Materials and Methods: Blood flow parameters in the ophthalmic (OA) and the central retinal arteries (CRA) and the central retinal veins of 31 type 2 diabetic patients with nonproliferative retinopathy and 35 healthy subjects were investigated using CDU before and one month after cataract extraction by facoemulsification ör extracapsular methods.

Results: No significant difference was found between pre- and postoperative orbital blood flow parameters in healthy subjects (p>0.05). Resistivity index (RI) in the OA was found to be decreased significantly at the first month visit compared to the preoperative levels in diabetic patients (p=0.03). RI's in the OA and the CRA at the preoperative measurements were significantiy higher in diabetic group (p=0.002, p=0.021, respectively). End diastolic velocities (EDV) in the OA and the CRA and peak systolic velocity (PSV) in the CRA were significantly lower in diabetic group, preoperatively (p=0.002, p=0.006, p=0.009, respectively). One month after cataract surgery PSV and EDV in the CRA were found to be lower and RI was found to be higher significantly in diabetic patients compared to the healthy group(p<0.001, forall)

Conclusion: Orbital blood flow parameters were found to be uninfluenced by cataract surgery in healthy subjects. The differences in orbital blood flow parameters in preoperative and postoperative first month measurements in diabetic patients suggest that existence of diabetes mellitus probably has a greater effect on orbital blood flow than cataract surgery. Keywords : Diabetes mellitus, Diabetic retinopathy, Cataract surgery, Color Doppler ultrasonography, Orbital blood flow.