Recognition and chemotherapy of oculomycosis

Abstract

Oculomycosis may be divided into the orbital infections of phycomycosis of Aspergillus and other species and the infections of the globe. The latter comprise endogenous, post-surgical or traumatic intra-ocular infections and direct infections of the cornea: these are the commonest form of oculomycosis. They are not easy to differentiate from other, more common causes of septic infection of the eye. The early recognition of fungal infections of the eye thus rests on maintaining an efficient service for all septic infections of the eye.

Candida albicans and other dimorphic fungal infections are best treated with flucytosine combined with either polyenes such as amphotericin B and natamycin or combined with imidazoles such as clotrimazole or miconazole.

Aspergillus spp. account for about 50% of the cases of filamentous fungal infection of the cornea but more than 100 species of varying pathogenicity and drug sensitivity have been implicated. Econazole, clotrimazole or miconazole combined with thiabendazole are recommended for Aspergillus spp. Econazole, thiabendazole or miconazole combined with flucytosine for Cladosporium sp. For Fusarium solani and other species econazole is the best drug but some isolates are sensitive to thiabendazole or other imidazoles.

Alternatively, filamentous fungal infections may be treated with natamycin which has a broad spectrum of activity; but does not penetrate well and, like other polyenes, should not be combined with imidazole antifungal chemotherapy because of antagonistic drug interaction.

Overall, econazole emerges as the most widely acting drug; but successful results are dependent on rather complex investigation with intensive and protracted care that can best be provided in a few centres of referral.