• microbial keratitis
• antibiotics

Microbial keratitis is an ocular emergency that requires prompt and appropriate management to ensure the best visual outcome for the patient. If possible, this means identification of the causative organism(s) and selection of the best antimicrobial agent(s) to treat the patient.

A clinical diagnosis of corneal infection does not give an unequivocal indication of the causative organism because a wide range of organisms can produce a similar clinical picture. The clinical history together with the duration and severity of symptoms and signs may make the clinical diagnosis of one type of organism more likely, but without attempting to identify the causative organism(s) treatment can only be based on clinical judgment.

The identification of organisms responsible for microbial keratitis is desirable because a positive result indicates the appropriate class of antimicrobial agent to use. Knowing the causative organism also gives the treating clinician confidence to pursue a particular line of therapy and avoids the unnecessary use of ineffective and potentially toxic drugs. Culturing allows sensitivity testing to a range of agents so that treatment modification can be made in an informed manner if the clinical response to initial treatment is inadequate.