Hollenhorst plaque

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Fundus photograph of right retina with labelled ischemic area and cholesterol embolus ("Hollenhorst plaque") Retinal embolism.png
Fundus photograph of right retina with labelled ischemic area and cholesterol embolus (“Hollenhorst plaque”)
Right eye findings. a Fundus photo showing superior pale retina. b Presence of Hollenhorst plaque in the superotemporal vessel (arrow) Right eye findings, Pale Retina and Hollenhorst plaque.png
Right eye findings. a Fundus photo showing superior pale retina. b Presence of Hollenhorst plaque in the superotemporal vessel (arrow)
Hollenhorst plaque
Specialty Cardiovascular

A Hollenhorst plaque (also known as a retinal cholesterol embolus) is a cholesterol embolus that is seen in a blood vessel of the retina. 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] This is a medical exam finding, and is not a medical condition, though it may be related to cardiovascular conditions such as atherosclerosis of the internal carotid artery. [1] It was first described by American ophthalmologist Robert Hollenhorst in 1961. [2]

Contents

Cause

A Hollenhorst plaque is the result of embolization (breaking off) of cholesterol forming an atheromatous plaque. This occurs in a blood vessel that is upstream of the eye, such as the internal carotid artery on the same side as the eye (ipsilateral), or the aorta. [1] This cholesterol embolus is then able to travel via the bloodstream to distal (downstream) vessels. [1] When it reaches the tiny blood vessels in the retina of the eye, the plaque may become lodged, where it is visible on eye exam by a physician as a bright crystal (the Hollenhorst plaque). [1] The plaques most commonly lodge at vessel bifurcations, meaning areas where the blood vessel branches into two or more smaller vessels. [1]

Associated conditions

Hollenhorst plaques may cause retinal occlusion, where the plaque blocks blood flow through the retinal vessels, resulting in temporary or permanent vision loss in the affected eye. [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. [1]

While Hollenhorst plaques generally not cause problems with health of the eye, they may be a sign of systemic health issues, particularly of the cardiovascular system. [2] These plaques are more common in men than in women, and are more likely to be present in people who have hypertension, past or current smokers, older patients, and those with history of any vascular disease (including history of transient ischemic attack, stroke, coronary artery disease, and/or peripheral vascular disease). [2] Appearance of retinal plaques is associated with strokes and may be a risk factor for stroke, however because plaques may disappear on their own, discovery of plaques is not predictive of an impending stroke. [2] Risk of death after a stroke may be increased in those who are noted to have Hollenhorst plaques compared to stroke patients who do not. [2] The most common condition associated with appearance of a Hollenhorst plaque is carotid artery disease, including carotid artery stenosis (narrowing of the space inside the vessel). [3]

Management

Standard workup and recommendations

Hollenhorst plaques still require more research, and because of this, there is a wide range of testing that a physician may or may not choose to complete. While there are many possible options, the American Academy of Ophthalmology recommends the following steps be taken when an asymptomatic plaque is first noted. [1]

Other testing and management options

While there is disagreement among medical professionals on what testing is considered necessary, several forms of testing are not shown to be effective in evaluating patients for cardiovascular disease after a retinal cholesterol embolus is found. [1] This recommendation is for patients who do not have any symptoms or concerning past medical history, and testing is ultimately decided by the physician on a case-by-case basis for the individual patient. These include:

Eponym and discovery

The phenomenon is named after the American ophthalmologist Robert Hollenhorst.

The first recorded description of "bright" retinal emboli was made in 1927 by TH Butler. While other retinal emboli had been described, the bright nature of these differentiated them from prior descriptions. [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] [5] [6] They further hypothesized that these plaques were composed of cholesterol. However, it was Hollenhorst who went on to establish the link between these bright emboli and cerebrovascular disease. [2] He further discovered the relationship between presence of these plaques, and increased mortality from cardiovascular disease. In his study of patients with carotid artery disease, he noticed that the plaques occurred on the same side as the affected artery. [2] In 1960 he expanded his research, and noted that the plaques could be made to move by applying pressure to the eye. [2] Additionally, he found that the plaques often occurred after a patient had had carotid artery surgery. [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. They found development of similar retinal plaques in these animals. [2] In 1963, the cholesterol composition was confirmed by researchers via autopsy of a patient who died during carotid surgery. [2]

Hollenhorst continued to study these plaques, detailing associations with their appearance and cerebral ischemic events. He also noted that survival these patients was decreased compared to those without plaques. [2]

Work continued on this topic, and studies include the 1997 Blue Mountain Eye Study conducted in Australia and the Beaver Dam Eye Study in Wisconsin, of which patients have been followed up for the past 15 years. [1] [7] [8] In 2005, one study looked at data from both the Atherosclerosis Risk in Communities (ARIC) study, and the Cardiovascular Health Study (CHS) and suggested evaluation composed of cardiovascular workup and smoking cessation. [1] [9] Other work continued to build on this and includes 2008 the Los Angeles Latino Eyes Study (LAKES) study, [1] [10] and the 2017 Singapore Epidemiology of Eye Disease Study (SEEDS). [1] [11]

Related Research Articles

A transient ischemic attack (TIA), commonly known as a mini-stroke, is a minor stroke whose noticeable symptoms usually end in less than an hour. TIA causes the same symptoms associated with strokes, such as weakness or numbness on one side of the body, sudden dimming or loss of vision, difficulty speaking or understanding language, slurred speech, or confusion.

<span class="mw-page-title-main">Atherosclerosis</span> Form of arteriosclerosis

Atherosclerosis is a pattern of the disease arteriosclerosis, characterized by development of abnormalities called lesions in walls of arteries. These lesions may lead to narrowing of the arterial walls due to buildup of atheromatous plaques. At onset there are usually no symptoms, but if they develop, symptoms generally begin around middle age. In severe cases, it can result in coronary artery disease, stroke, peripheral artery disease, or kidney disorders, depending on which body part(s) the affected arteries are located in the body.

<span class="mw-page-title-main">Ischemia</span> Restriction in blood supply to tissues

Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism. Ischemia is generally caused by problems with blood vessels, with resultant damage to or dysfunction of tissue i.e. hypoxia and microvascular dysfunction. It also implies local hypoxia in a part of a body resulting from constriction.

<span class="mw-page-title-main">Stroke</span> Death of a region of brain cells due to poor blood flow

Stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functioning properly.

<span class="mw-page-title-main">Amaurosis fugax</span> Medical condition

Amaurosis fugax is a painless temporary loss of vision in one or both eyes.

<span class="mw-page-title-main">Atheroma</span> Accumulation of degenerative material in the inner layer of artery walls

An atheroma, or atheromatous plaque, is an abnormal accumulation of material in the inner layer of an arterial wall.

<span class="mw-page-title-main">Carotid endarterectomy</span> Surgical procedure

Carotid endarterectomy is a surgical procedure used to reduce the risk of stroke from carotid artery stenosis. In endarterectomy, the surgeon opens the artery and removes the plaque. The plaque forms and thickens the inner layer of the artery, or intima, hence the name of the procedure which simply means removal of part of the internal layers of the artery.

<span class="mw-page-title-main">Carotid artery stenosis</span> Medical condition

Carotid artery stenosis is a narrowing or constriction of any part of the carotid arteries, usually caused by atherosclerosis.

An embolus, is described as a free-floating mass, located inside blood vessels that can travel from one site in the blood stream to another. An embolus can be made up of solid, liquid, or gas. Once these masses get "stuck" in a different blood vessel, it is then known as an "embolism." An embolism can cause ischemia—damage to an organ from lack of oxygen. A paradoxical embolism is a specific type of embolism in which the embolus travels from the right side of the heart to the left side of the heart and lodges itself in a blood vessel known as an artery. Thus, it is termed "paradoxical" because the embolus lands in an artery, rather than a vein.

<span class="mw-page-title-main">Watershed stroke</span> Medical condition

A watershed stroke is defined as a brain ischemia that is localized to the vulnerable border zones between the tissues supplied by the anterior, posterior and middle cerebral arteries. The actual blood stream blockage/restriction site can be located far away from the infarcts. Watershed locations are those border-zone regions in the brain supplied by the major cerebral arteries where blood supply is decreased. Watershed strokes are a concern because they comprise approximately 10% of all ischemic stroke cases. The watershed zones themselves are particularly susceptible to infarction from global ischemia as the distal nature of the vasculature predisposes these areas to be most sensitive to profound hypoperfusion.

<span class="mw-page-title-main">Fibromuscular dysplasia</span> Human arterial disease

Fibromuscular dysplasia (FMD) is a non-atherosclerotic, non-inflammatory disease of the blood vessels that causes abnormal growth within the wall of an artery. FMD has been found in nearly every arterial bed in the body, although the most commonly affected are the renal and carotid arteries.

<span class="mw-page-title-main">Vascular disease</span> Medical condition

Vascular disease is a class of diseases of the vessels of the circulatory system in the body, including blood vessels – the arteries and veins, and the lymphatic vessels. Vascular disease is a subgroup of cardiovascular disease. Disorders in this vast network of blood and lymph vessels can cause a range of health problems that can sometimes become severe, and fatal. Coronary heart disease for example, is the leading cause of death for men and women in the United States.

Ocular ischemic syndrome is the constellation of ocular signs and symptoms secondary to severe, chronic arterial hypoperfusion to the eye. Amaurosis fugax is a form of acute vision loss caused by reduced blood flow to the eye; it may be a warning sign of an impending stroke, as both stroke and retinal artery occlusion can be caused by thromboembolism due to atherosclerosis elsewhere in the body. Consequently, those with transient blurring of vision are advised to urgently seek medical attention for a thorough evaluation of the carotid artery. Anterior segment ischemic syndrome is a similar ischemic condition of anterior segment usually seen in post-surgical cases. Retinal artery occlusion leads to rapid death of retinal cells, thereby resulting in severe loss of vision.

Central retinal artery occlusion (CRAO) is a disease of the eye where the flow of blood through the central retinal artery is blocked (occluded). There are several different causes of this occlusion; the most common is carotid artery atherosclerosis.

<span class="mw-page-title-main">Cholesterol embolism</span> Medical condition

Cholesterol embolism occurs when cholesterol is released, usually from an atherosclerotic plaque, and travels as an embolus in the bloodstream to lodge causing an obstruction in blood vessels further away. Most commonly this causes skin symptoms, gangrene of the extremities and sometimes kidney failure; problems with other organs may arise, depending on the site at which the cholesterol crystals enter the bloodstream. When the kidneys are involved, the disease is referred to as atheroembolic renal disease. The diagnosis usually involves biopsy from an affected organ. Cholesterol embolism is treated by removing the cause and giving supportive therapy; statin drugs have been found to improve the prognosis.

Robert W. Hollenhorst was an American ophthalmologist remembered for describing Hollenhorst plaques.

<span class="mw-page-title-main">Arterial embolism</span> Interruption of blood flow to an organ

Arterial embolism is a sudden interruption of blood flow to an organ or body part due to an embolus adhering to the wall of an artery blocking the flow of blood, the major type of embolus being a blood clot (thromboembolism). Sometimes, pulmonary embolism is classified as arterial embolism as well, in the sense that the clot follows the pulmonary artery carrying deoxygenated blood away from the heart. However, pulmonary embolism is generally classified as a form of venous embolism, because the embolus forms in veins. Arterial embolism is the major cause of infarction.

John David Spence is a Canadian medical doctor, medical researcher and Professor Emeritus at the University of Western Ontario. He is affiliated with the University of Western Ontario and the Robarts Research Institute, one of Canada's leading medical research organizations. Before his retirement from clinical practice in July 2022, he was also affiliated with the London Health Sciences Centre's University Hospital. He is a recognized expert in stroke prevention and stroke prevention research, with more than 600 peer-reviewed publications since 1970. He delivered more than 600 lectures on stroke prevention in 42 countries. In 2015, he received the Research Excellence Award from the Canadian Society for Atherosclerosis, Thrombosis and Vascular Biology. In 2019, he was appointed a Member of the Order of Canada, and in 2020 he received the William Feinberg Award from the American Heart Association for excellence in clinical stroke research.

<span class="mw-page-title-main">Branch retinal artery occlusion</span> Medical condition

Branch retinal artery occlusion (BRAO) is a rare retinal vascular disorder in which one of the branches of the central retinal artery is obstructed.

The BaleDoneen Method is a risk assessment and treatment protocol aimed at preventing heart attack and stroke. The method also seeks to prevent or reduce the effects of type 2 diabetes. The method was developed by Bradley Field Bale and Amy Doneen.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Riese, Nicole; Smart, Yelena; Bailey, Melissa (January 2023). "Asymptomatic retinal emboli and current practice guidelines: a review". Clinical & Experimental Optometry. 106 (1): 4–9. doi:10.1080/08164622.2022.2033600. ISSN   1444-0938. PMID   35109784.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Graff-Radford, Jonathan; Boes, Christopher J.; Brown, Robert D. (April 2015). "History of Hollenhorst Plaques". Stroke. 46 (4). doi:10.1161/STROKEAHA.114.007771. ISSN   0039-2499. PMID   25593136.
  3. Kaufman, Evan J.; Mahabadi, Navid; Patel, Bhupendra C. (2023), "Hollenhorst Plaque", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID   29261979 , retrieved 2023-09-11
  4. Wolintz, Robyn J. (December 2005). "Carotid Endarterectomy for Ophthalmic Manifestations: Is It Ever Indicated?". Journal of Neuro-Ophthalmology. 25 (4): 299–302. doi: 10.1097/01.wno.0000189065.20552.88 . ISSN   1070-8022. PMID   16340498.
  5. Witmer, R.; Schmid, A. (2010-03-23). "Cholesterinkristall als retinaler arterieller Embolus". Ophthalmologica. 135 (5–6): 432–433. doi: 10.1159/000303337 . ISSN   0030-3755. PMID   13553256.
  6. 1 2 Hollenhorst RW (1961). "Significance of bright plaques in the retinal arterioles". JAMA. 178: 23–29. doi:10.1001/jama.1961.03040400025005. PMC   1316410 . PMID   13908419.
  7. Klein, R.; Klein, B. E.; Linton, K. L.; De Mets, D. L. (August 1991). "The Beaver Dam Eye Study: visual acuity". Ophthalmology. 98 (8): 1310–1315. doi:10.1016/s0161-6420(91)32137-7. ISSN   0161-6420. PMID   1923372.
  8. Joachim, Nichole; Mitchell, Paul; Burlutsky, George; Kifley, Annette; Wang, Jie Jin (December 2015). "The Incidence and Progression of Age-Related Macular Degeneration over 15 Years: The Blue Mountains Eye Study". Ophthalmology. 122 (12): 2482–2489. doi:10.1016/j.ophtha.2015.08.002. ISSN   1549-4713. PMID   26383995.
  9. Wong, T; Larsen, E; Klein, R; Mitchell, P; Couper, D; Klein, B; Hubbard, L; Siscovick, D; Sharrett, A (April 2005). "Cardiovascular Risk Factors for Retinal Vein Occlusion and Arteriolar Emboli – The Atherosclerosis Risk in Communities & Cardiovascular Health studies". Ophthalmology. 112 (4): 540–547. doi:10.1016/j.ophtha.2004.10.039. ISSN   0161-6420. PMID   15808241.
  10. Hoki, Susan Liu; Varma, Rohit; Lai, Mei Ying; Azen, Stanley P.; Klein, Ronald (January 2008). "Prevalence and Associations of Asymptomatic Retinal Emboli in Latinos: The Los Angeles Latino Eye Study (LALES)". American Journal of Ophthalmology. 145 (1): 143–148. doi:10.1016/j.ajo.2007.08.030. ISSN   0002-9394. PMC   2219465 . PMID   17981255.
  11. Cheung, Ning; Teo, Kelvin; Zhao, Wanting; Wang, Jie Jin; Neelam, Kumari; Tan, Nicholas Y. Q.; Mitchell, Paul; Cheng, Ching-Yu; Wong, Tien Yin (2017-10-01). "Prevalence and Associations of Retinal Emboli With Ethnicity, Stroke, and Renal Disease in a Multiethnic Asian Population". JAMA Ophthalmology. 135 (10): 1023–1028. doi:10.1001/jamaophthalmol.2017.2972. ISSN   2168-6165. PMC   5710493 . PMID   28837736.