Carotid occlusive disease: effect of complete occlusion of internal carotid artery on intraocular pulse/pressure relation and on ophthalmic arterial pressure.

The intraocular pressure (IOP), the intraocular pulse to pressure (pulse/pressure) relationship, and the ophthalmic arterial pressure have been measured in 20 patients with either unilateral or bilateral hemodynamically significant lesions of the internal carotid arteries (ICA) as determined from arteriography. Studies were repeated in 5 of hte patients after surgical endarterectomy on the obstructed ICA. In age matched normal subjects the pulse/pressure relations were symmetrical in pairs of eyes, and the ophthalmic arterial systolic pressure was 89.0 +/- 2.1 mm Hg; this was 66 +/- 1% of the brachial arterial systolic pressure. In 19 of 20 patients with carotid occlusive disease in this study the IOP, pulse amplitudes and the pulse/pressure relationships differed in pairs of eyes. The ophthalmic arterial systolic pressure on the sides with 95 to 100% ICA stenosis was 49.9 +/- 4.05 mm Hg, which was 33 +/- 3% of the brachial arterial systolic pressure. In the remaining eyes the degree of stenosis of the ipsilateral ICA was 36.5 +/- 7.9%; the corresponding eyes had an ophthalmic arterial systolic pressure of 70.f1 +/- 51.18 mm Hg, which was 45 +/- 4% of the brachial arterial systolic pressure. Endarterectromy of the occluded arteries caused a significant increase in the ophthalmic arterial pressure on the ipsilateral side and a smaller increase in the contralateral eye; these changes were associated with a statistically significant increase in the intraocular pulse and improvement in the pulse/pressure relation.