Definition: occurs when there is a problem with the tear film that normally keeps the eye moist and lubricated. It can occur as a result of various conditions.The tear film is made up from three layers – the main middle watery layer, the thin outer lipid (oily) layer, and the thin inner mucus layer.
Classification / type of disease:
Epidemiology:it becomes more common with increasing age. Dry eyes affects about 7 in 100 people in their 50s, and about 15 in 100 people in their 70s. Women are affected more often than men.
Presenting symptoms / signs: often bilateral irritation, ritty, burning, slight blurring of vision, photophobia, pain when wearing contact lenses. EYES DO NOT GO RED!
Diagnostic investigations:clinical diagnosis, Schirmer Tear Test
- Medication: diuretics, antidepressants, antihistamines, some treatments for anxiety and other psychological problems, COCP, beta-blockers such as propranolol, atenolol, etc; some eye drops used to treat other eye conditions.
- Illness: rheumatoid arthritis, SLE, and Sjogren’s syndrome
- Increased evaporation of tears: Low humidity, Low blink rate, Windy conditions, Inability to completely cover the eyes when closing the eyelids.
- Damage to the outer part of the eyes, eyelids, etc, from disease, injury or surgery.
- Blepharitis = inflammation of the eyelids
- Unknown. Some younger people have no apparent cause.They simply produce less than the normal amount of tears.
Pathophysiology: complications can include conjunctivitis, keratitis, corneal ulceration or perforation of globe
Treatment / management:
Artificial tears: Eye drops and gels, and are usually good at relieving symptoms. There are several types of artificial tear drops and gels with different ingredients. Occasionally, some people find one type may irritate. A change to a different preparation may help if the first does not suit. Try to avoid prolonged use of products containing benzalkonium hexachloride as this is toxic to the cornea.
Eye ointment: It may also help to use a soothing and lubricating ointment at bedtime for overnight.
Other treatments: drugs are sometimes used to boost tear production by the tear gland and surgery is sometimes done to block the tears from draining away.