ORBITAL COLOR DOPPLER IMAGING IN CAROTID OCCLUSIVE DISEASE

Objective: To define orbital circulation abnormalities identified by c olor Doppler imaging in patients with severe carotid occlusive disease . Patients: Twenty-four patients referred to a hospital-based neuro-op hthalmology service with hemodynamically significant carotid occlusive disease (>75% stenosis) were prospectively studied. Eight had signs o f ocular ischemic syndrome; 12 of the 24 patients underwent endarterec tomy. Main Outcome Measures: Peak systolic velocity of the central ret inal, posterior ciliary, and ophthalmic artery and pulsatility indexes as determined by color Doppler imaging. Methods: Color Doppler imagin g was performed using a 7.5-MHz probe. Both eyes were studied in all p atients 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 ciliar y, and ophthalmic arteries and higher pulsatility indexes compared wit h normal control patients. Endarterectomy improved peak systolic veloc ities. Reversal of ophthalmic flow direction as a separate variable wa s unassociated with altered mean central retinal or posterior ciliary artery flow velocities. Patients with ocular ischemic syndrome may hav e similar orbital color Doppler imaging findings compared with patient s with severe carotid occlusive disease without overt manifestations o f chronic ocular ischemia. Conclusion: Orbital circulation is highly a daptable even when faced with severe compromise in proximal blood flow .