Comparison of the different disinfecting capacities of contact lens solutions for rigid gas permeable (RGP) lenses against ocular pathogens

Abstract number: 902_p1175

Lai S.Y.


To evaluate the disinfectant capacity of three commercially available disinfecting solutions and to determine if they are able to meet the FDA criteria for contact lens disinfectant solutions. To determine the effects of storage conditions on disinfectant activity because although manufacturer's recommend a 3-month period of use this does not take into account higher temperatures experienced in tropical and sub-tropical areas.


Disinfectants were challenged with Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans according to the FDA standalone criteria. Duplicate bottles of those meeting the minimum criteria of a 3.0 log reduction in viable count (for bacteria) and 1 log reduction (for Candida) within the minimum recommended disinfection period were then stored at a range of temperatures and conditions and challenged at weekly intervals for 1 month.


Boston Simplicity met the FDA acceptance criteria for the standalone procedure for all organisms and for all conditions tested. Boston Advance though meeting the criteria for all organisms when careful handling was employed, failed to adequately reduce numbers of S. aureus when poor handling technique over a 1-month period was utilised. Poor handling reduced activity against Ps aeruginosa for all solutions. Alcon Optisoak failed to meet the FDA criteria against S. aureus and E. coli in initial testing. Fridge storage resulted in reduced activity of Boston Simplicity against two organisms. All solutions showed some loss of activity after storage in a covered water bath at 30[compfn]C (simulating bathroom conditions in warm climates) for 1 month.


Microbial keratitis, which can lead to severe loss of visual acuity, is associated with breeches in correct handling of contact lenses. Poor handling techniques may result in loss of disinfectant activity, confirming the need for reinforcement of education of contact lens users. Storage at temperatures other than room temperature adversely affects the activity of disinfectants and clients should be advised not to store solutions in the fridge and to dispose of solutions after a shorter period of time if the ambient temperature exceeds 25°C. Failure of one solution to meet the FDA requirements may be a cause for concern.


Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Location: Oxford, UK
Presentation type:
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