Conjunctivitis
is inflammation of the conjunctiva, the delicate mucous membrane
that covers the eye and lines the eyelids. On the eyeball itself,
the conjunctiva is transparent and has few visible blood vessels.
In conjunctivitis, the conjunctiva becomes red and inflamed.
The eye is sticky and sore (rather than painful, people describe
it ‘like having sand in the eye’). There is usually no difficulty with vision and, unlike the more serious condition, iritis, there is no particular increase in sensitivity to light. There is usually some discharge. In bacterial conjunctivitis, the commonest form, the discharge is purulent and sometimes there is more obvious pus than inflammation. This is particularly so in babies who are very prone to conjunctivitis. Quite often, conjunctivitis affects only one eye, but if only one eye is inflamed, medical attention should be sought lest there is another condition present, such as a foreign body in the eye, a corneal injury, or even a developing acute glaucoma, a serious condition causing blindness. In viral conjunctivitis there is often no pus, but a watery discharge. The condition is very contagious, so invariably both eyes are affected – and so may be any friends and family who happen to get close! Viral conjunctivitis can be a great nuisance sometimes lasting several weeks and causing marked discomfort. Bacterial conjunctivitis is usually short-lived, again is contagious, but has the advantage of being easily treatable. One more severe form of bacterial conjunctivitis, particularly in new-born infants who catch it as they pass through an infected birth canal, is chlamydial conjunctivitis ( see. Vaginal discharge). It is a strain of chlamydia that is the infective agent of trachoma, a cause of much blindness in the Third World. Allergic conjunctivitis is very common. There is itching, redness and swelling of the conjunctiva sometimes sufficient to make the eyeball itself look swollen. It is particularly common during the hay fever season (see Hay Fever). Chemical fumes and irritants can all cause conjunctivitis.
In the mildest cases, simple management, such as bathing the eye with clean water, using cotton wool, is often sufficient. Bacterial conjunctivitis usually responds rapidly to locally applied antibiotics available from the doctor. Viral conjunctivitis generally has to run its course, but for conjunctivitis caused by the Herpes Simplex virus (see Cold Sores) local aciclovir can be used. Conjunctivitis from irritants should resolve when the irritant is removed. For the treatment of allergic conjunctivitis, see Hay Fever. |
