Hollenhorst Plaques: Causes, Risks, and Vision Impact
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What is a Hollenhorst plaque?
A Hollenhorst plaque is a piece of plaque that breaks free elsewhere in the body and blocks a small blood vessel in the retina, a form of retinal artery occlusion that usually affects one eye. Most cause no symptoms, but because they usually stem from carotid artery disease, a cardiovascular check is needed. Sudden vision loss is an emergency.
What the research says
Asymptomatic Hollenhorst plaques are linked to later cerebrovascular events. A systematic review of 17 studies included 1,343 patients with asymptomatic cholesterol emboli seen on an eye exam. Of 780 patients followed for 6 to 86 months, 93 had a stroke, a transient ischemic attack, or death from a major carotid event (about 12%). The authors concluded these patients warrant referral for medical optimization of cardiovascular risk factors, and found no current recommendation supporting carotid endarterectomy for Hollenhorst plaques alone (Ghoneim et al., Vascular, 2023) [3].
Retinal emboli are uncommon, and they cluster with vascular risk factors. A review reports retinal arteriolar emboli in approximately 1% of adults older than 40, more often in men than in women. They are associated with carotid artery plaque and stenosis, hypertension, and cigarette smoking. Available data suggest that retinal emboli in otherwise asymptomatic people are linked to a higher risk of stroke and stroke death, independent of conventional risk factors (Wong & Klein, Current Opinion in Ophthalmology, 2002) [2].
Not every patient has severe carotid narrowing, and studies do not fully agree. In a single-center review of 130 consecutive patients with a Hollenhorst plaque or retinal artery occlusion, carotid narrowing on the same side was under 30% in 68%, 30% to 60% in 22%, and over 60% in only 8%. Overall survival was 94% at 36 months, and the authors found these eye findings were not associated with a high risk of hemispheric neurological events (Dunlap et al., Journal of Vascular Surgery, 2007) [4].
Key Takeaways
Category | Details |
What it is | A piece of plaque that breaks free from another artery and blocks a small artery in the retina [1] |
Usual cause | Carotid artery disease (carotid artery stenosis) [1] |
Symptoms | Often none; sometimes sudden, painless vision loss or blurring in one eye [1] |
Higher risk | |
Diagnosis | Eye exam, visual acuity test, and imaging such as carotid ultrasound, angiography, or MRI [1] |
Treatment | |
Main concern | |
Emergency sign | Sudden loss of vision in one eye: go to the emergency room [1] |
Understanding Hollenhorst Plaques
Hollenhorst plaques are blockages in the blood vessels of the retina, the layer at the very back of the eyeball that turns light into signals your optic nerve sends to your brain [1]. Plaque is a sticky substance made of fat, cholesterol, calcium, and other substances. As it builds up, arteries become hard and narrow. A Hollenhorst plaque forms when a piece of plaque from somewhere else in the body breaks free and blocks a blood vessel in the retina [1].
Hollenhorst plaques are a form of retinal artery occlusion, also called an eye stroke, and they typically affect only one eye [1]. On an eye exam they can appear as bright yellow plaques inside small retinal arteries, often where the arteries branch [5]. The plaque itself is tiny, but it points to disease elsewhere in the arteries, which is why finding one matters beyond the eye.
How common are they?
Hollenhorst plaques make up more than 80% of all retinal blockages, but retinal blockages themselves are rare: fewer than 2% of people older than 49 ever develop one [1]. Another review estimates that retinal emboli are found in about 1% of adults older than 40 and that they become more frequent with age [2].
Symptoms and Warning Signs
Most Hollenhorst plaques do not cause symptoms, which makes them hard to notice until they damage the eye [1]. Some are found during an eye exam in people who feel fine [3].
When symptoms do occur, they come on suddenly rather than gradually. One eye might lose sight completely or suddenly become blurry, because the plaque blocks blood flow to the retina [1]. Hollenhorst plaques do not cause eye pain [1].
When to Get Care
See your healthcare provider as soon as you notice any change in your eyes or vision [1]. Go to the emergency room if you have any of these [1]:
A sudden loss of vision
Severe eye pain
New flashes or floaters in your eyes
Risk Factors
Anyone can develop a Hollenhorst plaque, but some groups and health conditions raise the risk [1][2]:
Causes: Where the Plaque Comes From
Hollenhorst plaques form when a piece of plaque from elsewhere in the body travels through the blood vessels and gets stuck in the retina. They are usually caused by carotid artery disease (carotid artery stenosis), in which a carotid artery, the large artery on either side of the neck, becomes blocked by plaque [1]. Carotid artery stenosis raises the risk of stroke, and it is a form of atherosclerosis, the hardening of arteries caused by gradual plaque buildup [1].
In some people the retinal plaque is part of a wider problem. Cholesterol embolization syndrome occurs when cholesterol crystals from an atherosclerotic plaque break loose from a large artery and block smaller arteries elsewhere. Seeing Hollenhorst plaques on a retinal exam supports that diagnosis [6].
Diagnosis and Clinical Evaluation
An eye care specialist diagnoses a Hollenhorst plaque with an eye exam, which includes looking inside your eyes, and a visual acuity test [1]. Because the plaques can signal wider vascular disease, you may need imaging tests as well [1][3].
Test | What it is for |
Eye exam | Lets the specialist see the retina and its blood vessels directly [1] |
Visual acuity test | Measures how sharp your vision is [1] |
Carotid ultrasound | Uses sound waves to look for plaque or narrowing in the carotid arteries in your neck [1] |
Doppler ultrasound | Measures blood flow through a vessel [1] |
Angiography | Uses imaging to show the blood vessels [1] |
MRI | Gives detailed images that your provider may use to look for vascular damage [1] |
Experts continue to discuss how far the work-up should go. A Mayo Clinic review of 237 patients with Hollenhorst plaques concluded that everyone with asymptomatic plaques should have a medical workup, including carotid ultrasonography [8]. Your provider will decide which tests are right for you.
Management and Prevention Strategies
There usually is no treatment needed for a Hollenhorst plaque itself [1]. Some plaques are found only after they have damaged the retina, and that damage is usually permanent [1]. For that reason, care focuses on the conditions that caused the plaque and on lowering your risk of stroke [1][3].
For eye strokes in general, a review notes that no treatment has been shown to work reliably, and that identifying people at the highest risk of stroke and preventing further ischemic events remain the main focus [7]. A systematic review found no current recommendation supporting carotid endarterectomy, a surgery on the carotid artery, for Hollenhorst plaques alone, and said more studies are needed [3]. Whether any carotid procedure is appropriate depends on your carotid artery findings and is a decision for your specialists.
Lifestyle and Medical Prevention
The best way to prevent Hollenhorst plaques is to prevent conditions like atherosclerosis. Steps include [1]:
Eat a healthy diet low in saturated and trans fats, cholesterol, sodium, and sugar.
Exercise regularly and maintain a healthy weight.
Manage any health conditions, especially diabetes, high blood pressure, and high cholesterol.
Quit smoking.
Visit your healthcare provider and eye care specialist regularly.
How Often Should You Have Your Eyes Examined?
Cleveland Clinic suggests the following schedule, depending on your age [1]:
Adults under 40: every five to 10 years.
Adults between 40 and 54: every two to four years.
Adults older than 55: every one to three years.
You may need your eyes checked more often if you wear glasses or contacts, and people with diabetes need exams more often than this schedule [1]. Ask your eye care specialist how often you need an eye exam.
Outlook
Hollenhorst plaques can cause permanent damage to your retina. Some people lose sight in the affected eye for the rest of their lives, and others have low vision [1]. You will need regular eye exams to monitor changes in your eyes or vision [1]. People with Hollenhorst plaques have an increased risk of stroke, so talk to your provider about how to reduce your risk and which warning signs to watch for [1]. Studies differ on how large that risk is (see the research box above), and your own outlook depends on what caused the plaque and what other conditions you have [1][3][4].
Conclusion
A Hollenhorst plaque is a tiny blockage in an eye artery, but it can be an important warning about the health of your arteries. Many cause no symptoms, while others cause sudden vision loss in one eye. Regular eye exams, healthy blood pressure and cholesterol, good diabetes control, not smoking, and emergency care for sudden vision loss are the most effective ways to protect your sight and lower your stroke risk. If a Hollenhorst plaque has been found, ask your provider about a cardiovascular evaluation.
Frequently Asked Questions
Can Hollenhorst plaques be removed?
There usually is no treatment needed for the plaque itself, and damage the plaque has already caused to the retina is usually permanent [1]. Care focuses on the underlying cause, such as carotid artery disease.
Are Hollenhorst plaques painful?
No. Hollenhorst plaques do not cause eye pain [1].
Do Hollenhorst plaques always cause blindness?
No. Most Hollenhorst plaques do not cause symptoms [1]. They can permanently damage the retina, though. Some people lose sight in the affected eye for the rest of their lives, while others have low vision [1].
Do Hollenhorst plaques affect one eye or both?
What is the most common cause of Hollenhorst plaques?
Carotid artery disease, also called carotid artery stenosis, is the usual cause [1]. Plaque breaks free from a blocked carotid artery in the neck and travels to the retina.
How common are Hollenhorst plaques?
Hollenhorst plaques make up more than 80% of all retinal blockages, but retinal blockages are rare: fewer than 2% of people older than 49 ever develop one [1]. A review estimated that retinal emboli are found in about 1% of adults older than 40 [2].
Is a Hollenhorst plaque a stroke?
It is a form of retinal artery occlusion, often called an eye stroke [1]. It is also linked to an increased risk of stroke in the brain [1][2].
Should I see a cardiologist if I have a Hollenhorst plaque?
A cardiovascular evaluation is usually sensible. A systematic review concluded that people with asymptomatic Hollenhorst plaques warrant referral for medical optimization of cardiovascular risk factors [3]. Ask your provider which specialist is right for you.
Can exercise help?
Regular exercise is one of the steps that helps prevent the conditions behind Hollenhorst plaques, along with a healthy weight and a heart-healthy diet [1]. It is a prevention step, not a treatment for a plaque already in the eye.
Does high cholesterol cause Hollenhorst plaques?
High cholesterol (hyperlipidemia) is a listed risk factor [1]. Plaque is made of fat, cholesterol, calcium, and other substances [1].
Are there medicines to dissolve Hollenhorst plaques?
There usually is no treatment for the plaque itself [1]. Your provider may recommend lifestyle changes or medicines to manage cholesterol, blood pressure, and diabetes, because managing cardiovascular risk factors is the main goal of care [1][3].
How often should I get my eyes examined?
Cleveland Clinic suggests every five to 10 years for adults under 40, every two to four years between ages 40 and 54, and every one to three years for adults older than 55 [1]. You may need exams more often if you wear glasses or contacts, and people with diabetes need them more often [1]. Ask your eye care specialist what is right for you.
What does a Hollenhorst plaque look like?
On an eye exam, Hollenhorst plaques can appear as bright yellow plaques inside small retinal arteries, often where the arteries branch [5].
Are Hollenhorst plaques related to cataracts, glaucoma, or macular degeneration?
No. A Hollenhorst plaque is a blockage in a retinal blood vessel [1]. Cataracts, glaucoma, and macular degeneration are different eye conditions.
What is the difference between a Hollenhorst plaque and an eye stroke?
Hollenhorst plaques are a form of retinal artery occlusion, which is also called an eye stroke [1]. They are the most common type of retinal blockage [1].
Can I see a Hollenhorst plaque myself?
No. The plaque sits inside the retina at the back of the eye. An eye care specialist finds it by looking inside your eyes during an exam [1].
Is a Hollenhorst plaque an emergency?
Sudden vision loss in one eye is an emergency, so go to the emergency room [1]. Severe eye pain or new flashes or floaters are also reasons to go to the emergency room [1].
Can diabetes cause Hollenhorst plaques?
Diabetes is a risk factor for Hollenhorst plaques [1]. Managing your blood sugar, blood pressure, and cholesterol helps lower your risk [1].
Does smoking increase the risk?
Retinal emboli are associated with cigarette smoking [2]. Quitting smoking is one of the recommended prevention steps [1].
Can high blood pressure lead to Hollenhorst plaques?
High blood pressure (hypertension) is a risk factor [1][2]. The best way to prevent Hollenhorst plaques is to keep your blood pressure and cholesterol at healthy levels [1].
Are men or women more likely to get Hollenhorst plaques?
Men are more likely to develop them [1]. A review also reports that retinal emboli are more common in men than in women [2].
Does age matter?
A review reports that retinal emboli become more frequent with age [2].
What is an ophthalmologist?
An ophthalmologist is a medical doctor who specializes in eye and vision care. Your provider may send you to one if they suspect a Hollenhorst plaque [1].
What is a carotid ultrasound?
It is an imaging test that uses sound waves to look at the carotid arteries in your neck. It is one of the tests used when a Hollenhorst plaque is suspected [1].
Does everyone with a Hollenhorst plaque need a carotid ultrasound?
Experts discuss this. A Mayo Clinic review of 237 patients with Hollenhorst plaques concluded that everyone with asymptomatic plaques should have a medical workup, including carotid ultrasonography [8]. Your provider will decide which tests you need.
What is retinal artery occlusion?
It is a blockage of an artery that supplies the retina. A review notes that central retinal artery occlusion is most often caused by an embolus from the carotid artery, the aortic arch, or the heart [7].
What is an embolus?
An embolus is a piece of material, such as plaque, that breaks loose, travels through the bloodstream, and blocks a vessel elsewhere. A Hollenhorst plaque is a plaque embolus lodged in the retina [1].
What is a visual acuity test?
It is the standard test of how sharp your vision is, and it is part of the evaluation for a Hollenhorst plaque [1].
Is the vision loss always sudden?
If you have symptoms, they come on suddenly rather than slowly. One eye might lose sight completely or suddenly become blurry [1].
How do doctors find a Hollenhorst plaque?
An eye care specialist uses an eye exam, including a look inside your eyes, and a visual acuity test [1]. Imaging tests such as a carotid or Doppler ultrasound, angiography, or an MRI may follow [1].
Can a Hollenhorst plaque be found if I have no symptoms?
Yes. Many studies of Hollenhorst plaques involve people who had no symptoms, because the plaques were found during an eye exam [3][8].
How high is the stroke risk with a Hollenhorst plaque?
Studies differ. A systematic review of 780 patients followed for 6 to 86 months found that 93 (about 12%) had a stroke, a transient ischemic attack, or death from a major carotid event [3]. A single-center study of 130 patients with a Hollenhorst plaque or retinal artery occlusion found no high risk of hemispheric neurological events [4]. Your own risk depends on your carotid arteries and other conditions.
Is carotid surgery needed?
Not routinely. A systematic review found no current recommendation supporting carotid endarterectomy, a surgery on the carotid artery, for Hollenhorst plaques alone [3]. Your specialists will decide based on your carotid artery findings.
What is cholesterol embolization syndrome?
It occurs when cholesterol crystals from an atherosclerotic plaque break loose from a large artery and block smaller arteries, damaging organs. Seeing Hollenhorst plaques on a retinal exam supports the diagnosis [6].
What is atherosclerosis?
Atherosclerosis is the hardening and narrowing of your arteries caused by the gradual buildup of plaque [1].
What is carotid artery stenosis?
It is a blockage of a carotid artery, the large artery on either side of your neck, made up of plaque. It raises the risk of stroke [1].
What lifestyle changes help prevent Hollenhorst plaques?
Eat a diet low in saturated and trans fats, cholesterol, sodium, and sugar, exercise regularly, keep a healthy weight, manage diabetes, high blood pressure, and high cholesterol, quit smoking, and see your healthcare provider and eye care specialist regularly [1].
Should I worry if a doctor finds a Hollenhorst plaque and my vision is normal?
It deserves follow-up even without symptoms, because Hollenhorst plaques can signal carotid artery disease and a higher risk of stroke [1][3]. Ask your provider about a cardiovascular evaluation.
What questions should I ask my doctor?
Cleveland Clinic suggests asking whether you will have permanent vision loss in the eye, how often you will need follow-up eye exams, whether you have carotid artery disease, and what you can do to lower your risk for a stroke [1].
Learn More
Related Reading
Carotid Artery Disease: The Silent Stroke Risk in Your Neck, Explained explains the neck artery plaque that usually causes Hollenhorst plaques.
Eye Stroke (Retinal Artery Occlusion): Symptoms, Causes, Diagnosis, Treatment, Outlook and When to Get Emergency Care — What You Need to Know explains blocked retinal arteries and emergency vision loss.
Amaurosis Fugax (Temporary Vision Loss): What It Means, Why It Happens, and When It's an Emergency covers brief vision loss that can warn of a coming stroke.
Carotid Ultrasound: Why It's Done, What to Expect and What Results Mean describes the scan used to check neck arteries for plaque.
References
Cleveland Clinic. Hollenhorst Plaques: Causes, Symptoms & Treatment. Cleveland Clinic. Last updated July 17, 2023. https://my.clevelandclinic.org/health/diseases/25136-hollenhorst-plaques
Wong TY, Klein R. Retinal arteriolar emboli: epidemiology and risk of stroke. Current Opinion in Ophthalmology. 2002;13(3):142-146. PMID 12011681. https://doi.org/10.1097/00055735-200206000-00002
Ghoneim BM, Westby D, Elsharkawi M, Said M, Walsh SR. Systematic review of the relationship between Hollenhorst plaques and cerebrovascular events. Vascular. 2024;32(4):784-791. PMID 36914563. https://doi.org/10.1177/17085381231163339
Dunlap AB, Kosmorsky GS, Kashyap VS. The fate of patients with retinal artery occlusion and Hollenhorst plaque. Journal of Vascular Surgery. 2007;46(6):1125-1129. PMID 17950567. https://doi.org/10.1016/j.jvs.2007.07.054
Gonzalez-Castellon M, Kadakia P, Willey J, Rudich DS, Odel J. Teaching video neuroimages: Hollenhorst plaque. Neurology. 2013;81(9):e60. PMID 23978727. https://doi.org/10.1212/WNL.0b013e3182a2ce2b
Saric M, Kronzon I. Cholesterol embolization syndrome. Current Opinion in Cardiology. 2011;26(6):472-479. PMID 21993354. https://doi.org/10.1097/HCO.0b013e32834b7fdd
Sharma RA, Dattilo M, Newman NJ, Biousse V. Treatment of nonarteritic acute central retinal artery occlusion. Asia-Pacific Journal of Ophthalmology. 2018;7(4):235-241. PMID 29717825. https://doi.org/10.22608/APO.201871
Bakri SJ, Luqman A, Pathik B, Chandrasekaran K. Is carotid ultrasound necessary in the clinical evaluation of the asymptomatic Hollenhorst plaque? (An American Ophthalmological Society thesis). Transactions of the American Ophthalmological Society. 2013;111:17-23. PMID 24072943. https://pubmed.ncbi.nlm.nih.gov/24072943/
Disclaimer
This article is for informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
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