Purpose
In recent years, there has been a large rise in the number of children and adolescents who are diagnosed with Type 2 diabetes mellitus (DM) in the United States. Yet, little is known about the incidence of diabetic retinopathy (DR) among children with Type 2 DM, how it compares with the incidence of retinopathy in children with Type 1 DM, and factors affecting the risk of developing retinopathy in youth with DM.
Methods
We reviewed health care claims database records to identify all children and adolescents age ≤ 21 years who were newly diagnosed with DM and underwent at least one eye exam by an ophthalmologist or optometrist. A previously validated algorithm was applied to characterize each youth with Type 1 or Type 2 DM. Next, we identified the children and adolescents who developed diabetic retinopathy based on ICD-9-CM diagnosis codes. Kaplan-Meier survival curves were plotted to depict the time from first DM diagnosis to first record of DR. Cox proportional hazard regression modelling was performed to identify sociodemographic factors associated with an increase in the hazard of developing diabetic retinopathy.
Results
Among the 2457 eligible youth with newly-diagnosed Type 1 DM and 1673 youth with Type 2 DM, 275 (6.7%) developed retinopathy. The proportion of youth with Type 1 DM and Type 2 DM who developed retinopathy was 9.2%, and 2.9 %, respectively. The incidence of DR was 25.8 and 8.9 per 1000 person-years among youth with Type 1 and Type 2 DM, respectively. Kaplan-Meier survival curves demonstrated that Type 1 diabetics developed DR faster than Type 2 diabetics (P<0.0001, Log-Rank test). Children and adolescents with Type 1 DM had a 322% increased hazard of developing DR compared to Type 2 diabetics (HR 4.22, 95% CI 2.98-5.99). Male youth had a 29% increased hazard of developing DR compared to female youth (HR 1.29, 95% CI 1.00-1.65). For each one-year increase in age at time of initial DM diagnosis, the hazard for developing DR increased by 7.7% (HR 1.08, 95% CI 1.05-1.10). There was no association of race, household net worth, or year of diabetes diagnosis with retinopathy development (p>0.05 for all comparisons).
Conclusions
Youth with Type 1 and 2 DM exhibit significant risk of retinopathy and should undergo regular screenings by eye care professionals to check for retinopathy, especially those diagnosed with DM at older ages.