Comparative efficacies of soft contact lens disinfectant solutions against microbial films in lens cases
L. A. Wilson, A. D. Sawant and D. G. Ahearn
Department of Ophthalmology, Emory University School of Medicine, Atlanta, Ga.
Biofilms of Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus
epidermidis, Streptococcus pyogenes, and Candida albicans, established in
the wells of a polyethylene contact lens case, retained viability to
certain soft contact lens disinfectant solutions after exposure for the
manufacturer's minimum recommended disinfection times. The relative order
of resistance of bacterial biofilms was as follows: S marcescens was
greater than P aeruginosa, which was greater than S epidermidis, which was
greater than S pyogenes. Air drying of biofilms for 10 hours increased the
efficacy of the disinfectant solutions, but drying was not enough to
decrease the incidence of recovery to 0% for all solutions. Hydrogen
peroxide was more effective against biofilms than disinfectant solutions
formulated with chlorhexidine gluconate or polyquaternium-1 or
polyaminopropyl biguanide. We recommend that determination of efficacy of
contact lens disinfectant solutions should include challenges against
biofilms.
