Causes Of Ocular Migraine
Ocular migraines are painless migraines that are characterized by visual disturbances. They are caused by the same triggers that cause all types of migraines. From stress and diet to genetics and hormones, culprits behind migraines are constantly being unraveled by research. Talk to your doctor to rule out any underlying condition and follow simple lifestyle changes to manage your condition.
An ocular or ophthalmic migraine is – hold your breath – a painless migraine! These are, however, associated with visual disturbances in both eyes. You may experience flickering or flashing lights, lines, stars, or blind spots that deter your vision. About 3–5 percent of migraine sufferers experience this kind of an aura, visual or otherwise. A painless migraine such as an ocular migraine is considered a migraine equivalent.1
What Does An Ocular Migraine Feel Like?
An ocular migraine begins with a sparkling and shimmering area that has a jagged border and that gradually spreads outward. It causes a small blinding spot that enlarges and blocks your vision temporarily. The brightness begins at the edge of your field of vision and gradually spreads to your line of vision. Zigzag lines or stars may also be seen. It is almost like looking through a broken window. Scotoma is the area where vision is disrupted and the whole episode is called a positive aura.
An ocular migraine is often referred to differently by different experts. While many call it a visual migraine or a typical aura without headache, the International Headache Society classifies such a migraine as a silent or acephalgic migraine.
Though it seems serious since you lose your vision partially, the condition is usually harmless and will resolve on its own within 20–30 minutes without any medical intervention. Complete visual darkness, or a negative aura, is not a symptom of an ocular migraine, but of some other underlying condition that needs to be investigated.2
Apart from visual disturbances, ocular migraines can also interfere with your speech. You may also feel tingling, weakness, or numbness in your hands and legs, experience size or space distortions, or feel confused. All of these, however, are rare.3
Causes Of Ocular Migraine
In spite of migraines being such a common phenomenon, the exact cause remains somewhat of a mystery. There are a few possible causes and several triggers that could result in a migraine, regardless of the type – with or without aura, with or without pain. There are no specific causes that can be related to just an ocular migraine. The reasons are the same, although a migraine manifests differently in different people.
Research today indicates that genetics is possibly one of the primary causes of migraines. Studies show that genetic mutations in the brain cause neurological abnormalities and that leads to migraines.4
2. Central Nervous System Disorder
Because of a disorder in the central nervous system, certain stimuli trigger a chain of biochemical and neurologic events. Some of these events affect the brain’s vascular or blood vessel system, resulting in a migraine.5
3. Cortical Spreading Depression
This is a complex event that affects the brain’s electrical impulses temporarily, impacting vascular and neural functions. From the 1940s, when it was first described, this phenomenon has been connected to the visual aura seen before or during a migraine.6
4. Chemical Imbalances
It is widely believed that magnesium deficiencies, serotonin imbalances (the neurotransmitter responsible for maintaining mood balance), and problems in the cell channels that transport electrical ions such as calcium cause migraines.7 Serotonin abnormality constricts or tightens blood vessels and thereby reduces blood supply to the brain. When oxygen supply is reduced to the brain, a migraine follows.
5. Hormonal Imbalances
Fluctuations in estrogen and progesterone seem to increase the risk and severity of migraines in many women. Hormonal changes during pregnancy, menstruation, menopause, and birth control medication can cause migraines.8 Even hormone additions through hormone replacement therapy (HRT) could trigger migraines. That is why ocular migraines are more common among women and they usually start later in life.9
6. Migraine Triggers
Brain chemistry can be impacted by a variety of events, leading to a migraine. These include:
- Emotional or physical stress
- Lack of sleep
- Skipping meals
- Weather changes
- Travel motion
- High altitudes
- Bright lights
- Certain odors
- Certain foods
Over 100 foods and beverages alone can be a migraine trigger. For example, take caffeine. Too much of it can lead to a migraine in some, while among people who are used to caffeine, lack of it can also trigger migraines. Chocolate, alcohol, artificial sweeteners like aspartame, Mono Sodium Glutamate (MSG, the infamous food additive), tyramine in aged cheese, smoked fish, sausages, soy products, and nitrites that are usually found in cured meats, hot dogs, and processed foods are some of the culprits that are attributed to migraines
Gender: Almost 75 percent of migraineurs are women. Boys and girls are equally affected at childhood, but after puberty, migraines are more common among girls because of the many hormonal changes.
Age: Although migraines generally affect people between ages 15–55, children are also known to suffer. Most children stop having migraines after reaching adulthood but those with a family history are likely to continue suffering.
Health Conditions: Some migraineurs have certain health conditions that don’t cause the migraines but are associated with them. Many migraine patients are known to have a history of high blood pressure, stroke, depression, anxiety, epilepsy, or irritable bowel syndrome.10
What Else You Should Know About Ocular Migraines
An ocular migraine is short-lived and may not be painful, but it can be debilitating – you have to be careful while doing daily activities like driving, reading, or writing. The chance of permanent vision loss due to an ocular migraine is rare but the reduced blood flow for a prolonged time can damage your retina. So it is a good idea to make an appointment with your ophthalmologist to check your condition.
Since hormones play such a big role in causing migraines, declining estrogen levels as women age and enter menopause is a reason why migraines usually reduce in severity in older women.11
Managing Your Migraine
A few lifestyle changes are the first step toward controlling your migraines naturally. If you are aware of the factors that trigger your migraine, you can take steps to avoid those triggers as far as possible.
- Maintain a diary and identify common triggers
- Eat regularly to avoid low blood sugar
- Avoid alcohol and quit smoking
- Get enough sleep
- Check if your birth control pills are a trigger and discuss other options with your OB/GYN. If you are undergoing hormone replacement therapy, talk to your doctor about changing the dosage or making other adjustments
- Reduce stress with deep breathing, meditation, and exercise.12
References [ + ]
|1.||↑||Bernstein, Carolyn; McArdle, Elaine. The Migraine Brain: Your Breakthrough Guide to Fewer Headaches, Better Health. Simon and Schuster, 2009.|
|2.||↑||Visual Migraine. Brigham and Women’s Hospital.|
|3, 5, 7, 10, 11, 12.||↑||Migraine headaches. University of Maryland Medical Center (UMMC).|
|4.||↑||Migraine Information Page. National Institute of Neurological Disorders and Stroke.|
|6.||↑||Charles, Andrew C., and Serapio M. Baca. “Cortical spreading depression and migraine.” Nature Reviews Neurology 9, no. 11 (2013): 637-644.|
|8.||↑||Stewart, W. F., C. Wood, M. L. Reed, J. Roy, and Richard B. Lipton. “Cumulative lifetime migraine incidence in women and men.” Cephalalgia 28, no. 11 (2008): 1170-1178.|
|9.||↑||Kitchen, Clyde K. Fact and Fiction of Healthy Vision: Eye Care for Adults and Children. Greenwood Publishing Group, 2007.|