2 DefinitionAcute inflammation of the conjunctiva due to either viral or bacterial infection
3 Causes Viral causes Bacterial causes Ophthalmia neonatorum include adenovirus, Herpes simplex.Bacterial causesinclude Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae..Ophthalmia neonatorumis conjunctivitis secondary to gonorrhoea or chlamydia within the first month of life.
4 Incidence Conjunctivitis is the most common cause of 'red eye'. Conjunctivitis accounts for around 44% of all eye problems presenting in general practice [Manners 1997].2-5% of all general practice consultations are eye related [Manners 1997].Viral conjunctivitis is more common than bacterial conjunctivitis [Baum 1995].
5 Symptoms and Signs 'Red eye' (diffuse conjunctival injection). Eye discomfort/burning/gritty sensation (not painful).Minimal pruritus.Vision is usually normal - although 'smearing', particularly on waking, may be common.Photophobia mild or absent.
6 Symptoms and Signs (cont.) May be unilateral or bilateral, although usually starts in one eye (not discriminatory of cause).Association with URTI, watery discharge, and preauricular lymphadenopathy are suggestive of viral cause.A purulent discharge suggests bacterial cause.History of contact with similarly affected person is common.
7 Differential Diagnosis Orbital cellulitisAdmit urgently if this is suspected (patient is unwell, tender sinuses, restriction of eye movements).Allergic conjunctivitissuggested by moderate to severe pruritus.Uveitis (Iritis)presents with pain, photophobia and excessive tearing.Acute glaucoma (angle closure).Symptoms of ocular and facial pain, unilateral blurring of vision and occasionally nausea and vomiting. The pupil is usually mid-dilated, oval and non-reactive to light.
8 Differential Diagnosis (cont.) Keratitispresents with a unilateral, acutely painful, photophobic, intensely injected eye.Scleritispresents with severe, boring ocular pain, which may also involve the adjacent head and facial regions.Episcleritispresents as a relatively asymptomatic acute onset localised redness in one or both eyes.Herpetic (dendritic) ulcerpainful, stains with fluorescein.Herpes zostervesicular eruption suggestive of shingles.
9 What can go wrong? Chronic conjunctivitis. Corneal ulceration. Wrong diagnosis.
10 Management Issues General measures Conjunctivitis is contagious (particularly adenoviral). Advice should be given regarding sharing of towels, utensils etc with others, time off school/work if necessary, and minimal hand/eye contact. Doctors should also be aware of sterile techniques to avoid cross-contamination of instruments etc. [Donahue 1996]Contact lenses should not be worn if conjunctivitis is present or if topical treatments are being instilled.
11 Treatment of infection A topical antibacterial preparation is usually prescribed empirically for the following reasonsIn most cases it is clinically difficult to distinguish between viral and bacterial infection.Bacterial superinfection can occur in cases of viral conjunctivitis.To relieve symptoms and shorten the course of disease (spontaneous remission is likely to occur within several weeks [Baum 1995; Barza 1983]).
12 Treatment (cont.) Chloramphenicol Fusidic Acid remains the drug of choice for all superficial eye infections in the U.K. as it is effective, reliable, broad spectrum and cheap. Previous concerns over its association with aplastic anaemia have largely been discountedFusidic Acidis an alternative that is more expensive but only twice daily