Acanthamoeba keratitis: persistent organisms without inflammation after 1 year of topical chlorhexidine.

Purpose: To report a non-contact lens wearer with persistent Acanthamoeba organisms in the cornea after being treated with medical therapy that included topical chlorhexidine as 1 agent for 1 year.

Methods: A 53-year-old man with Acanthamoeba keratitis was treated with medical therapy for >1 year, followed by a penetrating keratoplasty.

Results: Histopathologic examination of the keratoplasty specimen revealed viable-appearing Acanthamoeba cysts and trophozoites within the deep corneal stroma in a focus of corneal scarring.

Conclusions: The use of chlorhexidine as 1 agent in the medical management of Acanthamoeba keratitis may not eradicate the organisms.