Antimicrobial efficacy tests of multipurpose contact lens care solutions simulating poor contact lens hygiene behaviors.
OBJECTIVE
The aim of this study was to simulate the biofilm formation in contact lens (CL) case under poor hygiene behaviors; antimicrobial efficacies of multipurpose solutions (MPSs) against biofilm on the lens case were evaluated.


METHODS
Five MPSs (Epica Cold, Complete 10 min, ReNu MultiPlus, SoftOne Mois, and OPTI-FREE Plus) were tested. Lens cases containing ACUVUE2 were inoculated with 1×10, 10, or 10 colony-forming units (CFUs) of Staphylococcus epidermidis (SE). Each lens case was treated with 1 MPS for 4 hrs followed by the estimation of the number of SE by the CFU method. Disinfection efficacies of MPSs against SE biofilm were evaluated by biomicroscopy with safranin staining and scanning electron microscopy.


RESULTS
Lens cases, inoculated with 1×10 CFU, were disinfected by all MPSs. Epica Cold, Complete 10 min, ReNu MultiPlus, and OPTI-FREE showed almost a 2-log reduction of the CFU, whereas SoftOne Mois effect was almost a 1 log reduction, significantly lower than other MPSs (P<0.05). No biofilm formations were observed in Epica Cold, Complete 10 min, ReNu MultiPlus, and OPTI-FREE Plus-treated groups unlike significant biofilm formation in the SoftOne Mois-treated group (P<0.01).


CONCLUSIONS
Greater efforts to educate patients regarding compliant lens care behavior are needed to reduce the incidence of CL-associated microbial keratitis.
Department of Ophthalmology, Menicon Co., Ltd., Kasugai, Aichi, Japan.
Toshihiko
T
Uno
Yuichi
Y
Ohashi
Masaki
M
Imayasu
D000704:Analysis of Variance; D018441:Biofilms / Q000187:drug effects; D015169:Colony Count, Microbial / Q000706:statistics & numerical data; D018639:Contact Lens Solutions / Q000494:pharmacology*; D003261:Contact Lenses / Q000382:microbiology*; D004202:Disinfectants / Q000494:pharmacology; D004866:Equipment Contamination / Q000517:prevention & control*; D006920:Hygiene; D008855:Microscopy, Electron, Scanning; D013210:Staphylococcus / Q000187:drug effects* / Q000302:isolation & purification
D018639:Contact Lens Solutions; D004202:Disinfectants