Conjunctivitis
Alternative names:
inflammation of the conjunctiva; pink eye
Definition:
Inflammation or infection of the membrane lining the eyelids (conjunctiva).
Causes, incidence, and risk factors:
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:
|
