Recent US national population-based data on the prevalence of retinopathy in non-diabetic participants is limited.
To assess the prevalence and risk factors of retinopathy in a representative US population without diabetes.
Population-based, cross-sectional study.
A total of 4354 non-diabetic participants 40 years and older with valid fundus photographs in the 2005 to 2008 National Health and Nutrition Examination Survey.
Diabetes mellitus was defined as glycosylated haemoglobin (HbA1c) ≥6.5%, physician diagnosis of diabetes mellitus or use of diabetic medication. Retinopathy level was based on the Modified Airlie House adaptation from the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol. Risk profile was assessed from standardized interviews, clinical examinations and laboratory measurements.
Main outcome measures
Prevalence and risk profile of retinopathy in non-diabetic participants.
The overall weighted prevalence of retinopathy was 6.7% (n = 341). Among them, 98.2% (n = 331) had signs of minimal-to-mild non-proliferative retinopathy (ETDRS level 14-31) while only 1.8% (n = 10) had moderate-to-severe non-proliferative retinopathy (ETDRS level 41-51). After adjusting for multiple covariates, retinopathy signs in non-diabetic participants were associated with male gender (odds ratio [OR] 1.54; 95% confidence interval [CI] 1.22-1.93), systolic blood pressure (OR per 10 mmHg increase 1.11; 95% CI 1.03-1.19), HbA1c (OR per % increase 1.43; 95% CI 1.01-2.05) and history of stroke (OR 2.39; 95% CI 1.14-5.04).
Conclusions and relevance
Consistent with previous studies, signs of retinopathy are common in US persons without diabetes. Risk factors for retinopathy signs include gender, blood pressure, HbA1c and history of stroke.