Dry Eye Syndrome
Keratitis sicca; Xerophthalmia; Keratoconjunctivitis sicca

What is Dry Eye Syndrome?

Dry eyes are caused by a lack of adequate tears. Your tears are a complex mixture of water, fatty oils, proteins and electrolytes. This mixture helps make the surface of your eyes smooth and clear, and it helps protect your eyes from infection.

For some people, the cause of dry eyes is an imbalance in the composition of their tears. Other people don't produce enough tears to keep their eyes comfortably lubricated. Eyelid problems, medications and other causes, such as environmental factors, also can lead to dry eyes.

Poor tear quality:

The tear film has three basic layers: oil, water and mucus. Problems with any of these layers can cause dry eyes symptoms.

• • Oil. The outer layer of the tear film, produced by small glands on the edge of your eyelids (meibomian glands), contains fatty oils called lipids. These smooth the tear surface and slow evaporation of the middle watery layer. If your oil glands don't produce enough oil, the watery layer evaporates too quickly, causing dry eyes. Dry eyes are common in people whose meibomian glands are clogged. Meibomian dysfunction is more common in people with inflammation along the edge of their eyelids (blepharitis), rosacea and other skin disorders.
  
  
• • Water. The middle layer is mostly water with a little bit of salt. This layer, produced by the tear glands (lacrimal glands), cleanses your eyes and washes away foreign particles or irritants. If your eye produces inadequate amounts of water, the oil and mucus layers can touch and cause a stringy discharge.
  
  
• • Mucus. The inner layer of mucus helps spread tears evenly over the surface of your eyes. If you don't have enough mucus to cover your eyes, dry spots can form on the front surface of the eye (cornea).
  
  

Who is affected by Dry Eye Syndrome?

• • People older than 50. Tear production tends to diminish as you get older. Dry eyes are common in people older than 50.
  
  
• • Postmenopausal woman. A lack of tears is more common among women, especially after menopause. This may be due in part to hormonal changes.
  
  
• • Have a medical condition that reduces your tear production. Dry eyes are also associated with some medical conditions such as diabetes, rheumatoid arthritis, lupus, scleroderma, Sjogren's syndrome, thyroid disorders and vitamin A deficiency.
  
  
• • Have had laser eye surgery. Refractive eye surgeries such as laser-assisted in-situ keratomileusis (LASIK) also may cause decreased tear production and dry eyes. Symptoms of dry eyes related to these procedures are usually temporary.
  
  
• • Have tear gland damage. Damage to the tear glands from inflammation or radiation can hamper tear production.
  
  

What are common signs that indicate I may be suffering from Dry Eye Syndrome?

• • Reduced visual acuity
  
  
• • Thick cornea
  
  

There are special test that can evaluate your tear production.

• • Schirmer's test -- measures the rate of tear production using a calibrated paper wick placed on the edge of the eyelid
  
  
• • Slit lamp (biomicroscope) exam of the film of tears (a dye such as fluorescein may be placed in the eye to make the tear film more visible)
  
  

What are the different types of treatment available for Dry Eye Syndrome?

• • Hot compresses or eyelash cleaning
  
  
• • Lubricating ointments (in more severe cases)
  
  
• • Medications such as Restasis, topical corticosteroids, and oral tetracycline and doxyccycline
  
  
• • Tiny plugs placed in the tear drainage ducts to help the tears stay on the surface of the eye
  
  
• • Wetting drops called artificial tears
  
  

Medications that cause dry eyes

• • Certain types of drugs used to treat high blood pressure, such as central-acting agents and diuretics
  
  
• • Antihistamines and decongestants
  
  
• • Birth control pills
  
  
• • Certain antidepressants
  
  
• • Pain relievers, such as ibuprofen (Advil, Motrin, others) and naproxen (Aleve)
  
  
• • Isotretinoin-type drugs for treatment of acne
  
  

>h4>Other common dry eye causes:

• • Dry air
  
  
• • High altitude
  
  
• • Wind
  
  
• • Tasks that require concentration, such as reading, driving or looking at computers
  
  

Prognosis:

Keratoconjunctivitis sicca usually is a chronic problem. Its prognosis shows considerable variance, depending upon the severity of the condition. Most patients have mild-to-moderate cases, and can be treated with lubricants such as drops or oral nutrition. This typically provides an adequate relief of symptoms. When dry eyes symptoms become severe, they can interfere with quality of a person's life. Vision can become very blurry with use, or severe irritation to the point that they have trouble keeping their eyes open or they may not be able to work or drive.

Complications:

Ulcers or infections of the cornea are serious complications.