Contact Lens & Anterior Eye 38 (2015) 34–38 Contents lists available at ScienceDirect Contact Lens & Anterior Eye jou rnal h om epa ge : w ww.e l sevier.com/locate/clae Status of the effectiveness of contact lens solutions against keratitis-causing pathogens Ruqaiyyah Siddiqui, Sahreena Lakhundi, Naveed Ahmed Khan ∗ Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan a r t i c l e i n f o Article history: Received 8 July 2014 Received in revised form 22 August 2014 Accepted 9 September 2014 Keywords: Microbial keratitis Contact lens Cleaning solution a b s t r a c t Purpose: The aim of this study was to assess the antimicrobial effects of marketed contact lens disinfecting solutions. Methods: Using ISO 14729 Stand-Alone Test for disinfecting solutions, bactericidal, fungicidal and amoe- bicidal 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 per- formed. 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. Results: The 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. Ulti- mate 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. Conclusions: Because 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. © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved. 1. Introduction Microbial keratitis is a devastating ocular infection and an important cause of visual impairment/blindness that is frequently associated with contact lens (CL) wear [1–4]. The majority of cases are attributed to Pseudomonas aeruginosa, Serratia, Fusarium spp., and Acanthamoeba spp. [1–4]. The recognition and management of microbial keratitis require suspicion, early differential diagno- sis and aggressive treatment for successful prognosis otherwise it often has vision-threatening consequences. With over 120 million people wearing CL for refractive correc- tion and cosmetic purposes throughout the world, the associated ∗ Corresponding author at: Department of Biological and Biomedical Sciences, Aga Khan University, Stadium Road, Karachi, Pakistan. Tel.: +92 021 3486 4540; fax: +92 021 3493 4294. E-mail address: naveed5438@gmail.com (N.A. Khan). risk factors are a cause for concern. Recently the anti-amoebic effects of marketed CL disinfecting solutions were assessed [5]. The efficacies of different CL disinfecting solutions manufactured locally in Pakistan and internationally were evaluated against Acanthamoeba castellanii of the T4 genotype. Surprisingly, none of the solutions tested had any potent cysticidal effects [5]. Fol- lowing this alarming finding, the aim of the present study was to determine the antibacterial and antifungal efficacy of different CL disinfecting solutions against a range of bacterial and fun- gal pathogens: P. aeruginosa, Serratia marcescens, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus and Fusarium solani. Using the ISO 14729 Stand-Alone Test for CL disinfecting solutions, bactericidal and fungicidal effects of eight different CL disinfecting solutions including: ReNu MultiPlus, DuraPlus, Ulti- mate Plus, OptiFree Express, Kontex Clean, Kontex Normal, Kontex Multisol extra + , Kontex Soak was performed. To allow compari- son to our previous data of Acanthamoeba cysts, the CL disinfecting solutions were tested against A. castellanii of the T4 genotype. http://dx.doi.org/10.1016/j.clae.2014.09.001 1367-0484/© 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.