Dry eye syndrome (keratoconjunctivitis sicca) is a chronic reduction in the quantity or quality of tears, causing insufficient lubrication of the eye. It can cause mild to severe discomfort and damage to the tissues of the surface of the eye - the cornea and conjunctiva.
Symptoms of dry eye syndrome include:
- Eye irritation and redness
- A gritty or burning sensation to the eyes
- A foreign body sensation - the feeling that something is in your eye
- Filmy vision (that may clear with repeated blinking)
- Sensitivity to light
- Contact lens discomfort or intolerance
What causes dry eye syndrome?
The normal tear film of the eye has three components:
Water: Most of our tear film is composed of a watery substance, secreted by the lacrimal glands which are located above and behind our upper eyelids. This watery (or aqueous) component of our tears nourishes and cleans the cornea and other tissues on the front of the eye.
Oils: Oils secreted from Meibomian glands (located at the margins of our eyelids) help keep our tears from evaporating too quickly.
Mucin: Mucin is a mucous-like substance that is produced by cells in the conjunctiva and outer surface of the eye. It helps tears spread more easily across the cornea.
A deficiency in the quantity or quality of any of these three components of the tear film can cause dry eye syndrome. A deficiency in the watery component of tears is known as Aqueous Tear Deficiency (ATD). Keratoconjunctivitis sicca (KCS) is the medical term used to describe dry eye syndrome resulting from ATD. A more common form of dry eye is Evaporative Dry Eye which is related to meibomian gland dysfunction and blepharitis.
How can I reduce my risk of dry eye syndrome?
To reduce your risk of dry eyes, take the following precautions:
- Keep your body well hydrated regularly drinking water.
- Use "floral foam" in a pot of water to humidify the room.
- Avoid alcohol and caffeine as they have a dehydrating effect.
- Run a humidifier in your home during winter or if you live in a dry climate.Avoid sitting adjacent to an air-conditioner or heater.
- Avoid smoking.
- Moisten your contact lenses routinely with rewetting drops.
- Clean your contact lenses daily and replace them as directed. Wear close-fitting sunglasses when outdoors (particularly on windy days).
- Eat salmon or oily fish once a week and consider taking a daily supplement of omega-3 fatty acids.
- Check if any of your medications are likely to cause dry eye. Common medications that contribute to dry eye include classes of blood pressure medication, antihistamines, HRTs, some antidepressants and some acne medication.
Dry eye treatment can sometimes include a course of oral medications to improve your meibomian gland function. It can also involve eyedrops such as ciclosporin or anti-inflammatory drops to improve your tear gland function. Blephasteam with gland expression is also available to improve the tear glands.
It is important to understand sometimes dry eye is a chronic condition and cannot be cured. However, with appropriate treatment most sufferers will find relief.