EFFICACY OF OPHTHALMIC SOLUTIONS TO DETACH ADHERING PSEUDOMONAS-AERUGINOSA FROM CONTACT-LENSES

Purpose. To compare the efficacies of two all-in-one contact lens (CL) cleaning solutions and a detergent mixture on the detachment of a pat hogenic bacterium adhering to two types of contact lenses in the absen ce and presence of a tear film. Methods. Bacterial-detachment studies were carried out in a parallel-plate flow chamber. Rigid gas permeable (RGP) CLs with and without a tear film were fixed on the bottom plate of the flow chamber. After adhesion of Pseudomonas aeruginosa no. 3, bacterial detachment was stimulated by perfusing the system either wit h an all-in-one CL-cleaning solution, for soft contact lenses (SCL sol ution) and for rigid lenses (RCL solution), or with a detergent mixtur e of 0.25% (wt/vol) sodium lauryl sulfate (SLS) and 0.2% sodium methyl cocoyl taurate (Tauranol). In addition, the all-in-one RCL-cleaning s olution supplemented with 0.025% (wt/vol) SLS and 0.02% (wt/vol) Taura nol was evaluated. A surface physical-chemical analysis of the lenses before and after application of the solutions was done to determine wh ether remnants of the ophthalmic solutions or detergents could be foun d adsorbed to the CL surfaces. Results. Both all-in-one CL-cleaning so lutions stimulated minor bacterial detachment from CL surfaces with or without a tear film. The SLS/Tauranol detergent mixture, however, rem oved less than or equal to 95% of the adhering P. aeruginosa cells, wh ereas the RCL-cleaning solution supplemented with detergents also stim ulated significant detachment. Surface physical-chemical analysis clea rly demonstrated the presence of a tear film on the CL surfaces, but r emnants neither of the ophthalmic solutions nor of the detergents coul d be found. Conclusion. Ophthalmic solutions are not effective in stim ulating detachment of adhering bacteria from CL surfaces. Supplementin g of an all-in-one CL-cleaning solution with only small amounts of det ergents yielded a solution much more effective in stimulating bacteria l detachment while leaving no detectable remnants of the ophthalmic so lution or of the detergents on the CL surfaces.