|Classification and external resources|
Retinal migraine (also known as ophthalmic migraine, visual 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 an abnormal condition in the brain (cortical spreading depression) that may cause similar symptoms such as scintillating scotoma affecting vision in both eyes, also associated with migraine headaches.
Retinal migraine is associated with transient monocular visual loss (scotoma) in one eye lasting less than one hour. 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. Unlike retinal migraine, such a scintillating aura affects vision from both eyes, and sufferers may see flashes of light; zigzagging patterns; blind spots; and shimmering spots or stars. In contrast, retinal migraine involves repeated bouts of temporary diminished vision or blindness in one eye.
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.
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.
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.[dead link] One study suggests that more than half of reported recurrent cases of retinal migraine subsequently experienced permanent visual loss in that eye from infarcts. An infarction in the retina, however, is usually apparent to the patient.