A novel in-vitro method for assessing contact lens surface dewetting: Non-invasive keratograph dry-up time (NIK-DUT)

Marx, Sebastian; Sickenberger, Wolfgang

doi:10.1016/j.clae.2017.05.001

Cited by 17 publications

(31 citation statements)

References 14 publications

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“…A drop is deposited on a substrate and the substrate is inclined. At a given angle of tilt, the advancing and receding contact angles are reached on the two sides Multipurpose disinfecting solution [81,82]; solution in the manufacturer's blister pack [76], 'tear mimic' solution containing lipids, salts, urea, glucose, proteins and mucin [83] of the drop respectively, just before the drop starts moving on the surface. 2 Dynamic sessile drop goniometry (also known as the extension and contraction technique (Fig.…”

Section: Laboratory-based Surface Wettability Methodsmentioning

confidence: 99%

BCLA CLEAR - Contact lens wettability, cleaning, disinfection and interactions with tears

Willcox

Keir

Maseedupally

et al. 2021

Contact Lens and Anterior Eye

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Contact lens materials have undergone significant changes over the past 20 years, particularly with respect to the introduction of silicone hydrogel materials. Whilst this development addressed hypoxic issues, other important areas relating to contact lens success, notably comfort, require further research.Contact lens wettability remains a crucially important part of biocompatibility. Contact lenses can be made more wettable by incorporation of surfactants into blister packs, internal wetting agents, surface treatments or care solutions. However, there remains no clear association between contact lens wettability and comfort, making it challenging to determine the potential for these approaches to be of significant clinical benefit. Most contact lenses are used on a daily wear, reusable basis, which requires them to be disinfected when not worn. The ideal disinfecting solution would also improve comfort during wear. However, balancing these requirements with other factors, including biocompatibility, remains a challenge. Soft lens materials invariably take up and subsequently release certain components of disinfecting solutions onto the ocular surface. This may affect tear film stability and the normal ocular microbiome, and further research is needed in this area to determine whether this has any affect on comfort. Finally, contact lens materials sorb components of the tear film, and these interactions are complex and may change the biochemistry of the tear film, which in turn may affect their comfort.In conclusion, the interaction between lens materials, tear film and disinfection solution plays an important role in the biocompatibility of lenses. However, the exact role and whether this can be altered to improve biocompatibility and comfort during wear remains debatable. This report summarises the best available evidence to examine this complex relationship and the opportunities for practitioners to enhance in-eye comfort of contemporary lenses, along with providing suggestions for areas of study that may provide further information on this topic.

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Section: Laboratory-based Surface Wettability Methodsmentioning

confidence: 99%

BCLA CLEAR - Contact lens wettability, cleaning, disinfection and interactions with tears

Willcox

Keir

Maseedupally

et al. 2021

Contact Lens and Anterior Eye

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show abstract

“…10 Video topography has been shown to objectively and reproducibly assess the in vivo pre-corneal tear film and the in vitro drying of contact lens surfaces. [11][12][13] Video topography involves the projection of ring mires onto the pre-corneal tear film and contact lens surfaces and the simultaneous recording of reflected images. 12 These technological advances allow examination of a larger area, covering more than the optical zone of a contact lens, as well as allowing subjective assessments.…”

Section: Introductionmentioning

confidence: 99%

<p>Subjective Comparison of Pre-Lens Tear Film Stability of Daily Disposable Contact Lenses Using Ring Mire Projection</p>

Müller¹,

Marx²,

Wittekind³

et al. 2020

OPTO

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Purpose: To subjectively evaluate the in vivo tear film stability of three daily disposable contact lenses (DDCLs) using placido ring reflection at lens wear times of 5 mins and 8 and 12 hrs. Patients and Methods: This prospective, randomized, observer-masked, 3-way crossover study evaluated 28 subjects with good tear film stability. In vivo tear film stability was assessed for three DDCLs (nelfilcon A, etafilcon A, omafilcon A) on three different days over 12 hrs of lens wear. Time to first distortion by non-invasive keratography drying-up time (NIK-DUT f) was assessed by reviewing the captured videos. Lens wettability was also graded subjectively by three investigators using a scale from 0 (no visible distortions) to 3 (distortions in more than one-third of the ring reflection zone). Medians were analyzed statistically. Results: Mean NIKDUT f at 8 hrs was longer for nelfilcon A and shorter for etafilcon A and omafilcon A, but the differences were not significant. NIK-DUT f did not differ significantly among nelfilcon A, etafilcon A and omafilcon A DDCLs at all visits (p=0.36). Subjective wettability grades after 5 mins, 8 hrs, and 12 hrs differed significantly for etafilcon A (P <0.01) and omafilcon A (p < 0.01), but not for nelfilcon A (p = 0.05), DDCLs. Conclusion: Grading was sufficiently sensitive to differentiate the wettability performances of the three lens materials. Nelfilcon A maintained wettability over the wearing period, whereas etafilcon A material showed faster dewetting at 8 and 12 hrs than at 5 mins after lens insertion.

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“…The videos were analyzed by manufacturer-supplied software to determine ring mire distortion and contact lens surface dry-up time with investigator control. 40 A grid consisting of eight concentric rings with 12 meridians was overlaid virtually over a video that was recorded during the measurement ( Figure 2). This grid divided the area of the front surface of the lens into 192 small segments, which had to be marked subjectively as dewetted in each frame of a video file, ie, 32 times persecond.…”

Section: Study Populationmentioning

confidence: 99%

“…Multifunctional topographers (Keratograph 5M, Oculus) are simultaneously able to project ring mires onto the lens surface and capture a video of the reflected image (Figure 1). 40 The primary objective of the study was to compare the tear film stability of nelfilcon A and stenfilcon A daily disposable contact lenses using ring mires projection of the K5M Oculus NIK-BUT Mode after 12 hours of wear. The key variables recorded were time to reach 15% ring distortion and the speed of tear film break-up.…”

mentioning

confidence: 99%

<p>Objective Analysis of Pre-Lens Tear Film Stability of Daily Disposable Contact Lenses Using Ring Mire Projection</p>

Marx¹,

Wittekind²,

Sickenberger³

2020

OPTO

Self Cite

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Purpose: The primary objective of this study was to evaluate the in vivo pre-lens noninvasive drying-up time of two types of daily disposable contact lenses (DDCLs) after 12 hours of wear. Methods: This prospective, randomized, single-center, cross-over pilot study evaluated 31 subjects aged 18-44 years with normal eyes and good tear film stability who were adapted current soft contact lens wearers. Subjects wore nelfilcon A and stenfilcon A DDCLs for 12 hours each on two different days. Non-invasive video keratography drying-up time (NIK-DUT) videos of each eye were recorded 12 hours after lens insertion for about 25 seconds, with a 5-minute tear film recovery time allowed between video recordings of the right and left eyes to avoid bias. Post-blink time required to reach 15% distortion of the projected rings and the speed of break-up at 15 seconds post-blink were measured at each time point and oneye wettability was determined by ring mire projection under white light illumination. Results: Mean time to reach 15% ring distortion was similar for nelfilcon A (19.25±3.20 sec) and stenfilcon A (20.24±3.02 sec) DDCLs but varied highly among subjects. The mean speed of break-up at 15 sec post-blink was 0.3±0.38% distortion/sec (95% confidence interval [CI] 0.138-0.365% distortion/sec) for nelfilcon A and 0.2±0.23% distortion/sec (95% CI 0.048-0.279% distortion/sec) for stenfilcon A DDCLs. Conclusion: Multifunctional topography allowed the objective evaluation of in vivo prelens tear film stability using ring mire projection. This dynamic method was simple, fast and non-invasive, enabling measurements of NIK-DUT and evaluating wettability over a large area, greater than the optical zone of the contact lens surface, for the entire inter-blink interval.

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A novel in-vitro method for assessing contact lens surface dewetting: Non-invasive keratograph dry-up time (NIK-DUT)

Cited by 17 publications

References 14 publications

BCLA CLEAR - Contact lens wettability, cleaning, disinfection and interactions with tears

BCLA CLEAR - Contact lens wettability, cleaning, disinfection and interactions with tears

<p>Subjective Comparison of Pre-Lens Tear Film Stability of Daily Disposable Contact Lenses Using Ring Mire Projection</p>

<p>Objective Analysis of Pre-Lens Tear Film Stability of Daily Disposable Contact Lenses Using Ring Mire Projection</p>

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