What is Conjunctivitis?

Conjunctivitis is a condition in which the inner lining of the eyelid and the mucous membrane that covers the eyeball become inflamed. It can be infectious or non-infectious and has many different causes. Infectious conjunctivitis can be highly contagious and is common in children.

What causes conjunctivitis?

Bacterial conjunctivitis
The most common cause of conjunctivitis is infection with bacteria such as staphylococci, pneumococci or streptococci. Bacterial conjunctivitis is very common in children, and may occur after a viral illness such as a cold.

Viral conjunctivitis
In many cases viral conjunctivitis is associated with the symptoms of a cold. Viral conjunctivitis is also highly contagious, particularly among children.

Allergic conjunctivitis
Allergic conjunctivitis is most common in the spring and early summer when the pollen count is high. Other causes of allergic conjunctivitis may be household pets, dust, perfume or cosmetics.

What are the symptoms of conjunctivitis?

In bacterial conjunctivitis the eyes become swollen and red and are usually painful. There may be a sticky discharge from the eyes, which can vary from a moderate to a large amount. This discharge may cause the eyelids to become stuck together after sleep. The eyes may also be irritated and sensitive to light.

Viral conjunctivitis usually causes a watery discharge, unlike the sticky discharge caused by a bacterial infection. The eyes also become red and feel uncomfortable.

Allergic conjunctivitis is usually accompanied by other symptoms of allergy such as itchy eyes and excessive tear production. There may also be sneezing and an itchy or runny nose.

What treatment is available?

Eye drops or eye ointment containing an antibiotic may be prescribed for bacterial infections. These should be put directly into the eye for about a week. They are usually administered four times a day (or more frequently to begin with). Eye ointments may be used instead of drops or used only at night in conjunction with eye drops during the day.

The eye drops or eye ointment will usually contain an antibiotic called chloramphenicol (eg, Brochlor®, Chloromycetin®, Minims Chloramphenicol®) or fusidic acid. If these are not effective other antibiotic eye preparations may be prescribed. For example, ciprofloxacin (Ciloxan®), gentamicin (eg, Genticin®), levofloxacin (Oftaquix®), ofloxacin (Exocin®), moxifloxacin (Moxivig®), tobramycin (Tobravisc®) or azithromycin (Azyter®).

For viral or allergic conjunctivitis, eye drops containing either a corticosteroid or a non-steroidal anti-inflammatory drug (NSAID) may be given. These will reduce the inflammation and itching and may also be given together with antibiotics for the treatment of bacterial infections.

Corticosteroid eye drops include betamethasone (eg, Betnesol®, Vistamethasone®), dexamethasone (eg, Dexafree®, Dropodex®, Maxidex®, Minims Dexamethasone®), fluorometholone (FML®) and prednisolone (eg, Minims Prednisolone®, Pred Forte®, Predsol®). NSAIDs available as eye drops for use in seasonal allergic conjunctivitis include diclofenac (Voltarol® Ophtha).

Sometimes a preparation containing both a corticosteroid and an antibiotic may be prescribed. Combination preparations include Maxitrol® (dexamethasone + neomycin) and Betnesol®-N (betamethasone + neomycin).

Antihistamine eye drops may also be prescribed for allergic conditions. These include antazoline plus xylometazoline (Otrivine-Antistin®), azelastine (Optilast®), emedastine (Emadine®), epinastine (Relestat®), ketotifen (Zaditen®) and olopatadine (Opatanol®). Other eye drops available for the treatment of allergy include lodoxamide (Alomide®), sodium cromoglicate (eg, Catacrom®, Opticrom®, Vividrin®) and nedocromil (Rapitil®).

Fact sheet provided by MIMS

Date last reviewed: September 2016

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