What is dry-eye syndrome?

Tears lubricate the front of the eye and they allow the eyelids to glide up and down on the front of the eyeball as we blink. Sometimes the tear sacs do not produce enough tears. This causes friction as the eyelids rub off the eyeballs and produces the condition called ‘dry-eye syndrome’.

The medical terms used to describe dry-eye syndrome are keratoconjunctivitis sicca or keratitis sicca.

Symptoms of dry eye

• Itching
• Burning
• Irritation
• Redness
• Blurred vision that improves with blinking
• Excessive tearing
• Symptoms can often be worse in an environment where there is a lot of air conditioning or central heating.

With dry eye your eyes will feel irritated, scratchy, dry and uncomfortable. Your eyes may be red and feel like they are burning or that there is something in them like grit or an eyelash.

Sometimes, your vision may be blurred, but this normally goes away after a short while or when you blink.

Often you will have excess tears running down your cheek. So therefore it can be quite confusing to be diagnosed with dry eye. If your eyes stream like this, it is likely that they are not being lubricated enough and are producing more tears to compensate. However, these tears are mostly water and do not have the lubricating qualities or the rich composition of normal tears. They will wash debris away, but they will not lubricate the eye surface effectively.

If you have dry-eye syndrome, your eyes may be relatively comfortable in the morning because the eyes have been closed during sleep.

The volume of tears being produced by the tear sacs cannot be increased so you need to add artificial tears using eye drops.

There are also special eye lubricants available that can be used at night before going to sleep.

Treatment

The ideal treatment would be to eliminate the cause of the problem but that is not always possible. People need to take certain medications and could put their health at risk if they stopped just to avoid the side effect of dry eyes. It is probably not practical to avoid air conditioning or central heating if you work in an office. So the following are available options.

Artifical tears and ocular lubricants

Your GP can prescribe drops and ointments, usually available without prescription, to help lubricate the eye and alleviate symptoms. Often a watery drop may be used during the day and a thicker gel-like ointment at night.

Punctal occlusion

Reversible blocking or occlusion of the punctual ducts where the tears drain away from the eye allows tears to be retained in the eye and ease symptoms. This method of treatment does not work for everyone and is only useful in certain cases. It is reversible – the plugs can simply be removed.

Omega 3 Oils

In recent years, studies have reported that a diet rich in Omega 3 oils can reduce the risk of developing dry eye and also ease symptoms. Two of the best sources of omega-3s are dark, oily, cold-water fish, and flaxseeds. Flaxseed oil is available in liquid form, capsule form and can be ground down from the natural seed.

General advice for dry eye sufferers

• Blink more frequently if you work on a computer screen or read for long periods.
• Where possible, avoid excessive exposure to air conditioning and central heating.
• If you wear contact lenses ask your optometrist about high moisture or silicone hydrogel contact lenses.
• Include extra omega-3 oils in your diet.

Causes of dry eye

Ageing

Dry eye happens mostly as a part of the natural ageing process. As we get older our bodies produce less oils, including the oily outer layer of the tear film. This oily layer forms a protective coating over the tears and stops them from evaporating. A deficiency in this protective layer allows tears to evaporate and leaves areas of exposure on the surface of the eye.

Women frequently experience problems with dry eyes as they enter menopause because of hormonal changes.

Physical problems

Dry eye can also be caused by problems with blinking or problems with the glands which produce the tears. Eyelid abnormalities can include:

• Blocked meibomian glands which produce the protective oily layer of the tear film
• Damage to the glands producing the tears may also affect the volume of tears produced.

Medications

Some drugs can cause dry eye, like antihistamines and oral contraceptives. The medications below may have associated side effects of dry eye.

• Oral Contraceptive Pill
• Decongestants – used in hay fever and sinusitis control
• Beta Blockers – used in control of blood pressure
• Diuretics – used in fluid control

Contact lenses

Contact lenses carry an increased risk if you have dry eye. Water-based lenses will absorb moisture from the tear film, reducing the quantity of tears remaining. High moisture or silicone hydrogel contact lenses may work better for you.

Working on a screen

People working on computers may find they experience dryness symptoms specifically at work. It has been reported that people working on screens for long periods at a time tend to blink less often. This allows tears to evaporate more readily.

Sjogrens syndrome

Sometimes dry eye is a symptom of conditions affecting other parts of the body particularly arthritis or a condition called Sjogrens syndrome. Sjogrens syndrome is a condition where, as well as dry eyes, people can also have a dry mouth. This condition can also involve a type of arthritis.

Other medical conditions

Other medical conditions may also cause dry eye including:

• Thyroid conditions,
• Vitamin A deficiency,
• Arthritis
• Parkinson’s Disease