- One eye: First, the eye symptoms tend to be monocular, meaning they’re only in one eye.
- Visual disturbances: So what’s going on in this one eye? There are a variety of disturbances which other migraine sufferers may be familiar with. This might include flashing lights, or patterns in your visual field. There may be an area where your vision is impaired (ie dark spots), or even loss. Even blindness in one eye is possible with retinal migraine.
- Temporary: Permanent vision loss is another matter. With retinal migraine the symptoms are reversible.
- Headache: A headache typically starts during the visual disturbances, or within an hour after they stop. The headache typically lasts between 4 hours and 3 days, is often one-sided and pulsating, and usually either includes sensitivity to light and/or sound, nausea, or both. There is an increasing body of evidence showing cases of retinal migraine without headache as well. There is an argument that the "headache" not be necessary for a diagnosis of retinal migraine, but usually it’s still included.
- Repeated: In order to actually be diagnosed with retinal migraine, you need to have had at least 2 attacks.
Now that you’ve got the 5 signs, it’s time for the warning. It’s very important that other causes have been ruled out. It’s easy to get a misdiagnoses here, so some things are very important:
- It’s helpful to see your doctor during an attack, so she can ask the appropriate questions to diagnose you.
- You need to have a normal eye exam in between attacks. Remember, this is temporary. There are a number of things that can cause similar visual disturbances, such as brain damage, tumours, ischemic optic neuropathy (damage to the optic nerve) and other optic disorders. Even if the symptoms are coming and going, it’s very important to rule out other causes.
- Make sure your doctor has your medical history, and family medical history as much as possible. This will help her narrow down the possibilities to the most likely.
- If your symptoms don’t quite fit the above criteria, you may have another type of migraine. Migraine aura without headache is a typical suspect if you have no headache, especially if you’re having symptoms in both eyes. Migraine with aura is another possibility if you have the headache but your visual symptoms are more varied. If you’re not sure about what your doctor is telling you, get a second opinion.
Researchers suspect decreased blood flow to the eye or optic nerve may be to blame for the unique symptoms of retinal migraine. However, like other types of migraine, the overall cause is still a mystery.
The good news is that retinal migraine often decreases or disappears with typical migraine treatment. Be sure to see a specialist and discuss your options.