title: Detachment of trophozoites of Acanthamoeba species from soft contact lenses with BEN22 detergent, BioSoak, and Renu multi-purpose solutions.
abstract: OBJECTIVE
  BEN22 detergent was studied for its ability to detach Acanthamoeba from soft contact lenses without mechanical cleaning or separate cleaning agents.
  
  
  METHODS
  Trophozoites of Acanthamoeba castellanii and A. polyphaga were adhered onto nonionic, high water content soft contact lenses. The lenses were immersed for 2 hours in contact lens care solutions and the remaining trophozoites were counted microscopically. The counts were compared to the counts on the same lens before treatment.
  
  
  RESULTS
  BEN22 (50:50 mixture of L-alpha-L-rhamnopyranosyl-beta-hydroxydecanoyl-beta-hydroxydecanoate and 2-O-alpha-L-rhamnopyranosyl-alpha-L-rhamnopyranosyl-beta-hydroxydecanoyl-beta-hydroxydecanoate) (Kassell Industries, Inc., Wisconsin Dells, WI) in a concentration of 0.05% detached the trophozoites to a statistically significant greater extent than saline, but commercial ReNu Multi-Purpose Solution (Bausch & Lomb, Italy) and BioSoak (Finnsusp Ltd., Finland) did so as well. ReNu Multi-Purpose Solution was more effective than 0.005% BEN22 in detaching the trophozoites of both of the Acanthamoeba strains. After the 2 hour immersion period, a maximum of 97% of the initial trophozoites were detached. The variation between individual lenses was significantly greater than that within the different areas of one lens.
  
  
  CONCLUSIONS
  BEN22 had no reliable detaching effect on Acanthamoeba. The variation between lenses was great, and the rate of detachment was low with all the agents tested indicating that immersion and rinsing in the solutions tested cannot be considered as a safe substitute for proper disinfection against Acanthamoeba in contact lens care.
authors.affiliation: Parasitological Laboratory, Turku University Central Hospital, Finland.
authors.forename: E
authors.initials: E
authors.lastname: Raali
authors.forename: H H
authors.initials: HH
authors.lastname: Vaahtoranta-Lehtonen
authors.forename: O P
authors.initials: OP
authors.lastname: Lehtonen
mesh_terms: D000048:Acanthamoeba / Q000502:physiology*; D000268:Adhesiveness / Q000187:drug effects; D000818:Animals; D018639:Contact Lens Solutions / Q000494:pharmacology*; D003263:Contact Lenses, Hydrophilic; D003902:Detergents / Q000494:pharmacology
chemical_list: D018639:Contact Lens Solutions; D003902:Detergents