The sudden onset of an ocular migraine can temporarily cause distorted vision or vision loss. In this blog post, we will explore the two types of ocular migraines, their symptoms, what causes them, and the ways to prevent them.
What Is an Ocular Migraine?
While there is actually no such medical diagnosis as ocular migraine, according to the American Migraine Foundation it is a common term used to describe a type of migraine that produces visual disturbances, even if a headache is not present. For this blog, we will examine two types of ocular migraines: migraines with aura and retinal migraines.
Differences Between Migraine with Aura and Retinal Migraine
Migraine with aura is a type of migraine accompanied by neurological symptoms that can disrupt the central nervous system and affect hearing, motor skills, speech, or vision. Visual aura can include seeing jagged or wavy lines, stars, pulsating spots, or bright flashes often described as “kaleidoscope vision”. The aura usually precede the onset of a headache, although in some cases a headache does not occur.
Visual aura are not in one eye or the other but are usually in the same area of field of vision in each eye respectively. They are produced by the brain and are present even with your eyes closed. The aura usually last less than 30 minutes, can grow in size and do not cause permanent damage. The American Academy of Ophthalmology (AAO) states that visual aura is present in about 25% of people who experience migraines.
By comparison, a retinal migraine is a rare type of migraine that causes visual disturbances in one eye. Symptoms can include seeing twinkling lights (scintillations), areas of decreased vision (scotoma), or temporary blindness. These symptoms can progress from slight to severe over the course of the migraine. Retinal migraines can precede or accompany a headache and symptoms typically last less than an hour
Cause of Ocular Migraine
It is unclear what exactly causes ocular migraines.
Evidence suggests that aura associated with a migraine are caused by electrical or chemical waves moving around the brain. The parts of the brain touched by this wave determine the particular aura that are experienced. The visual cortex is the area of the brain that receives and processes visual information. If a wave moves across the visual cortex, nerves fire in abnormal ways causing the migraine’s visual effects.
Retinal migraines are believed to be caused by the narrowing of blood flow to the eye. The constriction of blood reduces the amount of oxygen delivered to the eye. Once the blood vessels relax, visual symptoms improve.
Ocular Migraine Triggers
There are many factors that can trigger migraine with aura and retinal migraine. The triggers vary in each individual, but here are some examples:
- Stress: Stress often initiates a vicious cycle for people with migraines. Stress can trigger migraines, and migraines can create more stress.
- High blood pressure: People are more likely to develop a migraine when blood pressure is high.
- Smoking: Cigarette smoke, including second-hand smoke, can trigger a migraine.
- Hormonal changes: Fluctuations in hormones during a woman’s menstrual cycle, menopause, or when taking birth control pills can increase the risk of ocular migraines.
- Dehydration: A lack of fluid intake can often cause migraines.
- Low blood sugar: When glucose levels fall below normal levels (also called hypoglycemia), a migraine can be triggered.
- Changes in weather: Excessive heat, changes in pressure, or changes in humidity can all play a role in the onset of a migraine.
- Caffeine: For some people, caffeine can help migraines, but daily use (especially in large doses) can trigger migraines.
- Alcohol consumption: Specifically, red wine tends to be the biggest trigger among alcoholic beverages due to histamines or tannins contained in the wine.
- Diet: Certain ingredients, such as monosodium glutamate, artificial sweeteners, nitrites, and food preservatives, have been linked to migraine triggers.
- Exposure to bright lights: For people sensitive to light, exposure to bright natural or artificial light can be a trigger.
How to Treat Ocular Migraines
Managing triggers is the best way to prevent ocular migraines. For example, if you smoke or drink red wine daily and suffer from ocular migraines, simply quitting smoking and cutting back on alcohol consumption can reduce migraine episodes.
Aside from avoiding certain triggers, there are certain medications that may help prevent or treat ocular migraines.
Preventative medications include:
- Blood pressure lowering medications including beta blockers and calcium channel blockers
- Certain anti-seizure medications
- Antidepressant medications
- Botox injections
- Calcitonin gene-related peptides monoclonal antibodies
Relief medications include:
- Pain relievers such as ibuprofen
- Triptans such as Imitrex or Maxalt, which help constrict cranial arteries to reduce painful dilation
- Lasmiditan, which is approved for treatment of migraine with or without auraGepants (calcitonin gene-related peptides antagonists) such as Ubrelvy or Nurtec
- Zavagepant, which is a migraine medicine nasal spray
In the future, additional treatment options might include timolol eye drops, a beta blocker that is directly administered into the eyes. The drops are typically used to treat glaucoma, but the AAO notes how they may be an effective abortive treatment for migraines. For people whose ocular migraines are triggered by light, FL-41 lenses can help.
