Retinal Vascular Reactivity in Patients with Diabetes Mellitus and with Atherosclerosis

Abstract
By means of fundus photography, a comparative study has been made of the constrictor response of retinal vessels to the inhalation of oxygen in 47 control subjects, 50 diabetic patients, and 15 persons with atherosclerosis unassociated with hypertension or diabetes. The diabetic group showed decreased reactivity of both arteries and veins, as indicated by a decreased constrictor response to oxygen. Retinal arterial reactivity was significantly reduced in diabetic subjects, even in the absence of retinopathy or hypertension. With the appearance of retinopathy, arterial reactivity was still further reduced. The patients with uncomplicated atherosclerosis did not show significant changes in retinal vascular reactivity.