Polymicrobial infection and the eye

Treatment for infection is typically determined following an assessment of the clinical features of the disease, the likely causative pathogen, and the spectrum of activity of the available drugs. This treatment can be modified subsequently when the results of clinical investigations are available. It would simplify management if each infection were caused by a single pathogen that was amenable to treatment with one antimicrobial agent. Unfortunately, multiple pathogens may be present and they may interact to confuse the clinical picture. Simultaneous or sequential polymicrobial infection can occur, both with similar organisms (for example, different species of bacteria) and with organisms from completely separate kingdoms (for example, bacteria, fungi, acanthamoeba) or non-living viruses.1 The presence of a polymicrobial infection has important management implications because it will modify the clinical course of the disease and the anticipated response to treatment. With the exception of topically applied antiseptics, the antimicrobials used in ophthalmology do not have a significant activity across groups of potential pathogens. Polymicrobial infection may be missed unless specific investigations are performed to identify all potential participants in the disease process, and protocols may need to be developed for effective treatment. Although polymicrobial infection in ophthalmology has been reported previously the clinical impact has received little attention (table 1).

The reported incidence of ocular …