Presence of Acanthamoeba in the ocular surface in a Spanish population of contact lens wearers

2018 ◽  
Vol 63 (2) ◽  
pp. 393-396 ◽  
Author(s):  
Javier Rodríguez-Martín ◽  
Pedro Rocha-Cabrera ◽  
María Reyes-Batlle ◽  
Atteneri López-Arencibia ◽  
Ines Sifaoui ◽  
...  
Keyword(s):  
Molecular Analysis ◽  
Canary Islands ◽  
Contact Lens ◽  
Ocular Surface ◽  
Poor Prognosis ◽  
Contact Lenses ◽  
Opportunistic Pathogens ◽  
Causative Agents ◽  
Axenic Conditions ◽  
Healthy Contact

Abstract Pathogenic strains of Acanthamoeba are causative agents of a sight-threatening infection of the cornea known as Acanthamoeba keratitis (AK) which mainly affects contact lens wearers and it is commonly related to poor hygiene of contact lenses and their cases. Moreover, treatment of AK is complex due to the existence of a highly resistant cyst stage and if not diagnosed early has poor prognosis, leading to blindness and/or keratoplasty. Even though AK is increasing worldwide as well as awareness among patients and clinicians, it is still a poorly studied pathogen. Additionally, a remaining question to be answered is whether these opportunistic pathogens are present in the ocular surface of healthy contact lens wearers since they are the main group at risk.In order to carry out this study, sterile Schirmer strip tests were collected from a group of individuals all of them contact lens wearers who were attending a local ophthalmology clinic in Tenerife, Canary Islands, Spain. The collected samples (100 eyes of 50 patients) were cultured in 2% Non-Nutrient Agar (NNA) plates and positive plates (16) were then cultured in axenic conditions for further analyses. Molecular analysis classified all isolated strains belonged to Acanthamoeba genotype T4 and osmotolerance and thermotolerance assays revealed that all strains were potentially pathogenic. In conclusion, the ocular surface of contact lens wearers included in this study was colonized by potentially pathogenic strains of Acanthamoeba and should be considered as a risk for AK infection in this region and worldwide.

scholarly journals The potential pathogenicity of chlorhexidine-sensitive Acanthamoeba strains isolated from contact lens cases from asymptomatic individuals in Tenerife, Canary Islands, Spain

2008 ◽  
Vol 57 (11) ◽  
pp. 1399-1404 ◽  
Author(s):  
Carmen M. Martín-Navarro ◽  
Jacob Lorenzo-Morales ◽  
M. Gabriela Cabrera-Serra ◽  
Fernando Rancel ◽  
Nieves M. Coronado-Álvarez ◽  
...  
Keyword(s):  
Canary Islands ◽  
Contact Lens ◽  
Contact Lenses ◽  
Pathogenic Potential ◽  
Biochemical Assays ◽  
Rdna Sequencing ◽  
Causative Agents ◽  
Asymptomatic Individuals ◽  
Potential Pathogenicity ◽  
High Pathogenic

Pathogenic strains of the genus Acanthamoeba are causative agents of a serious sight-threatening infection of the eye known as Acanthamoeba keratitis. The prevalence of this infection has risen in the past 20 years, mainly due to the increase in number of contact lens wearers. In this study, the prevalence of Acanthamoeba in a risk group constituted by asymptomatic contact lens wearers from Tenerife, Canary Islands, Spain, was evaluated. Contact lenses and contact lens cases were analysed for the presence of Acanthamoeba isolates. The isolates' genotypes were also determined after rDNA sequencing. The pathogenic potential of the isolated strains was subsequently established using previously described molecular and biochemical assays, which allowed the selection of three strains with high pathogenic potential. Furthermore, the sensitivity of these isolates against two standard drugs, ciprofloxacin and chlorhexidine, was analysed. As the three selected strains were sensitive to chlorhexidine, its activity and IC50 were evaluated. Chlorhexidine was found to be active against these strains and the obtained IC50 values were compared to the concentrations of this drug present in contact lens maintenance solutions. It was observed that the measured IC50 was higher than the concentration found in these maintenance solutions. Therefore, the ineffectiveness of chlorhexidine-containing contact lens maintenance solutions against potentially pathogenic strains of Acanthamoeba is demonstrated in this study.

scholarly journals Management of Post-LASiK Keratoectasia with a Piggyback Contact Lens System

2015 ◽  
Vol 77 (1) ◽  
pp. 7
Author(s):  
Lacey Haines ◽  
Luigina Sorbara
Keyword(s):  
Contact Lens ◽  
Ocular Surface ◽  
Contact Lenses ◽  
Single Case ◽  
Treatment Options ◽  
Ocular Surface Disease ◽  
Screening Methods ◽  
Lens System ◽  
Intrastromal Corneal Ring ◽  
Current Screening

This case report highlights the clinical challenges involved in managing a patient with post-LASiK keratoectasia. A single case is presented with a focus on contact lens fitting and concurrent ocular surface disease. A review of the literature indicates that current screening methods prior to refractive surgery have made improvements for detecting patients at higher risk of serious complications. Possible treatment options for iatrogenic keratoconus include contact lenses, intrastromal corneal ring segments, corneal cross linking, and keratoplasty. This report demonstrates that post-LASiK keratoectasia with concurrent ocular surface disease can be successfully managed with a piggyback contact lens system.

The Development of an Antimicrobial Contact Lens – From the Laboratory to the Clinic

2020 ◽  
Vol 21 (4) ◽  
pp. 357-368 ◽  
Author(s):  
Mark D.P. Willcox ◽  
R. Chen ◽  
P. Kalaiselvan ◽  
M. Yasir ◽  
R. Rasul ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Contact Lens ◽  
Ocular Surface ◽  
Contact Lenses ◽  
Research Progress ◽  
Clinical Testing ◽  
Contact Lens Wear ◽  
Loss Of Vision ◽  
Infection And Inflammation ◽  
Lens Wear

Contact lens wear is generally safe and provides excellent vision. However, contact lens wear is often associated with the risk of developing ocular surface infection and inflammation, and in severe cases, the infection can result in loss of vision. Antimicrobial peptide-coated contact lenses have been made to help reduce the incidence of infection and inflammation. This paper reviews the research progress from conception, through the laboratory and preclinical tests to the latest information on clinical testing of an antimicrobial contact lens. We provide insights into the pathways followed and pitfalls that have been encountered. The journey has not always been linear or smooth, but has resulted in some of the first published clinical testing of antimicrobial peptide-coated contact lenses in humans. We hope this may help lead to the development and commercialisation of antimicrobial contact lenses in the future.

scholarly journals Scleral Contact Lenses for Treatment of Ocular Surface Disorders: A Narrative Review

2021 ◽  
Vol 8 (2) ◽  
pp. 1-9
Author(s):  
Ramkishor Sah ◽  
Keyword(s):  
Contact Lens ◽  
Ocular Surface ◽  
Contact Lenses ◽  
Narrative Review

Scleral lenses have been in the origin of contact lenses back in 1880, when the pioneers did the first glass contact lenses. With the advent of highly oxygen permeable materials and the increasing need for advanced solutions for severe ocular surface disorders has produced the driving pressures for a great amount of different contact lens designs to be available.

scholarly journals An Engineered Contact Lens for Passive and Sustained Release of Lifitegrast, an Anti-Dry Eye Syndrome Drug

2021 ◽  
Author(s):  
Changhua Mu ◽  
Victoria Lee ◽  
Yiran Liu ◽  
Ying Han ◽  
gerard marriott
Keyword(s):  
Drug Utilization ◽  
Dry Eye ◽  
Contact Lens ◽  
Ocular Surface ◽  
Contact Lenses ◽  
Inflammatory Responses ◽  
Bond Cleavage ◽  
Tear Film ◽  
Dry Eye Syndrome ◽  
Zero Order Reaction

Lifitegrast is an FDA-approved drug that inhibits T-cell mediated inflammation associated with dry eye syndrome (DES). Lifitegrast is a potent inhibitor of the interaction between LFA-1 on T-cells and ICAM-1 on endothelial cells at the ocular surface. While effective in treating DES, 5% (81.2 mM) lifitegrast has low drug utilization and elicits off-target effects. Here we engineer contact lenses to release therapeutically relevant doses of lifitegrast to every tear film for up to 10-hours. Lifitegrast is coupled to the polymer of the soft hydrogel lens via a photolabile (caged) crosslinker. Exposures of the lens to the 400-430 nm wavelengths of indoor daylight excite the caged crosslinker molecules and trigger a bond-cleavage reaction that releases authentic lifitegrast passively to the tear film. The photoproduct of the reaction remains chemically linked to the polymer of the single-use lens. Our studies show that passive exposures of the lens to indoor light would generate an average of 990 nM lifitegrast to every tear film in a zero-order reaction for up to 10-hours. This concentration exceeds the Kd for the interaction between ICAM-1 and LFA-1 by ~330-fold and would sustain inhibition of inflammatory responses at the ocular surface. The amount of lifitegrast released from the lens increases during exposures to outdoor sunlight. Over a 10-hour exposure to indoor light, a single lens would release 0.44% of the lifitegrast present in two drops of commercial 5% lifitegrast. Compared to tear-drop approaches, our engineered lenses would sustain the passive delivery of therapeutically relevant doses of lifitegrast over a longer period, and exhibit improved drug utilization at a lower cost. Our technology could easily be integrated into daily-use contact lenses in order to prevent inflammation at the ocular surface, dry-eye and contact lens-mediated discomfort.

scholarly journals Tolerance to Systemic Isotretinoin Therapy in Two Patients Using Highly Wettable Contact Lenses

2014 ◽  
Vol 2014 ◽  
pp. 1-3
Author(s):  
Ayşegül Arman ◽  
D. Deniz Demirseren ◽  
Gulsen Akoglu
Keyword(s):  
Contact Lens ◽  
Ocular Surface ◽  
Contact Lenses ◽  
Tear Film ◽  
Film Stability ◽  
Function Tests ◽  
Tear Film Stability ◽  
Retinoid Therapy ◽  
Isotretinoin Therapy ◽  
Tear Film Function

Purpose.Numerous ocular side effects have been reported with the use of systemic isotretinoin therapy. Herein, we presented two contact lens user patients who did not have contact lens intolerance during systemic isotretinoin therapy.Methods.25-year-old male and 20-year-old female patients with severe acne vulgaris who were using highly wettable silicone hydrogel contact lenses which increase tear film stability were examined. Tear film function tests including Schirmer tests and tear break up time (TBUT) test and ocular surface staining with fluorescein were done. Subjective ocular complaints were scored with ocular surface disease index (OSDI) questionnaire. Patients were followed up monthly and examinations were repeated at each visit.Results.Both patients completed the therapy after a cumulative dose of 140 mg/kg isotretinoin in 6 months. The OSDI score and tear film function tests before and after treatment were all within normal limits.Discussion.Highly wettable contact lenses that provide increase in the tear film stability may be used during systemic retinoid therapy under close followups. Although isotretinoin affects ocular glands, the differences between tolerances to this retinoid therapy need to be investigated in larger patient groups using contact lenses.

Optimum Infinite is a new era of oxygen permeability material for contact lenses

The Eye ◽  
2020 ◽  
Vol 22 (129) ◽  
pp. 44-46
Author(s):  
Mark Eddleston
Keyword(s):  
Contact Lens ◽  
Oxygen Permeability ◽  
Contact Lenses ◽  
New Era ◽  
Lens Material ◽  
Insight Into

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.

Profilometry. Using Corneo-scleral topography for scleral lens fitting

The Eye ◽  
2019 ◽  
Vol 21 (128) ◽  
pp. 19-22
Author(s):  
Gregory DeNaeyer
Keyword(s):  
Ocular Surface ◽  
World Wide ◽  
Contact Lenses ◽  
The Past ◽  
The World ◽  
The Future ◽  
The Way

The world-wide use of scleral contact lenses has dramatically increased over the past 10 year and has changed the way that we manage patients with corneal irregularity. Successfully fitting them can be challenging especially for eyes that have significant asymmetries of the cornea or sclera. The future of scleral lens fitting is utilizing corneo-scleral topography to accurately measure the anterior ocular surface and then using software to design lenses that identically match the scleral surface and evenly vault the cornea. This process allows the practitioner to efficiently fit a customized scleral lens that successfully provides the patient with comfortable wear and improved vision.

Managing Corneal Epithelial Defects Using High Molecular Weight Fluorescein to Prevent Contact Lens Staining and Removal of Bandage Contact Lenses

2020 ◽  
Vol 3 (8) ◽  
pp. 20-22
Author(s):  
Muhammad Hamza ◽  
Chrishan Gunasekera ◽  
Samar Nahas ◽  
Z CX Lin ◽  
Hatch Mukherjee ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Contact Lens ◽  
Contact Lenses ◽  
Corneal Epithelial
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