Bright Sight

Oliver Backhouse, Consultant Eye Surgeon www.cataract.org.uk

Dry Eyes

Dry eyes are common and can give a feeling of itching, burning, grittiness, an intermittent blurring of the vision or even double vision. There are a number of treatments, medications, and procedures that can help dry eye symptoms. The tear film is made up of three layers: a mucous sticky layer, a middle salt water layer and an outer fatty layer which prevents the tears from evaporating. Tears are mainly produced in the Lacrimal gland which lies beneath the bone under our eyebrows. Tears drain through small holes (punctum) in the part of the eyelids closest to the nose.

Diagram of eye

Your eyelids can be thought of as the windscreen wipers that spread the tear film evenly over the surface of the eye. Any problems with the eyelids can affect the tear film and prevent it from functioning properly. The tear film is also an important focusing surface for the eye. Any problem that makes the tear film uneven or unstable, can lead to problems with focusing. A common complaint of people with dry eye syndrome is that when they read, their vision is clear at first, but after reading for 10 or 20 minutes, their vision becomes blurry and they can no longer see clearly.

Strangely excess watery tearing is a common symptom of dry eyes. This watering is due to reflex tearing that occurs in response to the irritation caused by change to the three layers of the tear film.

Why Are My Eyes Dry?

People who live in dry climates are more likely to be affected by dry eye. Low humidity causes more rapid evaporation of the tear film from the surface of the eye. Dust, dirt, mascara and pollution may also make dry eye syndrome worse. Women that have gone through menopause tend to have less tear secretion. Some medications can cause the eyes to be dry such as hormone replacement therapy, antihistamines and some antidepressants. You should always check with your doctor before stopping any prescription medication, even if you think it may be causing dry eye syndrome. More commonly the cause is unknown but sometimes it can be associated with other inflammations conditions of the body.

People whose eyes do not close completely when they blink, or who blink infrequently (for example, patients with Parkinson disease), are more prone to dry eye syndrome. People who read a lot or work on the computer a lot are also more prone to dry eye syndrome because when we read or concentrate, we blink less frequently. Dry eye symptoms are also common after cataract / lens surgery. This is due to the altered corneal sensation feedback to the lacrimal gland. Known tear film instability has been seen even two months after the surgery. In addition to this, eye drop medication or their preservatives can irritate the surface of the eye. It will settle but you may need a course of lubricating eye drops for several months.

Treatment of dry eye

There are many different treatments for dry eyes. For many patients using artificial tears is all that is needed. Other individuals may need surgery to correct an eyelid that is scarred or an eyelid that does not close properly.

Artificial tears can be got at any chemist and do not need a prescription. There are many different brands and types of artificial tears. Most people must experiment with different tears until they find one that works for them. Some tears are thicker than others. Some patients prefer thicker tears because they last longer. Other people donít like thicker tears because they momentarily blur their vision. For patients that need to use artificial tears frequently, doctors will sometimes recommend a preservative-free artificial tear solution.

Some of the more common ones I have found popular include:

Eye drop: Blink, Systane, Clinitas, Theazol, Artelac, Optive.
Eye Gel: Viscotears, Geltears, Systane Gel
Preservative free: Celluvisc.
Ointment: Lacrilube
Systane Balance or Optive plus are good for dry eye / blepharitis combination.

The ointment Lacrilube at bedtime is especially helpful for patients whose eyes donít close completely when theyíre asleep, or for patients who have more severe dry eye symptoms first thing in the morning. Do not use the ointment during the day as it will blur the vision.

If the symptoms are still bad having tried various different regimes, the addition of a weak anti-inflammatory steroid or blocking the punctum with punctal plugs can be very helpful. These can be temporary or permanent. Surgery is only necessary if patients have a scarred eyelid, if patients have eyelids that donít close completely, or if patients have an eyelid that is not positioned correctly.

Dry eyes is often part of a common chronic eyelash inflammation (Blepharitis) and treatment for this should be in combination with the eye drops for your dry eyes.

All dry eyes can benefit from increased dietary intake of omega-3 supplementation. This is found in oily fish (eg Sardines, Mackerel, Salmon) or as tablets in health food shops.

The information above is indicated to give you a general picture of Dry Eyes. Please ask if you are unsure of, or want more detail on, any points in relation to your own eye problem and general health.

Disclaimer: The author accepts no responsibility for misinformation contained in this leaflet. Adapted from the North American Neuro-Ophthalmology patient information sheet.