Possible Link Found Between Migraine, Dry Eye Disease

Patients with migraine headaches may have a risk of also having dry eye disease (DED), according to a study published Thursday.

Researchers used a database of deidentified patient data from visits to University of North Carolina—affiliated healthcare facilities from May 1, 2008, through May 31, 2018. The retrospective case-control study included 72,969 patients.

After accounting for confounders, the odds of having DED with a diagnosis of migraine headaches was at least 20% higher than that of individuals without a diagnosis of migraine headaches. The researchers cautioned that the association may not reflect cause and effect for unidentified confounders.

The group included 41,764 men (57.2%) and 31,205 women (42.8%). Of these, 5352 patients (7.3%) carried a diagnosis of migraine headache, and 9638 (13.2%) carried a diagnosis of DED. The odds of having DED given a diagnosis of migraine headaches was 1.72 (95% CI, 1.60-1.85) times higher than that of patients without migraine headaches. After accounting for multiple confounding factors, the odds of having DED given a diagnosis of migraine headaches was 1.42 (95% CI, 1.20-1.68) times higher than that of patients without migraine headaches.

In addition, advancing age and female sex may both play a role in determining the strength of the association between migraine headaches and DED. Before accounting for confounding factors, a statistically significant association was observed across women in all age groups, which may not be surprising, given that migraine headaches are significantly more common in women.

After accounting for confounding factors, results for men (odds ratio [OR] 1.96; 95%CI, 1.02-3.77) and women (OR, 2.47; 95% CI, 1.75-3.47) 65 years or older suggest a link between the 2 disorders. Below age 65, only men in the 55-64 age range showed a link between the 2 disorders.

DED is a disorder affecting a significant proportion of the general population, with estimate prevalence rates ranging from 7.4% to 33.7%, and previous studies have also suggested there may be a link between DED and migraine. The authors said this the other studies weren’t population-based, and the sample sizes were small.

The researchers said the mechanisms between migraine headaches and DED are not exactly known, but inflammatory processes play a role in both. Migraine headaches can be associated with increases in the levels of inflammatory markers and cytokines, such as C-reactive protein and interleukin 10. Neurogenic inflammatory mediators are thought to trigger the leakage of plasma and increase the hypersensitivity of neurons constituting the trigeminal ganglion, which plays a role in the development and progression of migraines.

Similar to migraine headaches, T-lymphocyte—mediated inflammation is one of the major mechanisms underlying DED. Inflammatory changes in DED might trigger similar events in neurovascular tissue, leading to the development and propagation of migraine headaches, or vice versa. Furthermore, excessive dryness can trigger reflex tearing via the trigeminal nerve, which could subsequently trigger auras and acute migraine attacks.

The study had several limitations characteristic of retrospective studies, such as an inability to check whether these were chance occurrences of the 2 disorders, and the fact that the study population came from just 1 healthcare system, which may affect generalizability.

Reference

Ismail OM, Poole ZB, BS; Bierly SL, et al. Association between dry eye disease and migraine headaches in a large population-based study [published online March 7, 2019]. JAMA Ophthalmol. doi:10.1001/jamaophthalmol.2019.0170.