Conjunctivitis

Causes and Risks:
The conjunctiva is exposed to bacteria and other irritants. Tears help protect the conjunctiva by diluting bacteria and washing it away. Tears also contain enzymes and antibodies which inhibit bacterial growth.

Conjunctivitis is the most common eye disease in the western hemisphere and varies in severity from mild inflammation with tearing to a severe inflammation that causes tissue injury and tissue death.

There are many causes of conjunctivitis. Viral infection is the most common cause; other types include bacterial, Chlamydial, fungal, and parasitic agents (rarely). Pink eye is a specific disease caused by a bacterium (one of the Hemophilus types of bacteria). Viral and bacterial forms of conjunctivitis are highly contagious, and can spread among children very rapidly, sometimes causing local epidemics. Other causes are allergies ( allergic conjunctivitis ), chemical exposure, and certain systemic diseases.

Newborns can be infected by bacteria in the birth canal. This condition is called ophthalmia neonatorum and must be treated immediately to preserve sight. Use of contact lenses, particularly extended-wear lenses, is a risk factor for conjunctivitis. Contact with a person who has conjunctivitis is also a risk factor.

See also:



Prevention:
Good hygiene can help prevent the spread of conjunctivitis:

  • keep hands away from the eye
  • wash the hands frequently
  • change pillowcases frequently
  • replace eye cosmetics regularly
  • do not share eye cosmetics
  • do not share towels or handkerchiefs
  • proper use and care of contact lenses



Symptoms:



Signs and Tests:



Treatment:
Treatment of conjunctivitis depends upon the cause.

Allergic conjunctivitis may respond to treatment for underlying allergies or may disappear on its own when the causative allergen is removed. Cool compresses may be soothing for allergic conjunctivitis.

Antibiotic medication, usually eye drops, is effective for bacterial conjunctivitis. Viral conjunctivitis will disappear on its own. The discomfort with viral or bacterial conjunctivitis can be soothed by applying warm compresses (a clean cloth soaked in warm water) to closed eyes.

Prognosis:
The outcome is usually good with treatment.

Complications:
Reinfection within a household or school may occur if preventive measures are not followed.

Call Your Healthcare Provider:
Call for an appointment with your health care provider if symptoms persist longer than 3 or 4 days.


This is an illustration of a cross-section and frontal view of the eye.