title: Biocide uptake in contact lenses and loss of fungicidal activity during storage of contact lenses.
abstract: OBJECTIVE
  With recent outbreaks of Fusarium keratitis related to contact lens wear, studies were conducted to determine the biocide uptake during lens storage, and the resulting effect on antifungal activity of related products.
  
  
  METHODS
  ACUVUE 2 (etafilcon A) soft, hydrophilic contact lenses (group IV) were soaked from 1 hour to 7 days in OPTI-FREE Express and OPTI-FREE RepleniSH multipurpose disinfecting solutions with POLYQUAD (polyquaternium-1) and ALDOX (myristamidopropyl dimethylamine) biocides and multipurpose solutions, Bausch & Lomb ReNu with MoistureLoc (Alexidine), ReNu MultiPlus (polyhexamethylene biguanide [PHMB]), and AMO Complete MoisturePLUS (PHMB). Storage solutions were tested to evaluate the effect of preservative uptake on the residual biocide activity against Fusarium solani.
  
  
  RESULTS
  Approximately 30% to 60% of the PHMB and Alexidine were depleted by 6 hours, with comparable loss of antimicrobial activity. Decreasing activity was noted with corresponding decreases in active concentration throughout the course of the evaluation. The POLYQUAD systems retained nearly 100% of the biocide and fungicidal activity and maintained their concentration in the solution.
  
  
  CONCLUSIONS
  OPTI-FREE Express and OPTI-FREE RepleniSH multipurpose disinfecting solutions maintained fungicidal efficacy after storage of lenses. The Alexidine- and PHMB-based multipurpose solutions tested showed significant uptake of preservative into group IV lenses, resulting in a decrease in the residual activity of the storage solution. The POLYQUAD systems showed a low uptake of biocide and maintained fungicidal efficacy against F. solani.
authors.affiliation: Alcon Research, Ltd., Fort Worth, TX 76134, USA. ruth.rosenthal@alconlabs.com
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Rosenthal
authors.forename: Nissanke L
authors.initials: NL
authors.lastname: Dassanayake
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Schlitzer
authors.forename: Barry A
authors.initials: BA
authors.lastname: Schlech
authors.forename: David L
authors.initials: DL
authors.lastname: Meadows
authors.forename: Ralph P
authors.initials: RP
authors.lastname: Stone
mesh_terms: D000935:Antifungal Agents / Q000378:metabolism* / Q000494:pharmacology; D001645:Biguanides / Q000378:metabolism* / Q000494:pharmacology; D018639:Contact Lens Solutions / Q000378:metabolism* / Q000494:pharmacology; D003263:Contact Lenses, Hydrophilic; D004202:Disinfectants / Q000378:metabolism* / Q000494:pharmacology; D017743:Equipment Reuse; D005670:Fusarium / Q000187:drug effects / Q000254:growth & development*; D010349:Patient Compliance
chemical_list: D000935:Antifungal Agents; D001645:Biguanides; D018639:Contact Lens Solutions; D004202:Disinfectants; C031233:polihexanide