In May, we wrote about a study of migraine and changes in the cornea. In the same study, researchers also found a connection between migraine and dry eye.
As we explained then, researchers believe the trigeminovascular network (also known as the trigeminal system) plays a critical role in migraine. This network includes nerve fibers that carry messages. In people with migraine, abnormality in these nerve fibers might contribute to eye pain. Activation of nerve fibers in the cornea are also thought to cause symptoms of dry eye.
For anyone with migraine, changes in the cornea could trigger migraine attacks or create more migraine symptoms. This is especially true in patients with dry eye, which itself could trip the trigeminal network. Another possibility is that abnormalities in the corneas of people who have chronic migraine could lead to a feeling of dry eyes.
Because the trigeminal system helps keeps tear ducts working properly, participants were also checked for symptoms of dry eye syndrome. In one test, all 19 of the participants with migraine scored in the range that would normally mean a diagnosis of dry eye. However, the tears of these participants were normal, which contradicts a dry eye diagnosis. Their findings, according to researchers, indicates that people with chronic migraine could have dry eye symptoms (though not necessarily dry eye syndrome) at a rate more than three times the general population. They also say it is impossible to tell if the dry eye symptoms are a result of abnormal functioning of the trigeminal nerve. It is unknown whether treating symptoms of dry eye could also improve migraine symptoms.
What does this study mean for people with migraine? This is early research, so it’s mostly just information for now. However, if you have migraine (chronic or not) and symptoms of dry eye, it’s worth bringing up the topic with your eye doctor. Dry eye treatment is often simple and noninvasive. Also, dry eye is another one of the many conditions that can cause photophobia. There’s a chance that relieving dry eye symptoms could help reduce your photophobia.
Kinard, K. I., Smith, A. G., Singleton, J. R., Lessard, M. K., Katz, B. J., Warner, J. E., Crum, A. V., Mifflin, M. D., Brennan, K. C. & Digre, K. B. (2015). Chronic Migraine Is Associated With Reduced Corneal Nerve Fiber Density and Symptoms of Dry Eye. Headache: The Journal of Head and Face Pain.