Pre-pubertal onset of type 1 diabetes and appearance of retinopathy

It was suggested that the years of diabetes preceding puberty may not contribute to the development of retinopathy but evidence for this is conflicting. To verify the influence of pre-pubertal diabetes, we compared the correlations between prevalence of retinopathy and diabetes duration in patients who developed type 1 diabetes before and after puberty.

Six hundred and twenty-eight patients with diabetes onset at age< or =29, on insulin treatment and aged< or =60 at the time of screening for retinopathy were considered retrospectively. Pre-pubertal age was defined as 0-12 in males and 0-11 in females. Two hundred patients had developed diabetes before puberty and 428 after puberty. Screening was by ophthalmoscopy + 35 mm photography or digital photography.

Prevalence of retinopathy was lower among patients with pre-pubertal onset and diabetes durations 10-14 and 15-19 years (p=0.006 and p=0.003, respectively) but prevalence rates became similar after 20 yrs duration.

That retinopathy is infrequent and mild during childhood, is probably due to the short duration of diabetes rather than a specific protective effect of pre-puberty. After 20 years' duration, however, the prevalence of retinopathy is no longer influenced by age at onset, suggesting that, in the longer term, pre-pubertal years do contribute to the onset of retinopathy.