Higher Risk of Diabetic Retinopathy for Patients Diagnosed with Type 1 Diabetes After Age 12

Factors such as diabetes duration as well as elevated HbA1c and diastolic blood pressure are associated with the presence of diabetic retinopathy (DR) in children (defined as 13 years to 17 years old) and young people (defined as 18 years to 20 years old), according to findings published in Eye.

In this study, researchers analyzed the data from 4172 patients with type 1 diabetes mellitus  (T1DM) who used the Diabetes Eye Screening Wales (DESW) service. All patients were diagnosed before the age of 18, and the median age was approximately 16.3. Researchers used a multivariate, multinomial logistic regression model to assess risk factors and other relevant data.

For participants of this study, the median duration of T1DM was 6.6 years, and researchers found they had varying DR status: 62.6% had no DR, 26.7% had background DR (BDR), and 10.7% had referable DR (RDR). Additionally, the older participants experienced a higher risk.

Patients diagnosed with T1DM at 12 years or older had an additional risk for each year they had diabetes compared with those diagnosed before age 12, controlling for the diabetes duration (odds ratios 1.23 and 1.34, respectively), the study concludes.

Researchers observed the presence of DR in 37.4% of the 4172 participants, and 10.7% of that group had RDR. However, all patients with RDR were over the age of 18 years. The researchers also found there was a linear association between BDR, RDR and age.

“Although none of the cohort had RDR at their first screening before the age of 19 years there was a linear increase thereafter increasing to 30.1% at the age of 25 years at first screening,” the researchers explained.

Furthermore, the research shows that participants were at higher risk of DR, BDR and RDR when they showed signs of increased diabetes duration, as well as elevated HbA1c and diastolic blood pressure.

A particular finding of the study, which was at variance with previous studies, was that BDR was present in approximately 10% of participants within the first 2 years of diagnosis. Researchers believe this may be due to the high quality of retinal images acquired, or to the diagnosis of DR having been dependent on only a small number of microaneurysms.

Limitations include that the study did not have access to data confirming the diagnosis of RDR from the hospital-based ophthalmological services. Also, participants who did a screening but did not have additional electronic health record data within 6 months were excluded from the study.

Reference

Rafferty J, Owens D, Luzio S, et al. Risk factors for having diabetic retinopathy at first screening in persons with type 1 diabetes diagnosed under 18 years of age. Eye. Published online December 1, 2020. doi:10.1038/s41433-020-01326-8