Laughter may be as effective as eye drops in improving symptoms of dry eye disease, according to a human trial conducted at the Guangdong Provincial Clinical Research Center for Ophthalmology in China and published in the British medical journal BMJ. On September 11, researchers believe that laughter exercises may be a first-line treatment to relieve the symptoms of dry eye disease.
dry eye
Dry eye disease is a chronic condition that is estimated to affect approximately 360 million people worldwide. Common symptoms include discomfort, redness, itching or irritation.
Evidence suggests that laughter therapy can relieve depression, anxiety, stress, and chronic pain, while boosting immune system function and is known to be a useful complementary and adjunctive treatment for a number of chronic conditions, including psychiatric disorders and diabetes. However, it is not known whether laughter therapy has a beneficial effect on dry eye disease.
To explore further, researchers from China and the United Kingdom set out to evaluate the effectiveness and safety of laughter exercises in patients with dry eye disease symptoms.
The study results are based on 283 participants aged 18-45, three-quarters of whom were women, who were assessed for dry eye disease using the Ocular Surface Disease Index, a 12-item questionnaire that assesses dry eye symptoms and their effects on vision-related function in the previous week of the patient’s life. The patients were randomly assigned to receive laughter exercises or 0.1% hyaluronic acid eye drops 4 times daily for 8 weeks.
Eye drops containing hyaluronic acid are one of the most widely used artificial tears and have a proven therapeutic effect in relieving the discomfort of dry eyes.
Participants with pre-existing eye conditions that might affect study results, injury, infection, or allergy, and those who had recently used contact lenses or any treatment for dry eye disease were excluded.
Laughter training
The first group, which received laughter exercises, watched an instructional video and were asked to repeat the phrases “Hee hee hee, ha ha ha, cheese cheese cheese, cheek cheek cheek, ha ha ha ha” 30 times in each 5-minute session using a mobile phone app that relied on facial recognition to standardize the exercise and reinforce facial movements.
While the eye drop group applied 0.1% hyaluronic acid drops to both eyes 4 times daily for 8 weeks, and tracked usage via the same app.
Treatments were stopped at week 8 and any change in ocular surface discomfort scores was measured at weeks 10 and 12.
The mean Ocular Surface Disease Index score at week 8 was 10.5 points lower (indicating less discomfort) in the laughter exercise group and 8.83 points lower in the drop group, with a mean difference of 1.45 points, indicating that laughter exercises were no less effective than eye drops.
Laughter exercises also showed significant improvements in a number of eye tests and mental health scores. No adverse events were observed in either group.
The authors acknowledge some limitations that may have affected the results, but they say the results suggest that laughter exercises were no less effective than hyaluronic acid drops in improving dry eye symptoms.