Ocular migraines are those that cause vision loss in one eye. They are usually harmless but may be accompanied by a headache. Although the direct cause of ocular migraines is unknown, some environmental factors may play a role in their development. Read on to find ways to combat ocular migraines and learn more about the disease as a whole.
What Are Ocular Migraines?
Ocular migraines (otherwise known as retinal, ophthalmic, or anterior visual pathway migraines) are visual disturbances in one eye possibly accompanied or followed by a headache. They are more common in adults under the age of 40 who have past histories of headaches or other migraines. Roughly 75% of ocular migraine patients suffer from occasional symptoms [R, R].
Ocular migraines are often confused with other types of migraines, such as migraines with aura (an acephalgic migraine). What makes ocular migraines different is that they affect only one eye while others can affect both [R].
The visual disturbances that accompany ocular migraine episodes are considered harmless. They usually last for less than 5 minutes, but at times can last up to half an hour. The longest recorded ocular migraine was 7 hours, but even then the patient fully recovered [R].
Although there are no data about ocular migraines, in particular, migraines are more common in women; every 1 in 5 women will have migraines, as opposed to only 1 in 15 men. People of European descent have a higher risk (20%), followed by those of African (16%) and Asian (9%) descent [R].
Ocular migraines are most common in adults between the ages of 40 to 60, but there are cases in children as young as 7 years old. Ocular migraines make up about 7% of all migraines in children [R, R].
Causes of Ocular Migraines
Unlike with other migraines, environmental factors do not contribute to ocular migraines much [R].
- High blood pressure
- Birth control pills
- Bending over
- High altitude
- Low glucose levels
Diet can influence the frequency of many types of migraines but usually does not play as large a role in ocular migraines. Overconsumption of alcohol, coffee, tyramine, monosodium glutamate, and aspartame may increase the frequency of ocular migraines [R].
It’s still unknown exactly how ocular migraines occur. One possible explanation is “spreading depression,” a phenomenon during which a wave of inactivity spreads across the brain, temporarily shutting down areas that were overactive [R, R].
Vision loss in ocular migraines may develop from:
- Overstimulation of neurons can cause inflammation and swelling in areas related to vision (cortex, retina, and optic disc). Inflammation of the blood vessels in the eye can cause sudden narrowing (vasospasm of the retinal artery), block blood flow, and disrupt vision (by affecting the pupil dilation) [R, R, R, R, R].
- Increased serotonin release, causing the production of inflammatory compounds (prostaglandins). Prostaglandins are cleared by the lungs, but minute levels escaping clearance can cause a migraine. This can also clog the eye’s arteries and reduce blood flow [R, R, R].
- Complete or partial vision loss
- Blind spots (scotoma)
- Visual disturbances in either the top or bottom field of vision (altitudinal visual field defects)
- Flashing lights
Often, these symptoms resolve within 30 minutes. A permanent visual loss is very rare [R].
Pupils may become dilated after ocular migraines (for seconds to hours in duration) [R].
Headaches are also common and may happen during, after, and in rare cases, before the visual loss. They are usually one-sided. It is estimated 41% of patients get headaches during the visual loss while 25% develop headaches at other times [R, R].
Complications from ocular migraines are rare. They are listed here:
- Complete or partial blockage of eye blood vessels (central retinal artery occlusion, central retinal vein occlusion, branch retinal artery occlusion, retinal infarction, ischemic optic neuropathy) [R, R, R, R, R, R]
- Blood leakage into the eyes (retinal hemorrhage, vitreous hemorrhage) [R, R]
- Swelling around the eyes (bilateral optic disc edema) [R]
- Severe loss of vision (due to changes in the pigments in the retina) [R, R]
- Changes in the pigments in the retina [R]
- Stroke [R, R]
Treatments and Prevention
1) Lifestyle Changes Can Help Prevent and Treat Ocular Migraines
Ocular migraines are usually temporary and are short in duration, so treatment is usually not required. If the ocular migraines occur less than once a month, treatment is usually not recommended [R].
When migraines happen more often, the first option is to make lifestyle changes. Decreasing stress, reducing smoking, and lowering blood pressure is key to preventing ocular migraines [R].
Reducing consumption of these foods/compounds can also help prevent ocular migraines [R]:
- Monosodium glutamate
*Although coffee may worsen migraines in some people, it may actually benefit others. It owes this effect to caffeine, which was shown to reduce some migraine types. Green and black tea also contain caffeine in high amounts [R].
2) Natural Remedies
There are many natural treatments for migraines that may help with ocular migraines or prevention. None have been studied specifically in people with ocular migraines, though. But since ocular migraines occur due to similar causes as other migraine types, the following natural treatments may help:
- Magnesium, especially since the majority of patients with migraines are deficient in magnesium [R]
- B vitamins, such as B6, B12, and folate
- Butterbur, which has been the most researched natural remedy for reducing migraines
- Feverfew and Willow Bark
- CoQ1, as deficiency is very common in children and adolescents with migraines [R]
- Cannabis, powerful pain reliever and standard treatment for migraines from 1874 to 1942 [R]; more research is now emerging around its effect on reducing pain and nausea in people with migraines [R]
- 5-HTP, a supplement that boosts serotonin levels
- Glandular Adrenal
The TENS device and tDCS may also improve migraines, based on several studies [R, R].
If you’re curious to learn more about natural migraine treatments, you can also read this SelfHacked post.
3) Calcium Channel Blockers
If lifestyle changes do not help, drug therapy is an option. The first-line drug therapy for ocular migraines is calcium channel blockers, such as nifedipine and verapamil. They work by reducing sudden contraction of the eye’s arteries, reducing the release of serotonin, and the occurrence of “spreading depressions” [R, R, R].
In a study (open-label) of 9 patients suffering from ocular migraines, the use of calcium channel blockers halted all episodes. When the treatment was discontinued, the ocular migraines returned [R].
Calcium channel blockers have a rapid onset of action. Nifedipine tablets placed under the tongue were able to block ocular migraines within 30 seconds in one patient and within 10 minutes in another [R].
Side effects of calcium channel blockers include [R]:
- Accumulation of fluids in the body causing swelling (peripheral edema)
- Overproduction of diluted urine (polyuria)
- Acid reflux
- Enlargement of gums (gingival hyperplasia)
It is not advised to take calcium channel blockers with beta-blockers [R].
Contraindications to calcium channel blocker use include heart, kidney, and liver failure, low blood pressure, and sick sinus syndrome [R].
4) NSAIDs and Anticoagulants
The use of Nonsteroidal Anti-inflammatory Drugs (NSAIDs) has not been studied for ocular migraines specifically, but they may able to treat some of the symptoms. NSAIDs are usually combined with other drug treatments. The NSAID drug mainly used is aspirin [R].
In a study (DB-RCT) of 22,071 physicians, 325 mg of aspirin reduced recurrences of migraines by up to 20% [R].
Heparin is an anticoagulant, otherwise used to reduce blood clotting. Heparin reduced migraine symptoms in isolated cases [R].
Side effects of aspirin use include stomach bleeding, increased risk of heart attack or stroke, and kidney toxicity [R].
Potential negative interactions can come from the concurrent use of blood pressure medications, blood thinners, antidepressants, alcohol, and antirheumatics [R].
5) Other Drugs
A case study of one patient suffering from ocular migraines found that acetazolamide and nitroglycerin were able to reduce ocular migraines [R].
Although not specifically for ocular migraines, certain antiepileptic drugs such as divalproex sodium, gabapentin, and topiramate have been shown to reduce migraine frequency [R].
A class of drugs called triptans reduces the pain felt during the headaches from ocular migraines. However, triptans may increase the risk of heart disease or stroke [R].
Risk Factors and Genetic Predispositions
Patients with blood clotting disorders are also 3 times more likely to develop a blockage in the artery involved in ocular migraines (retinal) [R].
There is a high possibility that genetics play a role in migraines; however, a genetic predisposition for ocular migraines has not been discovered. About 29 to 50% of patients with ocular migraines have a history of a migraine [R, R].
Other factors such as age and history of heart disease may play a role in developing ocular migraines [R].
Limitations and Caveats
A limitation of ocular migraine studies is that ocular migraines are not well-defined. To this day, there are many names for ocular migraines and physicians may be confused between the different types of migraines [R].
Migraines are difficult to characterize due to the many presentations and versions of a migraine. It is also rare for physicians to be present during the migraine attack. This makes naming, classifying, and treating migraines difficult [R].