EDITOR,—J M Mason and colleagues state that the performance of high street optometrists in the Department of Health's study of screening for diabetic retinopathy was poorer than that of general practitioners and that this is surprising.1 A tabulation that I have done of the results from that and other studies shows that the rate of detection of sight threatening diabetic retinopathy by high street optometrists and general practitioners when they use direct ophthalmoscopy alone is similar: the rate for general practitioners was …