Prevalence of diabetic retinopathy in Norway: report from a screening study

Purpose: The purpose of the present study was to investigate the prevalence of diabetic retinopathy (DR) in Norway and adherence to the Norwegian Guidelines for screening for diabetic eye disease. Methods: Two hundred and ninety-nine people with diabetes were randomly recruited from the patient lists of randomly selected general practitioners from three different regions in Norway. Retinopathy was evaluated from retinal photographs after dilation of the pupils using a red-free digital camera and visual acuity was measured using the Snellen chart. The patients were interviewed about their ophthalmological and general diabetes control, duration and type of diabetes and medical treatment. Results: The prevalence of any DR was 28%, 66% for type 1 and 24% for type 2 diabetes. The prevalence of proliferative retinopathy was 38% in type 1 and 1.5% in type 2 diabetes. Two patients (one type 1 and one insulin-treated type 2) were visually impaired (visual acuity 0.3 or worse in the better eye) because of proliferative DR. Twenty-six per cent of the patients had never been to an eye examination, and only 69% attended routine eye examinations. Patients who did not attend regular eye screenings were mostly people with type 2 diabetes. Conclusion: The prevalence of DR was higher than previously reported in Norway. Screening for DR did not follow guidelines in a considerable proportion of the patients with type 2 diabetes. There is place for improvement in the implementation of guidelines for screening for DR for people with type 2 diabetes in Norway.