Hollenhorst plaque

It is usually found when a physician performs ophthalmoscopy, during which a plaque will appear as a small, bright crystal that is refractile (reflects the light from the ophthalmoscope) and yellow.

[1] However, while Hollenhorst plaques do become lodged in retinal arteries, they generally do not fully prevent blood flow so do not cause ischemia.

[1] Once a Hollenhorst plaque is discovered in a retinal vessel, it may further migrate and lodge elsewhere, break into smaller pieces, or dissolve and disappear entirely.

[2] Hollenhorst further described finding bright plaques in 1958, at the same time they were independently described by German researchers R. Witmer and A. Schmid via a case study.

[2] In 1961, Hollenhorst published “Significance of Bright Plaques in Retinal Arterioles” in the Journal of the American Medical Association and described his findings.

[2][6] Besides the previously discussed points, he described that the plaques were able to break into smaller fragments, and generally did not completely block retinal arteries.

He also reported an experiment conducted with a neurologist named Jack Whisnant, that verified the idea that the plaques were composed of cholesterol.

[2] To do this, they took cholesterol crystals and material from atheromatous plaques in humans, and injected the into the carotids of dogs and Macaca rhesus monkeys.