Inflammation, angiogenesis and coagulation interplay in a variety of retinal diseases

Purpose To evaluate and correlate levels of various proteins involved in coagulation, inflammation and angiogenesis processes in the vitreous of patients with different vitreoretinal pathologies. Methods Vitreous samples were collected from patients scheduled for pars plana vitrectomy for the treatment of rhegmatogenous retinal detachment (RRD), vitreous haemorrhage or tractional retinal detachment associated with proliferative diabetic retinopathy (PDR). Macular hole and epiretinal membrane served as controls. Levels of vascular endothelial growth factor, thrombin-antithrombin III complex, interleukin-8, tissue factor, thrombomodulin, P-selectin, D-dimer and tissue factor pathway inhibitor were compared among the vitreoretinal pathology groups. Results Compared to controls, patients with PDR had significantly higher levels of thrombin-antithrombin III complex (p < 0.001), vascular endothelial growth factor (p < 0.001), D-dimer (p = 0.038) and interleukin-8 (p = 0.04), and patients with RRD group had significantly higher levels only of thrombin-antithrombin III complex (p < 0.001). There was a significant linear correlation between levels of P-selectin and D-dimer (p = 0.003), P-selectin and interleukin-8 (p < 0.001), and D-dimer and IL-8 (p = 0.007). These correlations were particularly strong in the PDR group compared to the other groups. Conclusion Patients with PDR manifest high coagulative and angiogenic activity in the vitreous. These pathways are highly correlated with the inflammatory cascade.