Clinical signs and medical therapy of early Acanthamoeba keratitis

Several diagnostic signs of Acanthamoeba keratitis have been reported recently. We treated three patients who developed a dendritiform epithelial pattern seen early in the course of Acanthamoeba keratitis that likely represents epithelial infection by Acanthamoeba before any stromal involvement. In these three cases, the early diagnosis of Acanthamoeba keratitis coupled with wide epithelial debridement and medical therapy proved effective in eradicating the protozoan. In two additional cases, Acanthamoeba keratitis was not diagnosed until significant stromal involvement was present. Medical therapy was effective in eradicating the organism in one case, although penetrating keratoplasty was necessary for visual rehabilitation. In the other case, medical therapy was ineffective, as corneal perforation resulted and Acanthamoeba cysts were demonstrated by fluorescent staining in the host corneal button.