Lysozyme and Lipid Deposition on Silicone Hydrogel Contact Lens Materials

Jones, Lyndon; Senchyna, Michelle; Glasier, Mary Ann; Schickler, Jillian; Forbes, Iain; Louie, Derek; May, Christopher

doi:10.1097/00140068-200301001-00021

Cited by 204 publications

(204 citation statements)

References 12 publications

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“…The high water content and the ionic material of some disposable soft lenses allow for more deposition of proteins, a fact that could explain the greater affinity of the Acanthamoeba protozoon for worn lenses than for unworn ones. 39 Jones et al 44 reported significant deposition of low levels of lysozyme and high levels of lipid on silicone hydrogel contact lens materials, as compared with ionic contact lens materials. The adhesion of Acanthamoeba in unwashed worn versus unwashed unworn contact lenses showed a significantly lower adherence of Acanthamoeba to new lenses.…”

Section: Duration Of Exposure and Protozoon Concentrationmentioning

confidence: 99%

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How Could Contact Lens Wearers Be at Risk of Acanthamoeba Infection? A Review

Ibrahim

Boase

Cree

2009

Journal of Optometry

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Contact lens wear is highly influential on the incidence of ulcerative keratitis worldwide, particularly in developed countries. The association between Acanthamoeba keratitis and contact lens wear is firmly established; it may account for up to 95% of the reported cases. Before the popularisation of soft contact lens wear, Acanthamoeba keratitis was extremely rare. In 2000 it was estimated that the number of contact lens wearers worldwide was about 80 million, out of whom 33 million were in the United States and 90% of them wore hydrogel soft lenses. Contact lens-related problems depend on many factors, such as lens material, wearing modality, lens hygiene, type of lens-caring solution, the degree of compliance of the lens user with lens wear and care procedures, lens overwear, sleeping in lenses, rate of changing lenses, and lens case hygiene. This paper is a thorough review of the literature aiming to highlight the role of one of the main risk factors of infectious keratitis, contact lens wear, and also to show the responsibility of lens users in aggravating this risk. RESUMENLa utilización de lentes de contacto es un factor que influye sumamente en la incidencia de la queratitis ulcerosa, en particular en los países desarrollados. La asociación entre queratitis por Acanthamoeba y el uso de lentes de contacto está firmemente establecida; podría representar aproximadamente hasta un 95% de los casos registrados. Antes de la popularización del uso de lentes de contacto, la queratitis por Acanthamoeba era muy poco frecuente. En el año 2000 se estimó que, a nivel mundial, había unos 80 millones de usuarios de lentes de contacto, de los cuales 33 millones residían en los Estados Unidos y, de ellos, el 90% utilizaban lentes de contacto blandas de hidrogel. Los problemas derivados del uso de lentes de contacto dependen de otros muchos factores, como el material del que está hecha la lente, la modalidad de uso, las medidas de higiene empleadas, el tipo de solución utilizada para la limpieza y el mantenimiento de la lente, el grado de cumplimiento terapéutico del usuario de las lentes respecto a su utilización y a su limpieza/mantenimiento, el uso de las lentes durante periodos excesivamente prolongados, el dormir con las lentes de contacto puestas, la frecuencia con la que el usuario se cambia de lentes y la limpieza de la funda de las lentes de contacto. Este artículo presenta una revisión minuciosa de la literatura, con el objetivo de resaltar el papel de uno de los principales factores de riesgo de desarrollo de queratitis infeccionsa, como es el uso de lentes de contacto, y con el fin de poner de relieve que el propio usuario de las lentes es, en ocasiones, el responsable de agravar este riesgo. (J Optom 2009;2:60-66 ©2009 Consejo General de Colegios de Ópticos-Optometristas de España) PALABRAS CLAVE: Acanthamoeba; queratitis; lentes de contacto; usuario de lentes de contacto; uso excesivo de las lentes de contacto.

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Section: Duration Of Exposure and Protozoon Concentrationmentioning

confidence: 99%

“…111 Old contact lenses could colonise more microorganisms due to the increased lens surface tear and wearrelated scratches 40 or to the accumulated deposits. [43][44][45] The relationship between repeated use of daily disposable lenses and risk of Acanthamoeba 112,113 and microbial keratitis 93,114 is well established.…”

Section: Non-compliant Contact Lens Usersmentioning

confidence: 99%

How Could Contact Lens Wearers Be at Risk of Acanthamoeba Infection? A Review

Ibrahim

Boase

Cree

2009

Journal of Optometry

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“…44 There were no differences in the TSQ after seven days of lens wear compared with the first day of wear, neither for the hydrogel nor for the silicone hydrogel lenses. This was in spite of the fact that group-4 hydrogels (high water content ionic materials) are known to significantly accumulate lysozyme deposits [45][46][47][48] and silicone hydrogel lenses are prone to lipid accumulation [48][49][50][51] over contact lens wearing time. One of the more interesting findings of this study was a slight, but statistically significant improvement in TSQ during the first day of silicone hydrogel lens wear.…”

Section: Discussionmentioning

confidence: 99%

Tear Film Surface Quality with Soft Contact Lenses Using Dynamic Videokeratoscopy

Kopf

Iskander

et al. 2008

Journal of Optometry

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PURPOSE:To investigate changes in tear film surface quality after commencing soft contact lens wear. METHODS: Tear film surface quality (TSQ) was assessed during the interblink period using dynamic videokeratoscopy at 25 Hz. A quantitative value of TSQ is derived for each raw Placido ring image. Eleven young subjects with normal tear characteristics participated in the study. Dynamic videokeratoscopy was taken three times per day; in the morning, at lunchtime, and in the afternoon. This was done on two baseline days (bare eye) and on the first and seventh days of lens wear for a conventional hydrogel lens and following a week of no lens wear, for a further week of silicone hydrogel lens wear. Additionally clinical tests to assess TSQ were conducted and subjects were also asked to rate the subjective dryness of their eyes. RESULTS: All lens wear measurements showed a significant worsening of TSQ compared to bare eye measurements (repeated measures ANOVA, P<0.01). A significant diurnal change was found on the first day of silicone hydrogel contact lens wear, where TSQ improved during the day (P=0.045). However, no diurnal changes were found in TSQ for the other lens wearing days or for the bare eye condition (P>0.05). The subjective rating of dryness correlated with TSQ values (Pearson's r=0.62, P<0.05) for the bare eye condition, but not during contact lens wear. TSQ derived from the right and left bare eyes of the same individuals showed a significant correlation (Pearson's r=0.61, P<0.05). CONCLUSIONS: The measurement of TSQ using dynamic videokeratoscopy differentiates between bare eye and lens wearing conditions. It also shows a small systematic improvement in tear surface quality during the first day of silicone hydrogel lens wear and a significant association with subjective dryness for the bare eye condition. (J Optom 2008;1:14-21 ©2008 Spanish Council of Optometrists) KEY WORDS: high speed videokeratoscopy; tear film; dry eye; contact lens. RESUMEN OBJETIVO:Investigar los cambios en la calidad de la superficie de la película lagrimal tras empezar a utilizar lentes de contacto blandas. MÉTODOS: Se evaluó la calidad de la superficie de la película lagrimal (CSPL) durante el periodo comprendido entre dos parpadeos consecutivos utilizando videoqueratoscopia (topografía corneal estándar) dinámica a 25 Hz. Para cada imagen registrada de los anillos de Plácido se derivó un valor cuantitativo de la CSPL. En el estudio participaron once sujetos jóvenes cuya lágrima presentaba características normales. Se realizaron medidas de videoqueratoscopia dinámica tres veces al día: por la mañana, a la hora de comer y por la tarde. Estas medidas se llevaron a cabo primero, en dos días distintos, para recabar datos de referencia (ojo desnudo, sin lente de contacto); posteriormente, el primer y el séptimo día de uso de una lente de contacto convencional de hidrogel y finalmente, y tras una semana sin utilizar lentes, se realizaron medidas el primer y el séptimo día de uso de una lente de hidrogel de silicona. De maner...

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“…Research on conventional poly-HEMA-based lens materials has shown that the deposition of lysozyme and albumin depends upon the polymer's composition (Bohnert et al, 1988), charge (Garrett et al, 2000;Soltys-Robitaille et al, 2001) and water content (Garrett et al, 1999). Silicone-hydrogel materials give rise to different deposition profiles to those associated with the use of conventional poly-HEMA hydrogel lenses in that they induce less protein deposition and more lipid deposition (Jones et al, 2003;Subbaraman et al, 2006;Carney et al, 2008). Surface roughness also need to be considered since deposits are more likely to form on imperfections of the lens surface (Hosaka et al, 1983).…”

Section: Introductionmentioning

confidence: 99%