Color Doppler imaging: a new technique to assess orbital blood flow in patients with diabetic retinopathy.

PURPOSE Color Doppler imaging is a new noninvasive technique that enables measuring blood flow velocity in small orbital vessels, arteries as well as veins. Because hemodynamic changes are seen in patients with diabetic retinopathy by other techniques, the authors compared 61 eyes with proliferative, 59 eyes with nonproliferative, and 26 eyes with preproliferative diabetic fundus changes with a matched control group of 70 patients without diabetes (128 eyes). METHODS The central retinal artery (CRA), short posterior ciliary artery (PCA), and ophthalmic artery (OA) of all patients were examined, and the systolic, diastolic, and mean velocities were measured for each vessel. RESULTS Differences between the groups were most prominent in the CRA. The perfusion velocity was significantly lower (P < 0.001) in proliferative eyes (Vsystolic 5.7 +/- 1.8 cm/sec) than in the control group (Vsystolic 9.4 +/- 1.2 cm/sec) or in nonproliferative eyes (Vsystolic 8.4 +/- 1.8 cm/sec). In the preproliferative group, there was greater variability in velocity distribution. Consequently, no statistically significant difference could be deduced, either in the group with background retinopathy or in the group with proliferative diabetes. In the OA and PCA, neither group showed significant differences from normal. CONCLUSIONS Measurements indicate a correlation between severity of diabetic retinopathy and decreased flow velocity in the CRA.