Migraine is the sixth most prevalent disease worldwide. In fact, according to data compiled by the Spanish Society of Neurology (SEN), migraine affects approximately 13% of the Spanish population, which means that more than 5 million people suffer from it in our country. However, there is another key negative fact to bear in mind: “75% of migraine patients take more than two years to get diagnosed”, which obviously increases the risk of the underlying cause of the migraine evolving and leading to more significant symptoms. This cause is sometimes directly or indirectly related to vision problems.
Types of migraines that affect vision
Not all migraine variants affect vision. Indeed, a recurring distinction is between migraine without aura, where there are usually no visual symptoms beyond some sensitivity to light, and migraine with aura, where flashes of light, zigzag lines and blind spots occur prior to the onset of the characteristic headache. Other types of migraines that affect vision are ocular migraine, which can involve severe visual symptoms, or basilar migraine, which involves a series of neurological symptoms at the base of the brain that include visual symptoms. We do not usually see these in vestibular or hemiplegic migraine.
Eye diseases that may promote the onset of migraine
Existen patologías oculares que pueden provocar o agravar un episodio de migraña. Un ejemplo que solemos encontrarnos los especialistas son los defectos de estrabismo, especialmente en personas que tienen dificultad para hacer movimientos de convergencia o que tienen tendencia a tener un ojo hacia fuera. Además, algunos defectos refractivos como son el astigmatismo o la diferencia de graduación entre un ojo y otro puede dar lugar a dolores de cabeza que en oftalmología conocemos como cefaleas refractivas que, a su vez, pueden desencadenar o incrementar la intensidad de la migraña ocular
Some eye diseases can cause or worsen a migraine episode. One example we specialists often encounter are strabismus defects, especially in people who have difficulties with convergence movements or who tend to have one eye turned outwards. Furthermore, some refractive errors, such as astigmatism, or prescription differences between one eye and the other can give rise to headaches known in ophthalmology as refractive headaches, which, in turn, can trigger or increase the intensity of ocular migraine.
Visual symptoms of migraine
The most typical ones are seeing bright lights, a kind of saw-like light that grows towards the periphery of the field of vision and tends to last 15 to 30 minutes. Other less common types of auras are scintillating scotomas, which involve problems seeing what is in the centre of the visual field, as well as visual snow, which is like seeing the dots of a scrambled TV channel. There is also palinopsia, the persistence of an image, even if it disappears from the visual field, and the Alice in Wonderland syndrome, where objects are seen smaller or larger than they should be.
Main keys to differentiate between headaches and migraines
The main difference between common headaches and ocular migraines and, in general, any type of migraine is the affected area: a migraine is usually a headache in one half of the head, not the whole of it, which helps us to differentiate them easily. Moreover, a migraine manifests itself through throbbing, whereas the classic headache tends to be more constantly present. Finally, migraine is often associated with photophobia, phonophobia and osmophobia, which means that the sufferer cannot stand light, noise or smells. This is why they tend to lock themselves in a dark and silent room.
When is it necessary to see a specialist if you think you may suffer from migraines?
Anyone who has never had migraines and suddenly experiences an episode should be examined to see whether or not there is any other risk or alarm factor. Furthermore, this examination allows us to identify the causes behind the episode and thus try to find the most appropriate treatment. In the event, for example, of an ophthalmological cause due to a refractive error or another type of eye problem, we can implement correction mechanisms. Likewise, any migraine lasting less than five minutes or more than an hour should prompt a visit to a specialist.
Influence of genetics on the onset of migraine
As with many other diseases, family history has a significant influence on the risk of suffering from migraine, with an approximate rate of 70%. However, lifestyle habits also play a very important role both in the onset or not of this condition and in the intensity with which it occurs.
Negative habits for our eyesight can cause migraines
There are many negative vision habits that can cause or intensify a retinal migraine: poor sleep hygiene, excessive caffeine consumption, very intense stress, alcohol consumption in certain people, near vision efforts without optimal breaks or performing tasks in contexts where there is a large difference in light intensity between the screen and ambient light. Other relatively common risk factors are beyond the control of patients, such as menstruation or vascular problems.
Migraine as a risk factor
The extent of the relationship between certain vascular conditions and migraine is such that the presence of migraine indicates an increased risk of glaucoma, a disease caused by intraocular pressure damage to the optic nerve. Migraine is also a risk factor for ocular ischaemic conditions. This is why I would again stress the importance of seeing a specialist to analyse each individual case, specifically a neuro-ophthalmologist, who is able to analyse all the possible triggers of migraine. A simple visit to the doctor can make a big difference.