[Clinical forms of acanthamoeba keratitis as viewed from the standpoint of biomicroscopy and confocal microscopy]

Clinical cases of 60 patients with acanthamebic keratitis examined by biomicroscopy and of 22 patients largely examined by confocal microscopy are generalized. Acanthamebic keratitis is a slowly progressing infectious lesion of the cornea, which is caused by acanthamebas freely residing in soil and water. Contaminated contact lenses are the key risk factor. The main clinical features of acanthamebic keratitis are defined; they are presence of risk factors; a unilateral lesion in young, healthy and immune-competent persons; a typical clinical pattern of surface keratitis mainly of the ring shape; corneal neuritis without corneal neovascularization but with a severe pain in the eye; and a slow chronic clinical course, i.e. lasting for several weeks and months. Confocal microscopy is the most effective and fast diagnostic tool because it ensures the detection of acanthamebic cysts and trophozoids in all strata of the corneal stroma. The authors isolate, within the clinical course of acanthamebic keratitis, 5 stages; they are surface epithelial keratitis; surface epithelial punctate keratitis; stromal ring-shaped keratitis; ulcerous keratitis; and keratoscleritis.