Objective: The objective of this study was to determine the contribution of prepubertal and pubertal onset and duration of diabetes to the development of diabetic retinopathy.
Study design: A total of 1391 standardized fundus examinations (stereo fundus-photography) were performed in 441 children or adolescents with type-1 diabetes (median age 15.5 years, median duration of diabetes 6.3 years).
Results: Mild nonproliferative retinopathy was present in 72 patients (median age 19.9 years). Life table analysis revealed a median duration of diabetes until retinopathy was first diagnosed at 16.6 years (95% confidence interval: 15.3 to 18.3). Patients were stratified according to diabetes onset before or in puberty (> or = 10.4 years in girls, > or = 12.2 years in boys). In children with a prepubertal onset of diabetes, retinopathy occurred after a pubertal duration of 10.9 years compared with 15.1 years in children with onset of diabetes in puberty (p < 0.01), demonstrating the additional risk conveyed by the prepubertal years of diabetes. Long-term metabolic control had a significant influence on the prevalence of retinopathy: patients with a median HbA1c > or = 7.5% had development of retinopathy on average after 15.5 years compared with 18.3 years in patients with lower HbA1c values (p < 0.05).
Conclusion: Both prepubertal and pubertal duration of diabetes are relevant for the development of background retinopathy. Good metabolic control should be attempted irrespective of age.