Background and purpose: Because no population-based estimates are available for asymptomatic retinal emboli, we aimed to assess prevalence and associations of this sign in a defined older Australian urban population.
Methods: A total of 3654 persons aged 49 years or older, representing 82% of residents in an urban area west of Sydney, underwent a detailed eye examination that included medical history, stereo retinal photography, and fasting blood tests including lipids. Retinal emboli were diagnosed clinically and from photographic grading and classified as cholesterol, platelet-fibrin, or calcific in type.
Results: Asymptomatic retinal emboli were found in 51 participants (1.4%; 95% confidence interval [CI], 1.0% to 1.8%). The prevalence was 0.8% in persons aged < 60 years, 1.4% for those aged 60 to 69 years, 2.1% for those aged 70 to 79 years, and 1.5% for those aged 80 years or older. Men had a significantly higher prevalence (2.2%) of retinal emboli than women (0.8%, P < .001) after adjustment for age (odds ratio [OR], 2.7; 95% CI, 1.5 to 4.8). Forty-one emboli (80%) were cholesterol type, 7 (14%) were platelet-fibrin, and 3 (6%) were calcific. Significant associations were found after age-sex adjustment, with hypertension (OR, 2.2; 95% CI, 1.2 to 3.8), a combined history of vascular disease (OR, 2.4; 95% CI, 1.3 to 4.4), past vascular surgery (OR, 3.5; 95% CI, 1.4 to 8.5), and current (OR, 2.2; 95% CI, 1.1 to 4.2) or any (OR, 2.6; 95% CI, 1.2 to 4.3), smoking history. These associations persisted after multivariate analysis. There were no significant associations with diabetes, obesity, or fasting blood test findings.
Conclusions: This study provides accurate prevalence rates for asymptomatic retinal emboli in the elderly and confirms associations with hypertension, smoking, and vascular disease.