Abstract
Abstract: :
Purpose: MCP–1 has been thought to play a key role in the pathogenesis of diabetic retinopathy (DR) by mediating inflammation and, to a lesser extent, promoting angiogenesis. PEDF demonstrates anti–angiogenic and antioxidant qualities, thereby serving as a potential protective factor in the progression of disease. Intravitreal injection of triamcinolone has been shown to improve and even reverse the pathophysiology associated with diabetic macular edema (DME) and DR. In this study, vitreous levels of MCP–1 and PEDF were assessed in patients with DME and different degrees of DR before and after triamcinolone administration. Methods: Vitreous samples from 94 patients were collected, including a set of 26 patients immediately before intraocular triamcinolone injection and one month post injection. The ocular disease categories were non–proliferative DR (NPDR) (n=36) and proliferative DR (PDR) (n=58), which included the subgroups of regressed PDR (n=8), active PDR (n=12), florid PDR (n=18), and neovascular glaucoma (NVG) (n=20). ELISA was employed to determine MCP–1 and PEDF levels. Results: MCP–1 levels were higher in the PDR groups than in the NPDR group. In all categories, triamcinolone treatment significantly reduced MCP–1 levels (p<0.05), with the greatest reduction seen in the severe PDR groups. PEDF was also higher in PDR patients vs. NPDR (p<0.05). There was a corresponding decrease in PEDF within each category following triamcinolone treatment, except in the NVG group. Conclusions: Triamcinolone treatment significantly reduced MCP–1 levels in patients with DME and all DR disease categories. This suggests that the inflammatory component of DME may be important in the pathogenesis of the disease. The reduction in PEDF following treatment may indicate that as MCP–1 values decrease, less PEDF is required. This study suggests the potential value of anti–MCP–1 treatment options in DR with DME, and explains, in part, one of the beneficial effects of triamcinolone injections for diabetic eye disease.
Keywords: corticosteroids • cytokines/chemokines • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled