AMONG 235 PATIENTS1 WHO HAD OCCLUSIVE DISEASE within the carotid arterial system and 93 patients with clinical symptoms and signs of involvement of the vertebral-basilar arterial system, 31 (9.4 percent) had from a single plaque to several dozen bright plaques that were orange, yellow, or copper in color and situated at various bifurcations of some of the retinal arterioles. A total of 35 such patients had carotid endarterectomy. Seven (20 percent) of these 35 surgical patients had such plaques; in five of the seven, the retinal plaques appeared during the operation, whereas they appeared 6 weeks afterward in another, and they remained unchanged postoperatively in the seventh patient. In two instances, the plaques occluded tiny peripheral retinal arterioles, with infarction in portions of the retina.These plaques were observed in 27 (11 percent) of the 235 patients who had signs and symptoms of involvement of the carotid arterial system (cases 1-20 and 25-31 in Tables 1 and 2), and in four (4 percent) of the 93 patients who had evidence of involvement of the vertebral-basilar arterial system (cases 21-24 in Table 1). Two of the four patients in the latter group had simultaneous signs and symptoms of occlusive disease in the carotid arterial system. Among twelve of these 31 patients, various changes in position of the plaques occurred; some of them disappeared (cases 2, 5, 13, 17, 25, 31), some new ones appeared (cases 2, 5, 17, 25-28, 30, 31), some moved to other locations within the retina (cases 12, 17, 20, 25), and some appeared as showers of plaques (cases 25, 28, 31).These plaques had a characteristically bright orange-yellow color. They reflected the light of the ophthalmoscope often in a heliographic fashion and tended to lodge simultaneously at several bifurcations of the same arteriole as though they were fragments of a larger plaque.