Laughter vs. Eye Drops: Which Eases Dry Eye?

observational-study PMID: 39260878

Quick Summary: Researchers compared laughter exercises to hyaluronic acid eye drops for dry eye. They found that laughter was just as good as the eye drops at relieving discomfort. Plus, the laughter group had better tear stability!

Does Laughter Really Help Dry Eyes?

Yes! This study looked at people with dry eye and compared two treatments: laughter exercises and 0.1% sodium hyaluronic acid eye drops (a common ingredient in artificial tears). The results showed that laughter exercises were just as effective as the eye drops in reducing dry eye symptoms.

Study Details

Who was studied: 299 people aged 18-45 with dry eye symptoms. Most participants were women.

How long: The study lasted for 8 weeks.

What they took:

Laughter Group: Watched a video and vocalized "Hee hee hee, hah hah hah, cheese cheese cheese, cheek cheek cheek, hah hah hah hah hah hah" for 5 minutes, 4 times a day.
Eye Drop Group: Used 0.1% sodium hyaluronic acid eye drops 4 times a day.

What This Means For You

Laughter could help: If you have dry eye, this study suggests that laughter exercises might help ease your symptoms. It's a free and easy way to potentially find relief!

Eye drops still work: Hyaluronic acid eye drops are still a good option. They were just as effective as laughter in this study.

Talk to your doctor: Always discuss any new treatments with your eye doctor.

Study Limitations

Not for everyone: The study focused on a specific age group and mostly women, so the results might not apply to everyone.

Short-term: The study only lasted 8 weeks. We don't know if the effects last longer.

Laughter consistency: The study didn't measure how well people followed the laughter exercise instructions.

Eye drop strength: The study used a low-dose hyaluronic acid eye drop. Stronger eye drops might have different results.

Key Findings

The study found that laughter exercise was non-inferior to 0.1% sodium hyaluronic acid (HA) eyedrops in reducing ocular surface discomfort in patients with dry eye disease. The laughter group showed a greater improvement in non-invasive tear break-up time (TBUT) compared to HA. Both interventions were safe, with no reported adverse events.

Study Design

This was a non-inferiority randomized controlled trial (RCT) conducted at Zhongshan Ophthalmic Center, China, from June 2020 to January 2021. Participants (n=299, mean age 28.9 years, 74% female) had symptomatic dry eye disease (ocular surface disease index [OSDI] scores 18-80, TBUT ≤8 seconds). They were randomized 1:1 to laughter exercise (n=149) or HA eyedrops (n=150) for eight weeks. The primary outcome was mean change in OSDI score (per protocol population), with a non-inferiority margin of 6 points.

Dosage & Administration

The HA group received 0.1% sodium hyaluronic acid eyedrops administered four times daily. The laughter exercise group followed a structured regimen: vocalizing the phrases "Hee hee hee, hah hah hah, cheese cheese cheese, cheek cheek cheek, hah hah hah hah hah hah" 30 times per five-minute session, four times daily. Investigators were masked to group assignments, but participants could not be masked due to the nature of the intervention.

Results & Efficacy

Primary Outcome: Mean OSDI score decreased by -10.5 points (95% CI -13.1 to -7.82) in the laughter group and -8.83 points (95% CI -11.7 to -6.02) in the HA group. The between-group difference (-1.45 points, 95% CI -5.08 to 2.19) met non-inferiority criteria (P=0.43).
Secondary Outcomes:
Laughter exercise improved TBUT by 2.30 seconds more than HA (95% CI 1.30 to 3.30, P<0.001).
No significant differences in corneal staining or proportion of patients achieving ≥10-point OSDI reduction.
Safety: No adverse events reported in either group.

Limitations

Open-label design: Participant unmasking may have introduced bias due to expectations about laughter exercise or eyedrops.
Short duration: Eight weeks may be insufficient to assess long-term efficacy or safety.
Demographics: Results may not generalize to older populations or males (74% female, mean age 28.9).
Standardization: Laughter exercise compliance and technique consistency were not quantitatively measured.
HA dosage: The 0.1% HA eyedrop is a low-concentration formulation, potentially limiting comparison with higher HA doses.

Clinical Relevance

For dry eye patients, laughter exercise offers a non-inferior alternative to 0.1% HA eyedrops for symptom relief, with added benefits of being cost-free, non-invasive, and improving TBUT. However, HA eyedrops remain a well-established treatment, particularly for those preferring pharmacological interventions. The findings suggest behavioral approaches like laughter exercise could complement or substitute for mild dry eye cases, though further research is needed to confirm efficacy across diverse populations and longer durations. Users of HA should note that this study used a low-concentration formulation, and higher HA doses might yield different results.

Study Registration: ClinicalTrials.gov NCT04421300.