Is the prevalence and incidence of visual impairment rising or falling in people with diabetes? This question is important given the large numbers of people estimated to develop diabetes in the future.1,2 Projected estimates based on current data from cohort studies have shown that the prevalence and incidence of visual impairment have decreased in those more recently diagnosed with type 1 diabetes compared with people diagnosed in the past.3- 6 In the Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR), a large cohort of persons with type 1 diabetes was examined at multiple intervals over a long period. This provided an opportunity to explore whether the period of diagnosis of type 1 diabetes affected the prevalence of visual impairment.4 For any specific duration of type 1 diabetes, those who were diagnosed to have type 1 diabetes in a more recent period were less likely to be visually impaired than those diagnosed in an earlier period (odds ratio [OR] per category, 0.91; 95% CI, 0.88-0.93; P < .001). The decline in visual impairment reported in the WESDR and other studies of persons with type 1 diabetes was attributed to a declining incidence of proliferative diabetic retinopathy and clinically significant macular edema resulting from improved glycemic control and more aggressive treatment of blood pressure sooner after diagnosis of diabetes.5- 9 In addition, education and screening programs have been developed for earlier detection and more timely treatment of eyes at high risk of severe visual loss due to diabetic retinopathy.10,11 The declining prevalence of visual impairment is consistent with declines in the estimated annual incidence of visual impairment in people with type 1 diabetes.4 In the WESDR, estimated annual incidence of any visual impairment over a 25-year period was markedly lower in the most recent period of the study (an annualized rate of 0.28 between the 1995-1996 and 2005-2007 examinations compared with an annualized rate of 0.65 between the 1980-1982 and 1990-1992 examinations).
Klein R, Klein BEK. Is the Prevalence of Visual Impairment Rising or Falling in the People With Diabetes Mellitus?It Depends on Who You Study. JAMA Ophthalmol. 2013;131(7):948–950. doi:10.1001/jamaophthalmol.2013.4023