Objective To assess retinopathy and its risk factors in an obesity WHO III cohort.

Methods In the Mannheim Obesity Study, 277 subjects with obesity WHO III aged 18–64 years were examined in a cross-sectional approach. Screening for retinopathy was performed using 3-field retinal photography. Endothelial function was assessed using arteriole-to-venule ratio and flicker light analysis. Subjects with and without retinopathy were analysed for anthropometry, metabolic, vascular and renal parameters.

Results Retinopathy was found in 18 of the 277 subjects (6.5%). Prevalence of retinopathy was 16.7% in subjects with and 3.4% in subjects without diabetes mellitus. Between subjects with and without retinopathy there were significant differences in diabetes prevalence (61.1% vs 21.7%, p<0.001), systolic blood pressure (145.56 vs 131.73 mm Hg, p=0.005), intima-media thickness (0.7 vs 0.59 mm, p=0.034), dilatation of retinal veins in response to flicker light (2.24% vs 4.28%, p=0.004) and creatinine (0.92 vs 0.83 mg/dL, p=0.011). Stepwise logistic regression analysis revealed that the presence of diabetes mellitus led to an 8.3-fold increased risk for retinopathy (OR 8.3, p=0.049, 95% CI 1.01 to 67.49), whereas risk for retinopathy decreased by nearly 50% (OR 0.54, p=0.032, 95% CI 0.30 to 0.95) with each percentage increase in venous dilatation in response to flicker light.

Conclusions Retinopathy prevalence in our obesity WHO III cohort is low. Presence of diabetes mellitus is the most important risk factor for retinopathy. Preserved venular function indicates protection from retinopathy.

Trial registration number NCT00770276, Results.