Mechanisms of retinal arterial occlusive disease in African American and Caucasian patients

Background and Purpose-The aim of our study was to evaluate the causes of r etinal arterial occlusive disease in African American patients and to compa re these etiologies with those observed in Caucasian patients with retinal ischemic symptoms. Methods-We performed a retrospective analysis of a series of consecutive pa tients evaluated by both the ophthalmology department and the neurology/str oke clinic. Patients had a diagnosis of amaurosis fugax, branch retinal art ery occlusion, central retinal artery occlusion, or intra-arterial retinal plaques. Results-Twenty-nine African American patients and 17 Caucasian patients wer e evaluated. African American patients had a mean age of 61 years (range, 3 0 to 77 years) and Caucasian patients a mean age of 73 years (range, 56 to 94 years) (P=0.003). There was no statistically significant difference betw een the 2 groups with respect to visible emboli on funduscopy (P=0.462). Af ter adjusting for age, there was also no difference between the 2 groups wi th regards to risk factors for arterial occlusive disease such as hypertens ion, coronary artery disease; hypercholesterolemia, tobacco use, and histor y of stroke or transient ischemic attacks. Caucasian patients had a 41% inc idence (7/17) of high-grade ipsilateral internal carotid artery stenosis, m easured by carotid duplex, compared with 3.4% incidence (1/29) in African A merican patients (P=0.002). Conclusions-There are racial differences in the causes of retinal arterial occlusion. African American patients have a low prevalence of moderate to s evere extracranial carotid stenosis, and a high proportion of African Ameri can patients have cryptogenic retinal ischemia. In Caucasian patients there is a stranger association between extracranial carotid artery disease and retinal arterial occlusion.