Removal of Biofilm from Contact Lens Storage Cases

Abstract

Based on this study, digital rubbing and rinsing and/or wiping the lens cases with tissue is recommended. Air-drying or recapping the lens case lids after use without any additional cleaning methods should be discouraged with non-antimicrobial lens cases.

The Effectiveness of Various Cleaning Regimens and Current Guidelines in Contact Lens Case Biofilm Removal

“…The rationale of not involving a soaking step in the present study was that soaking alone reduced the viable biofilm 15 to a level that did not allow sufficient discrimination between subsequent mechanical cleaning and drying practices. Hence, we designed the series of experiments in the present study to specifically assess the impact of each sequential hygiene practice against a more robust and consistent biofilm.…”

“…These strains were chosen for their ability to form adequate biofilms on lens storage cases. 15 Each strain was obtained from a bacterial stock stored at Ϫ80°C and streaked on a heated blood ("chocolate") agar plate (Oxoid; Adelaide, SA, Australia) for recovery. Plates were incubated in O 2 at 37°C for 24 hours.…”

“…A previous study 15 evaluated the various steps in the cleaning regimen and found that rubbing and tissue-wiping separately were effective at reducing levels of biofilm in lens cases, and soaking alone reduced the level of viable biofilm to a level comparable to the median level of case contamination in the community. However, the level of residual biofilm varied when different multipurpose disinfecting solution types were used.…”

Inhibitory Effects of 2,2′-Dipyridyl and 1,2,3,4,6-Penta-O-Galloyl-b-D-Glucopyranose on Biofilm Formation in Contact Lens Cases

“…4,25 Microorganisms within the biofilm are more likely to survive after disinfection and may act as potential pathogens of microbial keratitis. 14,16 Typically, the development of a biofilm is a three-step process involving an initial attachment, a subsequent maturation phase, and final dispersion.…”

Assessment of biofilm formation of E. meningoseptica, D. acidovorans, and S. maltophilia in lens cases and their growth on recovery media

“…The number of bacteria bound to the lens case surface can be enumerated by removing the bacteria using a calcium alginate swab and culturing on recovery media [46]. Also, the metabolic activity can be assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) as an indirect measurement of determining the number of viable cells adhered to a lens case surface [47]. MTT is reduced by respiratory enzymes in the cell walls of bacteria and detection of the resulting reduced molecule, formazan, can be used to assess the viability of microbial biofilms [48].…”