What is Dry Eye Syndrome? (Keratoconjunctivitis sicca)

At Maine Eye Center we are committed to helping our patients overcome dry eye syndrome. Dry eye is a general term used to describe a heterogeneous group of diseases resulting from inadequate wetting of the cornea and conjunctiva by the precorneal tear film (PCTF). Millions of people worldwide suffer from dry eye.

Despite its high prevalence, dry eye is not always easy to diagnose. The vast majority of patients have symptoms that are mild to moderate in severity. Although these patients are genuinely suffering discomfort, objective signs of dry eye may be missed, and without proper diagnosis, patients may not receive the attention and treatment that this condition warrants.

The signs and symptoms of dry eye can be misinterpreted as evidence of other conditions such as infectious, allergic, or irritative conjunctivitis.

What causes Dry Eye?

Dry eye conditions are classified as various types of abnormalities that can lead to insufficient wetting of the corneal surface. These classifications are:

• Abnormalities of the aqueous layer
  
• Abnormalities of the mucin layer
  
• Abnormalities of the lipid layer
  
• Abnormalities of the corneal epithelium
• Abnormalities of the lids
  

What are the signs and symptoms of Dry Eye?

The symptoms of dry eye vary considerably from one individual to another. Most patients complain of a foreign body sensation, burning and general ocular discomfort. The discomfort is typically described as a scratchy, dry, sore, gritty, smarting or burning feeling. Discomfort is the hallmark of dry eye because the cornea is richly supplied with sensory nerve fibers.

A significant percentage of patients also experience photophobia and intermittent blurring or other problems with visual acuity.

Individuals with dry eye commonly remark that their eyes tire easily, making it difficult for them to read or watch television. The reason for this difficulty is that the frequency of blinking typically decreases during tasks that require concentration. As blink frequency decreases, there is more time for the tear film to evaporate. If blinking is infrequent enough, the duration of exposure will exceed the BUT, resulting in the formation of one or more dry spots on the corneal surface.

Contact lens intolerance can also be a symptom of dry eye. Sometimes, a patient with mild to moderate dry eye may not experience symptoms until contact lenses are fitted. The placement of a contact lens can upset the delicate balance of tear film production and distribution, leading to lens intolerance.

Content: Alcon Labs

For more information regarding dry eye or dry eye syndrome, please visit www.dry-eye-syndrome.net.