Risk Factors for the Development of Corneal Infiltrative Events Associated with Contact Lens Wear

Morgan, Philip B.; Efron, Nathan; Brennan, Noel A.; Hill, Elizabeth A.; Raynor, Mathew K.; Tullo, Andrew B.

doi:10.1167/iovs.05-0133

Cited by 127 publications

(111 citation statements)

References 18 publications

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“…Surprisingly, this trend did not hold for delays over 72 h. This may be because less severe events are associated with less severe symptoms, allowing individuals to tolerate symptoms for longer, a theory put forward in a recent study of corneal infiltrates. 27 The microbiological profile of cases here supports this theory; of the 24 cases that took greater than 72 h to seek treatment, 19 cultured Gram-positive bacteria, one was Acanthamoeba keratitis, and none cultured Gram-negative bacteria.…”

supporting

confidence: 62%

Characteristics of and risk factors for contact lens-related microbial keratitis in a tertiary referral hospital

Edwards

Keay

Naduvilath

et al. 2007

Eye

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Aim A retrospective case-control study was conducted at a tertiary referral hospital to determine the characteristics of and risk factors for contact lens (CL) related presumed microbial keratitis. Methods Two hundred and ninety-one cases of presumed microbial keratitis were retrospectively identified over a 2-year period. Records were reviewed for a history of CL wear and, where identified, CL, demographic, and clinical data were collected. Lens wearing controls (n ¼ 186) were identified by a community telephone survey. Multiple logistic regression estimated risk factors for infection and vision loss. Results Ninety-nine (34%) new cases of presumed microbial keratitis were associated with CL wear. Overnight soft CL use was associated with an increased risk of infection compared to daily disposable CL wear (odds ratio (OR): 8.03, 95% confidence interval (CI): 1.82-35.46). Compared with older CL wearers, 15-24 year olds had a 3.5 times greater risk of infection (OR, 95% CI: 1.7-7.4). Of the 84 cases with available data, 24 (29%) lost two or more lines of best-corrected visual acuity. Delaying treatment by 49-72 h had a 4.5 times (OR, 95% CI: 1.4-14.9) greater risk of visual loss compared to seeking treatment early. Of the 99 cases of infection, 88 were scraped and 78% (69/88) of these returned a positive culture. Gram-positive bacteria were the predominant causative organisms. Conclusion Overnight use of CL and youth carry a greater risk of infection. Practitioners should reinforce the importance of proper CL care at all times, and early presentation following the onset of symptoms.

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supporting

confidence: 62%

Characteristics of and risk factors for contact lens-related microbial keratitis in a tertiary referral hospital

Edwards

Keay

Naduvilath

et al. 2007

Eye

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“…Modifiable risk factors include extended and overnight contact lens wear, 7,8 poor hand hygiene, 4,9 infrequent or omission of lens disinfection, 7,8 case hygiene and case replacement, 6,10 and smoking. 4,6,11 Nonmodifiable risk factors include gender, 2,7,11 young age, 2,7 and socioeconomic status. 9 Systemic risk factors for contact lens-related microbial keratitis include poor general health, 12 diabetes, 9 and thyroid disease.…”

Section: Introductionmentioning

confidence: 99%

Risk factors for contact lens-related microbial keratitis in Singapore

Lim

Carnt

Farook

et al. 2015

Eye

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Purpose: To investigate independent risk factors for contact lens-related microbial keratitis in Singapore and estimate their impact on disease load. Methods: Cases were contact lens wearers presenting to Singapore National Eye Centre with microbial keratitis between 2008 and 2010. Community contact lens wearers were recruited as controls. All wearers completed a previously validated questionnaire describing contact lens wear history, hygiene and compliance habits, and demographics. Risk factors significant in univariate analysis (Po0.2) were evaluated in a multivariate model. Results: In all, 58 cases of microbial keratitis and 152 contemporaneous controls were identified. When controlling for other variables, Chinese had a 7 × lower risk compared with other races (95% CI: 2.3-21.3, P = 0.001). Those aged between 25 and 44 years were at 3 × increased risk compared with younger wearers (95% CI: 1.1-9.6, P = 0.04). Occasional overnight contact lens wear (less often than one night per week) was associated with a 4 × higher risk (95% CI: 1.2-15.4, P = 0.03) compared with daily use. Not washing hands before handling was associated with a 13 × increased risk (95% CI: 1.9-84.8, P = 0.008). Use of multipurpose solution A carried a 16 × higher risk compared with hydrogen peroxide (95% CI: 1.5-174.0, P = 0.02). The combined PAR% for modifiable risk factors (occasional overnight wear, not washing of hands, and MPS A) was 82%. Conclusions: Consistent with previous findings, independent risk factors for contact lens-related microbial keratitis include poor hand hygiene, occasional overnight wear, and type of lens care solution. Prolonged overnight or extended contact lens use was infrequent in this population.

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“…While normal, healthy human corneas remain resistant to infection, contact lens wear or corneal injury/surgery can enable susceptibility (5,15,26). The mechanisms by which these factors predispose to infection are not yet well understood.…”

mentioning

confidence: 99%

Clearance of Pseudomonas aeruginosa from a Healthy Ocular Surface Involves Surfactant Protein D and Is Compromised by Bacterial Elastase in a Murine Null-Infection Model

et al. 2009

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Our previous studies showed that surfactant protein D (SP-D) is present in human tear fluid and that it can protect corneal epithelial cells against bacterial invasion. Here we developed a novel null-infection model to test the hypothesis that SP-D contributes to the clearance of viablePseudomonas aeruginosa from the healthy ocular surface in vivo. Healthy corneas of Black Swiss mice were inoculated with 10 7 or 10 9 CFU of invasive (PAO1) or cytotoxic (6206) P. aeruginosa. Viable counts were performed on tear fluid collected at time points ranging from 3 to 14 h postinoculation. Healthy ocular surfaces cleared both P. aeruginosa strains efficiently, even when 10 9 CFU was used: e.g., <0.01% of the original inoculum was recoverable after 3 h. Preexposure of eyes to bacteria did not enhance clearance. Clearance of strain 6206 (low protease producer), but not strain PAO1 (high protease producer), was delayed in SP-D gene-targeted (SP-D ؊/؊ ) knockout mice. A protease mutant of PAO1 (PAO1 lasA lasB aprA) was cleared more efficiently than wild-type PAO1, but this difference was negligible in SP-D ؊/؊ mice, which were less able to clear the protease mutant. Experiments to study mechanisms for these differences revealed that purified elastase could degrade tear fluid SP-D in vivo. Together, these data show that SP-D can contribute to the clearance of P. aeruginosa from the healthy ocular surface and that proteases can compromise that clearance. The data also suggest that SP-D degradation in vivo is a mechanism by which P. aeruginosa proteases could contribute to virulence.Pseudomonas aeruginosa, an opportunistic pathogen, is a leading cause of bacterial keratitis. While normal, healthy human corneas remain resistant to infection, contact lens wear or corneal injury/surgery can enable susceptibility (5,15,26). The mechanisms by which these factors predispose to infection are not yet well understood.A murine scarification model has been used exclusively to study the pathogenesis of P. aeruginosa corneal infection (3,9,30). That model involves scratching the cornea with a sterile needle prior to adding bacteria, which enables bacteria to directly access the exposed stroma. The resulting disease resembles P. aeruginosa infection in people. More recently, we used a healing model of murine corneal infection to show that 6 h after scratching, the mouse cornea remains susceptible to infection, but by 12 h, it regains resistance to infection despite loss of barrier function to fluorescein staining (18). These injury models that enable P. aeruginosa to infect the cornea have led to a wealth of information about how infection develops and resulting pathology. Yet, the mechanisms by which the normal ocular surface remains healthy under normal circumstances have not been explored in vivo. This cannot be studied using a scratch model. The corneas' ability to resist disease despite constant daily exposure to potential pathogens is remarkable, and learning about the mechanisms involved could help us to develop new therapies for disea...

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Risk Factors for the Development of Corneal Infiltrative Events Associated with Contact Lens Wear

Cited by 127 publications

References 18 publications

Characteristics of and risk factors for contact lens-related microbial keratitis in a tertiary referral hospital

Characteristics of and risk factors for contact lens-related microbial keratitis in a tertiary referral hospital

Risk factors for contact lens-related microbial keratitis in Singapore

Clearance of Pseudomonas aeruginosa from a Healthy Ocular Surface Involves Surfactant Protein D and Is Compromised by Bacterial Elastase in a Murine Null-Infection Model

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