[Acanthamoeba keratitis in subjects with contact lenses]

A new case of Acanthamoeba keratitis in a young woman using contact lenses is reported. Although the patient strictly complied with decontamination rules, she developed a huge corneal abscess invading the anterior chamber. After a misleading initial phase, the diagnosis was suspected on clinical grounds and was confirmed by parasitologists. The infection followed a favourable course, thereby avoiding surgery and its unpredictable consequences, but an opaque speck remained in the centre of the cornea. This case illustrates a pathology which is getting less and less exceptional, even in France where such pathogens can be found in the water for normal household use. Subjects wearing contact lenses and who are particularly exposed should be warned of the risk of infection they incur. Doctors should be taught to bear this diagnosis in mind in order to guide parasitological investigations and to obtain confirmation as early as possible.