Effect of Intracarotid Prostaglandin E1 on Regional Cerebral Blood Flow in Man

artery in the neck. Obviously the pressure is not always so low and will depend on the collateral circulation which may be much better to the eye than to the brain. On the contrary, one might expect to find a near-zero low diastolic retinal artery pressure in some patients with a stroke without carotid artery occlusion but with a retinal artery stenosis or thrombosis (near-zero low pressure is not the ordinary finding in this disease) or with a unilateral glaucoma with a markedly increased intraocular pressure. These situations are, however, undoubtedly exceptionally rare. The clinical consistency of ophthalmodynamometry is symptomatic carotid artery occlusion and can be summarized as follows: Retinal artery pressure is practically always lower on the side of the occlusion than on the other. The diastolic retinal artery pressure is often near zero, low on the side of the occlusion. The finding of a near-zero low diastolic retinal artery pressure nearly always indicates an ipsilateral occlusion of the internal carotid artery.