<i>Acanthamoeba </i>Keratitis and Contact Lens Disinfecting Solutions

Abstract

Objectives: To report cases of culture-proved Acanthamoeba keratitis in Greece over a 10-year period and to evaluate the effectiveness of the commonly used commercial contact lens disinfecting systems in clinical cases of Acanthamoeba keratitis. Material and Methods: During the years1994–2004, 45 contact lens wearers and 3 non-contact lens wearers presenting with symptoms and signs of keratitis underwent corneal sampling. The scrapings obtained were inoculated directly onto appropriate culture media for bacteria, fungi and Acanthamoeba. All proved positive for Acanthamoeba. The contact lenses and contact lens disinfecting solutions (16 one-step 3% hydrogen peroxide and 3 multipurpose solutions) of 19/45 patients with culture-proven Acanthamoeba keratitis were cultured for bacteria, fungi and Acanthamoeba.Results:Acanthamoeba was isolated from contact lenses and contact lens disinfecting solutions in all 19 cases of Acanthamoeba keratitis studied. Conclusions: The main risk factorfor corneal infection in contact lens wearers isthe use of contact lens disinfecting systems ineffective at killing Acanthamoeba cysts and trophozoites, as well as bacteria and fungi. Improvement or development of new contact lens disinfecting systems by manufacturers is needed to prevent Acanthamoeba keratitis

National Outbreak ofAcanthamoebaKeratitis Associated with Use of a Contact Lens Solution, United States

“…However, propylene glycol is not unique to AMOCMP and is an ingredient of at least 1 other multipurpose solution, as well as several brands of artificial tears. Published results on the performance of multipurpose solutions, including AMOCMP, against Acanthamoeba organisms have shown varying efficacy ( 14 – 16 ). Assessment of anti- Acanthamoeba solution efficacy is limited by a lack of standardized testing methods ( 17 ).…”

How Could Contact Lens Wearers Be at Risk of Acanthamoeba Infection? A Review

“…The use of ineffective contact lens disinfecting solutions is strongly linked to the threat of Acanthamoeba infection in contact lens wearers. A 10-year survey (1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004) 62 showed that Acanthamoeba was isolated in contact lenses and contact lens disinfecting solutions in all cases of Acanthamoeba keratitis. The one-step 3% hydrogen peroxide and multipurpose solutions were found to be ineffective in killing Acanthamoeba cysts and trophozoites, as well as bacteria and fungi.…”

Acanthamoeba Keratitis and Contact Lens Wear: Static or Increasing Problem?

“…2 Unfortunately, the susceptibility of Acanthamoeba trophozoites, but particularly the amoebic cysts, is limited to a small number of chemical compounds. 33,34 Propamidine isethionate (Brolene [not yet FDA approved in the U.S.], Aventis, Bridgewater, NJ), polyhexamethylene biguanide (PHMB), chlorhexidine, and hexamidine have shown effectiveness against the trophozoite and, to a degree, the cyst. 33 There is some optimism, however, that newly developed biguanides (alexidine) and antifungal agents (caspofungin) may have greater effect against the Acanthamoeba cyst.…”