"Regular dry eye screening in patients with migraine might help in reducing the burden of disability from the two conditions."

Treating dry eye disease with ocular lubricants significantly reduced migraine severity in patients with both conditions, according to the findings of a randomized crossover trial. This supports the shared pathophysiological mechanisms between dry eye and migraine and suggests that ocular lubrication could be a noninvasive adjunct treatment.

Conducted at the Prince of Wales Hospital in Sydney, Australia, the trial included 24 adults who were diagnosed with both migraine (episodic or chronic) and dry eye disease (DED). Participants were randomly assigned to use either Systane Hydration UD (preservative-free) or saline eye drops four times daily for 4 weeks, followed by a 2-week washout period and crossover to the alternate treatment. Outcome measures included:

• Migraine severity, measured by Headache Impact Test-6 (HIT-6) and Migraine Disability Assessment (MIDAS)

• Dry eye symptoms, measured by Ocular Surface Disease Index (OSDI) and Dry Eye Questionnaire-5 (DEQ-5)

• Clinical signs, such as tear osmolarity, tear breakup time, and corneal staining

• Tear calcitonin gene–related peptide (CGRP) levels

Participants who received Systane had a mean HIT-6 score reduction of −3 and participants who received saline had a mean HIT-6 score reduction of −3.9. Downward trends were noted in MIDAS score, but changes were not statistically significant. The researchers suggested that this finding may be due to the 3-month timeframe of the MIDAS assessment, which is longer than the study’s duration.

Regarding DED symptoms, patients on Systane showed a decrease of 8.3 points on OSDI and a decrease of 2.1 on the DEQ-5. Participants on saline had a decrease of 6.4 points on OSDI and 1.5 on DEQ-5. Grade of corneal staining for Systane was −2.2 and −1.5 for saline.

“A longer period of observation may be needed to identify any discriminatory effect between the two treatments, as it could take up to 4 months for ocular signs to improve,” Nur Amalina Md Isa, MOptom, of the School of Optometry and Vision Science at University of New South Wales, in Sydney, noted with colleagues. There was no significant change following either treatment for CGRP levels in tears, and no significant improvement in tear osmolarity or tear breakup time during the treatment period.

The researchers proposed that both dry eye and migraine involve activation of the trigeminovascular system, particularly via the ophthalmic (V1) division of the trigeminal nerve. Ocular surface inflammation in DED may increase peripheral nociceptive input and potentially exacerbate migraine symptoms. Lubricants may interrupt this feedback loop by stabilizing the tear film and reducing corneal nerve irritation.

The sample primarily included patients with severe migraine-related disability, which may have limited generalizability. A larger sample and longer treatment period may be needed to detect differences between lubricant types. Larger sample size would also help in exploring CGRP levels further, the researchers described.

“We hypothesized that, because [CGRP] levels are elevated in the tears of patients with migraine, lower [CGRP] levels resulting from ocular treatment may be associated with reduced migraine disability,” they wrote. Because no significant alterations were found, larger studies could “detect meaningful changes, as [CGRP] levels display considerable variability.”

"Regular dry eye screening in patients with migraine might help in reducing the burden of disability from the two conditions," the authors concluded. "Where dry eye disease and migraine coexist, the severity of both conditions may be reduced by the use of readily available ocular lubricants as a possible treatment option in some patients."

No conflicts of interest were reported

Source: Optometry and Vision Science