Acanthamoeba KeratitisA sight-threatening disease with a favourable prognosis if diagnosed and treated early. Acanthamoeba keratitis follows minor corneal trauma, and is usually associated with contact lens use. Amoebae are introduced to the cornea of otherwise healthy people through environmental exposure—e.g., swimming whilst wearing contact lenses or using contaminated contact lens solutions, especially if homemade. Corneal infection does not lead to systemic disease, but is associated with cataracts, hypopyon, and increased intraocular pressure.
Epidemiology 1–2/million/year; 1/10,000/year contact lens wearers
Clinical findings Foreign-body sensation, pain, tearing, photophobia, blepharospasm, blurred vision
Management Propamidine, miconazole nitrate, and neomycin; or propamidine isethionate, a cationic antiseptic (polyhexamethylene biguanide or chlorhexidine)