Therapeutic agents and biocides for ocular infections by free-living amoebae of Acanthamoeba genus

Surv Ophthalmol. 2017 Mar-Apr;62(2):203-218. doi: 10.1016/j.survophthal.2016.10.009. Epub 2016 Nov 9.


Acanthamoeba keratitis is a sight-threatening infectious disease. Resistance of the cystic form of the protozoan to biocides and the potential toxicity of chemical compounds to corneal cells are the main concerns related to long-term treatment with the clinically available ophthalmic drugs. Currently, a limited number of recognized antimicrobial agents are available to treat ocular amoebic infections. Topical application of biguanide and diamidine antiseptic solutions is the first-line therapy. We consider the current challenges when treating Acanthamoeba keratitis and review the chemical properties, toxicities, and mechanisms of action of the available biocides. Antimicrobial therapy using anti-inflammatory drugs is controversial, and aspects related to this topic are discussed. Finally, we offer our perspective on potential improvement of the effectiveness and safety of therapeutic profiles, with the focus on the quality of life and the advancement of individualized medicine.

Keywords: Acanthamoeba keratitis; PHMB; biguanides; chlorhexidine; cornea; diamidines; eye drops; hexamidine; propamidine.

Publication types

  • Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acanthamoeba Keratitis / drug therapy*
  • Acanthamoeba Keratitis / parasitology
  • Acanthamoeba*
  • Amoeba / isolation & purification*
  • Animals
  • Antiprotozoal Agents / therapeutic use*
  • Disinfectants / therapeutic use*
  • Eye Infections, Parasitic / drug therapy*
  • Eye Infections, Parasitic / parasitology
  • Humans


  • Antiprotozoal Agents
  • Disinfectants