ROLE OF OXIDATIVE STRESS, INFLAMMATION AND ENDOTHELIAL DYSFUNCTION IN THE PATHOGENESIS OF DIABETIC RETINOPATHY

BACKGROUND: Oxidative stress, inflammation and endothelial dysfunction are commonly found in persons with type II diabetes mellitus (DM), but their role in the pathogenesis of diabetic retinopathy (DR) is not fully elucidated. Therefore, the present study investigates the relationship and the role of these factors in the incidence and progression of different stages of DR. METHODS: This study included 85 subjects divided into four groups. First group consisted of 20 healthy subjects who served as controls. The second group consisted of 23 patients with type II DM without retinopathy, while the third group consisted of 20 patients having non-proliferative diabetic retinopathy (NPDR), and finally the last group consisted of 22 patients having severe proliferative diabetic retinopathy (SPDR). For all subjects in all groups, the levels of glycated hemoglobin (HbA1c %), lipid profiles, malondialdehyde (MDA) and nitric oxide ( NO) were measured spectrophotometrically, while tumor necrosis factor-alpha (TNF-alpha) and soluble Eselectin (sE-selectin) were measured using ELISA technique. RESULTS: All the above measured parameters were significantly elevated in all diabetic patients with or without retinopathy when compared to control subjects, with the most significant increase in case of the SPDR group. There was a significant positive correlation between plasma MDA with both TG & HbA1c%, NO & TNF-alpha and finally s-Eselectin & HbA1c%. CONCLUSION: Oxidative stress, inflammation and endothelial dysfunction have a fundamental role in the pathogenesis of DR.