Inhibition of Bacterial Adherence to Contact Lens Cases and Soft Contact lenses, Including High Dk Continuous Wear Silicone Hydrogels; A New and Unique Attribute of ReNu® With MoistureLocTM Solution

Abstract

Abstract: : Purpose: Pseudomonas aeruginosa, Staphylococcus aureus and Serratia marcescens are among the most frequently encountered etiological agents associated with contact lens related adverse events. Published studies have suggested the lens may act as a vector of the bacterium from contaminated lens solutions or cases to compromised corneal tissue (from hypoxia or manipulation of the lens on the eye). Once attached to a contact lens case or contact lens, some adherent cells show enhanced tolerance or resistance to antimicrobials. This enhanced tolerance state increases the probability of the attached bacterium surviving, making contact with and potentially binding to corneal tissue. This study examined the effectiveness of ReNu^® with MoistureLoc^TM, in reducing the primary attachment of mixed bacterial cultures to the surfaces of contact lenses and lens cases. Methods: ReNu^® with MoistureLoc^TM Multi–purpose Solution was evaluated with a radiolabeled cell procedure for its capacity to reduce adhesion of a mixed biofilm composed of P. aeruginosa, S. aureus and S. marcescens established on contact lens cases and worn (for one day) and unworn hydrogel lenses. Results: The in–vitro primary adhesion of various single and mixed bacteria to various lenses soaked for 4 h in the ReNu^® with MoistureLoc^TM was reduced by over 70% compared to non–soaked lenses. ReNu^® with MoistureLoc^TM adsorbed on the surface of the contact lens case gave residual inhibition of adhesion (more than 90%) and was biocidal for cells in suspension. Conclusions: ReNu^® with MoistureLoc^TM , a mixture of cellulosic polysaccharide (Polyquaternium 10) and a polymer surfactant (Poloxamer 407), significantly reduced the degree of bacterial adhesion to both cases and lenses. Inhibition of bacterial adhesion has been suggested as a strategy for reducing the risk of microbial keratitis and other contact–lens related adverse events.

Keywords: contact lens • bacterial disease