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Dealing with dry eyes
The questions you should ask to help diagnose and treat this common condition
Dry eyes may sound like a minor issue but for some it can be agonising and persistent, with a significant impact on quality of life.
The condition is estimated to affect about 7.4% of Australians. Older people, women, office workers and contact lens wearers are more likely to report having dry eyes.
While dry eye syndrome is a common presentation in pharmacies, it can be mistaken for a variety of other eye conditions.
We take a look at how to differentiate dry eyes from other conditions, treatment options and more.
What is it?
Dry eye syndrome (keratoconjunctivitis sicca) is a multifactorial condition, explains Luke Arundel, Optometry Australia’s senior resident optometrist.
“There are two main types of dry eye – aqueous deficient dry eye caused by reduced tear output due to dysfunction of the lacrimal gland, and evaporative dry eye caused by increased evaporation from the tear film,” says Arundel.
Symptoms of dry eye syndrome include:
- Irritation
- Grittiness
- Burning
- Soreness
- Watery eyes
- Reflex tearing
- Visual disturbances including fluctuating blurred vision
Pharmacists can also look out for bulbar conjunctival hyperaemia, says Arundel.
A variety of reasons and risk factors can lead to the presentation of dry eyes (see box: Risk factors for dry eye).
For example, aqueous deficient dry eye due to dysfunction of the lacrimal gland can be a result of a blockage or bacterial infection.
Meanwhile, Vitamin A deficiency and chemicals burns can contribute to evaporative loss of the tear film, causing evaporative dry eye.
Dry eyes can also be caused by dry environments or prolonged exposure to computer monitors or television screens, which leads to a reduced blink rate.
Diagnosis
Pharmacists may be able to help patients identify what might be causing their symptoms of dry eye, then manage, treat and/or refer as appropriate, says Dr Esther Lau, a pharmacist from the Faculty of Health at Queensland University of Technology.
“It would also be useful for pharmacists to follow up with patients to see if the treatment worked,” she tells AJP.
However diagnosing dry eye syndrome may not be as easy as it seems.
According to a survey by The Pharmaceutical Journal, 81% of community pharmacists reported they felt somewhat or very confident in diagnosing dry eye conditions, but mystery shopper studies held in the UK revealed only 42% of pharmacy staff actually gave a correct diagnosis of dry eye.
Diagnoses given by pharmacy staff instead of dry eye in the studies included sore eyes, tired eyes, hay fever, irritation, foreign body and infection – a few of which are actually symptoms of dry eye.
The studies found pharmacists who diagnosed dry eye correctly were more likely to have asked the ‘right’ questions, covering duration or symptoms, severity, laterality (one or both eyes affected) and whether or not there was any “dryness”.
Questions to ask:
What are your symptoms? Itchiness suggests allergic disease, while pain or a foreign body sensation could suggest another cause.
What is your vision like? Does it change when you blink? Since the tear film is affected, variability in vision between blinks indicates dry eye syndrome.
How long have you been experiencing the symptoms for? Dry eye syndrome is a chronic condition that is unlikely to have a sudden onset.
Do your eyes have any stickiness, crusting or discharge? These are indications of an infectious cause.
Have you had any eye-related incidents before onset of the symptoms? Ocular surgery, starting contact lens wear or starting a new medicine can be source of dry eye symptoms.
Do you have any allergies or tissue disorders? These conditions can cause dry eye, and treating the original cause can alleviate the dry eye.
Are both eyes affected or just one? Dry eye generally affects both eyes.
Differential diagnoses include:
- Conjunctivitis
- Sjögren’s syndrome
- Filamentary keratitis
- Infectious diseases including chlamydia, herpes simplex and herpes zoster
- Corneal abrasion, erosion, foreign body or mucous plaques
Treatment
Arundel says the mainstay treatment of dry eye syndrome is tear replacement with artificial tears.
People with mild dry eye should be started on less viscous products and work up to gels and ointments for more severe dry eye.
“In many cases eye drops and basic general advice is all that is required. Some drops have ingredients which are more suited to aqueous deficient dry eye while others are more tailed to evaporative dry eye.
“Understanding the properties of the different compounds of the artificial tears is essential to assisting patients to select the optimal product for their needs and to get the most benefit from their treatment,” he says.
Some optometrists and pharmacists believe preservatives in eye drops should be avoided.
“The single most critical advance in the treatment of dry eyes is the elimination of preservatives,” argues Elaine Mann, who is an ophthalmic, ENT, maxillofacial and dental pharmacist based in the UK.
“Benzalkonium chloride (BAK), the most common preservative used in eye drops, can damage the ocular surface of the eye producing conjunctival inflammation, tear film instability, corneal cytotoxicity and a decrease in the density of goblet cells and mucus production,” she writes in The Pharmaceutical Journal.
Arundel agrees that people who find they are dosing with multiple eye drops a day should change to unit dose drops to avoid issues with preservatives.
Associate Professor Louis Roller, from the Faculty of Pharmacy and Pharmaceutical Sciences at Monash University, reminds pharmacists to be vigilant about the impact dry eye treatments may have in combination with other medicines.
Source: AJP, 5 October 2016, https://ajp.com.au/features/dealing-dry-eyes/.
Our iTherapeutics module Caring for Dry Eyes featured below contains further useful information.
