As indicated previously, the threshold for referral would depend on specific circumstances, but in the presence of normal visual acuity and absence of any corneal defect or suggestion of corneal infiltrate it may well be appropriate for first line management with a topical antibiotic to be given. These cases are often self limiting and first line management is with topical chloramphenicol or trimethaprim and polymyxin four to twelve times daily dependent upon severity. Change to alternative antibiotics if the clinical progress is suggestive of resistance, preferably after cultures are taken for microbiological analysis. An acute conjunctivitis with mucopurulent or watery discharge associated with a follicular reaction rather than a papillary response is most likely to be viral. The differential diagnosis would commonly lie between the adenovirus, possibly the herpes virus, or chlamydia.
Advice concerning the risks of cross infection and contagion is important.
Antivirals are ineffective against adenovirus. Topical antibiotic treatment may sometimes be given appropriately to reduce the risk of secondary bacterial infection or to eliminate possible mis-diagnosis of bacterial conjunctivitis. If, after five days, such cases are deemed to be making poor clinical progress, they should be referred for investigation to exclude chlamydia. Symptoms of ocular discomfort, hyperemia and foreign body sensation may take up to two months to resolve following, for example, the adenovirus. Occasional corneal scarring is seen in these cases and the classical adenovirus infection is associated with a preauricular lymph node.