Laughter Soothes Dry Eyes as Effectively as Eye Drops, Study Finds

Context

With an estimated 360 million cases worldwide, DED is a prevalent illness marked by chronic pain, tear film instability, and visual abnormalities. DED is not life-threatening, but it lowers quality of life considerably and costs a lot of money.

Because of aging populations, more time spent in front of screens, and growing air pollution, its prevalence has increased. A increasing amount of research indicates a significant connection between DED and mental health issues including anxiety and depression in addition to physical symptoms, with emotional variables frequently escalating the symptoms.

Laughter therapy is an emotion-focused intervention that has long been known to improve immunological function and reduce symptoms of chronic pain, anxiety, and depression. Although it has been successful in enhancing mental health, it is uncertain how it would affect DED, a disorder that is strongly related to lifestyle choices and mental health.

Laughing may instantly enhance tear film stability and lessen symptoms of dry eyes, according to pilot studies. Building on this data, the current study’s researchers hypothesized non-inferiority between the two methods by comparing the efficacy of laughter exercise with fake tears in treating DED.

About the Study

Through marketing and social media, 299 volunteers from clinics and the surrounding areas were recruited for the current two-arm, non-inferiority randomized controlled experiment.

The age range of the eligible individuals was 18 to 45 years, they had a fluorescein tear break-up time (TBUT) of eight seconds or less, symptomatic DED, and an ocular surface disease index (OSDI) score between 18 and 80.

Exclusion criteria included significant corneal staining, glaucoma, contact lens wearers, eye surgery, eye infections, trauma, allergies, severe ocular surface scarring, and neurological disorders.

The enrolled individuals received four daily doses of 0.1% sodium hyaluronic acid eye drops as the control group (n = 150) or laughter exercise group (n = 149) at random (1:1). The eight-week period was used to administer both treatments.

Laughter exercise, which was modified from laughter treatment techniques already in use, entailed using a special face recognition app to track your movements while you repeated particular vocalizations while using your facial muscles. By reminding patients and recording their sessions, the app made sure they were following their treatment plan.

Participants in the control group also recorded using eye drops on the app. The primary outcome was the change in OSDI score from baseline to eight weeks. Non-invasive TBUT, corneal fluorescein staining, and extra assessments of life satisfaction, psychological well-being, and subjective happiness were among the secondary results.

Adverse events and follow-up visits for a maximum of 12 weeks were monitored. The Shapiro-Wilk test, Student’s t-test, multiple imputations, generalized estimated equation models, and Benjamini-Hochberg adjustment were all used in the statistical study.

In summary

The current study concludes that, in terms of reducing DED symptoms, laughter exercises four times a day are not less effective than 0.1% sodium hyaluronic acid eye drops. For people with symptomatic DED and mild corneal staining, laughter exercise may be the first-line, at-home treatment option due to its low cost, safety, and environmental friendliness.

For more information: Effect of laughter exercise versus 0.1% sodium hyaluronic acid on ocular surface discomfort in dry eye disease: non-inferiority randomized controlled trial, British Medical Journal, doi: https://doi.org/10.1136/bmj-2024-080474