Risk factors for Acanthamoeba keratitis:
(1) soft contact lenses, especially daily wear or extended wear
(2) use and care of contact lenses (see below)
(3) ocular trauma
(4) exposure to contaminated water (swimming, hot tubs, etc.)
Contact lens use, care:
(1) use of nonsterile and/or homemade lens solutions, including tap water
(2) disinfecting solutions using chlorine alone may show little effect on the organism and are less effective than decontamination using hydrogen peroxide or other chemical systems
(3) less frequent disinfection than recommended by the manufacturers
(4) wearing of contact lenses while swimming
(5) some disinfection solutions such as chlorine release may show little effect on the organism
