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Dr Lisa Devine

Dry eye or dry eye syndrome (also known as keratoconjunctivitis sicca or, more recently, dysfunctional tear syndrome) is a multifactorial disorder of the tear film and the surface of the eye. It is associated with symptoms of ocular discomfort.

While the importance of this condition is easy to lose sight of, in the context of the many different conditions with which people present on a daily basis, it is usually a priority for the patient sitting in front of us.

The GPnotebook section on this condition provides a logical and easy-to-remember approach to considering the possible causes, while a related new page gives us some information on the use of laughter therapy in its management. The idea of this treatment was too eye-catching for me not to take a look.

Before diving into the trial on which the new content is based, this page offers some helpful background information on the anatomy and physiology of the condition, which I thought was very interesting. It notes that the condition relates to the structure and function of the tear film, which has three layers. The middle layer plays the main part, while the other two layers have ‘supporting’ roles:

  • The middle or aqueous layer is the largest and thickest layer and is produced by the glands of upper lids and tear glands. It keeps the eyes moist and helps in the removal of dust, debris and foreign particles.
  • The innermost mucin or mucus layer is produced by the cells of the conjunctiva and helps spread the overlying water layer over the eye evenly.
  • The uppermost lipid layer is produced by the meibomian glands and oil glands in the eyelids. It helps to decrease evaporation of the watery layer beneath it.

Where the tear film is interrupted, dry eye can result, and specific causes of the dysfunction of the various layers can be found here.

Some useful tips on making sure the diagnosis of dry eye is correct can be found here, along with pointers on spotting secondary causes such as Sjögren’s syndrome.

For me, a particular reminder was to consider whether prescribed medications could be a culprit. Some commonly used medications that exacerbate or cause dry eye include beta-blockers, oestrogen, antihistamines and tricyclic antidepressants.

 

What is laughter therapy and where does it fit into the management of dry eye?

A recent randomised controlled trial pitched a laughter exercise against sodium hyaluronic acid and measured its effectiveness in relieving subjective symptoms after 8 weeks.

The laughter exercise required trial participants to vocalise and repeat the phrases “hee hee hee, hah hah hah, cheese cheese cheese, cheek cheek cheek, hah hah hah hah hah hah” 30 times over at least 5 minutes four times per day. This was to stimulate the ocular muscles. The control group instead applied 0.1% sodium hyaluronic acid drops four times a day.

The laughter exercise was found to be non-inferior to sodium hyaluronic acid in relieving subjective symptoms at 8 weeks.

The page relating to this trial can be found here.

I must confess that this time-consuming therapy could be a harder sell than conventional treatments for dry eye, but there could be some people who might like to give it a go.

GPnotebook also provides useful information on some more conventional treatment options. These include other lifestyle interventions that we can recommend to our patients, such as obtaining sufficient sleep, avoiding prolonged exposure to air conditioning, and smoking cessation (of course, these may be simpler to suggest than to do).

Excessive screen time is also common in daily life and can impact dry eye. Reducing excessive exposure to digital screens can improve tear-film stability. The 20-20-20 rule – taking a 20-second screen break every 20 minutes to look at an object at least 20 feet away – is a practical tip to improve dry eye that many people will be able to follow.

The information also includes some helpful pointers on the use of artificial tears and prescribed drops, and when to refer for a specialist opinion.

So, is dry eye ever a laughing matter? I think that our patients would feel that it certainly is not, although perhaps this randomised controlled trial has given us one instance where it might be!

I hope that you enjoyed this email, and I look forward to writing for you again next month.

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