor In The Vitreous And Serum With Proliferative Diabetic Retinopathy

Objective: To determine the levels of VEGF and PEDF in the serum and vitreousof patients with proliferative Diabetic Retinopathy (PDR) and Macular Hole (MH),analyzing their relationship with PDR. Besides we will discuss the role of VEGF andPEDF in the fibrosis procedure of PDR.Methods: vitreous and serum sample was collected from45PDR patients and12MH patients. Enzyme-linked immunosorbent assay(ELISA)was used to determine thelevel of VEGF and PEDF in the paired serum and vitreous.Results:1.The serum VEGF level(222.53±131.28pg/ml; mean±SD) and PEDF level(15.43±3.73ug/ml) in PDR patients was significantly higher than that in controls(VEGF98.72±57.08pg/ml; PEDF11.98±2.51ug/ml).2.There is no significant difference in serum VEGF level and PEDF level betweeneach of the sub-group of PDR (VEGF P=0.79; PEDF P=0.19).3.The vitreou level of VEGF(506.04±193.99pg/ml) in PDR group wassignificantly higher than that in controls(VEGF43.31±31.60pg/ml), whereas the PEDFlevel(0.95±0.44ug/ml) in the vitreous of PDR shows a significant lower value ascompared with controls(PEDF1.59±0.55ug/ml).4.Both VEGF and PEDF level in the vitreous of PDR patients decreased as thestage of diabetic retinopathy advanced. For VEGF there was no significant differencebetween each sub-group(VEGF P=0.24).But PEDF level decreased significantly in theadvanced stage of PDR (PEDF P=0.03).5. The PEDF level in the vitreous of PDR patients decreased as the stage of fundus fibrosis advanced. Still there was no significant difference between each group.(P=0.09).6. Both VEGF and PEDF levels in serum correlated signifcantly with their level inthe vitreous(VEGF r=-0.535P <0.001；PEDF r=-0.491P=0.001).8.The serum level of PEDF in PDR group was positively associated with bodymass index(r=0.601P <0.001)and HbA1c(r=0.547P=0.010).Conclusions: High levels of PEDF and VEGF in the serum may be related to theprogression of diabetic retinopathy. But both serum VEGF level and serum PEDF levelwere not necessarily a useful factor for accurately predicting the stage and severity ofDR. The unbalanced level between VEGF and PEDF in vitreous may be related with theprogression of DR. Both VEGF and PEDF may involved in the fibrosis procedure ofPDR as their level decreased when firosis became manifested. The serum level of PEDFmay be a useful predictor for the occurrence of DR.