Purpose. The introduction of contact lens multipurpose disinfection solution (MPDS) that can be used in conjunction with a “no-rub” regimen has simplified lens care requirements. Once adhered to a surface, microorganisms can become less susceptible to disinfection. The aim of the study was to evaluate the effect of various regimen steps on the efficacy of MPDS when used with silicone hydrogel and conventional lenses.
Methods. Commercially available MPDSs containing polyquad or polyhexamethylene biguanide were used in conjunction with two types of silicone hydrogel (lotrafilcon B and galyfilcon A) and one type of conventional soft contact lenses (etafilcon A). Challenge microorganisms included Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 9027, Serratia marcescens ATCC 13880, Fusarium solani ATCC 36031, Candida albicans ATCC 10231, or Acanthamoeba polyphaga Ros. The effect of regimen steps “rub and rinse,” “rinse-only,” or “no rub and no rinse” on the disinfection efficacy of test MPDSs was examined using the ISO 14729 Regimen Test procedure.
Results. Overall, the greatest efficacy of MPDSs was observed when “rub and rinse” was performed before disinfection with each of the microorganisms tested, regardless of lens type. “No rub and no rinse” steps resulted in a greater load of microorganisms remaining on lenses compared with the other regimens (p < 0.05). When “rinse-only” was performed before disinfection, the MPDS containing polyquad performed generally better (p < 0.05) than MPDSs containing polyhexamethylene biguanide against bacteria. Significantly, less microorganisms were recovered from galyfilcon A than from other lenses (p < 0.05) when MPDSs were used with “rinse-only” step.
Conclusions. This study has demonstrated that “rub and rinse” is the most effective regimen and should be recommended in conjunction with all multipurpose lens care solutions and all contact lens types, particularly with silicone hydrogel lenses.