Deep microsporidial keratitis after keratoconjunctivitis

Abstract

[Extract] Microsporidia are intracellular pathogens of animals andhumans. Although not hyphal, a recent study suggests theyare fungi descended from an ancestral zygomycete. Theyhave a unique method for invading susceptible tissue: an internal coiled tube everts rapidly and sporoplasm moves into the cell as if through a hypodermic needle. In the human eye, microsporidial infection presents as keratoconjunctivitis or stromal keratitis. The former has been reported in HIV+ patients because of Encephalitozoon and in immunocompetent patients because of several genera. Stromal infection is seen in immunocompetent patients and is caused mostly by Vittaforma corneae. We report a case in which keratoconjunctivitis preceded deep stromal infection in a patient with a low neutrophil count.