What is tear film?

   Tear film, which constantly covers the eye, is made up of three layers.  The oily outer layer reduces evaporation of the tears.  The watery middle layer cleanses the eye and washes away foreign particles or irritants.  The inner layer consists of mucus which coats the surface evenly and allows the tears to adhere to the surface of the eye.

Two types of tears

   The lacrimal glands, which are located above the eyeball, produce watery tears to moisten the eye and "crying tears" in response to injury and emotion.  The smaller tarsal glands in the eyelids produce a tear film which constantly moistens and lubricates the eye.  Both types of tears drain from the eye through the punctum, located in the eyelid.  The tears then travel through a canal into the tear sac and finally into the nasal passages.

   Tears, are important to the maintenance of good vision.  The tear film, which is spread over the eye by blinking, keeps the surface of the eye smooth and optically clear.  Tears also protect the eye from infection, since they contain a substance called lysozyme which acts as an antibacterial agent.

What are the symptoms of dry eyes?

   Patients with dry eyes often complain that their eyes feel gritty, itchy, scratching, and dry.  Other common symptoms include burning, stinging, redness, stringy mucus and sensitivity to light.  Some patients may experience their eyelids sticking together in the morning.  Patients with dry eyes may also have difficulty wearing contact lenses, which normally float on top of the tear film.  If not enough tear film is produced, irritation and redness may result from the contact lens rubbing against the surface of the eye. Some people also experience a "foreign body sensation," the feeling like there's something in the eye. And, it may seem odd, but sometimes watery eyes can result from dry eye syndrome, because the excessive dryness works to over stimulate the watery component of your eye’s tears.

   Surprisingly, watering of the eyes is also a symptom of dry eyes, as excess tears are produced in response to irritation.  However, these excess tears are "crying tears" which consist mostly of water.  The excess tears lack the oil necessary to keep them from evaporating and,  therefore, do not function to lubricate the eye.

  Your Ophthalmologist may want to measure the amount of tears in your eyes. A thin strip of filter paper placed at the edge of the eye, called a Schirmer test, is one way of measuring this.

What causes dry eyes?

   The causes of dry eyes are numerous.  Normally, tear production decreases with age, leaving the delicate eye tissues exposed to the irritating effects of the environment. 

   Dry eyes often occur in patients with arthritis.  Medications and Vitamin A deficiency may also cause dry eyes by reducing tear secretion.  In addition, environmental factors such as sun, wind, and smoke contribute to the occurrence of dry eyes.  An overly large punctum (drainage channel) or abnormal eyelid location may cause dry eyes.  Tears bathe the eye, washing out dust and debris and keeping the eye moist. They also contain enzymes that neutralize the microorganisms that colonize the eye.  Sometimes the eye doesn't produce enough tears, or the tears have a chemical composition that causes them to evaporate too quickly. Other times dry eye results when you don't blink often enough.  Computer users, for example, often forget to blink for long periods of time, so even if their tear film is normal, it eventually evaporates, leading to discomfort.  Dry eye syndrome has several causes. It occurs as a part of the natural aging process, especially during menopause; as a side effect of such medications as antihistamines, antidepressants and birth control pills; or because you live in a dry, dusty or windy climate. 

   Dry eyes are also a symptom of systemic diseases such as lupus, rheumatoid arthritis or Sjogren's syndrome (a triad of dry eyes, dry mouth, and rheumatoid arthritis or lupus).  If medications are the cause of dry eyes, discontinuing the drug generally resolves the problem. In this case, the benefits of the drug must be weighed against the side effect of dry eyes. Sometimes switching to a different type of medication alleviates the dry eye symptoms while keeping the needed treatment. Treating the underlying eyelid disease helps as well. This may call for antibiotic or steroid drops plus frequent eyelid scrubs. 

   Long-term contact lens wear is another cause; in fact, dry eyes are the most common complaint among contact lens wearers. Recent research indicates that contact lens wear and dry eyes can be a vicious cycle. Dry eye syndrome makes contact lenses feel uncomfortable, yet the rubbing of the lenses against the conjunctiva seems to be a cause of dry eyes, according to a report in the January 2001 Contact Lens Academy of Optometry Journal.  Incomplete closure of the eyelids, eyelid disease and a deficiency of the tear-producing glands are other causes.  Dry eye syndrome is more common in women, possibly due to hormone fluctuations, especially during change of life or pregnancy. Recent research suggests that smoking and taking multivitamins can increase your risk of dry eye syndrome. 

   Dry eye syndrome is an ongoing condition that cannot be cured, but the accompanying dryness, scratching and burning can be managed. Your eye care practitioner may prescribe artificial tears, lubricating eye drops that may alleviate the dry, scratching feeling. Sometimes too much moisture drains out of the eye through the lacrimal (tear) ducts. Temporary or permanent silicone plugs in the lacrimal ducts usually solve this problem very well. They can be inserted painlessly in the eye doctor's office and are normally not felt once inserted. Sometimes, however, the ducts need surgical blockage.

How are dry eyes diagnosed?

   Dry eyes are often diagnosed with a simple eye examination.  The Schirmer Test, which measures tear production, may be used.  In the Schirmer tear strip test, filtered paper strips are placed just inside the lower eyelid to measure the rate of tear production.

   In some cases, temporary closure of the punctum may be performed to determine if eye discomfort is due to dry eyes.  A tiny collagen implant, about the size of a grain of rice, is painlessly placed in the tear drainage canals.  The implants permit only a small percentage of tears to pass into the nasal passages, thus building up a layer of tears on the surface of the eye.  The implants are absorbed by the body in 3 to 5 days, giving the patient and doctor time to evaluate the effectiveness and comfort provided by an increase in the amount of tears on the surface of the eye.

How are dry eyes treated?

   Artificial tears are the most common treatment for dry eyes.  Eye drops, which are available without a prescription, are used to lubricate the eyes and replace missing moisture.  Slow release medicine inserted just inside the lower lid which gradually releases moisture during the day is also helpful.  Difficulty opening the eyes in the morning may be treated with an ointment at bedtime.  Restasis (cyclosporine in a castor-oil base) eyedrops help your eyes to increase tear production; this new treatment is the first of its kind.

   Patients who suffer from dry eyes can also take steps to prevent the evaporation of tears.  Using a humidifier to add moisture to the air and avoiding smoke, wind and other irritating conditions may provide relief.

   If artificial tears alone fail to provide sufficient relief from dry eyes, soft contact lenses may be used to keep moisture on the surface of the eye.  Soft contact lenses have a tendency to absorb water and other fluids and act as a bandage which protects the cornea.  When used to treat dry eye, soft contact lenses trap artificial tears and medicine drops on the surface of the eye, thus providing needed moisture and lubrication.

   Doctors sometimes recommend special supplements for dry eyes. Studies have found that supplements containing certain essential fatty acids (linoleic and gamma-linolenic) can decrease dry eye symptoms.  Quite a few products are in testing for possible dry eye treatment. For example, both trehalose (a carbohydrate) and castor oil solutions improved dry eye symptoms in small studies, but further testing is needed.

   In some cases, the punctum must be permanently narrowed or sealed to keep the tears from draining out of the eye quickly.  The punctum may be blocked by the insertion of permanent punctum plugs.  Unlike the dissolvable type used in testing, these plugs remain in place unless removed.  The punctum can also be narrowed or blocked using surgical techniques or lasers.  This procedure can usually be performed in the office and is painless, as a local anesthetic is administered before the treatment.  Although it is possible to reopen the punctum once it has been closed, the need to do so is rare.

   If you are suffering from dry eyes or other eye discomforts, you should obtain a complete eye examination.  Dr. Cano has the experience to diagnose this or any other optical condition.  To make an appointment, just click below.

       Do You Suffer From
       Dry Eye Syndrome?

               Get the Facts.

By decreasing inflammation, and augmenting the oil and water layers of the tear film, omega-3 supplementation with EPA-enriched flaxseed oil promises to provide the foundation for a broad spectrum of dry eye treatment regimens and make a link to the following information sites and stating that we carry TheraTears Nutrition Now:
   

  http://www.theratears.com/

      RESTASIS™ (cyclosporine ophthalmic emulsion) 0.05% is the first and only therapy for patients with keratoconjunctivitis sicca (Dry Eye Disease) whose tear production is presumed to be suppressed due to ocular inflammation. Dry Eye Disease is a painful and irritating condition involving abnormalities and deficiencies in the tear film initiated by a variety of causes. Unlike artificial tears, RESTASIS™ is the first drug proven to effectively treat a cause of Dry Eye Disease rather than only temporarily alleviate symptoms.  www.Restasis.com

For information regarding plugs that Dr. Cano uses, click on the Medennium logo below.

   The following are a few good links for those patients looking for information regarding
dry eyes, especially those with a disorder causing it called Sjogrens syndrome:

             www.sjogrens.org                   www.dry.org

             What is Dry Eyes and What Causes It

Visit Us at:

Se habla Español