Retinopathy with and without diabetes: Risk factors and visual impairment.

Abstract

Diabetic retinopathy is a well-known complication of diabetes and a major cause of visual impairment and blindness in developed countries. We explored visual impairment and diabetic retinopathy among participants with diabetes in the Tromsø Eye Study. The prevalence of visual impairment (corrected Snellen visual acuity < 20/40) was 4.1% in the better-seeing eye. We found no legally blind participants. The prevalence of diabetic retinopathy was 26.9% and macular edema 3.9%. In a multivariable logistic regression model, retinopathy was associated with longer diabetes duration, insulin use, non-fasting glucose and urinary albumin excretion. We found a very low microalbuminuria cut-off level for increased risk of diabetic retinopathy (urinary albumin-creatinine ratio > 1.16 mg/mmol). Visual impairment and diabetic retinopathy were also explored in diabetes patients recruited from general practitioners in a multi-centre study conducted in Tromsø, Tønsberg and Stavanger. In this study the prevalence of visual impairment (corrected Snellen visual acuity < 20/40) was 5.4% and one participant was legally blind. The prevalence of diabetic retinopathy was 28.2%. This study also showed that about one third of the diabetes patients did not attend at least biannual eye examination as recommended by the national guidelines. Retinopathy lesions, such as microaneurysms and retinal haemorrhages, are also common in subjects without diabetes. We explored retinopathy in subjects without diabetes in the Tromsø Eye Study, and the overall prevalence of retinopathy was 14.8%. Men had a higher prevalence of retinopathy compared to women (15.9% vs. 14.0%, p=0.04). In men retinopathy was associated with hypertension and HbA1c. In women retinopathy was associated with age, hypertension and urinary albumin excretion. In women, the microalbuminuria cut-off level for increased risk of retinopathy was very low (urinary albumin-creatinine ratio > 0.43 mg/mmol). Visual impairment was also explored in a general population using data from both diabetic and non-diabetic participants in the Tromsø Eye Study and the overall prevalence of visual acuity < 20/60 was 1.2%.