Pathogenesis of acanthamoebic keratitis: hypothesis based on a histological analysis of 30 cases.

The results of a histopathological study of 30 cases of Acanthamoeba keratitis are construed as indicating a four stage pathogenetic sequence: (1) initial infection, involving breaching of the surface epithelium; (2) keratocyte depletion by the invading trophozoites; (3) inflammatory response mediated by neutrophil polymorphonuclear leucocytes; (4) stromal necrosis attributable to leucocytic activity.