Conjunctiva Definition

The conjunctiva is the clear, thin membrane that covers part of the front surface of the eye and the inner surface of the eyelids. It has two segments: Bulbar conjunctiva. This portion of the conjunctiva covers the anterior part of the sclera (the "white" of the eye). The bulbar conjunctiva stops at the junction between the sclera and cornea; it does not cover the cornea. Palpebral conjunctiva. This portion covers the inner surface of both the upper and lower eyelids. (Another term for the palpebral conjunctiva is tarsal conjunctiva.) The bulbar and palpebral conjunctiva are continuous (see illustration). This feature makes it impossible for a contact lens (or anything else) to get lost behind your eye. Conjunctiva Function The primary functions of the conjunctiva are: Keep the front surface of the eye moist and lubricated. Keep the inner surface of the eyelids moist and lubricated so they open and close easily without friction or causing eye irritation. Protect the eye from dust, debris and infection-causing microorganisms. The conjunctiva has many small blood vessels that provide nutrients to the eye and lids. It also contains special cells that secrete a component of the tear film to help prevent dry eye syndrome. Conjunctiva Problems A number of conditions can affect the conjunctiva. Among the more common conjunctival problems are: Conjunctivitis. Also called pink eye, this is inflammation of the conjunctiva. It can have several causes. Conjunctival pallor. This is an unhealthy pale appearance to the palpebral conjunctiva that can be a sign of anemia. Injected conjunctiva. This is a red eye caused by dilation of blood vessels in the conjunctiva. It can have many causes.

Conjunctival melanoma. This is an elevated, dark or relatively clear cancerous growth in the bulbar conjunctiva. Conjunctival melanomas are uncommon but potentially lethal. The cancer cells from a conjunctival melanoma can infiltrate the eyeball and spread via the lymphatic system or bloodstream to the lungs, liver, brain and bones. Conjunctival lymphoma. This is a tumor of the front surface of the eye that usually appears as a salmon-pink, "fleshy" patch. Conjunctival lymphomas typically are hidden behind the eyelids and painless; therefore they may be present for quite some time before they are discovered — especially in people who don't have routine comprehensive eye exams. If you have a growth on your eye that resembles this description of a conjunctival lymphoma, immediately see an ophthalmologist who can evaluate it and perhaps perform a biopsy to determine the proper treatment.

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Sarah Rose

Journal Manager Journal of Eye Diseases and Disorderss