Type 2 diabetes and diabetic retinopathy in Finland during 2000–2017 based on nationwide survey and register data

PURPOSE: To evaluate changes in the prevalence and incidence of type 2 diabetes, the association between type 2 diabetes and diabetic retinopathy (DR), and the impact of type 2 diabetes and DR on visual acuity (VA) in Finland during 2000-2017. METHODS: We used three nationwide health examination surveys conducted in 2000, 2011 and 2017, with a total of 18 966 participants representing the Finnish population aged 18 years and older. All surveys were linked to national health registers covering diagnoses related to diabetes and DR between 2000 and 2017. All surveys included a health examination, in which distance and near VAs were measured. All data were analysed at the individual level. RESULTS: The prevalence of type 2 diabetes increased from 2.6% to 9.6% between 2000 and 2017, while its annual incidence increased from 0.5% to 0.7%. The annual incidence of DR among type 2 diabetes patients decreased from 1.4% to 0.3% between 2000 and 2017. Both distance and near VA were the best among individuals without diabetes, significantly worse among type 2 diabetes patients without DR, and the worst among type 2 diabetes patients with DR. Both distance and near VAs significantly improved between 2000 and 2017 in these study groups. CONCLUSIONS: The prevalence of type 2 diabetes has increased during the 2000s, which can be explained by the improved screening and unfavourable changes in lifestyle. However, the incidence of DR has decreased among type 2 diabetes patients, indicating the successful development and effectiveness of screening and therapies for both diabetes and DR.