Global temporal trends of DR-related blindness and vision loss from 1990 to 2021: an age-period-cohort analysis of the contributions of type 1 and type 2 diabetes.

Abstract

The current study aims to investigate how age, period and cohort effects have shaped the patterns of diabetic retinopathy-related vision loss globally, distinguishing between loss associated with type 1 versus 2 diabetes. A secondary analysis of data from the Global Burden of Disease (GBD) 2021 study was conducted by using estimates of blindness and vision loss due to DR across different socio-demographic index (SDI) categories. Age-standardised prevalence rates, relative percentage changes, net drift and local drift were analysed. Globally, age-standardised prevalence (ASPR) of diabetes-related blindness and vision loss rose from 48.8 per 100 000 in 1990 to 67.3 per 100 000 in 2021, with type 1 diabetes-related blindness and vision loss ASPR showing a modest decrease (from 1.8 to 1.7 per 100 000). The highest relative increase was recorded in the high SDI group (45.8%). For Type 1 diabetes, low-middle and low SDI groups exhibited more pronounced declines in associated ASPR. Increasing ASPR with advancing age was consistent across SDI groups though less pronounced for type 1 than type 2 diabetes. Unfavourable period and cohort effects were observed for type 2 but not type 1-related blindness and vision loss risk. High-middle SDI and middle SDI groups showed the most notable increase in period and cohort effect, whereas low-middle and low SDI groups experienced favourable period and cohort risks during the study duration. Substantially different trends were observed for ASPR, period and cohort effects in recent decades for type 1 versus type 2 diabetes across different SDI.