Publications by authors named "Yvonne T Wu"

Article Synopsis
  • Tear fluid was shown to impact the gene expression of Pseudomonas aeruginosa, regulating around 180 genes, including those related to virulence and antibiotic resistance.
  • The study utilized RNA-sequencing and other methods to explore how tear fluid exposure affected bacterial behavior and response to antibiotics.
  • Results indicated that while tear fluid made P. aeruginosa more resistant to certain antibiotics, it significantly increased sensitivity to polymyxin B, highlighting its complex role in bacterial adaptation.
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Purpose: To compare the risk of vision loss following contemporary laser-assisted in situ keratomileusis (LASIK) with different types and modality of use of contact lenses.

Methods: Data from a previously published study were used to derive the incidence of vision loss (≥ 2 line loss of best corrected spectacle acuity) following microbial keratitis for different contact lens types and wearing modality, stratified by duration of lens wear. A literature search on vision loss following LASIK was performed between 2003 and 2019.

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Research with animal models of Pseudomonas aeruginosa keratitis has shown that use of a topical corticosteroid alone against an established infection can significantly increase the number of colonizing bacteria or worsen clinical disease. Moreover, retrospective analysis has suggested that corticosteroid use in humans is associated with an increased risk of keratitis in eyes with pre-existing disease. Thus, while corticosteroids are often used to reduce ocular inflammation in the absence of infection, the risk of opportunistic infection remains a concern.

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Purpose: The type III secretion system (T3SS) is a significant virulence determinant for Pseudomonas aeruginosa. Using a rodent model, we found that contact lens (CL)-related corneal infections were associated with lens surface biofilms. Here, we studied the impact of human tear fluid on CL-associated biofilm growth and T3SS expression.

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A contaminated contact lens case can act as a reservoir for microorganisms that could potentially compromise contact lens wear and lead to sight threatening adverse events. The rate, level and profile of microbial contamination in lens cases, compliance and other risk factors associated with lens case contamination, and the challenges currently faced in this field are discussed. The rate of lens case contamination is commonly over 50%.

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Purpose: Pseudomonas aeruginosa keratitis is a sight-threatening complication of contact lens wear, yet mechanisms by which lenses predispose to infection remain unclear. Here, we tested the hypothesis that tear fluid at the posterior contact lens surface can lose antimicrobial activity over time during lens wear.

Methods: Daily disposable lenses were worn for 1, 2, 4, 6, or 8 hours immediately after removal from their packaging or after presoaking in sterile saline for 2 days to remove packaging solution.

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Purpose: To assess the association between the levels of lens case contamination and lens wearers' hygiene behaviors.

Methods: Contact lens wearers were surveyed for information on wearer demographics and contact lens hygiene behavior. Microbial analysis of lens cases was performed.

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Purpose: Lens storage case hygiene practices are important for safe contact lens wear. However, the effectiveness of the manufacturer's direction for use and various cleaning regimens in reducing biofilm load is yet to be evaluated and compared. This in vitro study compared the effectiveness of several cleaning methods using silver-impregnated lens case and hydrogen peroxide disinfection systems.

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Purpose: Lens case contamination is a risk factor for microbial keratitis. The effectiveness of manufacturers' lens case cleaning guidelines in limiting microbial contamination has not been evaluated in vivo. This study compared the effectiveness of manufacturers' guidelines and an alternative cleaning regimen.

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Purpose: Lens case hygiene is important for safe contact lens wear. However, there are no evidence-based data to suggest optimum hygiene regimens. This in vitro study aimed to evaluate and compare the effectiveness of manufacturers' guidelines and several other regimens in removing biofilm using various types of contact lens cases and disinfecting agents.

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Purpose: Wearing goggles over contact lenses while swimming is often recommended by eye care professionals. Limited data are available to assess this recommendation. The purpose of this study was to examine whether wearing goggles while swimming limits bacterial colonization on contact lenses and whether the type of lens worn affects contamination rates.

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Purpose: Lens case hygiene practices are important in maintaining safe contact lens wear. However, the effectiveness of various lens case cleaning practices have not been evaluated and compared. This in vitro study aimed to evaluate and compare the efficacy of cleaning practices that are most commonly carried out by lens wearers and recommended by practitioners.

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Purpose: To determine the rate and type of microbial contamination when contact lens cases are air-dried in two different positions (face up and face down) and in four different locations (toilet, bathroom, office, and bedroom).

Methods: Unused contact lens cases (n = 97) were rinsed with 2-ml sterile phosphate buffered saline and then placed on facial tissue paper in different locations: humid (toilet and bathroom) and non-humid (office and bedroom) and air-dried at room temperature. After 24 h, the contact lens cases were collected and sampled for microbial numbers and microbial types identified using standard techniques.

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Purpose: To evaluate the frequency level and profile of contact lens storage case contamination in asymptomatic contact lens wearers and to examine whether different areas of the same lens case may show a different rate and profile of contamination. The relationship between lens storage case contamination and the age of the lens storage case was also examined.

Methods: Sixty-four lens cases and case age information were collected from asymptomatic contact lens wearers.

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