Treatment of Acanthamoeba keratitis

Purpose. To review the available treatment modalities for Acanthamoeba keratitis and to assess the most effective regimens. Methods. The efficacy of therapeutic modalities and chemotherapeutic agents used in the treatment of Acanthamoeba keratitis was reviewed. Potential synergistic or additive drug interactions were documented both in vitro and in vivo. Results. Early diagnosis of Acanthamoeba keratitis plays a crucial role in successful medical treatment. The cationic antiseptic agents, chlorhexidine and polyhexamethylene biguanide (PHMB) have the lowest minimal amoebicidal concentrations. Synergistic effects are seen when used with pentamidine, and additive effects are seen with propamidine or neomycin. Penetrating keratoplasty should be deferred if at all possible until a medical cure has been achieved. Conclusion. Early diagnosis and wide epithelial debridement are important elements in the successful treatment of Acanthamoeba keratitis. Recommended therapy would include the cationic antiseptic agents, chlorhexidine or PHMB in combination with propamidine isethionate and neomycin as part of triple therapy. Surgical intervention should be avoided until a medical cure has been achieved.