Eye Strokes: What You Need To Know

Eye strokes, or retinal artery occlusions, are a medical emergency and require immediate attention. They occur when blood flow to the retina is blocked, typically by a blood clot, causing a sudden and often painless loss of vision in one eye. The blockage can happen in the main artery, known as central retinal artery occlusion (CRAO), or in smaller branch veins, called branch retinal vein occlusion (BRVO) or branch retinal artery occlusion (BRAO). Eye strokes can lead to permanent vision loss or blindness if not treated promptly. Treatment options include clot-busting medications, eye massage, and hyperbaric oxygen therapy.

An eye stroke is a medical emergency

An eye stroke, or retinal stroke, is a medical emergency that requires urgent attention. It occurs when blood flow to the retina is blocked, usually by a blood clot. This can lead to permanent vision loss or blindness if not treated promptly.

The retina is a thin film at the back of the eye that sends light signals to the brain, enabling us to see. When the retinal veins are blocked, fluids leak into the retina, causing swelling and preventing oxygen from circulating. This, in turn, affects your ability to see.

The hallmark signs of an eye stroke are sudden and painless vision loss or changes in vision, such as blurriness, floaters, a darkened area in your field of vision, decreased visual contrast, and light sensitivity. These symptoms typically occur in one eye only and can appear gradually or come on suddenly.

If you or someone you know is experiencing any of these symptoms, seek immediate medical attention. The faster you receive care, the more likely you will experience positive outcomes. Treatment options include clot-busting medications, hyperbaric oxygen therapy, and retinal specialist care.

It is important to note that eye strokes can also be early signs of other vascular events, such as ischemic strokes and heart attacks. Therefore, it is crucial to seek medical help as soon as possible to prevent further complications and to reduce the risk of future strokes.

Symptoms of an eye stroke

An eye stroke is a medical emergency that demands immediate attention. It occurs when blood flow to the retina is blocked, usually by a blood clot. The retina is the thin film at the back of your eye that sends light signals to your brain, allowing you to see. When retinal veins are blocked, fluids leak into the retina, causing swelling and disrupting oxygen circulation, which affects your vision.

The hallmark signs of an eye stroke are sudden and painless changes in vision or vision loss in one eye. These changes can manifest as blurriness, floaters (small grey spots in your field of vision), a darkened area in your field of vision, decreased visual contrast, and light sensitivity. While these symptoms typically appear rapidly, they can also develop slowly over hours or days.

Vision loss can be partial or complete and may occur gradually or suddenly. It can range from subtle to severe, sometimes mimicking a black curtain coming down in front of your eye. In some cases, the retina may appear pale with a cherry-red spot.

In severe cases of central retinal vein occlusion (CRVO), you may experience localized pressure or discomfort in the affected eye. Additionally, your retina may appear red or have blood spots throughout.

If you or someone you know is experiencing any of these symptoms, seek immediate medical attention.

Risk factors for an eye stroke

An eye stroke, or retinal artery occlusion, is a medical emergency that requires urgent attention. It is caused by a blockage, typically a blood clot, in an artery in the eye. This blockage interrupts the blood flow to the retina, which is the part of the eye that communicates with the brain to turn light into images.

High Blood Pressure

High blood pressure, or hypertension, may affect the flow of blood to the retina and prevent vital nutrients and oxygen from reaching the eye, causing possible nerve damage and vision loss.

Age

Age is a risk factor for eye strokes because, as a person gets older, they become more susceptible to cardiovascular diseases that can cause eye strokes and other conditions. According to the American Academy of Ophthalmology, people in their 60s may have the highest risk, especially men.

Smoking

Smoking restricts the flow of blood and oxygen throughout the body, increasing the risk of an eye stroke.

Diabetes

Diabetes is linked to higher levels of blood pressure in the eyes, which can increase the risk of an eye stroke. This includes a family history of diabetes.

High Cholesterol

High cholesterol, or hyperlipidemia, is a risk factor for eye strokes as it can contribute to blockages in the blood vessels.

Atherosclerosis

Atherosclerosis is the build-up of plaque in the arteries, which can increase the risk of an eye stroke.

Previous Heart Attack or Stroke

A personal or family history of a previous heart attack or stroke can increase the risk of an eye stroke.

Coronary Heart Disease

Coronary heart disease is another risk factor for eye strokes.

Diet and Lifestyle

Poor diet and lifestyle choices, such as a lack of exercise, can contribute to the risk of an eye stroke.

Diagnosing an eye stroke

Eye strokes are vastly underrecognized and undertreated. They require urgent medical attention and can lead to permanent vision loss or blindness if not treated quickly. To diagnose an eye stroke, an ophthalmologist will perform an eye exam in person or review a special picture called a fundus photo, which images the internal parts of your eye, including the optic nerve and retina. The diagnosis should be done as soon as possible in an emergency department.

• Recognising the symptoms: The hallmark signs of an eye stroke include sudden and painless vision loss or changes in vision in one eye. These changes can include blurriness, floaters, a darkened area in the field of vision, decreased visual contrast, and light sensitivity. While these symptoms usually come on quickly, they can also appear gradually.
• Seeking medical attention: If you or someone you know is experiencing these symptoms, it is important to seek immediate medical care. Eye strokes are a medical emergency and can lead to serious complications if left untreated.
• Ophthalmologist examination: Once you arrive at the emergency department, an ophthalmologist will perform a comprehensive eye examination. They may use specialised instruments such as an ophthalmoscope or a fundoscope to get a detailed view of the internal structures of your eye.
• Diagnostic imaging: In addition to the eye examination, the ophthalmologist may order diagnostic imaging tests to visualise the blood vessels in your eye. These tests can include optical coherence tomography (OCT) or fluorescein angiography. OCT is an imaging test that can detect swelling of the retina, while fluorescein angiography involves injecting a special dye into your arm to highlight the blood vessels in your eye.
• Reviewing medical history: The ophthalmologist will also take a detailed medical history and ask about your symptoms. They may inquire about any underlying health conditions, medications, or risk factors that could contribute to an eye stroke.
• Further evaluations: Depending on the findings and your medical history, the ophthalmologist may refer you to a vascular neurologist or cardiologist for further evaluations. These specialists may recommend additional imaging tests, such as an ultrasound, to determine if you have or are at risk for carotid artery disease or heart disease.

It is important to remember that the key to successful treatment of an eye stroke is prompt medical attention. The faster you receive care, the more likely you are to experience positive outcomes and preserve your vision.

Treating an eye stroke

An eye stroke is a medical emergency that requires urgent attention. If you are experiencing symptoms of an eye stroke, seek immediate care.

To diagnose an eye stroke, an ophthalmologist will perform an eye exam in person or review a fundus photo, which is a special image that shows the internal parts of your eye, including the optic nerve and retina. This diagnosis should be done as soon as possible in an emergency department.

The treatment for an eye stroke will depend on the type of blockage and the severity of the damage. Here are some possible treatments:

• Eye massage: A doctor will massage your closed eyelid with a finger to dislodge the clot.
• Carbon dioxide-oxygen therapy: You breathe in a mixture of carbon dioxide and oxygen to increase blood flow to the retina and widen the arteries.
• Paracentesis: A specialist uses a small needle to remove fluid from the front of your eye to reduce pressure and increase blood flow in the retina.
• Medications: Drugs such as clot-dissolving medications or medications to lower eye pressure may be prescribed. For example, Tissue Plasminogen Activator (tPA) is a clot-busting medication that must be administered intravenously within four-and-a-half hours of the onset of eye stroke symptoms.
• Hyperbaric oxygen therapy: This therapy uses large, pressurized chambers to deliver high levels of oxygen to your bloodstream, helping to preserve the retina's energy supply and optimize recovery.
• Anti-vascular endothelial growth factor drugs: These are injected directly into the eye.
• Corticosteroids: These can be injected into the eye to reduce inflammation.
• Pan-retinal photocoagulation therapy: This may be used if there is new blood vessel formation after an eye stroke.

The faster you receive treatment for an eye stroke, the more likely you will experience positive outcomes and preserve your vision. Therefore, it is crucial to seek immediate medical attention if you suspect you are having an eye stroke.

Frequently asked questions