PREVALENCE OF ASYMPTOMATIC RETINAL EMBOLI IN AN AUSTRALIAN URBAN-COMMUNITY

Background and Purpose Because no population-based estimates are avail able for asymptomatic retinal emboli, we aimed to assess prevalence an d associations of this sign in a defined older Australian urban popula tion. Methods A total of 3654 persons aged 49 years or older, represen ting 82% of residents in an urban area west of Sydney, underwent a det ailed eye examination that included medical history, stereo retinal ph otography, and fasting blood tests including lipids. Retinal emboli we re diagnosed clinically and from photographic grading and classified a s cholesterol, platelet-fibrin, or calcific in type. Results Asymptoma tic 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 sig nificantly 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 pl atelet-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, obesit y, or fasting blood test findings. Conclusions This study provides acc urate prevalence rates for asymptomatic retinal emboli in the elderly and confirms associations with hypertension, smoking, and vascular dis ease.