Status of the effectiveness of contact lens solutions against keratitis-causing pathogens

• Efficacy of contact lens solutions was determined against keratitis-causing microbes.
• Of the eight contact lens solutions tested, only three were effective in killing bacterial and fungal pathogens.
• None of them showed any cysticidal effects.
• These findings are of great concern for contact lens users.
• Urgent interventions are needed by health officials and contact lens manufacturers, along with special guidelines for developing countries regarding the manufacture and storage of contact lens disinfecting solutions.

PurposeThe aim of this study was to assess the antimicrobial effects of marketed contact lens disinfecting solutions.MethodsUsing ISO 14729 Stand-Alone Test for disinfecting solutions, bactericidal, fungicidal and amoebicidal assays of eight different contact lens solutions including: ReNu MultiPlus, DuraPlus, Ultimate Plus, OptiFree Express, Kontex Clean, Kontex Normal, Kontex Multisol extra+, Kontex Soak were performed. The efficacy of contact lens solutions was determined against keratitis-causing microbes, namely: Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, Fusarium solani and Acanthamoeba castellanii.ResultsThe results revealed that ReNu MultiPlus, DuraPlus and OptiFree Express were effective in killing bacterial and fungal pathogens as per manufacturer's minimum recommended disinfection time. Ultimate Plus was effective against F. solani and MRSA but ineffective against P. aeruginosa, S. marcescens and S. aureus. Of concern however, is that none of the locally formulated contact lens disinfecting solutions from Pakistan, i.e., Kontex Clean, Kontex Normal, Kontex Multisol extra+ and Kontex Soak were effective against any of the keratitis-causing organisms tested. All eight contact lens disinfecting solutions were unable to destroy Acanthamoeba cysts.ConclusionsBecause such ineffective contact lens disinfection solutions present a major risk to public health, these findings are of great concern to the health officials and to the manufacturers of the contact lens disinfection solutions and effective solutions are needed, along with emphasis on proper hygiene for contact lens care and special guidelines for developing countries regarding the manufacture and storage of contact lens disinfecting solutions.