The criteria for identifying retinal migraines include vision changes in one eye. These may consist of flickering lights or even temporary blindness. Visual symptoms tend to start gradually and last for up to an hour.
A headache will also occur at the same time or within an hour of the vision problems.
Around 1 in every 200 people who get migraines will have a retinal migraine.
People sometimes refer to this type of migraine as an ophthalmic migraine, a visual migraine, or an ocular migraine. However, the symptoms for these conditions are slightly different.
A retinal migraine will affect the vision in one eye.
Experts believe that a retinal migraine happens when a blood vessel in the eye spasms, causing a reduction in the blood flow to the eye.
As the blood vessel relaxes and blood flow returns to normal, the symptoms usually disappear, and vision comes back.
There are no triggers that are specific to a retinal migraine, but the following factors can trigger a regular migraine:
- emotional stress, tension, and being overtired
- sensitivity to ingredients in specific foods
- too much caffeine or caffeine withdrawal
- bright lights or loud noises
- changes in sleep pattern
- hormonal changes in women
- medications that lead to swelling in blood vessels
- excessive or regular use of pain relievers for headaches
- not eating or drinking enough
Some people have a higher risk of a retinal migraine than others, including:
- people under the age of 40 years
- individuals with a personal or family history of migraines
- people who have another condition, such as atherosclerosis, epilepsy, lupus, or sickle cell disease
Retinal migraines also affect women more often than men.
The visual disturbances may last for up to an hour, but a pulsating headache can continue for some time after.
A retinal migraine involves repeated attacks of certain visual disturbances, which usually happen before the headache phase of the migraine.
People often refer to the visual disturbances collectively as an aura.
In a retinal migraine, the aura occurs due to spasms in the blood vessel leading to the eye, and it affects only one eye.
The characteristics of an aura may include:
- flashing, sparkling, or twinkling lights
- a blind spot or partial loss of vision
- temporary blindness
The aura may spread gradually over 5 minutes or more and last between 5 and 60 minutes. Within 60 minutes of the visual symptoms beginning, the headache phase of a retinal migraine may begin.
Migraine headaches may be:
- pulsing or throbbing
- moderate to severe in pain intensity
- susceptible to exacerbation by activities, such as walking or climbing stairs
A migraine headache may also cause:
- nausea and vomiting
- increased sensitivity to light
- increased intolerance to sound
In one case study, a person who had recurrent retinal migraines experienced headaches lasting around 4 hours, occasionally with numbness in the jaw and arm on one side of the body.
There are no diagnostic tests to confirm a retinal migraine, but the ICHD-3 criteria can help a doctor assess the condition.
A doctor may diagnose a retinal migraine by considering the individual's personal and family medical history, asking about symptoms, and conducting a physical examination.
They will also rule out other possible causes for the symptoms.
In some cases, a specialist doctor might need to check that the symptoms are not due to a serious eye disease or stroke.
Some people who have visual disturbances might have hemianopia. Hemianopia is the loss of vision in half the visual field, which will occur on the same side of both eyes. It often develops as a result of stroke and traumatic brain injuries.
The medication that a doctor prescribes to treat retinal migraines may depend on a person's age and how frequently they have a retinal migraine.
The American Migraine Foundation note that if the attacks are not frequent, the treatment will be the same as for other types of migraine.
Medications might include:
- nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin or ibuprofen, to relieve pain and inflammation
- antinausea medications to prevent nausea and vomiting
A doctor will not prescribe triptans and ergotamines for a retinal migraine, although people use these to treat or prevent other types of migraine.
The doctor may also recommend some preventive measures, which may include:
- using beta-blockers to relax blood vessels in the brain
- taking calcium-channel blockers to prevent blood vessels constricting
- going on antidepressants to help prevent a migraine
- taking anticonvulsants to help prevent a migraine
- quitting smoking
- discontinuing any oral contraceptives
There are no specific guidelines for treating a retinal migraine. Most treatments focus on relieving headache pain and reducing exposure to potential retinal migraine triggers.
Vision loss is usually temporary. If it persists or attacks are frequent, the person should seek medical advice.
There is a small risk with a retinal migraine that the sudden reduction in blood flow to the eye may damage its retina and blood vessels.
As a result, vision loss is a potential complication of a retinal migraine, according to the American Migraine Foundation.
The medications that people use to treat a retinal migraine can sometimes cause other problems.
For example, NSAIDs may cause side effects that include stomach pain, bleeding, and ulcers.
The excessive use of medications can also result in overuse headaches. A review published in 2014 found that people who get migraines have a higher risk of medication overuse headaches.
Very rarely, a person may have permanent loss of sight following a retinal migraine. People who experience visual disturbances due to retinal migraines may need to visit an ophthalmologist to check for eye damage or other underlying problems.
The main feature of a retinal migraine is a temporary loss or disturbance of vision in one eye. Attacks vary in frequency, but many people who experience them will have one every few months.
The visual disturbance rarely lasts longer than an hour, but the subsequent headache can last from a few hours to a few days.
Anyone who has vision loss with a migraine should seek medical help to check that there is not a more severe underlying problem.