Contamination of contact lens storage solutions
We have investigated the contamination of storage solution bottles following two weeks of patient use. Forty-four subjects participated in the study and each used three types (Opti-free, ReNu, and AOSept) of soft lens storage solutions (cross-over study). A further 16 subjects used only one of the storage solutions over three consecutive two week periods (reliability study). Contamination of the storage solution bottles occurred in 12 of the 180 bottles sampled (ie 7%) and the level of contamination of these bottles ranged up to 10,000 colony forming units per millilitre. A wide range of microorganisms were identified in these positive samples, many of which were potentially pathogenic. For the subjects who used all 3 storage solutions in the cross-over study (n=44), a Friedman test on these data suggested that Opti-free was significantly more likely to be contaminated than either HeNu or AOSept (Chi-squared = 6.25, df = 2, p = 0.04). The results for an ANOVA on these data are Jess conclusive, suggesting a between treatments (product) difference, significant at p = 0.14 (F = 2.0, df = 2). There were no subjects in the overall study (n = 60) who showed contamination in more than one of the three bottles sampled. The rate of contamination of storage solution bottles was not influenced by the length of time the subjects had been wearing lenses (visit 1 to 3), by the time of year (season) at which the samples were collected, or by the subject's compliance with hand washing. Contamination of contact lens solution bottles presumably occurs through the suction of airborne microorganisms into the bottle, finger contact with the bottle tip, or leaving the bottle uncapped between uses. Advising patients to discard opened bottles of storage solution in a fixed period after opening (in line with manufacturers' instructions), irrespective of the rate of use, would seem to be prudent. Study funded by Ciba Vision Corp.
Impact and interest:
Citation counts are sourced monthly from and citation databases.
These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.
Citations counts from theindexing service can be viewed at the linked Google Scholar™ search.
|Item Type:||Conference Paper|
|Additional Information:||Abstract published in Optometry and Vision Science, 69(2), pp.97|
|Subjects:||Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > OPTOMETRY AND OPHTHALMOLOGY (111300)
Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > OPTOMETRY AND OPHTHALMOLOGY (111300) > Vision Science (111303)
|Divisions:||Current > Research Centres > Centre for Health Research
Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
|Copyright Owner:||Copyright 1992 Lippincott Williams & Wilkins|
|Deposited On:||25 Jan 2008 00:00|
|Last Modified:||10 Nov 2014 02:54|
Repository Staff Only: item control page