Abstract
Purpose:
This study compared the disinfecting efficacy of Rigid Gas Permeable (RGP) lens care products.
Methods:
The primary disinfecting solution from each lens care system was evaluated using the ISO/FDA Stand Alone Procedure for Disinfecting Products. Three distinct lots of each product were tested using the regimen time listed on the patient instructions. The systems tested using a 4 hour disinfection time included two-single bottle multipurpose products: Boston Simplus and Unique pH, a two bottle system: Boston Advance Cleaner and Conditioning Solution. The three 3 bottle system: Lobob Optimum, was tested using a 6 hour disinfection time. Products were challenged with 3 bacterial species, Staphylococcus aureus (Sa), Pseudomonas aeruginosa (Pa) and Serratia marcescens(Sm) a yeast, Candida albicans (Ca) and a mold, Fusarium solani (Fs). The primary acceptance criteria states that the number of bacteria recovered per mL shall be reduced by a mean value of not less than 3.0 logs within the minimum recommended disinfection period. The mold and yeast recovered per mL shall be reduced by a mean value of not less than 1.0 log within the minimum disinfection time with no increase at not less than 4 times the disinfection time. There are secondary acceptance criteria which require that there is a combined log reduction for the mean values of all three bacteria of not less than 5.0 logs within the recommended disinfection time. The minimum acceptable mean log reduction for any single bacteria type is 1.0 log. Stasis for the yeast and mold must be observed for the recommended disinfection time.
Results:
Disinfection efficacy results demonstrated Simplus, Advance and Unique pH passed the primary criteria, with >4.7 log reduction for all three bacterial species and >4.2 log reduction of the mold. Both single bottle systems gave >4.2log reduction for the yeast, while Advance demonstrated a 1.4 log reduction. Optimum failed to pass the primary criteria for 2 of 3 of the bacterial species (Sa-2.7 logs and Sm-0.6 logs) and also failed the secondary criteria for yeast and mold.
Conclusions:
RGP care products demonstrated varying degrees of effectiveness to in their ability to disinfect RGP contact lenses. Boston Simplus, Boston Advance, and Unique pH all passed the primary acceptance criteria for disinfection efficacy set forth by ISO and the FDA. Lobob Optimum had very weak activity, and failed to meet even the secondary stand alone criteria.
Keywords: 477 contact lens