Objectives
Despite the increasing prevalence of Type 2 diabetes mellitus (T2DM) among children and adolescents, little is known about their risk of developing diabetic retinopathy (DR). We sought to identify risk factors for DR in youth with DM, to compare DR rates for youth with Type 1 diabetes mellitus (T1DM) and T2DM, and to assess whether adherence to DR screening guidelines promoted by the American Academy of Ophthalmology, American Academy of Pediatrics, and American Diabetes Association adequately capture youth with DR.
Design
Retrospective observational longitudinal cohort study.
Participants
Youth aged ≤ 21 years with newly diagnosed T1DM or T2DM enrolled in a large U.S. managed care network.
Main Outcome Measure
Hazard ratios (HR) with 95% confidence intervals (CIs) for developing DR.
Methods
In this study of youth aged ≤ 21 years with newly diagnosed T1DM or T2DM enrolled in a large U.S. managed care network who were under ophthalmic surveillance, we identified the incidence and timing of DR onset for youth with T1DM and T2DM. Kaplan-Meier survival curves assessed the timing of initial diagnosis of DR for youth with each type of diabetes. Multivariable Cox proportional hazard regression modeling identified factors associated with the hazard of developing DR. Model predictors were age and calendar year at initial diabetes mellitus diagnosis, sex, race/ethnicity, net worth, and glycosylated hemoglobin (HbA1c).
Results
Among the 2240 youth with T1DM and 1768 youth with T2DM, 20.1% and 7.2% developed DR, over a median follow-up of 3.2 and 3.1 years, respectively. Survival curves demonstrated that youth with T1DM developed DR faster than youth with T2DM (P<0.0001). For every one-point increase in HbA1c, the hazard for DR increased by 20% (HR=1.20, CI 1.06–1.35) and 30% (HR=1.30, CI 1.08–1.56) among youth with T1DM and T2DM, respectively. Current guidelines suggest ophthalmic screening begin 3–5 years after initial DM diagnosis, at which point in our study, over 18% of youth with T1DM had already had received ≥1 DR diagnosis.
Conclusions
Youth with T1DM or T2DM exhibit a considerable risk for DR and should undergo regular screenings by eye-care professionals to ensure timely DR diagnosis and limit progression to vision-threatening disease.