Fig. 1.

Transition probabilities to referable background retinopathy (R3) or proliferative retinopathy (R4) from no visible retinopathy by sex and diabetes duration in type 1 diabetes for 1 or 2 yearly screening intervals when last screening showed no visible retinopathy (a) and when last screening showed no visible retinopathy but previous screening showed mild background retinopathy (b). Blue filled squares, men with 1 year screening interval; blue open squares, men with 2 year screening interval; red filled circles, women with 1 year screening interval; red open circles, women with 2 year screening interval