ABSTRACT
PURPOSE: To compare the antimicrobial effects of various kinds of multi-purpose solutions, study effective ways of washing contact lens (CLs), and suggest the most effective lens care system using P. aeruginosa-contaminated CLs. METHODS: Each disposable soft CL was incubated in 0.1 ml of diluted solution of P. aeruginosa standardstrain (10(8)CFU / mm(3)) and 0.9 ml tryptic soy broth in cell culture wells for 24 hours. In the first experimental group, to find the most antimicrobial solution, 40 CLs contaminated by P. aeruginosa were divided into four subgroups washed with four different kinds of multi-purpose solutions. Ten CLs were used in each subgroup and in the control group; Ten CLs contaminated by P. aeruginosa were washed with phosphate buffered saline (PBS) instead of cleaning solution. In the second experiment groups to find the most effective way of washing, using only Renu Multiplus multi-purpose solutionR we compared the antimicrobial effect of four different ways of washing including 30 seconds rubbing, 30 minutes soaking, 4 hours soaking, 30 seconds rubbing and 4 hours soaking. RESULTS: There was no significant difference of antimicrobial effect between four kinds of multi-purpose solutions. All methods have a significant antimicrobial effect over control group (P<0.001) and the most effective method of washing CLs was 4 hours soaking. CONCLUSIONS: we should advise all the soft CL users that they should have their CLs soaked over 4 hours everyday after wearing it.