Clinical and histologic evaluations of experimental Acanthamoeba keratitis.

Amoebic keratitis, a sight-threatening, progressive corneal disease, is commonly caused by ubiquitous, pathogenic, free-living Acanthamoeba spp., which are widely distributed in the environment. We investigated clinical findings and histology of Acanthamoeba keratitis in a rat cornea model. Experimental Acanthamoeba keratitis was induced in Wistar rats by intrastromal inoculation of Acanthamoeba castellanii trophozoites. The clinic features of Acanthamoeba keratitis by day 70 are observed. All rats inoculated with Acanthamoeba developed keratitis. Histologically, the eyes displayed blood vessels, edema, and amoebae in stroma. A mixed cellular response, including neutrophils, mononuclear cells, and spindle-shaped cells, was seen. In conclusion, progressive, suppurative Acanthamoeba keratitis can be induced in the rat cornea model. This rat cornea model assists researchers who study the pathogenesis of Acanthamoeba keratitis and devise treatment for this difficult condition.