Who is most at risk for developing an ocular infection from the protozoan acanthamoeba?

The highest risk of developing an ocular infection from the protozoan Acanthamoeba is attributed to individuals who use homemade salt solutions to clean their contact lenses. Acanthamoeba is commonly found in the environment, including water sources such as lakes, hot tubs, and poorly maintained tap water. When contact lenses are cleaned with non-sterile homemade solutions, it can introduce Acanthamoeba into the eye, leading to serious corneal infections known as Acanthamoeba keratitis.

Contact lens wearers are already at an increased risk for various eye infections due to the potential for introducing pathogens while handling or wearing lenses. Using non-commercial cleaning solutions that lack proper antimicrobial properties significantly heightens this risk. In contrast, swimming regularly, having chronic dry eye, or having diabetes can contribute to various ocular issues but do not directly create the same level of exposure to Acanthamoeba as the improper cleaning of contact lenses does. Heavy exposure to contaminated water through swimming, while a concern, is more related to hygiene practices surrounding contact lenses rather than inherent risks of the activity itself.