Exploring laughter as a treatment for dry eye disease

New research published in BMJ has explored whether regular laughter exercise sessions could help to ease ocular surface discomfort in patients with dry eye disease.

The trial involved 299 participants recruited through the Zhongshan Ophthalmic Center of Sun Yat-sen University in China.

All study participants were between the ages of 18 and 45, with symptomatic dry eye disease. They had ocular surface disease index scores ranging from 18 to 80 and a tear film break-up time of eight seconds or less.

The participants were randomly assigned into two groups: one group instilled artificial tears four times daily for eight weeks, while the other group completed laughter exercise sessions four times daily over the same period.

The laughter exercise sessions lasted for five minutes and required participants to repeatedly vocalise certain phrases associated with laughter. This group watched an instructional video at the outset of the intervention.

At the end of the eight-week period, the researchers concluded that the laughter exercise sessions performed no worse than regularly applying artificial tears when it comes to improving dry eye disease symptoms and clinical signs.

“As a safe, environmentally friendly, and low-cost intervention, laughter exercise could serve as a first-line, home based treatment for people with symptomatic dry eye disease and limited corneal staining,” the authors highlighted.

Reflecting on possible mechanisms that might explain the improvement of dry eye disease symptoms with laughter, the authors shared that laughing stimulates tear secretion through autonomic nervous system activation.

“Research has indicated that positive emotions in non-human animals can induce tear secretion through the release of oxytocin, which could be triggered by laughter,” the researchers suggested.