Materials and Methods: Twentyfive patients with proliferative diabetic retinopathy (PDR group), 25 patients with nonproliferative diabetic retinopathy (NPDR group) and 25 nondiabetic healthy subjects (control group) were included in the study. Fasting venous blood samples were collected from all subjects. Serum samples were analyzed for triglycerid, total cholesterol, HDL, LDL and VLDL cholesterol, lipid peroxides (thiobarbituric acid substances=TBARS), erythrocyte glutathione peroxidase and catalase activities and HbA1C. However Total antioxidant status was also studied in patients with PDR and NPDR.

Results: There was no statistically difference significant between 3 groups for total cholesterol, LDL and HDL cholesterol levels (p>0,05). Serum VLDL cholesterol and triglycerid levels were elevated in PDR group compared with control group (p=0,001). Serum TBARS level were higher in PDR and NPDR groups than control group (p<0,05). There was no correlation between TBARS and lipid levels in all groups (p>0,05). Total antioxidant status levels were higher in PDR group than NPDR group (p<0,05). HbA1C levels were elevated in diabetic patients compared with control subjects (p<0,001).

Conclusion: Free radical generation and antioxidant defense imbalance may play a role in the progression of diabetic retinopathy. Keywords : Diabetic retinopathy, oxidative stress, total antioxidant status, lipid peroxidation