Thirty-Year Time Trends in Diabetic Retinopathy and Macular Edema in Youth With Type 1 Diabetes

Objective: To examine trends in diabetic retinopathy (DR) and macular edema (DME) in adolescents with type 1 diabetes between 1990–2019.

Research Design and Methods: We analyzed 5,487 complication assessments in 2,404 adolescents (52.7% female, aged 12–20 years, diabetes duration >5 years), stratified by three decades (1990–1999, 2000–2009, 2010–2019). DR and DME were graded according to the modified Airlie House classification from seven-field stereoscopic fundal photography.

Results: Over three decades, the prevalence of DR was 40, 21, 20% respectively (p<0.001) and DME 1.4, 0.5, 0.9% (p=0.13). Continuous subcutaneous insulin infusion (CSII) use increased (0, 12, 55%; p<0.001); mean HbA1c was bimodal (8.7, 8.5, 8.7%; p<0.001) and the proportion of adolescents meeting target HbA_1c <7% did not change significantly (8.3, 7.7, 7.1%; p=0.63). In multivariable generalized estimating equation analysis, DR was associated with 1-2 daily injections (OR 1.88, 95% CI 1.42-2.48) and multiple injections compared to CSII (1.38, 1.10-1.74); older age (1.11, 1.07-1.15), higher HbA_1c (1.19, 1.05-1.15), longer duration (1.15, 1.12-1.18), overweight/obesity (1.27, 1.08-1.49) and higher diastolic blood pressure SDS (1.11, 1.01-1.21). DME was associated with 1-2 daily injections (3.26, 1.72-6.19), longer duration (1.26, 1.12-1.41), higher diastolic blood pressure SDS (1.66, 1.22-2.27), HbA1c (1.28, 1.03-1.59) and elevated cholesterol (3.78, 1.84-7.76).

Conclusions: One in five adolescents with type 1 diabetes had DR in the last decade. These findings support contemporary guidelines for lower glycemic targets, increasing CSII use and targeting modifiable risk factors including blood pressure, cholesterol and overweight/obesity.