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 retinal arterial occlusive disease in African American patients and to compare these etiologies with those observed in Caucasian patients with retinal ischemic symptoms. Methods-We performed a retrospective analysis of a series of consecutive patients evaluated by both the ophthalmology department and the neurology/stroke clinic. Patients had a diagnosis of amaurosis fugax, branch retinal artery occlusion, central retinal artery occlusion, or intra-arterial retinal plaques. Results-Twenty-nine African American patients and 17 Caucasian patients were evaluated. African American patients had a mean age of 61 years (range, 30 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 between the 2 groups with respect to visible emboli on funduscopy (P=0.462). After adjusting for age, there was also no difference between the 2 groups with regards to risk factors for arterial occlusive disease such as hypertension, coronary artery disease; hypercholesterolemia, tobacco use, and history of stroke or transient ischemic attacks. Caucasian patients had a 41% incidence (7/17) of high-grade ipsilateral internal carotid artery stenosis, measured by carotid duplex, compared with 3.4% incidence (1/29) in African American 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 severe extracranial carotid stenosis, and a high proportion of African American patients have cryptogenic retinal ischemia. In Caucasian patients there is a stranger association between extracranial carotid artery disease and retinal arterial occlusion.