Acanthamoeba is a genus of single-celled amoeba commonly found in water and soil environments. Some species of Acanthamoeba are also capable of causing infections in animals. Some species of Acanthamoeba are also capable of causing serious infections in humans, including brain infections, skin infections, and acanthamoeba keratitis (an eye infection that targets the cornea). Acanthamoeba keratitis affects the cornea and can cause significant pain, redness, blurred vision, sensitivity to light, and the sensation of something in the eye. It is most common in people who wear contact lenses, but anyone can get the infection. It is so painful because the outermost surface of the cornea is exquisitely sensitive – it has a nerve density that is 300–600 times that of the skin! (1). To prevent this relatively rare infection, it is so important to practice good hygiene, especially when handling contact lenses. Never use tap water on your contact lenses, because acanthamoeba can be found in tap water. Acanthamoeba can also survive in chlorinated swimming pools (2) so protecting your contact lenses with goggles if you cannot take them off completely is a good idea. If left untreated, acanthamoeba keratitis it can lead to corneal ulcers, serious vision loss and even blindness. Treatment involves the use of anti-amoebic medications and may also include surgical removal of infected tissue. Early diagnosis and prompt treatment are crucial for the best outcome – seek eye care urgently.
Bottom Image: Corneal melting and new inflammatory growth of blood vessels in a patient with Acanthamoeba keratitis. They lost vision in this eye. Reproduced via open access (3)
- Zander E, Weddell G. Observations on the innervation of the cornea. J Anat. 1951;85(1):68-99.
- Kaji Y, Hu B, Kawana K, Oshika T. Swimming with soft contact lenses: danger of acanthamoeba keratitis. The Lancet Infectious Diseases. 2005;5(6):392.
- Lorenzo-Morales J, Khan NA & Walochnik J: An update on Acanthamoebakeratitis: diagnosis, pathogenesis and treatment. Parasite, 2015, 22, 10.