Visual disturbances can be associated with migraine – with or without the headache.
Ocular Migraine is the visual disturbance or aura that may be associated with a migraine headache. An episode may appear before, during, or following a migraine headache. Or, in some cases, may occur without any associated headache or pain. It usually occur in one eye at a time but can also affect both eyes. Ocular migraine is also sometimes called ophthalmic, retinal, eye, visual, silent or monocular migraine.
How long will it last?
An episode of ocular migraine usually lasts from a couple of minutes to about half an hour. If you experience an episode lasting longer than one hour you should see a doctor to rule out other, more sinister causes.
Why does it happen?
Ocular migraine occurs when the blood vessels to the eyes tighten or constrict. This blood flow to one of your eyes is reduced and vision is temporarily affected. After the episode, the blood vessels open up again and the vision is usually returns to normal.
- Symptoms of ocular migraine include a range of visual disturbances, especially in the peripheral vision.
- Visual disturbances – also called auras – are often described as zig-zag lines, chequers, blind spots, colour fringes, rainbows, stars, geometric shapes etc.
- The visual effects (scintillations) may flash, throb, shimmer, twinkle or vibrate.
- ‘Shimmering’ is a word commonly used to describe the aura.
- Parts of your vision may be blurry, dim or missing
- These visual effects are often described as psychedelic or kaleidoscopic.
- Migraine headache (at the same time or recent) may or may not be present.
Who gets ocular migraine?
Both children and adults can experience ocular migraine, but they seem to be more common in people under 40.
Women experience all forms of migraine more often than men.
Not all migraine sufferers will experience the auras or visual disturbances associated with ocular migraine. Some estimates put it at one in five migraine sufferers, but it’s hard to be certain as the effects can be subtle.
If you have a family history or personal history of migraine headache, you are at greater risk of having ocular migraine.
Certain vascular diseases such as giant cell arteritis and arteriosclerosis can also be a cause this eye problem.
Migraine (with or without aura) can be triggered by certain foods (such as caffeine, red wine, MSG and other additives) as well as intense exercise, smoking, high blood pressure, birth control pills etc.
What does it look like?
The images below are graphic impressions of the visual disturbance characteristic of an ocular migraine:
Can it be serious?
Most episodes resolve within a few minutes to half an hour, when your vision returns to normal. Ocular migraine is not usually a sign of a serious eye problem. Rarely, however, similar symptoms could be associated with a serious medical conditions such as a brain lesion, stroke or giant cell arteritis. This is why it is important to report any episode of ocular migraine to your GP or optometrist. If you experience an episode lasting more than one hour, you should see your doctor straight away. You may need to have a visual field test, OCT or MRI to rule out something more serious. Reduced blood flow to the retina for a sustained period of time could lead to long-term vision impairment in rare cases.
For most people, however, there is nothing sinister about ocular migraine.