Microvascular retinopathy in subjects without diabetes: the Inter99 Eye Study

Retinal vascular lesions such as microaneurysms and haemorrhages, while typical of diabetic retinopathy, are also seen in subjects without diabetes where they are associated with elevated cardiovascular mortality. In theory, these lesions could be a consequence of past hyperglycaemia. We examined the prevalence and risk factors for retinopathy, including lens fluorescence, a biomarker of cumulative life-time glycaemia in adults without diabetes.

Cross-sectional population-based study of 711 subjects without diabetes (WHO 1999 criteria) aged 30-60 years, including oral glucose tolerance testing, clinical and laboratory examinations, non-invasive ocular lens fluorometry and seven-field fundus photography.

Retinopathy was present in 8.3% (CI(95) 6.3-10.3%) of subjects. Higher systolic blood pressure (SBP) (p = 0.032), increasing body mass index (BMI) (p = 0.014) and wider waist circumference (p = 0.014) were significantly associated with retinopathy after adjusting for age and sex. Retinopathy was not significantly related to long-term, short-term or current glycaemia (lens fluorescence, HbA(1c) , fasting plasma glucose). In the multivariate analysis, the odds ratio (OR) for retinopathy in subjects with SBP ≥160 mmHg compared to subjects with SBP <130 mmHg was 2.68 (CI(95) 1.07-6.70, p = 0.036) and in subjects with BMI ≥30 compared to subjects with BMI < 25 the OR for retinopathy was 2.14 (CI(95) 1.01-4.57, p = 0.049) when adjusting for both variables, age, sex, the presence of impaired glucose tolerance and impaired fasting glucose.

Retinopathy in subjects without diabetes was associated with hypertension and obesity. The study found no evidence that microvascular retinopathy in non-diabetic subjects was a consequence of past hyperglycaemia.