Diabetes-Related Risk Factors for Exudative Age-Related Macular Degeneration: A Nationwide Cohort Study of a Diabetic Population

PURPOSE: The purpose of this study was to identify diabetes-related risk factors for exudative age-related macular degeneration (AMD). METHODS: This was a nationwide population-based cohort study using authorized clinical data provided by the Korean National Health Insurance Service. A total of 1,768,018 participants with diabetes over 50 years of age participated in the Korean National Health Screening Program between 2009 and 2012. Data on covariates, including age, sex, income level, systemic comorbidities, behavioral factors, and diabetes-related parameters, including duration of diabetes, use of insulin for diabetes control, number of oral hypoglycemic agents used, and accompanying vision-threatening diabetic retinopathy, were collected from health screening results and claims data. Patients were followed up until December 2018. Incident cases of exudative AMD were identified using registered diagnostic codes from the claims data. The prospective association of diabetes-related parameters with incident exudative AMD was investigated using the multivariable-adjusted Cox proportional hazard model. RESULTS: During an average follow-up period of 5.93 years, 7331 patients were newly diagnosed with exudative AMD. Compared to those who had diabetes for less than 5 years, individuals with diabetes for 5 years or more had a greater risk of future exudative AMD development, with a hazard ratio (95% confidence interval) of 1.13 (1.07–1.18) in the fully adjusted model. Use of insulin for diabetes control and the presence of vision-threatening diabetic retinopathy were also associated with an increased risk of exudative AMD with a hazard ratio (95% confidence interval) of 1.16 (1.07–1.25) and 1.40 (1.23–1.61), respectively. CONCLUSIONS: A longer duration of diabetes, administration of insulin for diabetes control, and comorbid vision-threatening diabetic retinopathy were associated with an increased risk of developing exudative AMD.