Changes in Visual Impairment due to Diabetic Retinopathy During 1980-2019 Based on Nationwide Register Data

OBJECTIVE: To evaluate changes in the incidence, prevalence, severity, and onset age of visual impairment (VI) due to diabetic retinopathy (DR) and compare these trends in the screening and treatment of diabetes during 40 years based on Finnish national register data. RESEARCH DESIGN AND METHODS: We included people with VI with nonproliferative DR (NPDR; n = 2,490, 73% women) or proliferative DR (PDR; n = 2,026, 53% women) as the main diagnosis for VI during 1980-2019 in the Finnish Register of Visual Impairment. The number of patients with treated diabetes during 1986-2019 was obtained from the Social Insurance Institution of Finland registers based on reimbursed medication data. RESULTS: The annual incidence of reported VI due to DR has decreased since it peaked in the 1990s: regarding NPDR, it decreased from 102.3 to 5.5 per 100,000 patients with treated diabetes between the 1990s and 2010s; regarding PDR, the respective change was from 39.9 to 7.4. The incidence of patients with diabetes treated for DR increased during this period. Annual prevalence of reported VI and differences between sexes steadily decreased in the 2000s and 2010s. The severity of reported VI has decreased, and the age at the onset of reported VI increased during the 40 years. CONCLUSIONS: Prevalence and incidence of VI due to DR have dramatically decreased and shifted to older age during the 40 years despite the increasing prevalence of diabetes. These positive trends highlight the successful development and effectiveness of screening and therapies for diabetes and DR.