The North Jutland County Diabetic Retinopathy Study: population characteristics

Background: Several population-based studies have reported blood glucose levels and blood pressure to be risk factors for the development of diabetic retinopathy. These studies were initiated more than two decades ago and may therefore reflect the treatment and population composition of a previous era, suggesting new studies of the present population with diabetes. Aim and methods: This cross-section study included 656 people with type 1 diabetes and 328 with type 2 diabetes. Crude prevalence rates of proliferative diabetic retinopathy, clinically significant macular oedema and several specific retinal lesions were assessed, together with their association to a simplified and internationally approved retinal grading. Results: The point prevalence of proliferative retinopathy was found to be 0.8% and 0.3% for type 1 and type 2 diabetes. Equivalent prevalence rates of clinically significant macular oedema were 7.9% and 12.8%, respectively. The most frequently occurring retinal manifestations increased in number until retinopathy level 3, and then decreased. Conclusion: The point prevalence of proliferative retinopathy is lower than that found in previous studies, whereas it is increased for clinically significant macular oedema. These data suggest different risk factors for these clinical entities.