Studies comparing the incidence of blindness in persons with and without diabetes are scarce worldwide. In Germany, a decline in the incidence of blindness was found during the 1990s. The aim of this study was to analyze the recent time trend.
Data were based on administrative files in southern Germany to assess recipients of blindness allowance newly registered between 1 January 2008 and 31 December 2012. We estimated age- and sex-standardized incidence of blindness in people with and people without diabetes and the corresponding relative risk. Poisson regression was used to examine age- and sex-adjusted time trends.
We identified 1,897 new cases of blindness (23.7% of which were associated with diabetes). We observed a strong decrease in incidence in both the population with diabetes (2008, 17.3 per 100,000 person-years [95% CI 13.6–21.1], and 2012, 8.9 per 100,000 person-years [6.3–11.6]: 16% decrease [10–22] per year) and that without diabetes (2008, 9.3 per 100,000 person-years [8.3–10.3], and 2012, 6.6 [5.8–7.4]: 9% decrease [5–13] per year). The relative risk comparing those incidences was 1.70 (95% CI 1.32–2.16) and remained constant in the observation period. Regarding time trend, we found similar results for both sexes.
We found a significant reduction in incidence of blindness in the populations with and without diabetes, which was more prominent among individuals with diabetes compared with the 1990s. Our findings may be explained by effective secondary prevention therapies and improved ophthalmologic care beyond diabetic retinopathy, particularly regarding macular degeneration, which means earlier detection and earlier and better treatment.