Dry Eyes / Ocular Surface Disease
Dry, itchy eyes, or “Dry Eye Syndrome” is the most common complaint that eye doctors hear from patients. Canadians of both sexes, of all ages, and of all racial backgrounds have mild or severe instances of dry itchy eyes.
The eyes often reflect a larger problem that needs to be treated systematically. Certain nutrients such as vitamins A, C, D, E, & B6, Magnesium, GLA & DHA, Mucopolysaccharides (mucopolysaccharides are sugar molecules clumped together in a long chain) & turmeric may help ease chronic and severe dry eyes.
Dry itchy eyes are often related to other health conditions in the body such as other mucous membrane dryness, brittle nails, and in interior surfaces like the joints. The condition can an indicator of digestive imbalances or of serious autoimmune diseases, like Sjogren’s syndrome, rheumatoid arthritis, or lupus erthematosus.
Symptoms typically include irritation, dryness, burning, grittiness, difficulty reading for long periods of time, and, even though it may seem contradictory, excessive watering or tearing as the eyes attempt to solve the problem.
There are three interrelated layers of the “tear film” – the moisture laden surface of the eye and continuity of that surface and the production of tears relies on the function of three interrelated layers:
- Mucus layer which has some anti-microbial properties.
- Slightly alkaline watery layer comprising up 90% of the thickness of the tear film.
- Oily layer which slows evaporation of the tear film.
- Blinking renews the tear film by bringing material from the watery and oily layers removing debris. While normal blink rate is about 10-12 blinks per minute, when working on the computer our blink rate often slows. After about 10 seconds the tear film becomes unstable – leading to tired, dry eyes. This is also partially true when the blink is incomplete – not fully covering the cornea. It is the cornea that tells the brain to send messages to the body to produce more or less tears and when to blink.
Causes of Dry Eyes
- Any disruption in the tear production process. known as aqueous tear-deficient dry eye wherein the lacrimal glands don’t produce enough tear fluid.
- Tear evaporation known as evaporative dry eye, which may result from meibomian gland inflammation. Blepharitis with inflammed eyelids can cause dry itchy eye symptoms.
- Other diseases that may be connected to dry eyes are Diabetes, (especially with high blood sugar), migraine headaches, Rheumatoid Arthritis, Thyroid disease (lower lid does not move when blinking), Asthma, Lupus, and possibly Glaucoma.
- Age: Dry itchy eyes are experienced by 75% of those over 65, by which time you have 40% of the volume of tear film that you had when you were 18.
- Women’s hormonal changes can cause lowered tear production caused by menstruation, by pregnancy, lactation, and especially post menopausal hormonal changes.
- Other causes for dry eyes are smoking, drinking a lot of coffee, wearing contact lenses, being in air-conditioning or heated places with low humidity.
- Vitamin D deficiency is associated with eye pain, inadequate tear film, and unstable tear film.
Diagnosis There are a number of tests used by eye doctors to find the source of problems – which layer of the tear film is involved:
- Schirmer tear test (commonly used in dry eye research)
- Tear film break-up time (10 seconds) (commonly used in dry eye research)
- Conjunctival impression cytology (commonly used in dry eye research)
- Rose Bengal staining pattern
- Tear Osmolarity
- Tear protein levels (lactoferrin and lysozyme)
- Presence of corneal filaments
- Evaluation of debris in tear film