Trends in prevalence and incidence of diabetic retinal disease in patients with type 1 and type 2 diabetes mellitus

PURPOSE: To assess the prevalence and incidence of diabetic retinal disease (DRD) among patients with Type 1 (T1DM) and Type 2 diabetes mellitus (T2DM). METHODS: Data were abstracted from patients enrolled in commercial insurance and Medicare Advantage plans. Using ICD-10 coding, the yearly prevalence and incidence of DRD in T1DM and T2DM from January 1, 2016, to June 30, 2022, were analyzed. Assessments were also made into the prevalence and incidence of vision threatening disease (VTDR), defined as having a diagnosis of diabetic macular edema (DME) or proliferative diabetic retinopathy (PDR). Odds (OR) and incidence rate ratios (IRR) were also calculated. RESULTS: Prevalence of DRD in both cohorts increased from 2016 (T1DM:25.1%; T2DM:11.1%) through 2021 (T1DM:34.4%; T2DM:20.7%). T1DM DRD incidence decreased from 55.1/1000py in 2016 to 39.2 in 2022, while T2DM varied from 31.6 to 38.2, ending at 35.5 in 2022. VTDR (yearly OR = 4.61-4.92), DME (OR = 2.79-2.92), and PDR (OR = 6.43-6.72) each had higher prevalences in patients with T1DM vs. T2DM across all years studied (p < 0.001 for all comparisons). A similar pattern was seen for incidence as well (T1DM VTDR IRR = 2.36-2.94; DME IRR = 2.08-2.62; PDR IRR = 2.66-3.67; p < 0.001 for all T1DM vs. T2DM comparisons). CONCLUSION: All forms of DRD had uniformly higher prevalence and incidence in patients with T1DM compared with those with T2DM across all years observed. The incidence of T1DM DRD decreased, approaching the rate of T2DM in 2022, suggesting a reduction in the disparity between the two groups. Prevalence of VTDR, DME, and PDR was also higher in T1DM vs. T2DM. The incidence of these disease states decreased proportionally across both cohorts, maintaining relatively stable ratios.