What You Should Know About Ocular Migraine
[dropcap1]W[/dropcap1]hen most people hear the word “migraine,” they think of the throbbing, insistent pain that’s characteristic of most migraine events. But did you know a relatively small portion of migraine sufferers – about one out of every 200 – will experience visual symptoms without headache?
This type of visual symptom is most commonly referred to as an ocular migraine and it causes vision loss that lasts less than an hour and typically affects only one eye. It has also been called optical migraine, visual migraine, retinal migraine, ophthalmic migraine, or visual aura; however, the correct name and classification according to the International Headache Society is migraine aura without headache.
Regardless of the name, at Axon Optics we receive numerous emails about about ocular migraines. Neuro-ophthalmologist and Axon Optics founder Dr. Bradley Katz frequently sees patients who say they experience ocular migraines. The following guide is meant to help those suffering from this relatively uncommon condition.
Migraine Aura Without Headache: The Symptoms
Migraine with aura refers to visual symptoms that occur before a headache and other migraine symptoms develop, sometimes up to several hours before onset of a migraine. Aura occurs in about 20 percent of all migraine sufferers, and most of those people go on to develop the throbbing, deep headache most of us associate with the migraine experience.
In individuals who experience ocular migraines, or migraine aura without headache, the visual symptoms still occur, but they are not followed or accompanied by headache. Visual symptoms of an ocular migraine can include the appearance of twinkling or shimmering lights, starbursts or zigzagging lines in your visual field; areas in the visual field where vision is reduced or completely absent (blind spots); tunnel vision; and even complete temporary blindness.
Some patients may also experience additional symptoms of migraine, including nausea, fatigue, confusion and irritability, while others may experience only the visual symptoms.
As you can imagine, when an ocular or ophthalmic migraine occurs, the visual symptoms can be quite worrisome for those who don’t realize the symptoms’ association with migraine. And because ocular migraines don’t receive nearly as much attention in the literature as migraines with painful headaches, many people who experience a visual migraine mistakenly attribute their symptoms to a problem with their vision or even with serious medical events like stroke.
What Causes Migraines?
Not that long ago, researchers believed migraines were related to problems with blood flow in the brain. But more recent advances have led to a much more comprehensive understanding of migraines and the underlying processes that cause them to occur. Now, medical researchers and doctors believe migraines are caused by an interaction between the nerves and the blood vessels in the brain, classifying them as neurovascular events that occur when nerve activity causes changes in the circulation in the brain.
Whether they cause headache or not, migraines are usually triggered, or precipitated, by specific stimuli, including illness, stress, food sensitivities or allergies, sleep problems, exposure to bright lights or loud noises, or consuming caffeine or alcohol.
What Causes Visual Aura?
Most migraines occur in different “phases,” with the aura phase occurring prior to the development of a headache (when headaches occur), nausea and other symptoms. Researchers believe auras develop when the nerves in the brain are first hyper-stimulated and then enter a depressed state of low activity called “cortical spreading depression,” which spreads throughout the top layer (cortex) of the brain. As this wave of activity spreads, it travels through different parts of the brain, including the part responsible for vision. It’s this wave of altered neural activity that researchers believe is responsible for the visual symptoms present during the aura phase, as well as symptoms affecting hearing that may also be present during the aura phase.
Why Do Some People Have Ocular Migraines With No Headache?
The reason why some migraine sufferers may experience visual symptoms without any associated headache either following or before a visual symptom is unknown. What researchers do know is that light plays a role in most migraine events, and that this role can be played out even in patients who are blind. That suggests additional nerve pathways play a role in migraine symptoms, pathways that are not associated with vision. It also underscores the need for further research into migraines to examine the differences that exist between migraine sufferers, including why some patients have a migraine aura without a headache.
The good news is, today’s research has begun focusing on migraine pain and aura as two disparate events, leading to more studies focusing on migraine aura without headache (ocular migraine) to improve physicians’ and patients’ understanding of these events.
No matter what the underlying cause of these relatively unusual “silent” migraines, the symptoms of ocular migraines still can cause an interruption in daily activities as well as concern and stress for the people who suffer from them. Even though there may be no associated pain, migraine aura without headache still requires optimal treatment to reduce the occurrence of the events as well as to reduce the severity or duration of events that do occur.
Finding Ocular Migraine Relief
Historically, getting appropriate and effective treatment for ocular migraines has not been an easy task, due in part to some issues that arise in diagnosing the condition. Just as most patients associate migraines with headache, many healthcare practitioners also have a low level of awareness of the symptoms of migraine aura without headache. In the absence of headache symptoms, some healthcare practitioners seek other possible causes, including ocular problems and even chronic stress, resulting in delayed care for many sufferers. Even when a correct diagnosis is made early on, treatment options have been limited.
There are several medications on the market that have been developed to aid in the treatment of migraine symptoms, as well as to potentially prevent migraines from occurring or reduce the severity of migraines when they do occur. However, finding the right combination of medications has proven problematic, and for some people, medications have proven to be ineffective, and long-term use may cause side effects.
More recently, studies have focused on the effects of light as a migraine trigger, using special lenses to mitigate the light that enters the eye, filtering out the wavelengths that have been identified with an increase in migraine symptoms and activity. Studies dating back to the mid-1980s have demonstrated that lenses with a type of tinting have proven very effective in reducing the occurrence of migraines and limiting the symptoms and duration of migraines when they occur.
Axon Optics is a leading provider of these lenses thanks in part to the rigorous quality control standards it implements. If you have migraine aura with or without headache, Axon Optics’ migraine glasses could be just what the doctor ordered for helping you reduce your symptoms. To learn more about Axon Optics, explore our website, visit us on Facebook or ask your eye doctor if Axon Optics’ therapeutic lenses are right for you. You can also view our selection of lenses at our online webstore.