What is Dry Eye?Some people produce insufficient tears to keep the eye comfortable. This is known as dry eye.
About TearsThe eye is lubricated by two types of tears that are produced by the tear glands.
- Constant tears are produced at a slow rate to lubricate the eye
- Reflex tears are produced in response to irritation, injury or emotion and help rinse the surface of the eye
What is the Tear Film?A film of tears is spread over the eye by a blink. The tear film is necessary for a healthy eye and clear vision.
The tear film consists of three layers:
- An oily layer
- A watery layer
- A layer of mucus
The outer oily layer is produced by the meibomium glands and acts to reduce evaporation of the tears.
When the amount of constant tears is reduced, there is irritation that results in reflex tearing ie watery eye. These excess tears lack the oil that keeps them from evaporating and so do not lubricate the eye effectively.
The middle watery layer is produced by the lacrimal gland under the upper lid.
The inner mucus layer of the tears is produced by the conjunctiva. Mucus allows the tears to stick to the eye.
What are the Symptoms of Dry Eye?
- dry sensation
- scratching gritty feeling
- watery eyes
- mucus discharge
- irritation from wind or smoke
- tired eyes
- light sensitivity
- eye lid infections
- contact lens discomfort
- contact lens solution sensitivity
What Causes Dry Eyes?Ageing
Tear production normally decreases as we get older. Women are more often affected than men, especially after the menopause.
Arthritis may be accompanied by dry eyes and dry mouth. This combination of symptoms is termed Sjogren’s syndrome.
A variety of common medications reduce tear secretion. These include: beta-blockers, diuretics, anti-histamines, sleeping tablets, anti-depressants, pain relievers and alcohol.
Environmental conditions may reduce eye lubrication. These include: sunny, dry, windy conditions; air conditioners; areas with heaters; hair dryers; smoke or air pollution; dust; sand; pollen; chemicals.
People with dry eyes who wear contact lenses may experience irritation, increased protein deposition, pain and infection.
How is Dry Eye Diagnosed?An ophthalmologist is usually able to diagnose dry eye by examining the tear film. Sometimes tests to measure tear production may be necessary. A Schirmer’s test involves placing a filter paper strip under the lower eye lid to measure the rate of tear production. Sometimes drops of dye are placed in the eye to look for certain staining patterns.
How is Dry Eye Treated?Adding Tears
Artificial tears may be prescribed to supplement your own tears and lubricate the eye. People with dry eyes are often more prone to the toxic effect of eye drops. Some artificial tears contain preservatives that may irritate the eye. Special preservative free artificial tears may be required.
Tears drain out of the eye through the tear ducts to the nose. This is why your nose runs when you cry. Your ophthalmologist may close your tear ducts either temporarily or permanently in order to conserve your own tears and make artificial tears last longer.
Temporary closure is accomplished by inserting a tiny plug in your tear ducts. Dr Hornsby can then evaluate the effectiveness of tear duct closure. The plug will then dissolve and wash away with your tears.
Long term closure of the tear ducts can be achieved by placing a non-dissolving silicone plug in your tear ducts. These plugs are removable.
Permanent closure of the tear ducts can be achieved surgically.
You can take steps to decrease the rate of evaporation of your tears. Wrap around glasses may reduce the drying effect of wind. A humidifier indoors may be beneficial.
Dr Hornsby will work closely with you to reduce the discomfort and inconvenience of dry eye.
Change the text size
AddressSuite 15, Mater Medical Centre
76 Willetts Road
Mackay QLD 4740