Correlation between Progression of Retinopathy and Metabolic Control in a Two-year Follow-up Study of Mild Nonproliferative Retinopathy in Subjects with Type 2 Diabetes

Abstract

Abstract: : Objective: A two-year prospective study of mild nonproliferative retinopathy (NPR) subjects with type 2 diabetes to evaluate progression of the retinopathy versus metabolic control. Methods: Type 2 diabetic patients with mild NPR (ETDRS gradings 14 to 47) treated with an association of three hypoglycemic agents (metformin, acarbose, and a sulphonylurea) to optimize their metabolic control were selected. 59 patients were enrolled in the study. 45 patients completed the two-year follow-up period. The eyes were examined 5 times, at six-month intervals, by stereofundus photography (seven fields), ocular fluorometry and retinal thickness analysis. Metabolic control, blood pressure and lipids were measured at each visit. Results: The number of microaneurysms, the permeability of the Blood-Aqueous Barrier (BAB) and the permeability of the Blood-Retinal Barrier (BRB) increased, respectively, by 145%, 20% and 22% at two years in eyes of patients with HgA1c values ≥ 7.5% at baseline. These increases differ significantly for the same variables in eyes of patients with HgA1c values <7.5% at baseline that showed changes of +90%, –14% and –2%, respectively. Similar increases were found comparing two groups with HgA1c ≥ 7.5% and HgA1c < 7.5% throughout the study. Conclusions: Retinopathy progression (microaneurysms, hyperpermeability of BAB and BRB) in mild NPR in subjects with type 2 diabetes is clearly correlated with HgA1c values, which are indicators of metabolic control.

Keywords: diabetic retinopathy