Abstract: Objective] To find a rapid method for diagnosing Acanthamoeba keratitis and identifing Acanthamoeba . [Methods] 10% potassium hydroxide(KOH) wet mount preparations, Acanthamoeba culture, inverted phase contrast microscopy,and pathological examination using H.E. staining and PAS staining. [Results]Using corneal scrapings and corneal materials obtained from surgery,7 cases and 5 cases of Acanthamoeba keratitis were diagnosed by 10% KOH wet mount preparations. 6 strains of Acanthamoeba were isolated in corneal materials of 6 cases by protozoa culture method. The cysts, trophozoites and pseudopods on the trophozoites of Acanthamoeba were directly observed under the inverted phase contrast microscope. The cysts and trophozoites of Acanthamoeba were seen by H.E. staining and PAS staining with 20 h. [Conclusion] Acanthamoeba keratitis could be rapidly diagnosed by 10% KOH wet mount preparations and inverted phase contrast microscopy. Acanthamoeba organisms could be directly observed and identified under inverted phase contrast microscope.

Key words: Acanthamoeba keratitis, Acanthamoeba, rapid diagnosis, identification