Understanding Retinal Migraine
You’re probably familiar with the term migraine. It’s a well-known although often confused word that refers to a number of conditions. In fact, migraine is the third most common disease in the world, behind dental caries and tension-type headache¹. And it’s more prevalent than diabetes, epilepsy and asthma combined².
Headache, eyestrain or migraine?
Many people think of migraine as a bad headache. However, headaches and migraines are completely different conditions. And, although some people do experience a headache as part of a migraine, with some types of migraine, a headache can be mild or not present at all.
Eye strain can also sometimes cause headaches. This can happen when your eyes are not aligned properly as a result of short-sightedness, long-sightedness or astigmatism and so become strained when you try and focus over a long period of time.
If you experience eye strain, with or without a headache, you should visit your optician. They will be able to prescribe you with lenses and help correct the alignment of your eyes.
Eye strain is generally not considered to be a major cause of migraine. However, some types of migraine can affect your vision.
Types of Migraine
There are two main types of migraine:
- Migraine without aura, often referred to as a common migraine
- Migraine with aura, often referred to as a classic migraine or visual migraine
Sensory perception can be affected in both although the effects are more severe in migraine with aura.
Neither of these types of migraine should be confused with retinal migraine, which is a separate condition.
Migraine without aura
About 80% of all migraines are common migraines, or migraine without aura³. The main symptom of this type of migraine is a pulsing and throbbing pain usually on one side of the head. This is different from, for example, tension headaches, where pain is felt all around the head.
Unlike non-migraine headaches, the pain with common migraines can be made worse by movement. They can also be accompanied by nausea and/or vomiting. In addition, there is often heightened sensitivity to light (photophobia) and to sound (phonophobia).
Migraine with aura
Aura is a sensory phenomenon that may occur before or during a migraine. It’s caused by unusual activity in the brain and can be:
- Visual e.g. flashing lights, geometric patterns
- Auditory e.g. hearing buzzing or other sounds not present in the actual environment
- Olfactory e.g. smelling odours that aren’t there
- Tactile e.g. numbness or a tingling sensation
A migraine aura can be followed by a mild headache or no headache at all. This is known as a silent or acephalgic migraine.
Migraines where vision is significantly affected during an aura are sometimes referred to as ocular migraines. Again, these should not be confused with retinal migraines.
Retinal Migraine
Unlike the visual disturbances experienced in migraine auras and ocular migraines, which are caused by unusual activity in the brain, retinal migraine is when the blood vessels to the eye suddenly narrow and so reduce blood flow to the eye.
This narrowing can be seen using an instrument called an ophthalmoscope, but only during an attack. It is therefore more likely that the condition would be diagnosed based on an account of your symptoms.
The main symptoms of retinal migraine are:
- Partial or total loss of vision in one eye only. This usually lasts for 10-20 minutes (and very rarely longer than an hour) before vision returns to normal.
- Headache, which may happen before, during or after the vision attack
Retinal migraine can be triggered by:
- Stress
- Smoking
- High blood pressure
- Hormonal birth control pills
- Exercise
- Bending over
- High altitude
- Dehydration
- Low blood sugar
- Excessive heat
Retinal migraine is a rare condition. While some people get retinal migraine every few months, the frequency can vary.
It is really important to see an optometrist or medical doctor if you experience any loss of vision. There are many other causes of vision loss that need to be ruled out before a firm diagnosis can be made.
If you are diagnosed with retinal migraine there are treatment options which may be able to help you. These include aspirin, beta-blockers, calcium channel blockers, tricyclic antidepressants and anti-epileptics.
However, there is currently a lack of research about the best way to treat or prevent retinal migraines.
You can find out more information about migraines at the Migraine Trust, just click here.
REFERENCES
- Steiner TJ et al. Migraine: the seventh disabler. The Journal of Headache and Pain 2013, 14:1.
- Headache Disorders – not respected, not resourced. All-Party Parliamentary Group on Primary Headache Disorders. 2010.
- Gilmore, B; Michael, M (2011-02-01). “Treatment of acute migraine headache”. American Family Physician. 83 (3): 271–80.