Fungal infections of the cornea.

PURPOSE: To describe key aspects of fungal infections of the cornea, which constitute an important eye problem in outdoor workers in tropical and subtropical regions.
METHODS: Review of published studies and personal observations. OBSERVATIONS: Fungal infections of the cornea are frequently caused by species of Fusarium, Aspergillus, Curvularia, and Candida. Trauma is the most important predisposing cause; ocular and systemic defects and prior application of corticosteroids are also important risk factors. Culture remains the cornerstone of diagnosis; direct microscopic detection of fungal structures in corneal scrapes or biopsies permits a rapid presumptive diagnosis. A variety of antifungals have been evaluated in therapy of this condition. Natamycin can only be given topically, while amphotericin B, miconazole, ketoconazole, itraconazole, and fluconazole can be administered by various routes. Topical amphotericin B (0.1-0.3%) is frequently the treatment of choice for infections due to Candida and related fungi, while topical natamycin (5%) is the choice for keratitis due to filamentous fungi. Medical therapy may fail, necessitating surgical intervention.
CONCLUSIONS: Fungal infections of the cornea continue to be an important cause of ocular morbidity, particularly in the agricultural communities of the developing world. A proper understanding of agent and host factors involved in these infections will improve the outcome of this condition.