Your eyes produce tears containing natural infection-fighting antibiotics every second. Blinking spreads the tears over the eyes’ surface before being drained through two small holes in the nasal corner of your eyelids. These tear ducts are known as puncta and drain tears to the nose and throat.
If your tear glands make insufficient tears, or they drain away too quickly, the tear film is spread too thinly over the eyes’ surface. If your tear glands produce enough tears but are of poor quality, they evaporate too quickly before the next blink comes along, which can cause irritation.
If untreated, damage to the outer protective tissue of the cornea opens a route of infection with the risk of permanent scarring and sight loss.
What causes dry eyes?
A small handful of reasons are listed below:
- Central heating, air conditioning, contact lenses; activities that decrease blink rate, such as driving and VDU work
- Although dry eyes can be a side effect of disease, the most common cause is ageing. In fact, the volume of lubricating background tears is less than half at 65 than at 18. Not surprisingly then, dry eye affects one in five people over 55, but some more than others
- Medications such as anti-depressants, decongestants
- Several diseases result in secondary dry eye syndrome: Rheumatoid arthritis, Thyroid abnormalities, asthma and Sjogren’s syndrome
- For younger women: Hormonal changes brought on by pregnancy, lactation, oral contraceptives, menstruation, and post-menopause can cause dry eye conditions
- Laser eye surgery – dry eye is a confirmed side effect.
How are Dry Eyes Treated?
An assessment is required to determine whether you actually have dry eyes and if so which type is required. Around 80% of patients have dry eyes because of lack of tear volume (aqueous deficiency) and 20% have dry eyes caused by evaporation from defective tear oils where plug treatment is inappropriate. In evaporative dry eyes, a different treatment is prescribed. Many patients have both aqueous and evaporative components to their dry eye, so tests are needed.
Depending on the cause, dry eye syndrome can be treated as a temporary problem or a long-term condition. Either way, tears must be conserved or supplemented in order to provide relief.
Short-term relief by tear supplements
For less severe dry eye cases, artificial tears offer immediate relief. Unfortunately, many widely used bottles of eye drops contain preservatives which can cause a worsening of the dryness with time. New technology lubricants (hypotonic, unpreserved) work but are only temporarily. The best treatment is conservation of your existing tears.
In cases of more persistent dry eye symptoms, closure of the tear duct openings may be the best option. This conserves precious tears by restricting drainage. Your eyes are bathed with your own natural tears without the inconvenience of constantly supplementing the tear film with artificial drops