What is Retinal Migraine Headache?
Migraine is a common condition that was first documented in 1882 by Dr. Galezowski. A specific type of migraine called ocular or retinal migraines usually present as a temporary vision loss in one eye, or a blind spot, which is then followed by a headache within an hour of these visual symptoms starting. In some instances, some people have experienced continuing vision loss in one eye and unusual findings during an eye exam. The symptoms generally don’t last long, but the exact causes behind these lasting issues aren’t fully understood.
What Causes Retinal Migraine Headache?
Retinal migraine is a condition that affects the eyes, and it can be triggered by various factors, similar to other types of migraines, including migraines with or without visual disturbances known as ‘aura’. More specifically, things such as emotional stress, high blood pressure, and hormonal birth control pills could potentially cause retinal migraine. Additionally, physical activities, being in high altitude locations, dehydration, smoking, low blood sugar, and elevated body temperature (hyperthermia) may also bring it on.
Having certain health conditions alongside, known as ‘comorbidity’, can increase the chances of having retinal migraines. These conditions include lupus (an autoimmune disease), atherosclerosis (narrowing of the arteries), and sickle cell disease (a genetic blood disorder).
Risk Factors and Frequency for Retinal Migraine Headache
A retinal migraine is a type of migraine that’s quite rare and not as well-studied as other types. As a result, we don’t fully know how many people have this condition. However, when we look at migraines in general, we find that they affect around 18.2% of women and 6.5% of men. These migraines tend to be more common among white people, and then black people, and then Asian people. People can start experiencing retinal migraines as young as 7, but they usually start in the teens and peak in the 40s.
According to research by Pradhan and others, half of retinal migraine sufferers reported total vision loss in one eye. Other symptoms varied, with 20% reporting blurring, 12% reporting partial vision loss, 7% experiencing dimming, and 13% seeing blind spots (scotomas). Most of the time (over 75% of cases), a headache on the same side as the vision problem followed within an hour.
- 29% of retinal migraine sufferers also have a history of regular migraines.
- Half of them have a family history of migraines.
Signs and Symptoms of Retinal Migraine Headache
People with retinal migraines often experience a mix of symptoms. Some people may see flashing lights or “scintillating scotomas” which are sparkling or shining points in their field of vision. On the other hand, they may also experience negative symptoms like dark, shaded, or white areas obstructing their vision. These incidents might occur several times in a day, normally lasting anywhere between 5 to 20 minutes.
Retinal migraines have a lot in common with other types of migraines, such as those with an aura or acephalgic (pain-free) migraines, which sometimes makes them difficult to tell apart. Nonetheless, it’s not as common to have single-eye vision problems in acephalgic migraines or migraines with aura. Also, the visual symptoms of a retinal migraine usually don’t last as long as those in a migraine with aura.
A physical exam could reveal loss of vision or visual field in one eye during an episode of retinal migraine. However, the rest of the nerve and neurological exams will usually be normal.
Testing for Retinal Migraine Headache
The requirements for a migraine with aura diagnosis include the aura being completely reversible and only affecting one eye. Aura refers to sensations like seeing flashing lights, zigzag lines or experiencing vision loss that patients get before the onset of a migraine. This can be confirmed during an attack with a visual field exam or patient’s sketch of a field defect. Moreover, there are two other criteria:
- The symptoms spread gradually over 5 minutes or longer,
- The symptoms last from 5 to 60 minutes,
- A headache occurs within an hour of the visual symptoms.
Treatment Options for Retinal Migraine Headache
If you only experience the symptoms (attacks) about once a month, it’s generally not necessary to get treatment. However, if your symptoms become more frequent, the first step is usually to make some changes in your lifestyle. This might involve avoiding certain foods or drinks like alcohol and caffeine, managing conditions like high blood pressure, and quitting smoking.
If these lifestyle changes don’t help, you might be asked to start keeping a diary to record your symptoms and how you respond to treatment. This can help your doctor assess how well your treatment is working. You might then be prescribed some preventative medication. Generally, you would avoid medications like ergot and beta-blockers in cases of retinal migraines because of a higher risk of permanent vision loss. The go-to treatments are typically calcium channel blockers such as nifedipine and verapamil, although these might not be suitable if you have heart failure, low blood pressure, certain heart conditions, or liver or kidney failure.
Some other medications like coumadin, heparin, aspirin, and certain antiepileptic drugs have been shown to lower the severity of the attacks. However, they’re generally not the first choice of treatment. Because retinal migraine attacks don’t usually last long, the focus is more on preventing future attacks rather than dealing with ongoing ones.
Certain medications including Triptans, ergots, and beta-blockers are generally avoided in migraines with temporary vision loss as they can potentially lead to further constriction of blood vessels and increase the risk of lasting visual loss.
What else can Retinal Migraine Headache be?
When a patient is suspected of having a retinal migraine, the first step doctors will take is to figure out if the vision issues are in one eye (monocular) or both (binocular). If the doctor confirms that the vision loss is just in one eye, then they need to explore all other possible causes of vision loss in one eye. This is because a retinal migraine is something that is diagnosed by rule out everything else. There are several other conditions to consider, such as:
- Amaurosis fugax, which can occur due to clots from the heart or carotid artery
- Increased pressure within the brain
- A mass in the back part of the eye
- Optic neuritis, an inflammation of the optic nerve
- Giant cell arteritis, an inflammation of the lining of the arteries
- Migraine with visual disturbances
- Anterior ischemic optic neuropathy, a condition that disrupts the blood flow to the eye
What to expect with Retinal Migraine Headache
Retinal migraine is generally thought of as a harmless condition. However, even after the intense episodes have passed, some symptoms can still continue.
Possible Complications When Diagnosed with Retinal Migraine Headache
A retinal migraine may lead to several complications, some of which can seriously impact a person’s vision. These complications may include the blockage of blood flow in the central retinal artery or the central retinal vein, damage to the cells in the retina due to lack of blood flow, blockage in one of the smaller branches of arteries supplying the retina, bleeding in the retina that may result in swelling in the retina and the optic disc, lack of blood supply to the layer of blood vessels in the eye that provide oxygen and nutrients to the outer parts of the retina, or bleeding into the clear gel-like substance in the eye.
Possible Complications:
- Blockage of blood flow in the central retinal artery or vein
- Damage to retinal cells from lack of blood flow
- Blockage in smaller retinal arteries
- Bleeding in the retina, causing swelling
- Lack of blood supply to outer parts of the retina
- Bleeding in the gel-like substance in the eye
- Potential irreversible loss of vision
Certain medications, like triptans, ergots, and beta-blockers, can worsen these complications and should be avoided in patients with migraines that have temporary vision loss. This is because these medications could tighten the blood vessels and increase the risk of permanent vision loss.
Preventing Retinal Migraine Headache
It’s very important to let patients know about the warning signs of losing their vision. If patients experience something like darkness affecting their sight, they should look for medical help immediately and visit the emergency room. This is important because these symptoms could mean that the person is having a stroke or developing an eye condition that could permanently affect their sight. Changes in vision that are more related to migraines usually involve seeing things like flashing lights. It’s important to know that these migraine symptoms can occur even without a headache or any pain. Taking steps to prevent these attacks, such as daily treatment, can help lower the number of attacks and reduce their severity.
