In Vivo Assessment of Antimicrobial Efficacy of Silver-Impregnated Contact Lens Storage Cases

Abstract

More than 70% of the storage cases used in daily wear CL care for a month was contaminated irrespective of the types of cases. However, silver-impregnated cases were colonized by reduced levels of Gram-negative bacteria.

A Laboratory Assessment of Factors That Affect Bacterial Adhesion to Contact Lenses

“…Contact lenses will rarely be exposed to such high numbers of bacteria such as 1 × 10 10 CFU mL −1 during contact lens wear or even in lens cases. The range of bacterial numbers isolated from contact storage lens storage cases has been reported to be 1.24 × 10 4 CFU/case to 6.32 × 10 4 CFU/case [44,45,46,47,48,49]. Therefore, exposing contact lenses to this level of bacteria may be unrealistic.…”

Solutions for Care of Silicone Hydrogel Lenses

“…These lens cases have been shown to be able to reduce the biofilm formation by P. aeruginosa and S. aureus in lens cases in laboratory studies. 40 Likely sources of the common bacteria, coagulase-negative staphylococci and Grampositive bacilli, found in contact lens cases and potential pathogens such as Gram-negative bacteria include the eye, the fingers of lens users, and environmental sources such as water. One of these studies demonstrated that there was a significant reduction in the percentage of lens cases that were contaminated during use; for controls, there was a 63% to 67% lens case contamination rate and for silver-impregnated lens cases, there was a 26% to 38% lens case contamination rate.…”

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].…”