The diameters of the retinal veins and arteries have been measured on photographs of the retina of 346 juvenile diabetic and 147 normal subjects. Statistical analysis of data was made from the findings in 266 diabetic and 129 normal subjects.
The mean width of the retinal veins in the diabetic group was about 10 per cent greater than that of the normal group (p < 0.001). About 8 per cent of the diabetic patients had vein diameters outside the normal range. The arteries of the diabetic patients were dilated on the average about 5 per cent (p > 0.001). There was a weak correlation between the known duration of the diabetes and the vein diameter.
The average vein diameter was highest in patients with retinopathy. From an analysis of the relationship between duration of diabetes and the occurrence of the retinopathy and vein dilatation it is concluded that vein dilatation is not a particularly early phenomenon in the development of the diabetic retinopathy, but rather an integrated part of the retinopathy.