Thirty-Year Trends in the Prevalence and Severity of Diabetic Retinopathy at the First Visit in Patients with Untreated Type 2 Diabetes Mellitus.

ABSTRACT

PURPOSE: Although the rate of diabetic retinopathy (DR)-related blindness has decreased in developed countries in recent years, the reasons for this decrease have remained unclear. The prevalence/severity trends of DR at the first visit in patients with untreated type 2 diabetes mellitus (T2DM) patients seen between the1986s and 2018s were assessed. METHODS: A total of 1979 Japanese T2DM patients diagnosed between 1986 and 2018 were divided into four groups by the decade of their first visit the 1986 years (1986-1987), the 1996 years (1996-1997), the 2006 years (2006-2008), the 2016 years (2016-2018). The DR prevalence/severity trends were assessed. RESULTS: A significant decrease in the rate of prevalence of DR from the 1986s to 2016s was observed among previously untreated T2DM patients visiting our hospital for the first time (1986s 25.5%; 1996s 26.2%; 2006s 22.2%; and 2016s 15.6%). The prevalence was significantly higher in females (30.2%) than in males (21.3%). Although the severity trend of DR did not differ significantly among the four measurement years, the rate of simple DR was the highest in the 2016s. CONCLUSION: We found, for the first time, a significant decrease in the rate of prevalence of DR from the 1986s to 2016s in patients with untreated T2DM visiting our hospital for the first time. A decrease in the rate of DR prevalence could explain, at least in part, the observed reduction in the rate of blindness in patients with T2DM.