Waveform of Ophthalmic Artery Doppler Flow Predicts the Severity of Systemic Atherosclerosis

BACKGROUND: Doppler imaging of ophthalmic artery (OA), the first major branch of the internal carotid artery, provides anatomical advantages due to the vertical angle to the body surface and absence of ultrasonic obstacles. It was hypothesized that the Doppler waveform indices of OA correlate with severity of systemic atherosclerosis. METHODS AND RESULTS: The study subjects were 180 patients who underwent cardiac catheterization and OA Doppler imaging (90 patients with coronary artery disease (CAD) and 90 control patients). The ratio of stroke volume to pulse pressure, an index of arterial compliance, was closely associated with the ratio of systolic to diastolic mean velocity (Sm/Dm) in OA. The level of Sm/Dm increased in proportion with the increase in number of stenosed coronary arteries (0-vessel disease 2.1+/-0.3, 1-vessel disease 2.3+/-0.3, multi-vessel disease 2.6+/-0.5, P<0.0001). The Sm/Dm level in OA correlated positively with age, pulse pressure, pulse wave velocity, resistive index and pulsatility index in OA. The best Sm/Dm cut-off to predict CAD was 2.3, and patients with Sm/Dm >2.3 had 8.0-fold risk for CAD. CONCLUSIONS: The waveform indices of OA are clinically useful for evaluating the severity of CAD and may help explain the missing link between OA circulation and systemic arterial compliance.