Hollenhorst Plaque

Excerpt

Stroke is the third most common cause of death in the United States. Eighty percent of all strokes are due to vessel occlusion secondary to atherothrombosis or embolus. Hollenhorst plaque (HP) was discovered in 1961 by Dr. Robert Hollenhorst. He defined them as tiny emboli caused by cholesterol plaques and found in the retina's small blood vessels. The appearance of these emboli indicates that they are yellow, refractile, and typically located at an arterial bifurcation. Hollenhorst plague is the most common cause accounting for the ocular ischemic syndrome (OIS) following retinal artery occlusion (RAO).

History

In 1927, T. Harrison Butler first mentioned a bright retinal embolus involving the inferior temporal arteriole. Hollenhorst, Witmer, and Schmid described this lesion in 1958. Hollenhorst postulated that the cholesterol ester is the fundamental component of the lesion, and he proposed a temporal relationship, foreseeing the risk of subsequent cerebral ischemic events on the side ipsilateral to symptomatic carotid disease. He also confirmed that this plague was mobile upon manual ocular pressure. In 1961, Hollenhorst detailed the characteristics of these vivid, orange-appearing plaques in his paper titled "Significance of Bright Plaques in Retinal Arterioles." These plaques were identified in 11% of cohorts with carotid disease and 4% with vertebrobasilar diseases. The plaques rarely obstruct arterioles, instead frequently migrating to distal vessels and ultimately dissipating through fragmentation. Hollenhorst and Jack Whisnant reproduced retinal plaques mirroring those observed in humans through the injection of cholesterol crystals and human atheromatous material into the carotids of experimental animals. This was validated in 1963 from an autopsy of a patient who had similar appearing retinal plaques and who had died following carotid endarterectomy (CEA).