Abstract
Purpose :
A contact lens care product (CLC) is designed to clean, disinfect and store contact lenses (CL) in a manufacturer’s supplied lens case. Lens wearers contaminate their CLs and storage cases with microorganisms by routine handling. Many consumers fail to comply with cleaning regimens by not rubbing and rinsing their CLs, only soaking in the CLC to remove microbial contamination from their lenses. The impact of a storage case on a CLC can reduce its’ antimicrobial efficacy against some microorganisms and increase the risk of microbial contamination to the lens wearer. We hypothesize that incompatibility of a CLC with their manufacturer’s CLs and storage cases will decrease antimicrobial efficacy of the CLC.
Methods :
Six CLCs were evaluated for antimicrobial compatibility with their associated manufacturer’s storage cases and two CLs. CLCs were evaluated based on ISO 18259 against relevant microorganisms which historically known to cause eye infections. Storage cases or CLs+cases were inoculated with 105 CFU/mL of relevant microorganisms (C. albicans, F. solani). Cases were filled with CLCs and closed until disinfection time per label. Recovery of microorganisms was used to determine antimicrobial efficacy for all CLCs.
Results :
In the presence of the storage case, CLCs containing PHMB only had minimal antimicrobial efficacy against C. albicans (<0.2 log) and F. solani (1.1-1.6 log). In the storage case, PQ/PHMB CLC had a 1.1 log reduction for C. albicans and 2.3 log reduction for F. solani while PQ/Alexidine CLC had 1.7 log reduction (C. albicans) and 4.5 log reduction (F. solani). PQ/PHMB/Alexidine CLC had 2.0 log reduction (C. albicans) and 2.7 log reduction (F. solani) with a storage case only. PQ/Aldox CLC showed a 3.5 log reduction (C. albicans) and 4.7 log reduction (F. solani) in the storage case. CLCs with limited antimicrobial efficacy in the storage case were largely not further impacted by the addition of CLs for either microorganism. The addition of CLs to storage cases had significant impact to CLCs with high antimicrobial efficacy.
Conclusions :
The ISO 18259 microbiological compatibility standard is bringing to light incompatibilities between CLCs with their storage cases previously undetected by standard preservative uptake studies.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.