(LifeWire) - Imagine going about your normal daily activities when, suddenly, your vision seems to go haywire. Perhaps it is blurred or obscured by bright flashes of light and color. Or maybe, more frighteningly, a blind spot develops in one eye, causing you to lose all sight in that eye. These kinds of visual changes can signal a migraine episode called "retinal migraine."
Sometimes described as an ocular or eye migraine, retinal migraines usually last for approximately an hour and are followed by the complete return of normal vision. This type of migraine can occur with or without a headache, and may be experienced only once in a lifetime or at regular intervals. What distinguishes retinal migraines from classic migraines is the involvement of only one eye and the potential for temporary blindness in that eye.
Although individuals of any age can experience a retinal migraine, sufferers are most likely to be women in their 20s or 30s. In fact, within this age group, women are approximately three times more likely than men to experience migraines. Experts believe hormonal changes related to the menstrual cycle account for this difference.
Classic migraines may include an aura phase involving a variety of visual changes, which affect both eyes simultaneously. In contrast, retinal migraines involve visual changes that can cause visual blind spots or complete blindness in only one eye. During some episodes of retinal migraine, the visual changes occur alone; other times, these visual alterations lead to the throbbing, pulsing pain of a migraine headache, often accompanied by severe light sensitivity, nausea and vomiting. The retinal migraine headache usually begins within an hour of the onset of visual symptoms and develops on the side of the head where the visual changes occur.
Usually, the visual disturbances associated with a retinal migraine remain for only a few minutes, but may last as long as an hour. Generally, these visual changes are followed by the return of totally normal vision. One of the most frightening retinal migraine symptoms occurs when the loss of vision is prolonged, lasting days or months, or even permanently. Luckily, this is an extremely rare event.
Retinal migraines may occur frequently (monthly, daily), or may occur only once.
Diagnosis and Treatment
Individuals who experience these symptoms, but have never been diagnosed with a retinal migraine, should have a thorough medical exam to rule out any underlying causes, such as a blood clot or stroke. Some symptoms, such as the flashes of light, could also signal a detached retina, which requires immediate medical attention. Though there is no specific test to verify that an individual is experiencing a retinal migraine, the International Headache Society has developed the following guidelines to aid in diagnosis:
A. At least two migraine episodes that fulfill criteria B and C
B. Completely reversible visual changes (as described above) affecting only one eye during a given episode
C. Headache begins within an hour of the onset of visual changes, lasts for 4 to 72 hours, and is characterized by at least two of the following:
- One-sided head pain
- Throbbing in quality
- Moderate to severe head pain
- Routine physical activity (such as walking or climbing stairs) exacerbates headache symptoms
- Severity prevents routine physical activity
D. During headache, at least one of the following occurs:
- Nausea, with or without vomiting
- Severe sensitivity to light and/or sound
E. Normal eye exam between episodes
F. No other disease or condition responsible for visual symptoms or headache
Treatment of retinal migraines begins with the identification of any triggers that may induce the onset of an episode. These triggers are similar to the ones that can instigate other types of migraines, and may include stress, sleep deprivation, skipped meals, specific foods, or particular activities. By avoiding these triggers, individuals may be able to limit migraine frequency or completely prevent the migraine.
While some migraine headaches are treated with a class of medicines called "triptans," which can cause blood vessel constriction, their use is often avoided in retinal migraine treatment. Medications that may be used to treat retinal migraines include nonsteroidal anti-inflammatory medications (aspirin or ibuprofen) and high blood pressure medicines (verapamil or diltiazem).
Sources:Cutrer, Michael F., and Michael A. Moskowitz. "Headaches and Other Head Pain." Cecil Textbook of Internal Medicine. 23rd ed. 2008.
Freedom, Thomas, WM Jay. "Migrain With and Without Headache." Seminars in Opthalmology. 18.4.DEC 2003 210-217. 20 Mar. 2008 <http://www.ncbi.nlm.nih.gov/pubmed/15513008?ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum>.
Headache Classification Subcommittee of the International Headache Society, "The International Classification of Headache Disorders." Cephalalgia. 2003. International Headache Society. 20 Mar. 2008 <http://18.104.22.168/ihscommon/guidelines/pdfs/ihc_II_main_no_print.pdf>.
Lim, Chun. "Headache, Migraine." Ferri's Clinical Advisor. First ed. 2008.
McConaghy, John R.. "Headache in Primary Care." Primary Care: Clinics in Office Practice. 34.1. Mar. 2007 83-97. 20 Mar. 2008 <http://www.primarycare.theclinics.com/article/S0095-4543(06)00070-4/fulltext> (subscription)
Pryse-Phillips, William and T. Jock Murray. "Headache." Textbook of Primary Care Medicine. Third ed. 2001.
Silberstein, Stephen D. and William B. Young. "Headache and Facial Pain." Textbook of Clinical Neurology. Third ed. 2007.