Eye pain resulting from dry eye or postoperative complications may be conflated with migraine pain because all three travel along the same pain-processing pathways, according to new research published in the June issue of the Journal of Neuro-Ophthalmology.

According to the Utah-based investigator, “the proposed mechanisms of migraine, with its connection to the dura and autonomic elements, exactly parallels the innervation of the eye and orbital contents.” The study explains that “the caudal nucleus of the trigeminal nerve (V) is an important relay station to the thalamus and then into the sensory system of the brain. The first division of the trigeminal nerve has rich arborizing branches to the eye and orbit. In fact, the cornea has the highest density of trigeminal nerve endings anywhere in the body.”

The report re-evaluates previously published research into dry eye-related pain, such as a study that shows 46% of Sjögren’s-related dry eye sufferers report experiencing migraines and several other studies that show ocular symptoms of dry eye increases during a migraine. Additionally, migraine suffers have frequently reported visual symptoms such as aura, excessive floaters, palinopsia, photophobia, nyctalopia and others, even when they’re not having a migraine, the new research shows.

The publication offers four case reports to demonstrate the phenomenon. “We do not know if treatment of dry eye symptoms will improve migraine or not—but at least this is another level of understanding that we can add in taking care of our migraine patients, especially those with chronic migraine,” the author writes.