Orbital color Doppler imaging in carotid occlusive disease.

OBJECTIVE

To define orbital circulation abnormalities identified by color Doppler imaging in patients with severe carotid occlusive disease.

PATIENTS: Twenty-four patients referred to a hospital-based neuro-ophthalmology service with hemodynamically significant carotid occlusive disease (> 75% stenosis) were prospectively studied. Eight had signs of ocular ischemic syndrome; 12 of the 24 patients underwent endarterectomy.

MAIN OUTCOME MEASURES: Peak systolic velocity of the central retinal, posterior ciliary, and ophthalmic artery and pulsatility indexes as determined by color Doppler imaging.

METHODS

Color Doppler imaging was performed using a 7.5-MHz probe. Both eyes were studied in all patients and carotid duplex imaging was obtained.

RESULTS

All patients with hemodynamically significant carotid occlusive disease had lower mean peak systolic velocities in the central retinal, posterior ciliary, and ophthalmic arteries and higher pulsatility indexes compared with normal control patients. Endarterectomy improved peak systolic velocities. Reversal of ophthalmic flow direction as a separate variable was unassociated with altered mean central retinal or posterior ciliary artery flow velocities. Patients with ocular ischemic syndrome may have similar orbital color Doppler imaging findings compared with patients with severe carotid occlusive disease without overt manifestations of chronic ocular ischemia.

CONCLUSION

Orbital circulation is highly adaptable even when faced with severe compromise in proximal blood flow.