Agreement between invasive and noninvasive measurement of tear film breakup time.

The agreement between fluorescein breakup time (FBUT) estimates and noninvasive breakup time (NIBUT) estimates automatically acquired using two videokeratoscopes was assessed. Small-cone (E300, Medmont) and large-bowl (K5M, OCULUS) Placido-ring-based videokeratoscopes were utilized for automated NIBUT estimation and fluorescein strip method was used for FBUT estimation. 33 subjects completed the study.

The efficacy of ocular surface assessment approaches in evaluating dry eye treatment with artificial tears.

This study evaluates the effectiveness of objective techniques in assessing dry eye disease (DED) treatment compared with the subjective assessment commonly used in clinical practice. Thirty subjects were recruited for two visits separated by 28(± 3) days of treatment with artificial tears. A buttery of common subjective assessment methods were accompanied by a set of objective techniques including measurement of noninvasive tear film break-up time (NIBUT), lipid layer thickness (LLT), and quantitative evaluation of tear film surface quality and dynamics (TFD).

Tear Film Surface Quality in Modern Daily Disposable Contact Lens Wear.

Objectives: As reported previously, tear film surface quality (TFSQ) should be considered in contact lens (CL) fitting. This study followed noninvasive keratograph tear film break-up time (NIKBUT) in CL wearers for 12 months to validate its clinical utility in predicting CL performance.

Methods: Fifty-five subjects (M/F=17/38) aged 26±4 years were prescribed silicone hydrogel or hydrogel CLs.

Subjective and Objective Evaluation of the Effect of Blink Type on Tear-film Breakup Time and Its Estimation.

Significance: While evaluating the tear-film breakup time, a careful set of precise instructions should be given to the subjects regarding the blink type because it substantially impacts the assessment of tear-film surface quality.

Purpose: The purpose of this study was to determine to what extent the type of blink affects the tear-film breakup time and its assessment using two types of videokeratoscopes and the fluorescein test.

Methods: Thirty-three volunteers were assessed considering two different types of blinks: natural (short) and forced (unnaturally prolonged).

Meibomian glands structure in daily disposable soft contact lens wearers: a one-year follow-up study.

Purpose: To assess the impact of daily disposable soft contact lenses on meibomian gland morphology over a period of 12 months.

Methods: Forty-one subjects (33 experienced and 8 neophytes) were fitted with either silicone-hydrogel or hydrogel daily contact lenses. The study protocol included four visits: baseline, day-2 for contact lens fit and follow-up measurements, as well as after 6 and 12 months of lens wear.

A 12-month Prospective Study of Tear Osmolarity in Contact Lens Wearers Refitted with Daily Disposable Soft Contact Lenses.

Significance: Tear osmolarity has been reported as one of the best diagnostic tests for dry eye disease and its management. Contact lens wear is thought to influence tear homeostasis. Understanding how regular wear of contact lenses and their type affect tear osmolarity is important.

Unified approach to tear film surface analysis with high-speed videokeratoscopy.

Placido disk videokeratoscopy, when used in a dynamic acquisition mode, can be utilized for noninvasive assessment of tear film quality. The different commercially available videokeratoscopes that incorporate an automatic option to evaluate tear film do not provide consistent measurements due to differences in their designs as well as differences in the algorithms used to analyze the images. Here, a standardized algorithm that can be applied to different instruments is developed.

Supporting Dry Eye Diagnosis with a New Method for Noninvasive Tear Film Quality Assessment.

Significance: Noninvasive high-speed videokeratoscopy equipped with specific software has shown potential for assessing the homeostasis of tear film, providing clinicians with a fast and consistent tool for supporting dry eye diagnosis and management.

Purpose: The purpose of this study was to evaluate the efficacy of a recently proposed method for characterizing tear film dynamics using noninvasive high-speed videokeratoscopy in assessing the loss of homeostasis of tear film.

Methods: Thirty subjects from a retrospective study, of which 11 were classified as dry eye and 19 as healthy, were included.

Post-blink tear film dynamics in healthy and dry eyes during spontaneous blinking.

Purpose: The aim was to investigate the dynamics of post-blink tear film leveling in natural blinking conditions (NBC) for healthy subjects and those diagnosed with dry eye syndrome (DES) and to relate this phase to the tear film surface quality (TFSQ) before the following blink.

Methods: The study included 19 healthy persons and 10 with dry eye, grouped according to symptoms and signs observed during examination. Lateral shearing interferometry was used to examine TFSQ.

The utility of measuring tear film break-up time for prescribing contact lenses.

Purpose: To evaluate the clinical value of non-invasive keratograph tear film breakup time (NIKBUT) in the assessment of pre-corneal and pre-lens tear film quality for prescribing contact lenses (CLs).

Methods: Forty-six subjects aged 25.5±4.

Non-invasive pre-lens tear film assessment with high-speed videokeratoscopy.

Purpose: To evaluate the effect of two types of daily contact lenses (delefilcon A and omafilcon A) on the tear film and establish whether it is dependent on pre-corneal tear film characteristics using a new method to analyse high-speed videokeratoscopy recordings, as well as to determine the sensitivity of the method in differentiating between contact lens materials on eye.

Methods: High-speed videokeratoscopy recordings were analysed using a custom made automated algorithm based on a fractal dimension approach that provides a set of parameters directly related to tear film stability. Fifty-four subjects participated in the study.

Measurement variability of the TearLab Osmolarity System.

Purpose: To independently assess the measurement variability of TearLab System in a clinical setting of one visit and to estimate the minimum number of measurements required for reliable readings of tear osmolarity.

Methods: Ten consecutive osmolarity measurements were taken from both eyes by the same examiner at one visit for fourteen subjects. The ocular surface disease index symptoms questionnaire and tear film break up time were also performed.

Objective Measures of Pre-lens Tear Film Dynamics versus Visual Responses.

Purpose: To ascertain whether there is a correlation between objective measures of pre-lens tear film surface quality (TFSQ) dynamics and visual quality responses.

Methods: Thirty one subjects wore a pair of silicone hydrogel lenses for 1 hour before measurements. Acquisition of TFSQ dynamics was conducted for each subject in suppressed blinking conditions.

Tear film dynamics on soft contact lenses.

Purpose: To analyze and model the dynamics of tear film surface quality (TFSQ) in a group of subjects with healthy eyes, before and during contact lens (CL) wear, and in a group of subjects with dry eyes (DEs).

Methods: Four sets of TFSQ measurements with lateral shearing interferometry were retrospectively analyzed on two groups of subjects. The first group included 13 CL wearers for which TFSQ measurements corresponding to baseline, Best CL, and Worst CL were selected.

Automatic dynamic tear meniscus measurement in optical coherence tomography.

An image processing algorithm is developed for quantitative assessment of tear meniscus dynamics from continuous optical coherence tomography (OCT) measurements. Clinical utility of dynamic OCT tear meniscus measurement is assessed in studies of tear meniscus parameters. The results indicate that any apparent changes in the early post-blink phase meniscus parameters are essentially related to the longitudinal movements of the eye and not to the formation of tear meniscus corresponding to tear film build-up.

Comparison of tear film surface quality measured in vivo on water gradient silicone hydrogel and hydrogel contact lenses.

Objective: Recently, a new water gradient silicone hydrogel material has been introduced for a daily disposable lens. The aim of this study was to assess, in vivo, the prelens tear film surface quality (TFSQ) of this new lens in comparison with that of another daily disposable lens from the same manufacturer.

Methods: Eleven subjects wore two pairs of hydrogel nelfilcon A and silicone hydrogel delefilcon A lenses in two nonconsecutive days.

Future directions in non-invasive measurements of tear film surface kinetics.

Purpose: To review the methods for dynamic, non-invasive, and objective assessment of tear film surface quality and to outline their current state-of-the-art and their future potential.

Methods: Among the methods available, high-speed videokeratoscopy, lateral shearing interferometry, and dynamic wavefront sensing are being considered.

Results: The principles of operations, their advantages and disadvantages, and limitations of each method are being outlined.

Noninvasive in vivo assessment of soft contact lens type on tear film surface quality.

Purpose: To evaluate the effect of soft contact lens type on the in vivo tear film surface quality (TFSQ) on daily disposable lenses and to establish whether two recently developed techniques for noninvasive measurement of TFSQ can distinguish between different contact lens types.

Methods: Thirteen subjects wearing four different types of daily soft contact lenses participated in the study. Dynamic area high-speed videokeratoscopy (HSV) and lateral shearing interferometry (LSI) were used to quantitatively assess TFSQ in natural blinking conditions in the morning soon after lens insertion and in the afternoon following 8 hours of lens wear.