woman with ocular migraine symptoms after COVIDShare on Pinterest
Thanaporn Sae-Lee/EyeEm/Getty Images

Headaches are among the most common COVID-19 symptom. Some studies have reported headaches in as many as 70 percent of people with COVID-19.

Typically, people describe COVID-19 headaches as either like a migraine episode, or like a tightening on the sides of their head.

The term “ocular migraine” has been used to describe two conditions. It can refer to retinal migraine, which causes brief vision loss in one eye accompanied by a headache, or it can refer to migraine with aura, which causes visual disturbances.

In this article, we’ll examine the difference between these two types of migraine and look at the link between ocular migraine and COVID-19.

The term “ocular migraine” is often used to refer to any type of headache that causes visual changes. Sometimes it’s used to specifically refer to a type of migraine called retinal migraine.

Retinal migraine

Retinal migraine is a condition that causes partial or full vision loss in one eye and a headache within 60 minutes of vision loss.

The reason why these migraine episodes develop is controversial. Some researchers point to a possibility that a narrowing of the retinal or ciliary arteries causes them. Other researchers suggest electrical changes in the neurons of the retina cause them.

Partial or total vision loss typically lasts 10 to 20 minutes before returning to normal. Your vision may also become blurry or dim. You may experience flashes or mosaic patterns of light.

As of now, there’s no research connecting this specific type of migraine to COVID-19.

Migraine aura with visual disturbance

Migraine is a neurological condition that often causes intense headaches. Migraine tends to run in families.

A migraine aura is experienced by about 25 percent of people with migraine, either before or at the same time as a migraine episode.

Usually, people who have migraine with aura don’t experience an aura with all of their migraine episodes, just with some of them.

An aura is a temporary visual, auditory, motor, or other sensory change. Visual disturbances can include:

Among people who experience an aura, about 99 percent have at least one visual symptom with some of their auras.

Some people with a previous history of migraine report worsening migraine episodes during COVID-19. Some people without a history of migraine report experiencing migraine-like headaches.

A 2020 study found that among 47 people with COVID-19 who reported having headaches, 24 people (51 percent) reported migraine-like headaches, while 40 percent had symptoms of a tension headache.

Before they developed COVID-19, only 12 of the study participants had previously experienced migraine episodes.

According to a June 2020 research review, the most commonly reported neurological symptoms of COVID-19 are headache and loss of smell.

Severe neurological complications such as stroke or seizure have also been reported, although these aren’t common with COVID -19.

People who develop COVID-19 sometimes develop symptoms affecting their eyes. A January 2021 research review found that more than 11 percent of study participants with COVID-19 had eye symptoms.

The most common eye symptoms were:

  • dry eyes or foreign body sensation
  • redness
  • tearing
  • itchiness
  • eye pain
  • discharge

Researchers are still trying to figure out how the virus that causes COVID-19 interacts with our nervous system. Some people with a history of migraine report an increased frequency or intensity of migraine episodes during COVID-19.

A May 2021 study highlights three case studies of people with a history of migraine who experienced migraine episodes during COVID-19.

In two of the people, migraine with aura was the initial symptom of COVID-19. The third person developed visual auras at the same time as other COVID-19 symptoms.

Here’s a summary of the migraine symptoms the three people experienced before and during COVID-19 illness:

CaseBefore COVID-19During COVID-19
Case 1Migraine episodes approximately twice per month with good response to pain medication.Visual aura in both her eyes along with smell hypersensitivity that lasted 35 minutes. She experienced the most severe migraine episode of her life with a poor response to medication. Two days later, she lost her sense of smell and developed a fever and muscle pain.
Case 2Migraine episodes approximately once per month with good response to pain medication.Sudden burning in her ears with hearing impairment accompanied by a visual aura in her right visual field for 20 minutes. Two days later, she developed loss of smell and dry cough.
Case 3Migraine episodes occurred about 9 days per month. Had never experienced a visual aura.Developed visual aura without headache three times within a week. She described her symptoms as flashes of light and movements of images that lasted 15–30 minutes.

Why might COVID-19 increase migraine frequency or intensity?

In an August 2020 observational study, researchers examined the symptoms of 13 people with COVID-19 whose primary symptom was headaches. Five of the 13 people were previously diagnosed with migraine, and three of the people developed a headache as their initial symptom.

According to the study authors, headaches may form due to the coronavirus invading the trigeminal nerve, which could activate mechanisms that are known to cause migraine episodes and other types of pain. The trigeminal nerve is the largest of your 12 cranial nerves.

Research has found that parts of the trigeminal nerve lack the protective blood-brain barrier that helps prevent microorganisms from entering the central nervous system.

Autopsy studies have found evidence of degeneration of the trigeminal nerve in people with COVID-19, suggesting either direct damage from the coronavirus or damage from the body’s immune response.

The coronavirus is thought to enter cells in your body through receptors for the enzyme called angiotensin converting enzyme 2 (ACE2). ACE2 receptors have been found in neuron cells in the trigeminal nerve as well as many other parts of the body.

Effects of the pandemic on people with migraine

Various factors related to the COVID-19 pandemic unrelated to direct viral infection may have led to increased migraine frequency or severity in some people.

A September 2020 study found that in a group of 1,018 people with a history of migraine in Kuwait, more than half reported an increase in migraine frequency or severity from the pre-pandemic period.

Factors such as lack of communication with a neurologist and increased stress may have played a role.

Only 4 percent of the study participants developed COVID-19, but of those people, 63.4 percent reported their migraine worsening.

It’s possible that ocular migraine could persist even after recovery from COVID-19 in some people.

Some people develop headaches that last for months after COVID-19. For example, in one case study, a woman had persistent loss of smell and experienced headaches 80 days after the onset of her symptoms.

She experienced migraine-like headaches during her COVID-19 illness, but she reported that her subsequent headaches felt different.

Researchers are still trying to understand why some people develop long-haul COVID-19 symptoms after recovering from their initial infection. It’s possible that increased inflammation and neurological damage play a role.

Ocular migraine often refers to any headache that causes visual disturbances. It may also refer to a specific type of migraine that causes vision loss called retinal migraine.

Case studies report that some people with a history of migraine develop more frequent migraine episodes during COVID-19. Some people without a history of migraine also experience migraine-like headaches.