Risk Factors for Moderate and Severe Microbial Keratitis in Daily Wear Contact Lens Users
ABSTRACT 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.
SourceAvailable from: Eric Tzyy-Jiann Chong
Dataset: 1136 42
[Show abstract] [Hide abstract]
ABSTRACT: To determine the clinical performance of DAILIES TOTAL1 (DT1), Clariti 1Day (C1D), and 1-DAY ACUVUE TruEye (AVTE) silicone hydrogel daily disposable contact lenses (SiHy DDCLs). Eligible participants, subdivided into asymptomatic and symptomatic groups, wore each SiHy DDCLs for three consecutive days. Each participant attended three visits (on day 1 at 0 hours; on days 1 and 3 after 8 hours of wear) per lens type. The order of lens wear was randomized, with at least 1 day washout between lenses. Lens-related performance was evaluated by assessing lens surface deposits, wettability, pre-lens noninvasive tear breakup time, lens movement, and centration; ocular response assessments included conjunctival redness, corneal staining, and conjunctival staining and indentation. Fifty-one asymptomatic and 53 symptomatic participants completed the study. For all visits, the mean noninvasive tear breakup time was about 1 second longer with DT1 than with C1D and AVTE (p < 0.01). Overall, the wettability of all three lenses was good; however, DT1 was graded marginally better than the other lenses (both p < 0.01). On day 3, eyes wearing AVTE had significantly more dehydration-induced corneal staining compared with DT1 (AVTE, 24%; DT1, 11%; p < 0.01). After 8 hours, conjunctival staining was different between lenses (greatest with C1D and least with DT1; all p < 0.01). Conjunctival indentation was more prevalent with the C1D lenses (n = 70) compared with DT1 (n = 1; p < 0.01) and AVTE (n = 11; p < 0.01). There were no differences between asymptomatic and symptomatic lens wearers for any of the clinical parameters (all p > 0.05). Each of the three SiHy DDCLs performed well. Noninvasive tear breakup time was longest and wettability was greater with DT1. C1D had the most conjunctival staining conjunctival indentation. There was no difference between asymptomatic and symptomatic wearers with regard to ocular response and contact lens-related parameters. These results suggest that SiHy DDCLs may be an excellent contact lens modality for the symptomatic patient.Optometry and vision science: official publication of the American Academy of Optometry 01/2015; 92(3). DOI:10.1097/OPX.0000000000000514 · 1.53 Impact Factor
[Show abstract] [Hide abstract]
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.