The kinetics of VEGF and MCP-1 in the second vitrectomy cases with proliferative diabetic retinopathy

PurposeTo determine whether the concentrations of vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein (MCP)-1 in the vitreous changed after vitrectomy in patients with proliferative diabetic retinopathy (PDR).ParticipantsTwenty-one eyes of 21 patients who needed a second surgery for PDR were included. The reasons for the second surgery were tractional retinal detachment (TRD), neovascular glaucoma, persistent vitreous hemorrhage, macular pucker, and secondary intraocular lens (IOL) implant.MethodsWe measured the VEGF and MCP-1 levels using sandwich enzyme-linked immunosorbent assays in vitreous samples collected from patients with PDR before pars plana vitrectomy (without IOL implantation), and from the same patients during the second surgery.ResultsThere was not significant change in mean VEGF concentrations when comparing first (0.81±0.88 ng/ml) and second surgeries (1.09±1.51 ng/ml). The MCP-1 level was significantly elevated at the time of second surgery (2.20±2.21 ng/ml) compared with the first vitrectomy (0.72±0.57 ng/ml). The MCP-1 levels of the second surgery cases with TRD (3.18±2.27 ng/ml) increased significantly compared with those with other complications (1.72±2.10 ng/ml).ConclusionsAt the second vitrectomy, VEGF did not change significantly in the vitreous of the patients examined. The MCP-1 concentration was markedly elevated at the second vitrectomy, implying an association between the prolonged inflammation after vitrectomy and complications, especially TRD.