Retinal microvascular abnormalities and MRI-defined subclinical cerebral infarction - The atherosclerosis risk in communities study

Background and Purpose - Retinal microvascular abnormalities reflect cumulative small vessel damage from elevated blood pressure and may reflect subclinical cerebral microvascular changes. We examined their associations with MRI-defined cerebral infarcts. Methods - Population-based, cross-sectional study of 1684 persons 55 to 74 years of age without a history of clinical stroke, sampled from 2 US southeastern communities. Retinal photographs were obtained and graded for presence of retinal microvascular abnormalities, including arteriovenous nicking, focal arteriolar narrowing, retinal hemorrhages, soft exudates and microaneurysms. Photographs were also digitized, and retinal vessel diameters were measured and summarized as the arteriole-to-venule ratio (AVR). Cerebral MRI scans were graded for presence of cerebral infarct, defined as a lesion >= 3 mm diameter in a vascular distribution with typical imaging characteristics. Results - There were a total of 183 MRI cerebral infarcts. After adjustment for age, gender, race, 6-year mean arterial blood pressure, diabetes, and other stroke risk factors, cerebral infarcts were associated with retinal microvascular abnormalities, with odds ratios 1.90 (95% CI, 1.25 to 2.88) for arteriovenous nicking, 1.89 (95% CI, 1.22 to 2.92) for focal arteriolar narrowing, 2.95 (95% CI, 1.30 to 6.71) for blot hemorrhages, 2.08 (95% CI, 0.69, 6.31) for soft exudates, 3.17 (95% CI, 1.05 to 9.64) for microaneurysms, and 1.74 (95% CI, 0.95 to 3.21) for smallest compared with largest AVR. In stratified analyses, these associations were only present in persons with hypertension. Conclusions - Retinal microvascular abnormalities are associated with MRI-defined subclinical cerebral infarcts independent of stroke risk factors. These data suggest that retinal photography may be useful for studying subclinical cerebrovascular disease in population-based studies.