scholarly journals Silver Nanoparticles as a Novel Potential Preventive Agent against Acanthamoeba Keratitis

Pathogens ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 350 ◽  
Author(s):  
Edyta B. Hendiger ◽  
Marcin Padzik ◽  
Ines Sifaoui ◽  
María Reyes-Batlle ◽  
Atteneri López-Arencibia ◽  
...  

Free living, cosmopolitan amoebae from Acanthamoeba genus present a serious risk to human health. As facultative human parasites, these amoebae may cause Acanthamoeba keratitis (AK). Acanthamoeba keratitis is a severe, vision-threatening corneal infection with non-specific symptoms. The number of reported AK cases worldwide has been increasing every year. Moreover, 90% of Acanthamoeba keratitis cases are related to contact lens use. Wearing and storage contact lenses not in accordance with the physicians and manufacturers recommendations are the primary key risk factors of this disease. Amoebae can easily adhere to the contact lens surface and transmit to the corneal epithelium. Preventing amoebae adhesion to the contact lens surface could significantly decrease the number of AK infections. Until now, the effective therapy against AK is still under development. Currently proposed therapies are mainly limited to the chlorhexidine digluconate combined with propamidine isethionate or hexamidine applications, which are insufficient and very toxic to the eye. Due to lack of effective treatment, looking for new potential preventive agents is crucial to decrease the number of Acanthamoeba keratitis infections, especially among contact lens users. Nanoparticles have been already included in several novel therapies against bacteria, viruses, fungi, and protist. However, their anti-amoebic potential has not been fully tested yet. The aim of this study was to assess silver nanoparticles (AgNPs) and platinum nanoparticles (PtNPs) anti-amoebic activity and influence on the amoebae adhesion to the surface of four different groups of contact lenses—classified according to the Food and Drugs Administration (FDA) guidelines. The obtained results show that both tested nanoparticles were effective against Acanthamoeba trophozoites and decreased the amoebae adhesion to the contact lens surface. AgNPs showed better anti-amoebic activity to cytotoxicity dependence and reduced amoebae adhesion in a wider spectrum of the tested contact lenses. Our studies also confirmed that ionization next to hydration of the contact lens material is a crucial parameter influencing the Acanthamoeba adhesion to the contact lens surface. In conclusion, silver nanoparticles might be considered as a novel preventive agent against Acanthamoeba keratitis infection.

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 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. Results were statistically analyzed by ANOVA and Student-Newman-Keuls tests using the p<0.05 level of 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 selected contact lens solutions with AgTANPs might be a novel and promising approach as part of preventive actions of Acanthamoeba keratitis infections among contact lens users.


The Eye ◽  
2020 ◽  
Vol 22 (129) ◽  
pp. 44-46
Author(s):  
Mark Eddleston

Optimum Infinite is a new GP contact lens material, with an oxygen permeability of 180 barrer and was launched by Contamac at the GSLS 2019. This article provides an insight into the development and characteristics of this breakthrough material.


Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 995
Author(s):  
Allison Campolo ◽  
Valerie Harris ◽  
Rhonda Walters ◽  
Elise Miller ◽  
Brian Patterson ◽  
...  

Acanthamoeba keratitis is a serious ocular infection which is challenging to treat and can lead to blindness. While this pathogen is ubiquitous and can contaminate contact lenses after contact with water, its habits remain elusive. Understanding this organism’s natural behavior will better inform us on how Acanthamoeba colonize contact lens care systems. Acanthamoeba trophozoites were allowed to adhere to either a glass coverslip or non-nutrient agar (NNA) within a flow cell with nutrients (Escherichia coli or an axenic culture medium (AC6)) or without nutrients (Ringer’s solution). Images were taken once every 24 s over 12 h and compiled, and videos were analyzed using ImageJ Trackmate software. Acanthamoeba maintained continuous movement for the entire 12 h period. ATCC 50370 had limited differences between conditions and surfaces throughout the experiment. Nutrient differences had a noticeable impact for ATCC 30461, where E. coli resulted in the highest total distance and speed during the early periods of the experiment but had the lowest total distance and speed by 12 h. The Ringer’s and AC6 conditions were the most similar between strains, while Acanthamoeba in the E. coli and NNA conditions demonstrated significant differences between strains (p < 0.05). These results indicate that quantifiable visual tracking of Acanthamoeba may be a novel and robust method for identifying the movement of Acanthamoeba in relation to contact lens care products. The present study indicates that Acanthamoeba can undertake sustained movement for at least 12 h with and without nutrients, on both rough and smooth surfaces, and that different strains have divergent behavior.


2021 ◽  
Vol 26 (3) ◽  
pp. 2626-2630
Author(s):  
EVELINA MILCHEVA MARINOVA ◽  
◽  
DIMITAR STOIMENOV DABOV ◽  
YANI TODOROV ZDRAVKOV ◽  
EMILIA KRASIMIROVA NASEVA ◽  
...  

Objective: The purpose of our research is to emphasize the role of underestimated predisposing conditions for microbial keratitis in contact lens users, to draw attention to the complications of wearing contact lenses without ophthalmic examination, and to offer a short questionnaire for fast and easy estimation of the risk factors for bacterial keratitis. Methods: A series of 23 cases of healthy young individuals, treated for bacterial keratitis, provoked а research on the predisposing factors for its development. Results: 55% of the patients had started to wear contact lenses without specific examination. 75% had made mistakes in the hygiene and storage of the lenses. We identified risk factors for development of bacterial keratitis in all cases. Conclusions: A thorough anamnesis and ophthalmic examination are crucial in decision making about contact lens wearing because they could reveal some of the predisposing conditions for the occurrence of ocular complications. The usage of contact lenses without a prescription poses health risks and could have a negative impact on the social and healthcare system.


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.


2021 ◽  
Vol 37 (4) ◽  
Author(s):  
Ahmed Sohail ◽  
Zain Ul Abideen ◽  
Fatima Zahid ◽  
Wahid Bakhsh

Purpose:  To determine the awareness regarding contact lens related ocular complications among opticians of Lahore and to find out the relationship between the awareness and their educational qualification. Study Design:  Cross sectional survey. Place and duration of Study: University of Lahore from April 2020- December 2020. Methods:  This survey included opticians of different areas of Lahore, Pakistan. Two hundred and eleven opticians responded to a pre-tested, structured close ended questionnaire. Data comprised of demographics and contact lens selling experience. Information regarding awareness about contact lens related complications was also sought. The data were analyzed using SPSS 25.0. Results:  A total of 211 opticians participated in the survey. All subjects were males. Fifty four (25.6%) subjects were from the age group of 15 to 30 years, 122 (57.8%) were from the age group of 31 to 45 and 35 (16.6%) were from the age group of 46 to 60 years. Only 4.7% had contact lens dispensing diploma. Thirty seven percent patients had contact lens selling experience of 2 to 10 years. Similar percentage had more than 10 years of experience. Ten percent had less than one year of experience. Only 54 participants out of 211 had knowledge about dry eye, 9 knew about Acanthamoeba keratitis and Bacterial keratitis and only 2 were aware of corneal opacity. Conclusion:  Majority of the opticians of Lahore are unaware of the contact lenses related complications. Sale of cosmetic lenses for fashion purpose should be discouraged and banned if not prescribed by optometrist/ ophthalmologist. Key Words:  Opticians, Contact lenses, Bacterial Keratitis.


2016 ◽  
Vol 85 (2) ◽  
Author(s):  
Mirna Štabuc Šilih

Contact lenses are freely available without professional examination and fitting, as well as without adequate introduction and instructions on handling, disinfection and storage. Contact lenses may have physiological, metabolic and anatomic effect on the eyes, which is manifested both on the eyelids, lacrimal film, conjunctiva and in all layers of the cornea - the epithelium, stroma and the endothelium. We can see these complications too often at our everyday work. The purpose of this paper is to draw attention to the potential complications due to inappropriate use of contact lenses.Contact lenses are otherwise a safe and effective method of correcting visual acuity; they are also useful for therapeutic purposes. Complications related to contact lenses wear could be largely avoided with an appropriate professional approach and the compliance of contact lens wearers. It is important to discuss with patients their medical history, their desires and expectations, their working and living environment; followed by professional examination of patients and appropriate fitting of contact lenses. Patients should receive detailed oral and written instructions and be subscribed to regular checks. But unfortunately, all this is not enough, if patients do not comply every day with given instructions.


2019 ◽  
Author(s):  
Weiwei Li ◽  
Zhiqun Wang ◽  
Jinghao Qu ◽  
Yang Zhang ◽  
Xuguang Sun

Abstract Backgroud To report the clinical and microbiological features of Acanthamoeba keratitis (AK) related to contact lens in a tertiary hospital in China. Methods In this retrospective study, medical results of 61 cases of AK related to contact lens were reviewed from January 2000 to December 2017. The data included patients’ demographics, lens type, history, risk factors, the disease stages, reports of corneal scrapings and culture, treatment. Moreover, the genotype identification of part of these isolates was carried out with a PCR assay and sequence analysis of the 18S ribosomal DNA gene. Results There were 64 eyes included in the study. And 32.8% of cases wore soft contact lenses, 67.2% of patients used overnight orthokeratology. In the cases (20eyes) of early stage, 65% (13 eyes) had positive results in Giemsa stained smears, trophozoites were seen in 7 eyes (35%) in 0.9% sodium chloride (NaCl) wet mounts. Six eyes (30%) were diagnosed by confocal microscopy together with clinical sign. In the orthokeratology patients, 87.8% (36/41) of cases rinsed the lenses and/or cases with tap water, while 55% of soft lens wearers wore their lens during showering. The genotype of 9 isolates was determined, all the strains belonged to genotype T4. In the orthokeratology related cases, patients required therapeutic penetrating keratoplasty after 2005 were less than before 2005 (Chi-square test, χ2= 4.209,P = 0.04). Conclusions More than two thirds of cases were associated with orthokeratology. The examinations of Giemsa stained smears, 0.9% NaCl wet mounts and confocal microscopy should be done for the highly suspected cases of early stage to help the early diagnosis. The rate of therapeutic keratoplasty was decrease after 2005 compare with before 2005 in the cases of orthokeratology.


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.


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