Acanthamoeba keratitis is strongly associated with which practice?

• A. Contact lens wear
• B. Prolonged topical corticosteroid use
• C. Eating undercooked shellfish
• D. Exposure to freshwater activities

Answer: (B)

Acanthamoeba keratitis arises when the cornea becomes infected by Acanthamoeba, a microbe that can be found in water and soil. The key factor that makes this infection more likely is suppression of the eye’s local defenses. Prolonged topical corticosteroid use dampens the resident immune response and slows corneal healing, which can allow an invading organism to establish infection and worsen inflammation. Because steroids blunt the body's ability to fight off pathogens at the surface of the eye, this practice is strongly associated with developing Acanthamoeba keratitis. While contact lens wear and exposure to contaminated water also raise risk, the immunosuppressive effect of extended steroid use makes it a particularly potent predisposing factor. Eating undercooked shellfish has no relevance to this ocular infection.