A patient following use of contact lens, developed corneal ulcers and symptoms of conjunctivitis. Saline mount preparation of corneal scrapping shows polygonal cyst. What should be the probable diagnosis?

1. Acanthamoeba keratitis is associated with corneal injuries complicated by exposure to water or soil and with the wearing of contact lenses. 2. Acanthamoeba keratitis: Risk factors: Extended wear of lens Breaches in hygiene and disinfection procedures Swimming with contact lenses in place Use of homemade saline solutions contaminated with Acanthamoeba. 3. Wet mount examination: CSF or corneal scrapping is done to demonstrate both cysts and trophozoites. Trophozoite: One form, no flagellated form Thorn like pseudopodium (acanthopodia) 15-25 mm size. Giardia and Enthamaeba cause gastroenteritis Nigleria cause fulminant meningitis.