Retinal migraine

Retinal migraine (also known as ophthalmic migraine, and ocular migraine) is a retinal disease often accompanied by migraine headache and typically affects only one eye. It is caused by an infarct or vascular spasm in or behind the affected eye.

The terms "retinal migraine" and "ocular migraine" are often confused with "visual migraine," which is a far-more-common symptom of vision loss, resulting from the aura phase of the common migraine. The aura phase of migraine can occur with or without a headache. Ocular or retinal migraines happen in the eye, so only affect the vision in that eye, while visual migraines occur in the brain, so affect the vision in both eyes together. Visual migraines result from cortical spreading depression and are also commonly termed scintillating scotoma.

Symptoms

Retinal migraine is associated with transient monocular visual loss (scotoma) in one eye lasting less than one hour.^[1] During some episodes, the visual loss may occur with no headache and at other times throbbing headache on the same side of the head as the visual loss may occur, accompanied by severe light sensitivity and/or nausea. Visual loss tends to affect the entire monocular visual field of one eye, not both eyes. After each episode, normal vision returns.

It may be difficult to read and dangerous to drive a vehicle while retinal migraine symptoms are present.

Retinal migraine is a different disease than scintillating scotoma, which is a visual anomaly caused by spreading depression in the occipital cortex at the back of the brain, not in the eyes nor any component thereof.^[2] Unlike in retinal migraine, a scintillating scotoma involves repeated bouts of temporary diminished vision or blindness and affects vision from both eyes, upon which sufferers may see flashes of light, zigzagging patterns, blind spots, or shimmering spots or stars.^[3]

Diagnosis

The medical exam should rule out any underlying causes, such as blood clot, stroke, pituitary tumor, or detached retina. A normal retina exam is consistent with retinal migraine.^[4]

Treatment

Treatment depends on identifying behavior that triggers migraine such as stress, sleep deprivation, skipped meals, food sensitivities, or specific activities. Medicines used to treat retinal migraines include aspirin, other NSAIDS, and medicines that reduce high blood pressure.^[4]

Prognosis

In general, the prognosis for retinal migraine is similar to that of migraine headache with typical aura. As the true incidence of retinal migraine is unknown, it is uncertain whether there is a higher incidence of permanent neuroretinal injury. The visual field data suggests that there is a higher incidence of end arteriolar distribution infarction and a higher incidence of permanent visual field defects in retinal migraine than in clinically manifest cerebral infarctions in migraine with aura. One study suggests that more than half of reported recurrent cases of retinal migraine subsequently experienced permanent visual loss in that eye from infarcts,^[1] but more recent studies suggest such loss is a relatively rare side effect.^[5]

See also

• Entoptic phenomenon

References