What is Dry Eye?
Dry eye is caused by a reduction of the tear film, which is necessary to keep the eyes moist and clean.
The Tear Film
When we blink, tears form a film which spreads over the front of the eye. This keeps the surface smooth and clear enabling good vision. It is made up of the following 3 layers:
Oily - smoothes the tear surface and reduces drying up.
Watery - cleanses the eye washes away irritants
Mucous - allows water to spread over the eye evenly and helps the tears to stick to the eye like soap sticks to your skin when washing.
We blink approximately every 5 seconds this renews the tear film across the front of the eye. It then drains through a small opening at the corner of the upper and lower eye lids this is known as the punctum. If any of the tear film layers are of a poor quality you may suffer some of the following symptoms:
Watery Eyes - oil and mucus deficiency causes the eye to water, however it does not ‘wet’ the front of the eye, therefore you get the feeling of dryness.
• Gritty sensation
• Temporary /intermittent blurring of vision
• Foreign body sensation
• Mucus discharge
Aim of Treatment
• Relieve the discomfort
• Prevent corneal damage
Eye drops may be prescribed or bought over the counter. As there are a number of different types you may have to try a few to find one that suits you. Lubricant ointments /gels are helpful and some patients find them useful at night. Some people may find that a combination of eye drops and eye gels is the best solution for them, everyone is different. In some cases it is necessary to close off the punctum. This is known as punctal occlusion. This helps prevent the tear film disappearing to quickly.
Minimise the risks of Dry Eye
• Avoid smoky dry atmospheres.
• Use eye drops as instructed.
• Remember to blink when doing close work or concentrating.
• Sit away from direct heat such as gas/electric fires.
• The use of humidifier will reduce dry atmospheres caused by central heating.
Age - more common among women, or the over 65s however, any age group may be affected, due to a decrease in the volume of tear film.
Blepharitis - (inflammation of the eyelid at the base of the eyelashes) This may upset the balance of the tear film.
Contact Lenses - because of reduced blinking while looking at the screen, more common in the younger age group.
Hormonal changes - a reduced tear film due to pregnancy, menstruation (periods) menopause (change of life)
Medications - this includes some antibiotics, blood pressure medication, contraceptive pill, diuretics (water pills) antidepressants.
Computer - because of reduced blinking while looking at the screen.
Diseases - Rheumatoid Arthritis, Sjogrens Syndrome, Thyroid disease and Lupus.
Tear Test- (Schirmers) a simple test using 2 small strips of blotting paper to check the amount of tears produced over 5 minutes.
Dye Test- a drop of yellow or pink dye is placed in the eye, the Nurse or the Doctor will then examine the eye to see how quickly the tears disappear.
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Reference No 118213