In vitro efficiency of contact lens care solutions in removing cholesterol deposits from silicone hydrogel contact lenses

2013 ◽  
Vol 36 ◽  
pp. e41
Author(s):  
Lakshman Subbaraman ◽  
Hendrik Walther ◽  
Lise Kay ◽  
Lyndon Jones
2020 ◽  
Author(s):  
Edyta Beata Hendiger ◽  
Marcin Padzik ◽  
Agnieszka Żochowska ◽  
Wanda Baltaza ◽  
Gabriela Olędzka ◽  
...  

Abstract Background: Free living amoebae of Acanthamoeba genus are cosmopolitan, widely distributed protozoans causing severe, vision-threatening corneal infection known as Acanthamoeba keratitis (AK). Majority of the increasing number of AK cases are associated with contact lenses use. Due to lack of effective therapies against AK, proper eye hygiene and effective contact lenses disinfection are crucial in prevention of this infection. Currently available multipurpose contact lens disinfection systems are not fully effective against Acanthamoeba trophozoites and cysts. There is an urgent need to increase the disinfecting activity of these systems to prevent Acanthamoeba keratitis infections. Synthesized nanoparticles have been recently studied and proposed as a new generation of anti-microbial agents. It is also known that plant metabolites, including tannins, present anti-parasitic activity. The aim of this study was to evaluate the anti-amoebic activity and cytotoxicity of the tannic acid-modified silver nanoparticles (AgTANPs) conjugated with the selected multipurpose contact lens solutions.Methods: The anti-amoebic activity of pure contact lens care solutions and nanoparticles conjugated with contact lens care solutions were examined in vitro by colorimetric assay, based on the oxido-reduction of AlamarBlue. The cytotoxicity assays were performed using a fibroblast HS-5 (ATCC CRL-11882) cell line. The results were statistically analyzed by ANOVA and Student-Newman-Keuls tests using the p<0.05 level of a statistical significance.Results: The obtained results showed that nanoparticles enhanced anti-Acanthamoeba activity of the tested contact lens solutions without increasing their cytotoxicity profile. The activity is enhanced within minimal disinfection time recommended by the manufacturer.Conclusions: The conjugation of the selected contact lens solutions with AgTANPs might be a novel and promising approach as a part of preventive actions of Acanthamoeba keratitis infections among contact lens users.


Cornea ◽  
2012 ◽  
Vol 31 (10) ◽  
pp. 1170-1175 ◽  
Author(s):  
Toshihiko Uno ◽  
Yuichi Ohashi ◽  
Miya Nomachi ◽  
Masaki Imayasu

2020 ◽  
Author(s):  
Edyta Beata Hendiger ◽  
Marcin Padzik ◽  
Agnieszka Żochowska ◽  
Wanda Baltaza ◽  
Gabriela Olędzka ◽  
...  

Abstract Background: Free living amoebae of the genus Acanthamoeba are cosmopolitan, widely distributed protozoans causing a severe, vision-threatening corneal infection known as Acanthamoeba keratitis (AK). The majority of the increasing number of AK cases are associated with contact lenses use. Appropriate eye hygiene and effective contact lenses disinfection are crucial in prevention of this infection because of the lack of effective therapies against AK. Currently available multipurpose contact lens disinfection systems are not fully effective against Acanthamoeba trophozoites and cysts. There is an urgent need to increase the disinfecting activity of these systems to prevent Acanthamoeba keratitis infections. Synthesized nanoparticles have been recently studied and proposed as a new generation of anti-microbial agents. It is also known that plant metabolites, including tannins, present anti-parasitic activity. The aim of this study was to evaluate the anti-amoebic activity and cytotoxicity of the tannic acid-modified silver nanoparticles (AgTANPs) conjugated with the selected multipurpose contact lens solutions.Methods: The anti-amoebic activity of pure contact lens care solutions and nanoparticles conjugated with contact lens care solutions were examined in vitro by a colorimetric assay, based on the oxido-reduction of AlamarBlue. The cytotoxicity assays were performed using a fibroblast HS-5 (ATCC CRL-11882) cell line. The results were statistically analyzed by ANOVA and Student-Newman-Keuls tests using the p<0.05 level of a statistical significance.Results: We show that nanoparticles enhanced anti-Acanthamoeba activity of the tested contact lens solutions without increasing their cytotoxicity profile. The activity is enhanced within the minimal disinfection time recommended by the manufacturer.Conclusions: The conjugation of the selected contact lens solutions with AgTANPs might be a novel and promising approach as a part of preventive actions of Acanthamoeba keratitis infections among contact lens users.


2019 ◽  
Vol 31 (4) ◽  
pp. 1001-1004
Author(s):  
Nikola Peev

The modern world is very fast and dynamic. Consumer requirements rise to every commodity part of their everyday life - food, clothing, cosmetics, and medical devices. Eye care and eye health are also part of them. Companies producing contact lenses work daily to improve the safety and comfort of wearing, as well as on the technical characteristics of the material (type of material, wear time, module, Dk / t etc.). Silicon hydrogel contact lenses (SiHy) were introduced almost two decades ago. At that time it was estimated that there are about 70 million contact lenses all over the world. Since then, their number has doubled and a significant majority now have silicone-hydrogel contact lenses, resulting in a steady and noticeable reduction in the number of regular hydrogel lenses. When the first one-day silicon-hydrogel contact lenses were introduced in 2008, they were announced as breakthroughs in technology. When they were introduced to the market, they were presented in spherical, toric and multifocal designs, which led to a significant increase in the use / prescription of silicon-hydrogel daily disposable contact lenses. A survey conducted in 2014 by the International Consortium illustrates this point. Although, according to this study, the use of SiHy contact lenses varies widely across the world. In the United States, Canada, Australia and the United Kingdom, four to six times more patients were fitted with silicone-hydrogel CLs compared to hydrogels in 2014 and in each country, daily disposable SiHy contact lenses were prescribed with a larger frequency compared to daily disposable hydrogel lenses. It is important to make a good fit to ensure and increase the comfort of wearing contact lenses. In addition to some of the standard fitting techniques such as: keratometry and choice of base curve of the lens; size and eccentricity; an assessment of the mobility of a lens placed in the eye - look positions, mobility, push up test, can be added and the wetting of the contact lens. Even in perfect fit, if the lens does not interact well with the tear film, it would lead to complaints and discomfort in the patient. The degree of wetting is determined by the balance between adhesive and cohesive forces acting on the surface of the lens. CLs, which can support full wetting, allow a tight coating of the tear film, a smooth recovery of the tear layer after eyelid opening and good visual acuity. The interaction between CL, eye surface and tear film is vital to their successful fit. It has long been known that both the organic and inorganic components of the tear film and anterior surface of the eye can deposit deposits on the contact lenses. There are various non-invasive methods for assessing the tear film and, above all, the lipid layer. Some of these are Non invasive breakup time (NIBUT) and specular biomicroscopy. In the present work we will look at daily disposable silicone-hydrogel contact lenses that have been tested in vivo for good wetting, stability and good regeneration of the tear film.


Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 156
Author(s):  
Chen-Ying Su ◽  
Lung-Kun Yeh ◽  
Chi-Chun Lai ◽  
Mihaela Dubuisson ◽  
Yi-Fei Tsao ◽  
...  

Feeling comfortable is an important issue for contact lens wearers as contact lenses are worn for an extensive period of time. It has been shown that the in vitro friction coefficient of contact lenses is correlated to the degree of in vivo comfort, thus many studies focus on establishing friction testing methods for investigating the friction coefficient of contact lenses or contact lens care solution. We have previously demonstrated the lubricating property of poly-gamma-glutamic acid (γ-PGA)-containing care solution, and it could reduce the high friction coefficient caused by lysozyme. However, the mechanism of how γ-PGA-containing care solution reduces the lysozyme-induced friction coefficient of contact lenses is unclear. We investigated the bio-tribological effect of γ-PGA on ionic contact lenses in the presence of lysozyme by testing load and velocity variations. The ability to remove lysozyme deposition by γ-PGA and viscosity analysis of γ-PGA-containing care solutions were also investigated to understand the potential mechanism. Our results showed that the friction coefficient of γ-PGA-containing care solution with lysozyme was the lowest in both load and velocity variations, and γ-PGA functions distinctly in the lysozyme-ionic contact lens system. We proposed a model of how γ-PGA could reduce the friction coefficient in these two conditions.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Navneet Kumar ◽  
Rohan Aggarwal ◽  
Meenakshi K. Chauhan

Abstract Background Majorly, the reason for the permanent loss of vision is glaucoma. But the currently available common treatment methodologies such as eye drops have various disadvantages like patient incompliance due to repeated administration and poor (1–5%) bioavailability leading to poor efficiency. The objective of this research was to formulate Eudragit-based nanoparticles of levobunolol incorporated into a contact lens to obtain sustained ocular delivery of levobunolol at the therapeutics level. Eudragit nanoparticles of levobunolol were formulated by nanoprecipitation methodology utilizing different ratios of Eudragit S100 and polyvinyl alcohol. The prepared nanoparticles were evaluated and optimized by efficiency of entrapment, particle size, morphology of surface and zeta potential. The optimized nanoparticles were then entrapped into the matrix of the contact lens by the soaking method which were then characterized and compared for optical clarity study, equilibrium swelling study, shelf life and in vitro drug release in simulated tear fluid followed by ex vivo transcorneal permeation study. Results Formulation F3 was obtained as optimized nanoparticle formulation with 102.61 nm ± 3.92 of particle size, − 22.2 mV ± 2.76 of zeta potential and 86.995% ± 1.902 of efficiency of entrapment. The equilibrium swelling index and transmittance of nanoparticle incorporated into contact lenses showed better results when compared to drug solution-loaded lenses. In vitro release indicated more sustained drug profiles (84.33% ± 0.34 of drug release over a period of 12 days) as compared to drug solution-loaded lenses (89.282% ± 0.900 of drug release over a period of 3 days). Ex vivo transcorneal permeation studies showed more permeation (6.75% ± 0.170) through contact lenses as compared to marketed eye drops (3.03% ± 0.088). Conclusion This research demonstrates the remarkable results of drug-laden contact lenses to serve as a great medium for the continued delivery of ocular drugs without affecting the physical and optical characteristics of the lens content.


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