Relationship between contact lens coefficient of friction and subjective lens comfort

Kern, Jami; Rappon, Joe; Bauman, Erich; Vaughn, Ben

doi:10.1016/j.clae.2013.08.094

Cited by 17 publications

(21 citation statements)

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“…The linear actuator was then used to bring tissue samples into contact at three manually determined axial positions to correspond with axial loads of 0.3 ± 0.03, 0.5 ± 0.03, and 0.7 ± 0.03 N (normal pressures: 10.1–27.3 kPa based on an apparent contact area of 24.6 mm 2 ). Once in contact at a given axial position, a 12 s dwell time preceded four revolutions in both rotation directions (positive was defined to be counter‐clockwise and negative clockwise) directions at four different effective linear velocities (sliding velocities (ν eff = 30, 10, 1.0, 0.3 mm/s) where ν eff = ω· r eff and r eff = 2/3[( r 0 –

r_{i}^{3}

)/( r o –

r_{i}^{2}

)] . Torque and axial load data from each test was collected at 20 Hz.…”

Section: Methodsmentioning

confidence: 99%

“…An important part of the research effort in improving contact lens biomaterials is identifying testable material properties that correlate to their in vivo performance. At the time of writing, the friction of contact lenses is the only property that has been significantly correlated to subjective in vivo comfort of contact lenses . In addition to this, contact lens wear has been correlated to lid wiper epitheliopathy, a condition in which visible wear damage occurs in the epithelium of the lid wiper in a patients eye lid .…”

Section: Introductionmentioning

confidence: 99%

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Proteoglycan 4 and hyaluronan as boundary lubricants for model contact lens hydrogels

et al. 2017

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Clinical data show that in vitro contact lens friction is related to in vivo comfort. Solutions of biological lubricants hyaluronan (HA) and proteoglycan 4 (PRG4, also known as lubricin) reduce friction at a cornea-polydimethylsiloxane (PDMS) interface. The purpose of this study was to (1) determine if PRG4 can sorb to and lubricate model contact lens materials and (2) assess the boundary lubricating ability of PRG4 and HA compared to saline on model contact lens materials. PRG4 was obtained from bovine cartilage culture and suspended in saline at 300 µg/mL. N,N-Dimethylacrylamidetris (trimethylsiloxy) silane, (DMAA/TRIS) and methacryloxypropyltris (trimethylsiloxy) silane (pHEMA/TRIS) silicone hydrogels were prepared. A previously described in vitro eyelid-hydrogel and cornea-hydrogel biomechanical friction test was used to determine boundary lubricant effect. PRG4 sorption to the hydrogels was assessed using a soak-rinse protocol and western blotting. PRG4 effectively lubricated both silicone hydrogel materials and HA effectively lubricated pHEMA/TRIS, as indicated by a statistically significant reduction in friction compared to the saline control lubricant. An HA and PRG4 combination showed a synergistic effect for pHEMA/TRIS and effectively lubricated DMAA/TRIS. Biological boundary lubricants HA and PRG4 were shown to effectively lubricate silicone hydrogels when in solution. Additionally, HA and PRG4 showed synergistic lubrication for pHEMA/TRIS. The purpose of this study was not to replicate the friction coefficients of contact lenses, but rather to investigate lubricant-surface interactions for common contact lens constituents. These findings contribute to the potential development of biomolecule based lubricant drops for contact lens wearers. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1329-1338, 2018.

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r_{i}^{3}

)/( r o –

r_{i}^{2}

)] . Torque and axial load data from each test was collected at 20 Hz.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Proteoglycan 4 and hyaluronan as boundary lubricants for model contact lens hydrogels

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The Tear Film & Ocular Surface Society's recent report of the impact of contact materials, design and solutions on contact lens discomfort [8] reported that friction is currently the only material variable to correlate well with in vivo comfort scores, based upon data from two studies [9,10]. This work strongly suggests that superior frictional properties of lens materials are a key parameter that significantly correlates to contact lens comfort.…”

Section: Introductionmentioning

confidence: 90%

“…Additionally, significant differences were observed between narafilcon A and delefilcon A materials, indicating the cutting, and mounting, of lenses did not substantially inhibit the ability of the test to distinguish between lenses. While care must be taken when extrapolating these results to an in vivo situation, the previous studies correlating comfort and friction [9,10] did use friction measurements collected in in vitro settings. Collectively, these studies combined with the finding here that PRG4 in solution was able to effectively lubricate the SiHy lens made from senofilcon A suggests that PRG4 could be an effective lubricant for users of this lens, when administered in the form of a rewetting drop.…”

Section: Week Sihy Lensesmentioning

confidence: 99%

“…Peer-reviewed contact lens coefficient of friction data from over 700 one-month wearing trials demonstrated significant correlations to both end of day comfort and 2-h mean comfort data [9]. Another group, using an alternative method of determining friction coefficients, demonstrated statistically significant relationships between the coefficient of friction of 5 soft contact lens materials and subjective data for insertion comfort, overall comfort, and end of day comfort from a database of clinical trials [10]. The clinical relevance of ocular surface friction and damage clinically is further supported by 74% of symptomatic wearers presenting with a condition termed "lid wiper epitheliopathy" (LWE) [11].…”

Section: Introductionmentioning

confidence: 99%

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In vitro friction testing of contact lenses and human ocular tissues: Effect of proteoglycan 4 (PRG4)

Samsom

Chan

Iwabuchi

et al. 2015

Tribology International

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Hyaluronan incorporation into model contact lens hydrogels as a built‐in lubricant: Effect of hydrogel composition and proteoglycan 4 as a lubricant in solution

et al. 2017

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Contact lens friction significantly correlates with subjective comfort. Hyaluronan (HA) and proteoglycan 4 (PRG4) are natural boundary lubricants present in the body. The objective of this study was to assess the effect of crosslinked HA into the bulk of model contact lens materials pHEMA, pHEMA/TRIS, and DMAA/TRIS on surface wettability, protein sorption, and boundary lubricating properties at a material-cornea biointerface, both alone and synergistically with PRG4 in solution. Surface wettability was assessed by water contact angle measurement, protein sorption by lysozyme sorption assay, and boundary lubricating properties using an in vitro friction test method. HA incorporation (HA ) increased the surface wettability of all materials, and reduced protein sorption for pHEMA and DMAA/TRIS. HA increased friction for pHEMA, and DMAA/TRIS, whereas a decrease was observed for pHEMA/TRIS. A combination of HA and PRG4 had a synergistic effect of reducing friction only for pHEMA/TRIS. This combination had similar friction reduction compared with PRG4 alone for DMAA/TRIS. These results indicate HA incorporation could be an effective internal wetting agent, antiadhesive, and boundary lubricant for pHEMA/TRIS silicone hydrogels. In conclusion, HA incorporation can reduce friction of hydrogels alone and in combination with PRG4 in solution, though in a hydrogel composition-dependent (e.g., TRIS) manner. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1818-1826, 2018.

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Relationship between contact lens coefficient of friction and subjective lens comfort

Cited by 17 publications

References 0 publications

Proteoglycan 4 and hyaluronan as boundary lubricants for model contact lens hydrogels

Proteoglycan 4 and hyaluronan as boundary lubricants for model contact lens hydrogels

In vitro friction testing of contact lenses and human ocular tissues: Effect of proteoglycan 4 (PRG4)

Hyaluronan incorporation into model contact lens hydrogels as a built‐in lubricant: Effect of hydrogel composition and proteoglycan 4 as a lubricant in solution

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