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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    • "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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    • "The following risk factors are associated with these adverse events: lens care system, contact lens material, durability, wear schedule, lens power, contact lens solution, and patient-related factors such as smoking [6,7,8,9,10,11,12]. However, biometric risk factors have yet to be fully determined. "
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    ABSTRACT: Purpose To investigate the biometric risk factors for corneal surface complications associated with hydrogel soft contact lens (SCL) fitting in myopic patients in Korea. Methods This is a retrospective case-control study. The records of 124 subjects (124 eyes) who wore SCLs on a daily basis were reviewed. Thirty-one patients (31 eyes) who were diagnosed with corneal neovascularization (NV) while wearing SCLs were included in the complication group. Ninety-three age- and sex-matched patients (93 eyes) who wore SCLs, who did not have corneal NV and who visited our clinic for correction of refractive errors were included in the control group. The degree of spherical equivalent, astigmatism and corneal base curve radius (BCR) were compared in both groups. Results Patients with NV exhibited poorer best corrected visual acuity and more myopia than controls (p = 0.008 and 0.006, respectively). In univariate analysis, highly myopic patients (-9 diopters [D] or higher) were more likely to experience NV (odds ratio [OR], 2.232; 95% confidence interval [CI], 1.602 to 3.105). High astigmatism (≥2 D) increased the risk of complications (OR, 2.717; 95% CI, 1.141 to 6.451). Steep cornea, in which BCR was <7.5 mm, also raised the risk of complications (OR, 4.000; 95% CI, 1.661 to 9.804). Flat cornea was not a risk factor for the development of NV. Conclusions High myopia, high astigmatism, and steep cornea seemed to be risk factors in the development of corneal NV in SCL wearers.
    Korean Journal of Ophthalmology 08/2014; 28(4):292-7. DOI:10.3341/kjo.2014.28.4.292
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