Hollenhorst plaques serve as markers of past emboli events but are poor predictors of future events. These plaques may or may not cause an RAO. The discovery of asymptomatic emboli has a greater concern for a patient’s systemic health than visual health.

Statistics

The prevalence increased with age: 0.8% visible in participants ages 49 to 60, 1.4% in ages 60 to 69, 2.1% in ages 70 to 79. This prevalence then dropped to 1.5% in the population over 80 years old.

Retinal emboli were significantly more prevalent in men compared to women: 67%. The presentation of a single embolism (88%) was more prevalent than a presentation of multiple emboli (12%). Lastly, the majority of the emboli were cholesterol (80%), followed by platelet-fibrin (14%) and calcific (6%).[8]

Ocular testing may involve fluorescein angiography (FA) as a supplemental test. Expected results for an occlusion include: delay in the retinal arterial filling, delayed arteriovenous transit time, and variable amounts of residual retinal circulation. It is very rare to see a complete lack of retinal filling even though the vessel is completely occluded. The choroidal filling should be normal since the occlusion has occurred anterior to the ophthalmic artery. There is also a restoration of retinal circulation within days/weeks after an RAO via anastomoses with the central retinal artery; therefore, an FA is of little benefit if delayed.[4][9]

Unless a Hollenhorst plaque completely obstructs a vessel causing an RAO, no ocular treatment is necessary. All patients with retinal emboli should be referred to the patient’s primary care provider for bilateral carotid duplex. Ocular testing may involve fluorescein angiography (FA) as a supplemental test.[10][11]

Calcific emboli:  White, dull (non-refractile), due to their larger size typically found in the central retinal artery close to the optic disc. This finding is consistent with cardiac disease originating from heart valve calcifications.

Platelet-fibrin emboli: White/gray, dull (non-refractile), elongated. This can be a finding for both cardiac and carotid disease; however, cholesterol emboli are more common in carotid disease.

Talc emboli­: Small, white/yellow, highly refractile, typically located in the macular region. This finding is associated with intravenous drug abuse.

Lipid/fat emboli:  Usually cannot visualize the emboli, cotton wool spots are often seen. This finding is associated with long bone fractures and chest trauma, i.e., Purtscher retinopathy.

Tumor cells: These proliferative neoplastic cells which can fall off the main the main lesion and lodge in the retinal arterioles.

Septic emboli:  These deposits are associated with bacterial endocarditis

Atheromatous disease of the internal carotid artery can be associated with these Hollenhorst plaques and is usually an indicator of potential stroke. Carotid stenosis increase in stroke risk as 1.18 times for every 10% increase in stenosis. This risk of stroke rises less than 1% per year for a vessel that is less than 80% stenosed. Whereas a vessel that is greater than 90% stenosed rises at 4.8% per year.

The most common complication is a stroke.

Cholesterol emboli aka Hollenhorst plaque:  Yellow, refractile, typically located at the  carotid artery bifurcation. They tend to originate from carotid arteries or the aorta. This finding is consistent with carotid disease originating from atherosclerotic lesions.

• Hollenhorst plaques are considered to be the most common form of emboli
• Hollenhorst plaques are a common finding in the aging population
• Approximately 75% of Hollenhorst plaques seen in ophthalmic practice are asymptomatic

Even though there are several other causes of hollenhorst bodies, the most worrisome diagnosis is that of atherosclerosis of the internal carotid artery. Often the presence of a hollenhorst body is indicative of an impending stroke, especially in older individuals. Once a hollenhorst body has been diagnosed the management generally involves a neurologist, ophthalmologist, cardiologist, vascular surgeon, interventional radiologist, nurse, and a pharmacist, functioning as a cohesive interprofessional team. The patient should undergo a duplex ultrasound of the neck to determine the presence of atherosclerotic disease at the carotid bifurcation. If the lesion is ulcerated and more than 70% stenosis, the patient should be referred to the vascular surgeon or an interventional radiologist for stenting. The patient should be encouraged to lower his blood pressure and cholesterol, discontinue smoking and take aspirin while awaiting surgery. The nurse should educate the patient on the possible symptoms of a stroke and when to return to the emergency room. When patients with carotid artery atherosclerosis are managed with elective surgery or stenting, the morbidity and mortality rates are less than 3%. [4][9] THis type of interprofessional activity will drive improved results [Level 5]