Risk Factors for Moderate and Severe Microbial Keratitis in Daily Wear Contact Lens Users

Brien Holden Vision Institute, Sydney, Australia.
Ophthalmology (Impact Factor: 6.14). 04/2012; 119(8):1516-21. DOI: 10.1016/j.ophtha.2012.01.052
Source: PubMed


To establish risk factors for moderate and severe microbial keratitis among daily contact lens (CL) wearers in Australia.
A prospective, 12-month, population-based, case-control study.
New cases of moderate and severe microbial keratitis in daily wear CL users presenting in Australia over a 12-month period were identified through surveillance of all ophthalmic practitioners. Case detection was augmented by record audits at major ophthalmic centers. Controls were users of daily wear CLs in the community identified using a national telephone survey.
Cases and controls were interviewed by telephone to determine subject demographics and CL wear history. Multiple binary logistic regression was used to determine independent risk factors and univariate population attributable risk percentage (PAR%) was estimated for each risk factor.
Independent risk factors, relative risk (with 95% confidence intervals [CIs]), and PAR%.
There were 90 eligible moderate and severe cases related to daily wear of CLs reported during the study period. We identified 1090 community controls using daily wear CLs. Independent risk factors for moderate and severe keratitis while adjusting for age, gender, and lens material type included poor storage case hygiene 6.4× (95% CI, 1.9-21.8; PAR, 49%), infrequent storage case replacement 5.4× (95% CI, 1.5-18.9; PAR, 27%), solution type 7.2× (95% CI, 2.3-22.5; PAR, 35%), occasional overnight lens use (<1 night per week) 6.5× (95% CI, 1.3-31.7; PAR, 23%), high socioeconomic status 4.1× (95% CI, 1.2-14.4; PAR, 31%), and smoking 3.7× (95% CI, 1.1-12.8; PAR, 31%).
Moderate and severe microbial keratitis associated with daily use of CLs was independently associated with factors likely to cause contamination of CL storage cases (frequency of storage case replacement, hygiene, and solution type). Other factors included occasional overnight use of CLs, smoking, and socioeconomic class. Disease load may be considerably reduced by attention to modifiable risk factors related to CL storage case practice.

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    • "Bacterial infection of the cornea can vary from mild to severe keratitis and if left untreated often leads to progressive tissue destruction, with corneal perforation (U ¨ stündag ˘-Okur et al., 2014). Pseudomonas is one of the most common causes of bacterial keratitis in humans especially in patients wearing soft contact lenses (Stapleton et al., 2007, 2012). Ciprofloxacin (CIP) hydrochloride is an extremely effective antibacterial agent with potent activity against most gram positive and gram negative bacteria. "
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    ABSTRACT: Ciprofloxacin (CIP) was effective in treating bacterial keratitis. The purpose of this study was to prepare an effective prolonged-release of CIP by both temperature and pH-triggered in situ nanogels for the treatment of keratitis. Poly(N-isopropylacrylamide-methacrylicacide-vinylpyrrolidone) [P (NIPAAm-MAA-VP)] nanoparticles was synthesised and used for preparation of CIP-loaded nanogels. Antimicrobial and in vivo animal studies of the CIP-loaded nanoformulation were performed. Nanoformulation with a mean particle size between 10 and 50 nm and higher than 95% encapsulation efficiency was obtained. Ciprofloxacin released from the nanoparticles showed an enhanced antibacterial effect as determined by minimal inhibitory concentrations. In vivo studies demonstrated reasonable efficacy in severe keratitis using the developed nanoformulation. Nanoformulation had acceptable efficacy in treating bacterial keratitis in an animal model. Therefore, the developed system has the potential to be used in localised application for the treatment of keratitis.
    Journal of Microencapsulation 07/2015; 32(5):1-9. DOI:10.3109/02652048.2015.1065915 · 1.59 Impact Factor
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    • "and Serratia spp. were frequently isolated from contact lenses (Das et al., 2007; Goh et al., 2010; Stapleton et al., 2012) but some studies claimed that Gram positive bacteria like Staphylococcus spp. and Streptococcus spp. "
    Dataset: 1136 42

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    • "and Serratia spp. were frequently isolated from contact lenses (Das et al., 2007; Goh et al., 2010; Stapleton et al., 2012) but some studies claimed that Gram positive bacteria like Staphylococcus spp. and Streptococcus spp. "
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    ABSTRACT: Microbial keratitis is affecting approximately 4 to 5 per 10000 contact lens wearers worldwide and the seriousness of the disease is depends on type of microbial species contaminated on the contact lens. As number of contact lens wearer is increasing globally including Malaysia in the past ten years, there is a need to identify the type of microbial species that contaminated on contact lenses among Malaysian especially in college students. Therefore, this study was conducted to evaluate the microbial contamination on contact lenses among university students and the habit of the contact lens wearer within the university facility. A total of 67 pairs of used contact lens samples were collected. CFU/ml was calculated based on colonies growth on nutrient agar to represent the microbial population density and Gram staining was performed for all pure cultures with different morphologies. Two major groups of contaminant with different morphologies were subjected for identification using biochemical tests. Our results suggested that 41.79% of the samples collected were contaminated with microbial and the contamination status was significantly different in gender and duration of contact lens wearing per usage (p < 0.05). Besides, monthly disposable contact lens had the highest contamination rate with mean of 2410 CFU/ml when compared to daily and quarter-yearly (3 months) contact lenses. The Gram staining showed that 88.47% of microbial contamination was Gram negative mainly presented with Vibrio spp. and Aeromonas spp. Our study unexpectedly found that contact lenses among university students were contaminated with microbials that might be found in the tap water they used to wash their hands.
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