The conjunctiva is the thin, transparent membrane lining that covers the outer surface of the eye. The conjunctiva is nourished by tiny blood vessels that are nearly invisible to the naked eye. The conjunctiva also secretes mucus that moistens and lubricates the eye. Conjunctivitis is an inflammation of the conjunctiva. Conjunctivitis that persists for four or more weeks is considered chronic.
Chronic bacterial conjunctivitis is most commonly caused by Staphylococcus species (a distinct type of bacteria), but other bacteria can also be involved. This type of conjunctivitis is often associated with blepharitis. Symptoms can include redness of the conjunctiva, burning, frequent styes, foreign body sensation and morning eyelash crusting or eyelash loss.
Another type of chronic conjunctivitis is meibomitis. This is a chronic conjunctivitis caused by inflammation of the meibomian oil glands that line the posterior lid margin behind the eyelashes. These glands malfunction when inflamed, leading to chronic inflammation of the lid margins and the conjunctiva as well as dry eyes. Meibomitis and blepharitis (inflammation of the eyelid) are also often associated with the skin disorder acne rosacea.
Trachoma infection of the eyes can also cause chronic conjunctivitis and can lead to chronic keratoconjunctivitis. Trachoma infection is the most common cause of preventable blindness in the world. It is uncommon in North America, but patients from Africa, Asia, and the Middle East with this condition may experience scarring of the ocular surface and eyelids, leading to decreased vision.
Chronic conjunctivitis can be caused by a variety of microorganisms and environmental factors. Careful diagnosis is crucial for the efficacy of the treatment. Conjunctival culture or biopsy may be required for precise diagnosis.
Treatment might include antibiotics, artificial tears and other topical medications. Sometimes oral antibiotics may be needed. Chronic conjunctivitis is treated by the Ocular Surface Diseases and Dry Eye Clinic