Understanding Ocular Migraine
Visual impairments associated with migraine can happen with or without a headache
“Ocular Migraine” is a term that has been used to refer to a number of migraine subtypes that are characterized by a variety of visual disturbances including visual loss, blind spots, zig-zag lines, or seeing stars. Unlike other forms of migraine, they may occur without any accompanying head pain. It’s not uncommon for a single patient to experience a wide range of visual symptoms. Here’s what you need to know to better understand the migraine subtypes that affect vision.
Types of Ocular Migraine
Migraine with Aura
Migraine with Aura impairs vision, with symptoms like flashes of light, blind spots, seeing stars or patterns and other minor sight issues that go away after a short period. While the most noticeable symptoms are visual disruptions, aura can also affect other senses and interfere with speech, motor skills or other central nervous symptoms. Migraine aura can occur with headache or without, and is typically short in duration. When aura symptoms appear in conjunction with head pain, they usually occur between the premonitory phase and the peak pain phase of migraine, between the symptoms that warn of an impending attack and when the head pain itself hits. They may, however, last more than 1 hour in about 20% of individuals and may follow the onset of head pain in some instances. Migraine with Aura occurs in 25-30 percent of people with migraine, and less than 20% of individuals with migraine visual aura have the aura phase with every migraine attack.
Retinal Migraine refers to visual symptoms that occur in only one eye before or during the headache phase of a migraine attack. Retinal Migraine symptoms tend to be more intrusive than aura symptoms, and include decreased vision, the appearance of twinkling lights and temporary blindness. It can be difficult for patients to distinguish between Migraine with Aura and Retinal Migraine, so it’s important to consult a doctor if you think you may be experiencing Retinal Migraine symptoms. Irreversible visual loss may be a complication of Retinal Migraine.
What Causes These Migraine Subtypes with Vision Disturbance?
Migraine aura is considered to be a result of abnormal electrical activity involving certain regions of the cortex (outer surface) of the brain. This abnormal activity spreads across the cortex at a slow rate of about 3mm per minute and this spread is responsible for the growth and movement of the visual disturbance over the 20-60 minutes that the visual aura lasts. Retinal migraine may be due to the same type of disturbance except occurring at the back of the eye in the retina, or it may be due to a reduction in blood flow to the retina.
Like other types of migraine, harsh lights and electronic screens can be triggers. Straining your eyes by staring at a screen for long periods of time, spending time in fluorescent or other harsh lighting, driving long distances and other taxing visual activities can increase your risk for attacks. Talk to your eye doctor about how to avoid attacks.
Treating and Preventing Migraine With Aura or Retinal Migraine
For infrequent attacks, medications that target symptoms can be effective, from NSAIDs for pain to anti-nausea medications. Preventative therapies including calcium channel blockers, antiepileptic or tricyclic medications. Quitting smoking is recommended and cessation of oral contraceptives may be advised in certain circumstances. Some options for relief without drugs can include resting your eyes, removing yourself from bright sunlight or other harsh lighting, and taking a break from looking at a screen. As with all types of migraine, try to avoid triggers like stress, dehydration, high altitude, low blood sugar, excessive heat and extensive time spent staring at a screen.
While the symptoms can be disorienting and distressing, they are often short-lived, and almost always reversible. Take some time away from triggers and wait for the symptoms to fade. For more information, visit the American Migraine Foundation’s resource center, which includes content specifically related to Migraine with Aura, Retinal Migraine and more. The American Migraine Foundation is committed to providing comfort and information to people living with this disease. You are not alone: find your support network today.