There’s an old saying that “the eyes are the window to the soul”. This timeless quote, attributed to poets, playwrights and philosophers, is a reminder of the central role our eyes play in how we experience the world.
It reminds us of the importance of keeping our eyes comfortable and functioning optimally.
If you wake each morning with gritty, burning or “gungy” sensations in your eyes, your soul’s window could be clouding. This heralds the onset of dry-eye disease (DED), also known as dry-eye syndrome (DES).
“Dry eyes won’t kill you,” says Johannesburg ophthalmic surgeon Steph Lindeque. “Left untreated, they can negatively impact quality of life.”
DED has become a global health concern, with significant economic impact. In the US alone, it costs $55bn a year.
Prevalence rates range from 5% to more than 50%, depending on region, age and diagnostic criteria. DED affects mostly adults over age 50, but the young are not immune, especially in the digital age. Prevalence is higher in urban environments and populations where screen use is high.
In SA, research shows exceptionally high prevalence in some areas. A 2015 study of University of KwaZulu-Natal students aged between 18 and 30 showed that 41% had some degree of DED.
Yet dry eyes are not so much a specific diagnosis of disease or disorder as modern medicine’s catch-all term for a common complaint, said Lindeque. “It’s like saying you have a cough.”
Identifying the cause (or causes) is vital for optimum treatment and management. DED requires more detective work than coughs require because it is not just from one thing going wrong, said Lindeque. It results from a range of disruptions in the eye’s natural lubrication systems.
DED falls into two main categories: Evaporative dry eye (EDE), the most common form, and aqueous deficiency (AD), known in full as aqueous deficient dry eye (ADDE).
EDE happens when there is dysfunction of the meibomian glands, the tiny, sebaceous glands tucked into eyelids. There are about 30 of them in your upper eyelids and 25 in your lower lids. AD results from insufficient production of the aqueous (watery) component of the tear film by the lacrimal glands.
EDE and AD may coexist in one patient.
If you suspect that you have a dry-eye problem, Lindeque said that the best entry point is your local optometrist.
“Optometrists are the GPs of eye care,” he said.
They study for four years at university and are trained to spot pathology (disease process) in the eye. They know — or should know — when to refer patients to an ophthalmologist, a medical doctor who specialises in eye diseases. There are about only 400 ophthalmologists in SA. This makes judicious use of optometrists’ expertise critical to managing dry-eye problems.
Dry-eye conditions change the delicate balance of three layers of the eye’s tear film. These are:
- The oil layer secreted by the meibomian glands. Every time you blink, these glands release small amounts of oil that mix with your tears, sit on top of the tear film and keep your eyes from drying out too quickly by slowing evaporation. Think of your meibomian glands as your eyes’ natural moisturisers, quietly working behind the scenes to keep things smooth, comfortable and clear.
- The water layer that the lacrimal glands produce. This layer hydrates the eyes and carries oxygen, salts and antibacterial agents.
- The mucus layer, the innermost, “slimy” part of the eye. It is rich in glycoproteins that help tears stick to the eye’s surface.
“As you age, your body produces less oil and water,” said Lindeque. “Your skin and hair dries. The same process affects your eyes.”
Risk factors for DED include:
- Office environments: air-conditioning reduces humidity, dry air aggravates dry eyes (it’s that simple).
- Altitude: Johannesburg, for example, sits 1,735m above sea level. The thinner, less humid air makes life difficult for tear films.
- Allergies: pollens, pollution, animal fur and general urban irritants fuel inflammation and worsen dry-eye symptoms.
- Smoking: tobacco smoke is loaded with irritants, dries out mucous membranes, inflames eyes and reduces tear production.
- Infections: blepharitis is a common eyelid infection that clogs meibomian glands and disrupts oil secretion; conjunctivitis (“pink eye”, viral or bacterial) can inflame the ocular surface and interfere with tear-film stability; demodex infestation — tiny mites that live in eyelash follicles and meibomian glands — is linked to chronic blepharitis.
- Medical conditions, such as rheumatoid arthritis or Sjögren’s syndrome, an autoimmune disorder that primarily affects the glands that produce moisture.
- Medications: antihistamines, antidepressants and blood-pressure medications may affect tear production or alter tear-film composition.
- The digital era: you blink less when staring at screens, your meibomian glands release less oil and the tear film breaks down faster.
- Contact lenses: these are more tolerable at the coast where humidity supports the tear film.
New technologies and imaging techniques allow detailed analysis of health of meibomian glands and tear films. Proper diagnosis involves tests such as tear break-up time (TBUT) to assess tear stability.
If your tear film develops a dry spot in under 10 seconds, it is usually a sign of a dry-eye problem, said Lindeque. In inland areas, such as Johannesburg, many people score below this benchmark.
AD often has an underlying cause that must be identified as part of treatment, he said.
Treatment options are similar for both EDE and AD and include:
- Eye hygiene: keep hands away from eyes. Don’t touch or rub your eyes.
- Don’t smoke.
- Environmental changes: sit away from air-conditioning units and bright windows. Use a humidifier at home.
- Blink training: remind yourself to blink. Watch your young children or grandchildren and remember how much you blinked when you were young.
- Warm compresses: these are especially beneficial for EDE. Five minutes to 10 minutes twice daily may be all it takes to melt oils in meibomian glands and restore balance. There are expensive options but a clean cloth soaked in hot water can be an effective compress.
- Artificial tears: prefer preservative-free options as you can use these as often as needed.
- Allergy drops: one drop daily may alleviate dry-eye symptoms.
- Mild steroids: a short course can reduce inflammation. Doctors may prescribe antibiotic ointments for infections.
- Infrared light therapy: a relatively new modality for dry eyes, it is showing promising results for stimulating oil glands.
Optimum treatment for dry eyes is like “climbing a ladder”, said Lindeque, preferably under specialist medical supervision. He advises that you select treatment methods, which you can easily incorporate into your lifestyle, take one step at a time, monitor results and adjust as needed.
The key is sustainability, Lindeque said. If all else fails, he advises “climatotherapy”. “Consider moving to the coast. The humidity and clean air can radically improve dry-eye symptoms.”
Remember, dry eye it is not life-threatening but it chips away at quality of life. With knowledge and consistent care, you can keep the windows to your soul crystal clear.
Would you like to comment on this article?
Sign up (it's quick and free) or sign in now.
Please read our Comment Policy before commenting.