What is dry eye?

Tears are essential for your eye’s lubrication and nourishment. But any condition that affects the quantity and/or quality of the tears leads to dryness of the eyes. Dry eyes are the symptom not the disease itself. Which means that treatment of dry eyes depends mainly on treatment of the cause.  

Why are tears important?

Tears are a thin aqueous film spreading across the front of the eye, namely the cornea and sclera. Tears protect our eyes against:

• Bacterial infection.
• Foreign bodies on the surface of the eye like dust and sand.

Tears are produced from special glands in the eyes known as the lacrimal and Moebian glands and drain into the back of the nose. Any imbalance between the production of tears and drainage causes dry eyes. Tears consists of three components: oil, water and mucus. Each component has a function that aids in protecting and nourishment of the front surface of the eye. The oily layer prevents evaporation of the watery layer while the last mucin layer allows the tears to spread in an evenly matter over the eye’s surface.  

What are the most common causes of dry eyes?

Any factor that affects the quantity and/or quality of tears causes dry eyes; this includes:

1. Aging: tears production tends to decrease by age leading to chronic dry eyes especially after the age of 65 years.
2. Gender: women are more susceptible to dryness of the eye due to the hormonal imbalance associated with menstruation, pregnancy, oral contraceptives and menopause.
3. Environmental factors: pollution, wind and/or dry climates causes dry eyes as tears evaporate faster than normal weather conditions.
4. Medications: one of the most common side effects of many oral and local medications is dry eyes. This includes: antihistaminic drugs, decongestants, anti-hypertension drugs, antidepressants, retinoids and more.
5. Chronic diseases: Many chronic diseases cause dry eyes. Most commonly: rheumatoid arthritis, diabetes mellitus, thyroid gland problems, scleroderma, Lupus, Sjogren’s syndrome and many others.
6. Local eye diseases: Inflammation of the eyelids (blepharitis), inflammation of the conjunctiva (conjunctivitis), ptosis of the eyelids and bulging of the eyes may cause dry eyes.
7. Dry eye syndrome: a syndrome known as keratoconjunctivitis sicca is a common disease affecting the quantity of the watery layer of the tears.
8. Smoking: if you are a smoker, you will always complain of dry eyes!
9. Staring at screens: failing to blink regularly due to staring at computer or mobile screens is a common reason for dry eyes.
10. Refractive errors: if you have nearsightedness, you may complain of dry eyes. And wearing contact lenses without regularly changing them may lead to dry eyes. Also, in LASIK surgery, it is common to complain about dry eyes for a few days after the surgery.

 

What are the symptoms of dry eyes?

Feeling that your eyes are dry may not be as straightforward as you think, in fact you may complain of any of the following first:

• Irritated eyes
• Gritty eyes
• Scratchy eyes
• Burning eyes
• Excess tearing (yes, it is a paradoxical symptom as your eyes respond by trying to produce more tears)
• Blurred vision
• Stinging eyes
• Thread mucus in or around your eyes
• Extra Sensitivity to light
• Pink eye.
• Feeling like you have something in your eyes
• Getting more difficult to wear your contact lenses
• Difficult driving especially at night.
• Eye fatigue
• Any of these symptoms may occur on top of the original cause (like inflammation of the eyelids)!

 

How does your ophthalmologist diagnose dry eyes?

Dry eyes diagnosis depends mainly on knowing the cause. To know the reason behind your dry eyes, your doctor will:

• Take full medical history.
• Take full family history.
• Ask about any medications or environmental factors.
• Ask about any previous procedures or eye surgeries.
• Examine the eye thoroughly including the eyelids and how frequent do you blink.
• Evaluate the quantity and quality of your tears through special tests that include:
• Special dyes to observe the flow of tears, check for any abnormalities in the spreading of the tear film and how long till your tears evaporated.
• Schirmer test: blotting strips of paper are put directly under your lower eyelids. Within five minutes your doctor will measure the amount of tears soaking this strip.

 

Treatment of dry eyes

Treating dry eyes depends on two main strategies, replacing the inadequate tears with artificial ones, and treating the underlying cause. Artificial tears are easily found in pharmacies and are sold without prescription. But it is best to be given under your ophthalmologist’s supervision to avoid side effects and to detect the underlying cause and treat it the disease and its symptoms once and for all! Managing the underlying cause: For example:

• If a medication is causing you dry eyes, then ask your doctor if you can replace this drug with another one.
• If you have a chronic disease, consult your doctor to keep it under control and avoid its complications.
• If you live in a dry environment, try staying indoors as often as possible.
• If you are a smoker, then quitting smoking is in order.
• If the problem is in the eyes, like inflammation or infection then antibiotics whether locally or orally are recommended.
• If you wear contact lenses, try giving your eyes rest and go back to wearing eyeglasses for a few days.
• Daily warm compresses can help clear up the blocked glands.
• Another method includes decreasing tear loss by blocking its drainage using removable silicon plugs.
• Recent options for treatment of dry eyes include: Using intense-pulsed light therapy followed by eyelids massage to stimulate the lacrimal glands to produce more tears.

 

Magrabi’s advice

Dry eyes are common condition that affects our eyes due to any change in the quantity of quality of our tears. This change could be due to general, environmental or medical causes. Although it is easily treated by artificial tears, treating the underlying cause is a better more permanent option. Visit your ophthalmologist if you suspect dry eyes to avoid its serious complications.