The Tear Gland secretes tears constantly at a slow and steady rate. The blink spreads the tears all over the ocular
surface to keep the eye lubricated. Then the tears are drained into
the nose through the lacrimal drainage system. Some of the tears
evaporate.
Good eye lubrication is dependent on a continuous balance
between secretion, drainage and evaporation. The loss of this
balance leads to Dry Eyes.
The eye uses two different methods to produce tears. It can make
tears at a slow, steady rate to maintain normal eye lubrication
(Basic Tears). It can also produce large quantities of tears in
response to eye irritation or emotion (Reflex Tears).
What Are the Symptoms of Dry Eye?
The usual symptoms include:
- Stinging or burning eyes
- Scratchiness
- Stringy mucus in or around the eyes
- Excessive eye irritation from smoke or wind
- Excess tearing
- Discomfort when wearing contact lenses
- Redness and Sore eyes
- Light sensitivity
- Tired and heavy eyes especially later during the day
- Foreign body sensation
- Fluctuation of vision
- Patients with recent LASIK, uncontrolled diabetes, or other ocular or systemic problems might not feel
anything or might have a milder version of the above complaints
Excess tearing from “dry eye” may sound illogical, but it can be understood as the eye’s response to discomfort. If
the tears responsible for maintaining lubrication do not keep the eye wet enough, the eye becomes irritated. Eye
irritation prompts the lacrimal gland to release a large volume of tears, overwhelming the tear drainage system.
These excess tears then overflow from your eye.
What Is the Tear Film?
When you blink, a film of tears spreads over the eye, making the surface of the eye smooth and clear. Without this
tear film, good vision would not be possible. The tear film consists of three layers: - Oil
- Water
- Mucus
Each layer has its own purpose.
The oily layer, produced by the meibomian glands of the lids, forms the outermost surface of the tear film. Its main
purpose is to smoothen the tear surface and reduce evaporation of tears. This layer is affected by Blepharitis and
Acne Rosacea.
The middle watery layer makes up most of what we ordinarily think of as tears. This layer, produced by the lacrimal
gland, cleanses the eye and washes away foreign particles or irritants.
The inner layer consists of mucus produced by the conjunctiva. Mucus allows the watery layer to spread evenly over
the surface of the eye and helps the eye remain moist. Without mucus, tears would not stick to the eye.
What Causes Dry Eye?
1-Aging: Tear production normally decreases as we age. Although dry eye can occur in both men and women at any
age, women are most often affected. This is especially true after menopause.
2-Arthritis: Systemic inflammation associated with arthritis can lead to dry mouth and dry eyes. This is Sjögren’s
syndrome.
3-Medications: A wide variety of common medications can cause dry eye by reducing tear secretion. Be sure to tell
Dr. Farah the names of all the medications you are taking, especially if you are using:
- Diuretics for high blood pressure;
- Beta-blockers for heart or high blood pressure;
- Antihistamines for allergies;
- Sleeping pills;
- Antidepressants;
- Pain killers;
- Contraceptive pills;
- Anti Acne (Vitamin A Roacutane) pills
4-Contact Lenses use: Dry eyes can be the cause of extensive long-term contact lens wear and can lead to contact
lens intolerance. LASIK can exacerbate dryness for the first few months.
5-The environment: Sunny, dry, and windy conditions, heaters, fans, air conditioners, smoke, office work and
continuous computer use can lead to excessive tear evaporation and subsequently to dry eyes.
How Is Dry Eye Diagnosed?
The ophthalmologist is usually able to diagnose dry eye by examining the eyes.
Sometimes tests that measure tear production are necessary. One test, called the
Schirmer tear test, involves placing filter-paper strips under the lower eyelids to measure
the rate of tear production under various conditions. Another test uses a diagnostic drop
to look for certain patterns of dryness on the surface of the eye especially Erosions and
to decide on the severity of Dry Eyes.
How Is Dry Eye Treated?
Computer Use Instructions: Write the word BLINK on top of your computer to remind yourself of blinking. Look for
far every 20-30 minutes to relax your eye muscles. Close the blades of the ventilator that direct the airflow towards
you.
Artificial Tears Eye-drops: They lubricate the eyes and help maintain moisture. Artificial tears range from liquids to
gels to ointments. There are many generations, the newer ones containing Sodium Hyluronate. You can use the
artificial tears as frequently as you need.
Punctal Plugs: Conserving your own tears is the best approach to keeping the eyes moist. Tears drain out of the eye
through a small channel
into the nose (which is why
your nose runs when you
cry). Putting a Punctal Plug
closes these channels
temporarily. The plugs
conserve your own tears
that contain the necessary
hormones 24/ 24 hours.
The Plugs are made of silicone and are inserted into one of lids.
The plugs are very practical for all patients especially those with busy and fast-paced lifestyle. They are easy to
insert, painless (takes few seconds in the office), have virtually no significant side effects, and can be removed at any
time.
Restasis Eye-drops (Cyclosporin A) may increase tear production. It is mainly given when there are signs of ocular
surface inflammation and redness.
Other Methods Tears evaporate like any other liquid. You can take steps to prevent evaporation. In winter, when
indoor heating is in use, a humidifier or a pan of water on the radiator adds moisture to dry air. Special eye-glasses
may reduce the drying effect of the wind and act as moisture chambers.
A person with dry eye should avoid anything that may cause dryness, such as an overly warm room, hair dryers, or
wind. Smoking is especially bothersome.
Some people with dry eye complain of “scratchy eyes” when they wake up. This symptom can be treated by using an
artificial tear ointment at bedtime.