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Scanning Light Scattering Profiler (SLPS) Based Methodology to Quantitatively Evaluate Forward and Backward Light Scattering from Intraocular Lenses
Published on: June 6, 2017
Clinical and laboratory testing of a silver-impregnated lens case
Christopher F Amos1, Melanie D George
1CIBA Vision Corporation, 11460 Johns Creek Pky, Duluth, GA 30097, USA.
Purpose:
Lens case contamination is a well-documented occurrence for contact lens wearers despite the efficacy of current lens disinfectants. Several microorganisms have a propensity to attach to surfaces and may become more tolerant of disinfection upon attachment. Non-compliance with disinfection regimens occasionally occurs wherein patients store their lenses in saline or in tap water. A silver-impregnated lens case was developed in an attempt to decrease case contamination. These studies examine the performance of the case both in vitro and in vivo.
Methods:
In vitro, lens cases were challenged with 10(3) microorganism suspensions of bacteria. After 24h incubation at room temperature, aliquots of inocula were removed and spread plated onto appropriate growth media. Surviving colonies were counted and microorganism log drop values from initial challenge inocula were determined. Two 40-subject 1-month contralateral clinical studies were conducted with SOLO-care Aqua solution using one bowl of a silver-impregnated case and one bowl of a standard lens case for lens storage. Lens cases were collected and cultured for aerobic bacteria.
Results:
In vitro efficacy data show significantly lower numbers of recovered microbes from silver-impregnated cases than from control cases. In both clinical studies, silver-impregnated cases had a statistically significantly lower proportion of bacterial contamination than control cases. The majority of microorganisms isolated from silver-impregnated cases were members of the normal skin flora.
Conclusion:
The performance of the silver-impregnated case in vitro and the observed lower proportion of contaminated silver-impregnated lens cases in a clinical setting demonstrate the case's ability to decrease bacterial contamination.
Insights
A novel silver-impregnated contact lens case significantly reduces bacterial contamination compared to standard cases. This innovation offers improved hygiene for contact lens wearers, decreasing microbial load in lens storage solutions.
Area of Science:
- Ophthalmology
- Microbiology
- Materials Science
Background:
- Contact lens case contamination is a common issue, despite effective disinfectants.
- Microorganisms can adhere to surfaces, potentially increasing tolerance to disinfection.
- Patient non-compliance with disinfection protocols, such as using tap water, exacerbates contamination risks.
Purpose of the Study:
- To evaluate the efficacy of a novel silver-impregnated contact lens case in reducing microbial contamination.
- To assess the performance of the silver-impregnated case both in vitro and in vivo.
Main Methods:
- In vitro: Lens cases were inoculated with bacterial suspensions (10^3 CFU/mL) and incubated for 24 hours. Surviving colonies were quantified to determine log reduction.
- In vivo: Two 1-month, 40-subject clinical studies utilized contralateral eyes with a silver-impregnated case and a standard case for lens storage with SOLO-care Aqua solution. Cases were cultured for aerobic bacteria.
Main Results:
- In vitro studies demonstrated significantly lower microbial recovery from silver-impregnated cases compared to controls.
- Clinical studies revealed a statistically significant reduction in bacterial contamination in silver-impregnated cases versus standard cases.
- The predominant microorganisms found in silver-impregnated cases were typical skin flora.
Conclusions:
- The silver-impregnated lens case effectively reduces bacterial contamination, as evidenced by in vitro and clinical findings.
- This case design shows promise in enhancing contact lens hygiene and potentially reducing infection risk.