Trial reportBMJ (Clinical research ed.)2024
Effect of laughter exercise versus 0.1% sodium hyaluronic acid on ocular surface discomfort in dry eye disease: non-inferiority randomised controlled trial.
Trial report in BMJ (Clinical research ed.), 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT04421300 (Clinical Efficacy of Smile Exercise Versus 0.1% Hyaluronic Acid Sodium Eye Drops for Dry Eye Symptoms in Patients With Dry Eye Disease), which is not on this map. Cited by 11 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Clinical Efficacy of Smile Exercise Versus 0.1% Hyaluronic Acid Sodium Eye Drops for Dry Eye Symptoms in Patients With Dry Eye Disease: a Randomized, Controlled, Non-inferiority Trial
Who cites it
11 citing papers in PubMed.
- Standardized Lacrimal Sac Massage vs Probing for Congenital Nasolacrimal Duct Obstruction in Infants: A Noninferiority Randomized Trial.JAMA ophthalmology · 2026Trial
- The translation paradox: how full translation increases cognitive load and impairs medical vocabulary retention.BMC medical education · 2026Trial
- Laughter Exercise for Symptomatic Improvement in Dry Eye Following Cataract Surgery: A Randomized Controlled Trial.Clinical ophthalmology (Auckland, N.Z.) · 2026Trial
- The Role of Behavioral and Psychological Interventions in Chronic Ocular Pain.Current pain and headache reports · 2026Review
- Accelerometer-derived moderate-to-vigorous physical activity patterns and incident dry eye disease: a prospective UK Biobank cohort study.BMC public health · 2026Article
- β-Adrenergic Signaling Contributes to Circadian and Lipid Dysregulation in Meibomian Glands During Chronic Psychological Stress.Investigative ophthalmology & visual science · 2026Article
- Efficacy of intradermal acupuncture for ocular surface diseases secondary to refractory peripheral facial palsy: a randomized controlled trial study protocol.Frontiers in medicine · 2026Article
- Global burden of early-onset mental disorders in adolescents and young adults: a systematic analysis based on the Global Burden of Disease study 2021.BMC psychiatry · 2025Article
- The Impact of 3% Diquafosol Ophthalmic Solution on Tear Film and Corneal Nerve Density in Patients with Diabetes and Dry Eye Disease: A Randomized Controlled Study.Ophthalmology and therapy · 2025Article
- Dry eye disease and psychosomatics-benefits of mind-body therapy for dry eye disease.Frontiers in medicine · 2025Review
- Effects of regular spectacle wear on binocular accommodative function in myopic adults with dry eye disease.Frontiers in medicine · 2025Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
11 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectiveTo assess efficacy and safety of laughter exercise in patients with symptomatic dry eye disease.
designNon-inferiority randomised controlled trial.
settingRecruitment was from clinics and community and the trial took place at Zhongshan Ophthalmic Center, Sun Yat-sen University, the largest ophthalmic centre in China, between 18 June 2020 to 8 January 2021.
participantsPeople with symptomatic dry eye disease aged 18-45 years with ocular surface disease index scores ranging from 18 to 80 and tear film break-up time of eight seconds or less.
interventionsParticipants were randomised 1:1 to receive laughter exercise or artificial tears (0.1% sodium hyaluronic acid eyedrop, control group) four times daily for eight weeks. The laughter exercise group viewed an instructional video and participants were requested to vocalise 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. Investigators assessing study outcomes were masked to group assignment but participants were unmasked for practical reasons.
main outcome measuresThe primary outcome was the mean change in the ocular surface disease index (0-100, higher scores indicating worse ocular surface discomfort) from baseline to eight weeks in the per protocol population. The non-inferiority margin was 6 points of this index score. Main secondary outcomes included the proportion of patients with a decrease from baseline in ocular surface disease index score of at least 10 points and changes in dry eye disease signs, for example, non-invasive tear break up time at eight weeks.
results299 participants (mean age 28.9 years; 74% female) were randomly assigned to receive laughter exercise (n=149) or 0.1% sodium hyaluronic acid (n=150). 283 (95%) completed the trial. The mean change in ocular surface disease index score at eight weeks was -10.5 points (95% confidence interval (CI) -13.1 to -7.82) in the laughter exercise group and -8.83 (-11.7 to -6.02) in the control group. The upper boundary of the CI for difference in change between groups was lower than the non-inferiority margin (mean difference -1.45 points (95% CI -5.08 to 2.19); P=0.43), supporting non-inferiority. Among secondary outcomes, the laughter exercise was better in improving non-invasive tear break up time (mean difference 2.30 seconds (95% CI 1.30 to 3.30), P<0.001); other secondary outcomes showed no significant difference. No adverse events were noted in either study group.
conclusionsThe laughter exercise was non-inferior to 0.1% sodium hyaluronic acid in relieving subjective symptoms in patients with dry eye disease with limited corneal staining over eight weeks intervention.
trial registrationClinicalTrials.gov NCT04421300.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.