Most of us are familiar with a stroke, also called a cerebral stroke, and that it happens when blood supply is cut off to the brain. But how many of us are familiar with the symptoms and dangers of an eye stroke?
Both types of strokes are similar in that blood flow is blocked or reduced. The eye stroke, however, results in vision loss that could turn out to be permanent. It’s important to know the signs and sources of different types of eye stroke to be aware of possible risk factors and what symptoms to watch for.
Penn Medicine describes an eye stroke as a “dangerous and potentially debilitating condition that occurs from a lack of sufficient blood flow to the tissues located in the front part of the optic nerve.” Serious eye strokes can happen without warning and cause sudden partial blindness. Penn Medicine explains that many patients who suffer eye strokes begin having mild symptoms in the morning with a painless loss of vision or shadowy dark patch in their line of vision in one eye. Getting immediately to the emergency room is highly recommended to try and prevent permanent damage.
8. What Causes an Eye Stroke?
The optic nerve depends on a consistent blood supply to function properly. An eye stroke can occur if blood vessels feeding oxygen and nutrients to and from the optic nerve get blocked or have poor circulation. The circulation in our blood vessels depends on the overall healthy function of our blood pressure. If blood pressure is compromised, the risk for eye stroke goes up.
Eye strokes then result when the optic nerve is damaged. Penn Medicine states, “if the optic nerve’s nutrient and oxygen supply is cut off, nerve tissue is damaged and lost, resulting in vision loss.”
About 90% of eye strokes occur in people over 45, so aging is a risk factor. People with cardiovascular disease and blood pressure dysregulation are at higher risk for eye stroke as well. Penn Medicine notes that some patients experience significant drops in blood pressure during sleep prior to having eye strokes. This can happen with patients on medications for hypertension (high blood pressure), which may cause their blood pressure to dip down too low overnight.
7. Eye Stroke Symptoms
If you’re experiencing blind spots, peripheral vision loss, or vision that seems distorted, these could be symptoms of an eye stroke.
The most common symptom of eye stroke is partial vision loss that comes on suddenly. According to an article from the American Academy of Ophthalmology, this vision loss is painless. The type of eye stroke you’re experiencing will determine whether the initial vision loss is in part of one eye or the entire eye. Read on for details about specific types of eye strokes and how they manifest.
6. Retinal Vein Occlusions
The American Society of Retina Specialists explains how blocked veins (occlusions) can cause eye strokes. “Retinal vein occlusions occur when there is a blockage of veins carrying blood with needed oxygen and nutrients away from the nerve cells in the retina. A blockage in the retina’s main vein is referred to as a central retinal vein occlusion (CRVO), while a blockage in a smaller vein is called a branch retinal vein occlusion (BRVO).”
The branch retinal vein occlusion begins with pain-free sudden vision loss, or it can go undetected if the blockage manifests as tiny vision “floaters” caused by leaking blood vessels.
5. Retinal Arterial Occlusions
Much like the retinal vein occlusion, a retinal arterial occlusion is a blockage of the retinal artery. Significant vision loss can happen when oxygen can’t get to the eye to nourish nerve cells supported by this essential pathway. Also, as with a retinal vein block, the main symptom of retinal arterial occlusion is sudden and painless loss of vision.
The outcome of a blocked retinal artery depends on which artery has shut down. If the main artery (the ophthalmic artery) is the cause of blockage to the retina, it can lead to significant vision loss. This condition is called a central retinal arterial occlusion (CRAO).
4. Ischemic Optic Neuropathy
The American Academy of Ophthalmology describes ischemic optic neuropathy (ION) as one that occurs “when blood flow to the optic nerve is reduced or blocked, the nerve does not get enough oxygen or nutrition. The optic nerve stops working properly, and eventually dies.” If the optic nerve dies, there’s no repairing it. As a result, loss of vision becomes permanent.
Symptoms of ischemic optic neuropathy are sudden loss of central or peripheral vision. Often this is experienced as quick blips where your vision is blocked for a few seconds and then restored again, known as transient ischemic attacks. Someone with this symptom should get immediate medical care before the optic nerve suffers irreversible damage.Related: Drooping Eyelids: Is It Aging or Something More?
3. Non-Arteritic Ischemic Optic Neuropathy
An eye stroke from non-arteritic ischemic optic neuropathy, whether anterior or posterior, typically stems from an underlying vascular condition as part of the cause. People with vascular disease like diabetes are at higher risk, as are people with heart disease. It’s also possible that patients with elevated levels of vitamin B6, lipoprotein and plasma homocysteine are susceptible to non-arteritic ION symptoms.
As with other eye stroke conditions, these symptoms include sudden and painless loss of vision in usually one eye. The vision loss doesn’t normally progress quickly and it often comes on first thing in the morning.
2. Get Immediate Medical Attention
No matter the cause of sudden vision loss, whether minimal or otherwise, it’s important to get to your eye doctor or even the emergency room immediately. Your condition might not require emergency care, but that’s a risk you don’t want to take by waiting or avoiding seeing a doctor. If you call an ophthalmologist first, be sure to tell them you have vision loss symptoms that might need immediate care. The eye doctor may recommend you go straight to the ER.
1. Eye Stroke Treatment
A thorough eye exam with highly detailed photos of your eyes will determine the recommended treatments. When possible, the main goal will be to unblock the blood vessels keeping oxygen and nutrients from moving through. If blood clots are detected, you will probably be prescribed medication to dissolve them and perhaps be put on a blood thinner to prevent new clots from forming. If blood pressure issues are a possible source of eye stroke, your doctor will help regulate your blood pressure as part of the treatment.Related: Eye Twitching: What Causes It and How to Stop It