Material and Methods: In our study we examined a total of 90 subjects consist of 60 type 2 diabetic patients and 30 healty controls. All patient's fasting blood glucose level before doppler ultrasonography, HbA1c, LDL, HDL levels, duration of diabetes mellitus (DM), systolic/diastolic and mean blood pressure were recorded. Visual acuity, intraoculer pressure, anterior segment examination were done all patients. Diabetic patients were divided into 2 groups according to the degree of diabetic retinopathy. Diabetic patients without retinopathy (group 2) and mild non proliferatif diabetic retinopathy (group 3) were classified. The peak systolic (Vmax) and diastolic blood flow (Vmin), resistivity index (RI) and pulsatility index (PI) of ophtalmic artery (OA), central retinal artery (CRA), short posterior ciliary artery (SPSA) were measured.

Results: In group 3 fasting blood glucose level before doppler ultrasonography, HbA1c, LDL, HDL levels, duration of DM were significantly higher than control and group 2. Vmax and Vmin was lower and mean RI was higher in the diabetic retinopathy than control group regarding the OA, CRA, SPSA. Vmax and Vmin was lower and mean RI was higher in group 2 than group 3. There was significantly positive corelation between OA-RI and HbA1c values and duration of DM.

Conclusion: We found that increasing duration of DM and higher HbA1c levels increased vascular resistance and reduced retrobulber flow. Keywords : Color doppler ultrasound, diabetic retinopathy, ocular circulation, resistivity index