Trends in diabetic eye disorders and associated comorbidities in Taiwan: a 10-year nationwide population-based cohort study

Background/aims In-depth analysis is needed to investigate trends in diabetic retinopathy (DR), diabetic macular oedema (DME) and associated comorbidities in patients with type 2 diabetes mellitus (T2DM) so that we can better understand their prevalence and incidence. Methods A retrospective population-based study was conducted using data from Taiwan's National Health Insurance Research Database from 2005 to 2015, and T2DM, DR and associated comorbidities were identified based on diagnostic codes. We used a standardised incidence rate with age and sex adjustment to estimate the prevalence and incidence of DR, proliferative DR (PDR), advanced PDR (aPDR) and DME, while the difference in each study period was calculated as the annual percentage change. We used the absolute standardised difference to analyse changes in related comorbidities in different periods. Results The population of patients with DM increased over 50% between 2005 and 2015, while the prevalence and incidence of DR decreased, as did the incidence of PDR and aPDR. However, the prevalence and incidence of DME increased over the course of 10 years, with an upward trend in all forms of DR. The percentage of patients with hyperlipidaemia in DME and all DR increased, and the percentage of patients with end-stage renal disease (ESRD) was also elevated in DME. Conclusion The prevalence and incidence of DR, PDR and aPDR decreased with time in patientsT2DM, while the ratio of DME increased gradually. The incidence of hyperlipidaemia also increased in all forms of diabetic eye disorders, while ESRD increased solely in DME.