Effect of storage temperatures and time on the efficacy of multipurpose solutions for contact lenses.
OBJECTIVE
To determine the effect of storage time and temperature on the efficacy of four multipurpose solutions for soft contact lenses.


METHODS
Aliquots of multipurpose solutions (OPTI-FREE Express, ReNu MultiPlus, COMPLETE and SOLO-care) stored at different temperatures over a 3-month period, were challenged with contact lens-related ocular pathogens, Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans.


RESULTS
The results showed that OPTI-FREE Express had the best activity against Ps. aeruginosa at all temperatures; ReNu MultiPlus performed well at 25 degrees C; COMPLETE barely achieved activity requirements at all temperatures, and lost efficacy after 2 months. SOLO-care maintained its activity best against Ps. aeruginosa at 30 degrees C. Storage at fridge temperature reduced activity of all solutions. Regardless of storage temperature, activities of all solutions against S. aureus markedly decreased by 2 months. Only OPTI-FREE Express met FDA requirements against C. albicans.


CONCLUSIONS
Performance of multipurpose solutions is affected by time and temperature of storage. Contact lens users should be aware that the efficacy of opened solutions may not be sustained for as long as 3 months. Manufacturers should reconsider their recommendations to further safeguard the ocular health of contact lens wearers.
Leung
Polly
P
Biomedical Science Section, School of Nursing, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China. hspolly@inet.polyu.edu.hk
Boost
Maureen V
MV
Cho
Pauline
P
D002176:Candida albicans; D015169:Colony Count, Microbial; D018639:Contact Lens Solutions; D003261:Contact Lenses; D004340:Drug Contamination; D004356:Drug Storage; D006801:Humans; D011550:Pseudomonas aeruginosa; D013211:Staphylococcus aureus; D013696:Temperature; D013997:Time Factors
D018639:Contact Lens Solutions