Migraine without pain: more than meets the eye

Most migraine sufferers just want the aching to go away, but Baylor College of Medicine ophthalmologists state even "painless" migraines can still pack a punch.

An estimated 20 percent of migraine sufferers experience migraine without a headache. However, they have other problems including visual disturbances driving many of them to seek the help of an ophthalmologist.

"People are usually surprised they can be diagnosed with migraines without ever having a headache," said Dr. Rod Foroozan, assistant professor of ophthalmology at BCM. "Most people are used to understanding a migraine to mean pain."

Some common symptoms of migraine without headache that affect sight are transient loss of vision, blind spots, flashing light or shadowy spots and double vision.

"It's not uncommon for me to see one or two people a week with visual problems related to migraines," Foroozan said. "If it's strictly a migraine issue rather than an eye problem, we'll refer them to a neurologist."

Migraines without headaches are not directly related to the eyes. Instead, the migraine activity occurs in the visual cortex of the brain located in the back of the skull.

Many factors can contribute to migraine, some serious and some less so. For example, in some rare cases, a prolonged migraine, with or without headache, can cause a stroke. Foroozan said it is important to identify the actual problem.

One way doctors rule out sight problems is by giving a visual field test. It is a computer-based test that displays lights in different parts of the field of vision while the eye is focused on a target. When the patient sees a flash of light, he or she hits the buzzer. This lets the doctor know what areas of the eye detect the light.

Foroozan said once the correct diagnosis is given, the proper treatment can be determined to help prevent or minimize migraine side effects.