Onset of retinopathy precedes diagnosis of type 2 diabetes

Prevalence of retinopathy in relation to years after onset of diabetes among patients in southern Wisconsin (blue circles) and rural western Australia (red squares). At diagnosis (year 0), clinical retinopathy was already present in 10 to 20% of patients. The lines extrapolate back to an estimated onset of retinopathy 4 to 7 years before the clinical diagnosis was made.