Laughter Exercise for Symptomatic Improvement in Dry Eye Following Cataract Surgery: A Randomized Controlled Trial

Background: The effectiveness of laughter exercise in dry eye disease (DED) remains uncertain. This study aimed to evaluate the efficacy and safety of laughter exercise in patients with DED who had undergone cataract surgery. Methods: This was a parallel-group, randomized controlled trial. A total of 72 participants were randomly assigned to either the laughter exercise group (n=36) or the control group (n=36). Participants in the intervention group performed guided laughter exercises four times a day for 4 weeks. Outcomes were measured preoperatively and at 1, 4, and 12 weeks postoperatively. The primary outcome was the mean change in dry eye symptom scores. Secondary outcomes included tear meniscus height, tear break-up time, health status scores (both physical (PCS) and mental (MCS) component summaries), intervention participation, satisfaction, and incidence of adverse events. Results: Repeated measures ANOVA was used to analyze dry eye symptom scores. The results showed a significant group×time interaction ( P 0.05). No adverse events were observed in either group. Conclusion: Laughter exercises can relieve dry eye symptoms in patients who have undergone cataract surgery and improve their physical and mental health. Although this therapy has no significant effect on improving objective clinical symptoms, it can be a safe and effective adjuvant treatment. Keywords: laughter exercise, dry eye disease, randomized controlled trial, effect analysis