Association Between Contact Lens Discomfort and Pre-lens Tear Film Kinetics.

PubMed

Guillon, Michel; Dumbleton, Kathryn A; Theodoratos, Panagiotis; Wong, Stephanie; Patel, Kishan; Banks, Gaidig; Patel, Trisha

2016-08-01

The relationship between contact lens wettability and comfort has been extensively evaluated; however, a direct correlation between the characteristics of the pre-lens tear film and the symptoms associated with contact lens discomfort has yet to be established. In addition, there is relatively limited knowledge relating to the entire tear film kinetics during the inter-blink period in contact lens wearers. The purpose of this analysis was to identify the characteristics of the pre-lens tear film kinetics that may be associated with the symptoms of contact lens discomfort. The study population comprised 202 soft (hydrogel and silicone hydrogel) contact lens wearers attending pre-screening visits at the OTG-i research clinic. All participants completed the Ocular Surface Disease Index (OSDI) questionnaire and the tear film was quantified via post hoc, masked analysis of high definition digital Tearscope videos recorded at the visit. The tear film kinetics of the least symptomatic wearers (OSDI lowest quintile scores, n = 45) were compared to the tear film kinetics of the most symptomatic wearers (OSDI highest quintile scores, n = 43). The hypothesis tested was that the tear film kinetics of asymptomatic wearers were better than tear film kinetics of symptomatic wearers. The distribution of lens types worn was as follows: Daily Disposable 46.5%, 1-Month Replacement 39.6%, and 2-Week Replacement 13.6%. 48.2% of lenses were silicone hydrogel and 51.8% hydrogel. Symptomatic wearers had a shorter break-up time (4.7 s vs. 6.0 s; p = 0.003), lesser surface coverage by the tear film during the interblink period (95.1% vs. 98.5%; p < 0.001) and greater surface exposure at the time of the blink (9.4% vs. 3.9%; p = 0.001). The current study demonstrated that the tear film kinetics of asymptomatic and symptomatic contact lens wearers were different, the findings supporting the hypothesis of poorer tear film kinetics for symptomatic than asymptomatic wearers in a general contact

Anterior Segment Optical Coherence Tomography for Tear Meniscus Evaluation and its Correlation with other Tear Variables in Healthy Individuals

PubMed Central

Dhasmana, Renu; Nagpal, Ramesh Chander

2016-01-01

Introduction Dry eye is one of the most common ocular diseases in this cyber era. Despite availability of multiple tests, no single test is accurate for the diagnosis of dry eye. Anterior segment optical coherence tomography is the recent tool which can be added in the armentarium of dry eye tests. Aim To evaluate tear meniscus with anterior segment optical coherence tomography and its correlation with other tear variables in normal healthy individuals. Materials and Methods In this prospective cross-sectional observational study, right eye of 203 consecutive patients were studied. All the patients were divided into three groups Group 1, 2 and 3 according to their age ≤20 years, 21-40 years and >40 years respectively. All patients underwent routine ophthalmologic examinations along with slit-lamp bio-microscopy for tear meniscus height measurement, tear film break up time, Schirmer’s I test (with anaesthesia) and optical coherence tomography imaging of inferior tear meniscus height. After focusing of the instrument with a Cross Line (CL) centered on lower tear meniscus at 6’0 clock of cornea, a 6 mm long scan was obtained. The tear meniscus height (μm) and tear meniscus area (mm2) were measured manually with help of callipers by joining upper corneo-meniscus junction to the lower lid-meniscus junction and tear meniscus height and area within the plotted line respectively and calculated by using the integrated analysis available in the custom software. Results There was significant decrease in the all tear variables with the increase in the age. According to age groups in group 1, the mean Schirmer’s (24.0±4.9)mm, tear film break up time (11.1±1.9) sec, tear meniscus height on slit lamp (600.2±167.3)mm were higher but decreased in group 2 (21.5±5.4,10.8±1.4, 597.5±186.3) and group 3 (19.8 ± 5.1, 10.2 ± 1.6, 485.6 ± 157.7) respectively. Schirmer’s test values and tear film break up time were similar in both sexes (p=0.1 and p= 0.9). Tear meniscus

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

PubMed

Szczesna-Iskander, Dorota H

2018-01-01

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. 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. Post-blink tear film dynamics was modeled by an exponential function, characterized by the decay parameter b, and a constant, describing the level of the stabilized TFSQ. Pre-next-natural-blink TFSQ dynamics was modeled with a linear trend, described by a parameter A. The post-blink tear film dynamics reached its plateau at a significantly (P = 0.006) lower level in the normal tear film group than in the dry eye group. The median exponential decay parameter b was statistically significantly higher for the control group than for the DES group, P = 0.026. The parameter b calculated for each interblink interval was significantly correlated with the corresponding parameter A (Spearman's R = 0.35; P < 0.001). Correlation between the median b and tear film fluorescein break-up time for each subject was also found (R = 0.41, P = 0.029). Significantly faster leveling of post-natural-blink tear film was observed in the group with DES than in healthy eyes. This dynamic was correlated with the pre-next-natural-blink TFSQ and tear film stability. The results of this pilot study support previous works that advocate the importance of polar lipids in the mechanism of tear film lipid spreading. Copyright © 2017 Elsevier Inc. All rights reserved.

TFOS DEWS II Tear Film Report.

PubMed

Willcox, Mark D P; Argüeso, Pablo; Georgiev, Georgi A; Holopainen, Juha M; Laurie, Gordon W; Millar, Tom J; Papas, Eric B; Rolland, Jannick P; Schmidt, Tannin A; Stahl, Ulrike; Suarez, Tatiana; Subbaraman, Lakshman N; Uçakhan, Omür Ö; Jones, Lyndon

2017-07-01

The members of the Tear Film Subcommittee reviewed the role of the tear film in dry eye disease (DED). The Subcommittee reviewed biophysical and biochemical aspects of tears and how these change in DED. Clinically, DED is characterized by loss of tear volume, more rapid breakup of the tear film and increased evaporation of tears from the ocular surface. The tear film is composed of many substances including lipids, proteins, mucins and electrolytes. All of these contribute to the integrity of the tear film but exactly how they interact is still an area of active research. Tear film osmolarity increases in DED. Changes to other components such as proteins and mucins can be used as biomarkers for DED. The Subcommittee recommended areas for future research to advance our understanding of the tear film and how this changes with DED. The final report was written after review by all Subcommittee members and the entire TFOS DEWS II membership. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of diquafosol sodium eye drops on tear film stability in short BUT type of dry eye.

PubMed

Shimazaki-Den, Seika; Iseda, Hiroyuki; Dogru, Murat; Shimazaki, Jun

2013-08-01

To investigate the effects of diquafosol sodium (DQS) eye drops, a purinergic P2Y2 receptor agonist, on tear film stability in patients with unstable tear film (UTF). Two prospective studies were conducted. One was an exploratory nonrandomized trial on 39 eyes with dry eye symptoms and short tear film break-up time (BUT), but without epithelial damage. Changes in symptoms, BUT, Schirmer value, and ocular surface fluorescein staining (FS) scores were studied for 3 months. The other was a randomized clinical trial of DQS and artificial tears (AT) in 17 eyes with short BUT. Eyes with decreased Schirmer values (≤ 5 mm) were excluded. Changes in symptoms, BUT, FS scores, and tear film stability using continuous corneal topographic analysis were studied for 4 weeks. In the exploratory study, while Schirmer values were not significantly increased, significant improvements in symptoms and BUT were noted at both 1 and 3 months. In the randomized clinical trial, significant improvements in symptoms were noted in the DQS group, but not in the AT group, at 2 weeks. BUT was significantly prolonged in the DQS group at 4 weeks but not in the AT group. No significant changes were noted in FS scores or tear film stability. DQS improved subjective symptoms and prolonged BUT in eyes with UTF not associated with low tear secretion and ocular surface epithelial damage. Because many patients who have UTF are refractory to conventional treatments, DQS may offer benefits in the treatment of dry eyes.

Effectiveness of Combined Tear Film Therapy in Patients with Evaporative Dry Eye with Short Tear Film Breakup Time.

PubMed

Kim, Yung Hui; Kang, Yeon Soo; Lee, Hyo Seok; Choi, Won; You, In Cheon; Yoon, Kyung Chul

2017-10-01

The aim of this study was to evaluate the effectiveness of combined tear film therapy targeted to aqueous, mucin, and lipid layers in patients with refractory evaporative dry eye (EDE) with short tear film breakup time (TBUT). The patients who had EDE with short TBUT and severe symptoms refractory to artificial tears were treated with hyaluronic acid (HA) 0.15% and diquafosol tetrasodium (DQS) 3% (Group 1), HA and carbomer-based lipid-containing eyedrops (Liposic EDO Gel, LPO) (Group 2), or HA, DQS, and LPO (Group 3). Ocular Surface Disease Index (OSDI) score, visual analog scale (VAS) symptom score, TBUT, Schirmer score, and corneal and conjunctival staining scores were evaluated, and noninvasive tear film breakup time (NIBUT) and tear meniscus height were measured using Keratograph ® 5 M before and 1 and 3 months after treatment. OSDI scores, VAS scores, TBUT, and NIBUT were improved at 1 and 3 months after treatment in all groups (all P < 0.05). At each follow-up visit, the total OSDI, OSDI symptom, and all VAS scores were significantly lower in group 3 compared with groups 1 and 2 (all P < 0.05). In addition, TBUT and NIBUT were significantly higher in group 3 compared with groups 1 and 2 (all P < 0.05). No significant adverse effects were noted in the groups during treatment. Mucin or lipid-targeting agents combined with aqueous supplements in patients with refractory EDE with short TBUT might improve subjective symptoms and TBUT. Of this, targeting whole tear film layers was most effective in improving ocular symptoms and tear film quality.

Structure and microanalysis of tear film ferning of camel tears, human tears, and Refresh Plus.

PubMed

Am, Masmali; Ra, Fagehi; El-Naggar, Ahmad H; Tm, Almubrad

2018-01-01

This study aimed to investigate the tear ferning pattern and chemical elements of the tear film of camel tears compared with human tears and Refresh Plus eye lubricant. Refresh Plus was used as a control because it provides a healthy ferning pattern, due to the presence of an optimum ratio of carboxymethylcellulose (CMC) sodium and electrolytes. The main research focus is elucidating the viability of camel tear film in the dry, harsh environment of the desert. The tears were collected from five camels, five male desert workers (20-25 years old) at a small village located 100 km from Riyadh, Saudi Arabia, and five male subjects (20-25 years old) from Riyadh. A small drop (1 μl) of tears was dried on a glass slide and observed under a light (Olympus BX1) and scanning electron microscope (Inspect S50, Field Electron and Ion Company [FEI]). Energy-dispersive X-ray spectroscopy (EDS) of the tear film and Refresh Plus were investigated with a JEOL 1400 scanning transmission electron microscope. The camel tear film pattern was surrounded by thick, peripheral, homogenous layers containing small oily droplets, particles, and tiny branches in the tear ferning. The tear ferning of the camel was grade 0-1, whereas the tear ferning of human tears and Refresh Plus was grade 1-2. The mass percentage of chloride was highest in the camel tears. The mass percentage of potassium in the camel tears was greater than that in the human tears, but it was less than that in the Refresh Plus lubricant. Camel tears exhibit a better quality than human tears and Refresh Plus lubricant do. The presence of oily droplet-like structures at the periphery of tear ferning suggests that camel tear film may have a higher quality and quantity of minerals and lubricants, which may help the animal to avoid eye dryness. Future work is required to investigate the identification of the elements present in the peripheral and central part of the tear ferning.

Short-term effect of topical antiglaucoma medication on tear-film stability, tear secretion, and corneal sensitivity in healthy subjects.

PubMed

Terai, Naim; Müller-Holz, Matthias; Spoerl, Eberhard; Pillunat, Lutz E

2011-01-01

The purpose of this study was to investigate the short-term effect of topical antiglaucoma medication on tear-film stability, tear secretion, and corneal sensitivity in healthy subjects. In this prospective, double-blind crossover trial, break-up time and basal secretion (Jones test) were measured 60 minutes before, and 30, 60, and 90 minutes after topical antiglaucoma drop application in 30 healthy subjects. Corneal sensitivity was measured 60 minutes before, and five, 10, and 15 minutes after drop application using a Cochet-Bonnet esthesiometer. Reduction of break-up time in the latanoprost group was -23.8% after 30 minutes (P = 0.21), -26.7% after 60 minutes (P = 0.03) and -51.4% after 90 minutes (P ≤ 0.003), which was statistically significant. Reduction of break-up time in all other treatment groups was not statistically significant. The Jones test revealed a significant reduction of basal secretion after application of brimonidine (-17.8%, P = 0.002; -22.5%, P < 0.001; -30.5%, P < 0.001), followed by apraclonidine (-10%, P = 0.06; -20.1%, P = 0.02; -22.1%, P = 0.002), latanoprost (-2.4%, P = 0.64; -18.6%, P = 0.001; -20.1%, P = 0.001) and dorzolamide (-0.5%, P = 0.9; 14.3%, P = 0.018; -17.3%, P = 0.004) at 30, 60, and 90 minutes after drop application. Reduction of basal secretion in all other treatment groups was not statistically significant. Latanoprost showed the most statistically significant reduction in break-up time, and brimonidine showed the most significant reduction in basal secretion of all the glaucoma medications used in this study. In conclusion, our data may be helpful for treatment decisions in glaucoma patients who also suffer from ocular surface problems.

Interferometric characterization of tear film dynamics

NASA Astrophysics Data System (ADS)

Primeau, Brian Christopher

The anterior refracting surface of the eye is the thin tear film that forms on the surface of the cornea. When a contact lens is on worn, the tear film covers the contact lens as it would a bare cornea, and is affected by the contact lens material properties. Tear film irregularity can cause both discomfort and vision quality degradation. Under normal conditions, the tear film is less than 10 microns thick and the thickness and topography change in the time between blinks. In order to both better understand the tear film, and to characterize how contact lenses affect tear film behavior, two interferometers were designed and built to separately measure tear film behavior in vitro and in vivo. An in vitro method of characterizing dynamic fluid layers applied to contact lenses mounted on mechanical substrates has been developed using a phase-shifting Twyman-Green interferometer. This interferometer continuously measures light reflected from the surface of the fluid layer, allowing precision analysis of the dynamic fluid layer. Movies showing this fluid layer behavior can be generated. The fluid behavior on the contact lens surface is measured, allowing quantitative analysis beyond what typical contact angle or visual inspection methods provide. The in vivo interferometer is a similar system, with additional modules included to provide capability for human testing. This tear film measurement allows analysis beyond capabilities of typical fluorescein visual inspection or videokeratometry and provides better sensitivity and resolution than shearing interferometry methods.

Agreement and repeatability of objective systems for assessment of the tear film.

PubMed

Fernández, Joaquín; Rodríguez-Vallejo, Manuel; Martínez, Javier; Tauste, Ana; García-Montesinos, Javier; Piñero, David P

2018-04-18

To assess the agreement and repeatability of two objective systems for measuring the tear film stability. Retrospective analysis of the tear film stability of 99 healthy right eyes measured with a videokeratoscope (VK) and the Optical Quality Analysis System (OQAS, Visiometrics). Two consecutive measures were taken with both systems, with an interval of 10 min between them. Variables included in the study were first and mean non-invasive break-up times (NIBUT and MNIBUT) measured with VK, and mean and standard deviation of the optical scattering index (OSIm and OSIsd) measured with OQAS. The agreement and repeatability of grading scales provided by both devices were also evaluated using the Cohen's k with quadratic weights. The Ocular Surface Disease index (OSDI) questionnaire was also passed out to all subjects. Correlations and associations between subjective and objective metrics were analyzed. Significant differences were found between consecutive measurements of NIBUT (p = 0.04) and MNIBUT (p = 0.01), but not for OSIm (p = 0.11) and OSIsd (p = 0.50). Grading scales resulted in fair (k = 0.20) or poor agreement (k = 0.04) between systems depending if the first or second trial was considered. The repeatability of the grading scale was good for OQAS (k = 0.59) and fair for VK (k = 0.37). No significant correlations or associations were found between OSDI and any of the metrics obtained with both devices (p ≥ 0.36). The two devices evaluated cannot be used interchangeably for the assessment of tear film stability. Good intrasession repeatability was obtained for tear film grading of the OQAS whereas it was fair for VK.

Evaporation-driven instability of the precorneal tear film.

PubMed

Peng, Cheng-Chun; Cerretani, Colin; Braun, Richard J; Radke, C J

2014-04-01

Tear-film instability is widely believed to be a signature of eye health. When an interblink is prolonged, randomly distributed ruptures occur in the tear film. "Black spots" and/or "black streaks" appear in 15 to 40 s for normal individuals. For people who suffer from dry eye, tear-film breakup time (BUT) is typically less than a few seconds. To date, however, there is no satisfactory quantitative explanation for the origin of tear rupture. Recently, it was proposed that tear-film breakup is related to locally high evaporative thinning. A spatial variation in the thickness of the tear-film lipid layer (TFLL) may lead to locally elevated evaporation and subsequent tear-film breakup. We examine the local-evaporation-driven tear-film-rupture hypothesis in a one-dimensional (1-D) model for the evolution of a thin aqueous tear film overriding the cornea subject to locally elevated evaporation at its anterior surface and osmotic water influx at its posterior surface. Evaporation rate depends on mass transfer both through the coating lipid layer and through ambient air. We establish that evaporation-driven tear-film breakup can occur under normal conditions but only for higher aqueous evaporation rates. Predicted roles of environmental conditions, such as wind speed and relative humidity, on tear-film stability agree with clinical observations. More importantly, locally elevated evaporation leads to hyperosmolar spots in the tear film and, hence, vulnerability to epithelial irritation. In addition to evaporation rate, tear-film instability depends on the strength of healing flow from the neighboring region outside the breakup region, which is determined by the surface tension at the tear-film surface and by the repulsive thin-film disjoining pressure. This study provides a physically consistent and quantitative explanation for the formation of black streaks and spots in the human tear film during an interblink. Copyright © 2013 Elsevier B.V. All rights reserved.

Poly(lactic acid) (PLA) Based Tear Resistant and Biodegradable Flexible Films by Blown Film Extrusion

PubMed Central

Mallegni, Norma; Phuong, Thanh Vu; Coltelli, Maria-Beatrice

2018-01-01

Poly(lactic acid) (PLA) was melt mixed in a laboratory extruder with poly(butylene adipate-co-terephthalate) (PBAT) and poly(butylene succinate) (PBS) in the presence of polypropylene glycol di glycidyl ether (EJ400) that acted as both plasticizer and compatibilizer. The process was then scaled up in a semi-industrial extruder preparing pellets having different content of a nucleating agent (LAK). All of the formulations could be processed by blowing extrusion and the obtained films showed mechanical properties dependent on the LAK content. In particular the tearing strength showed a maximum like trend in the investigated composition range. The films prepared with both kinds of blends showed a tensile strength in the range 12–24 MPa, an elongation at break in the range 150–260% and a significant crystallinity. PMID:29342099

Effect of Omega-3 Fatty Acids Dietary Supplementation on Ocular Surface and Tear Film in Diabetic Patients with Dry Eye.

PubMed

Georgakopoulos, Constantine D; Makri, Olga E; Pagoulatos, Dionisios; Vasilakis, Panagiotis; Peristeropoulou, Politimi; Kouli, Vasiliki; Eliopoulou, Maria I; Psachoulia, Caterina

2017-01-01

The objective of this study was to investigate the effect of dietary supplementation with omega-3 fatty acids on ocular surface and tear film in patients with type 2 diabetes suffering from dry eye. Thirty-six patients suffering from type 2 diabetes and moderate to severe dry eye syndrome were included in the study. Patients were assigned to receive omega-3 long-chain polyunsaturated fatty acids for 3 months. Tear film break-up time test, Schirmer-I test, and conjunctival impression cytology analysis were performed on all patients at baseline and after 1 and 3 months. The subjective symptoms of dry eye were evaluated with the Ocular Surface Disease Index (OSDI) questionnaire at the same time points. Patients' average age was 65.57 ± 4.27 years and the mean duration of diabetes was 14.85 ± 5.4 years. There was a statistically significant increase in Schirmer-I test results and tear break-up time score after 3 months of supplementary intake of omega-3 fatty acids compared to baseline (p < 0.05 and p < 0.001, respectively). Impression cytology demonstrated a significantly lower grade of conjunctival squamous cell metaplasia after 1 and 3 months of omega-3 fatty acids intake compared to baseline (p < 0.05 and p < 0.01, respectively). The OSDI score was statistically significant lower both at 1 and 3 months after omega-3 fatty acids supplementation compared to baseline (p < 0.001). Omega-3 fatty acids may effectively improve tear film characteristics, reverse ocular surface features, and alleviate the subjective symptoms associated with dry eye syndrome in patients with type 2 diabetes.

Tear film measurement by optical reflectometry technique

PubMed Central

Lu, Hui; Wang, Michael R.; Wang, Jianhua; Shen, Meixiao

2014-01-01

Abstract. Evaluation of tear film is performed by an optical reflectometer system with alignment guided by a galvanometer scanner. The reflectometer system utilizes optical fibers to deliver illumination light to the tear film and collect the film reflectance as a function of wavelength. Film thickness is determined by best fitting the reflectance-wavelength curve. The spectral reflectance acquisition time is 15 ms, fast enough for detecting film thickness changes. Fast beam alignment of 1 s is achieved by the galvanometer scanner. The reflectometer was first used to evaluate artificial tear film on a model eye with and without a contact lens. The film thickness and thinning rate have been successfully quantified with the minimum measured thickness of about 0.3 μm. Tear films in human eyes, with and without a contact lens, have also been evaluated. A high-contrast spectral reflectance signal from the precontact lens tear film is clearly observed, and the thinning dynamics have been easily recorded from 3.69 to 1.31 μm with lipid layer thickness variation in the range of 41 to 67 nm. The accuracy of the measurement is better than ±0.58% of the film thickness at an estimated tear film refractive index error of ±0.001. The fiber-based reflectometer system is compact and easy to handle. PMID:24500519

Dynamic measurement of the corneal tear film with a Twyman-Green interferometer

NASA Astrophysics Data System (ADS)

Micali, Jason D.; Greivenkamp, John E.; Primeau, Brian C.

2015-05-01

An interferometer for measuring dynamic properties of the in vivo tear film on the human cornea has been developed. The system is a near-infrared instantaneous phase-shifting Twyman-Green interferometer. The laser source is a 785 nm solid-state laser, and the system has been carefully designed and calibrated to ensure that the system operates at eye-safe levels. Measurements are made over a 6 mm diameter on the cornea. Successive frames of interferometric height measurements are combined to produce movies showing both the quantitative and qualitative changes in the topography of the tear film surface and structure. To date, measurement periods of up to 120 s at 28.6 frames per second have been obtained. Several human subjects have been examined using this system, demonstrating a surface height resolution of 25 nm and spatial resolution of 6 μm. Examples of features that have been observed in these preliminary studies of the tear film include postblink disruption, evolution, and stabilization of the tear film; tear film artifacts generated by blinking; tear film evaporation and breakup; and the propagation of foreign objects in the tear film. This paper discusses the interferometer design and presents results from in vivo measurements.

[Effects of acupuncture on lactoferrin content in tears and tear secretion in patients suffering from dry eyes: a randomized controlled trial].

PubMed

Shi, Jing-lin; Miao, Wan-hong

2012-09-01

With the understanding of the immune inflammatory response in the pathogenesis of dry eyes, and the limitations of widely used artificial tears and numerous pharmaceuticals and methods to promote tear secretion, clinicians pay more attention to the therapies that can promote tear secretion actively. Acupuncture treatment for dry eye may meet this requirement. To observe the clinical efficacy of acupuncture treatment on dry eye and the effects on duration, and to examine the mechanisms of acupuncture in treating patients with dye eyes. The study was performed at Department of Ophthalmology, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine from August 2010 to May 2011. Patients with the primary diagnosis of dry eye were enrolled. Sixty-five patients were randomly divided into treatment group and control group, and were given 3 weeks of acupuncture treatment or artificial tear therapy respectively. The enzyme-linked immunosorbent assay was used to detect the lactoferrin content of the tears before and after treatment. In order to evaluate the efficacy of the treatment methods, the Schirmer I test and break-up time were also measured. Compared with before treatment, the lactoferrin content in the tears of patients in the treatment group increased, break-up time was prolonged and the result of the Schirmer I test showed improvement after 3 weeks of treatment. The indexes mentioned above did not change in the control group after treatment. There were no significant differences in tear lactoferrin and Schirmer I test between one week after treatment and after 3-week treatment in the treatment group, but break-up time was significantly shortened. The result of Schirmer I test in the treatment group was significantly higher than that in the control group one week after treatment. Acupuncture can increase tear lactoferrin level, extend tear film break-up time and promote tear secretion in patients with dry eye in a time-limited trial. With the end of

Tear-Film Evaporation Rate from Simultaneous Ocular-Surface Temperature and Tear-Breakup Area.

PubMed

Dursch, Thomas J; Li, Wing; Taraz, Baseem; Lin, Meng C; Radke, Clayton J

2018-01-01

A corneal heat-transfer model is presented to quantify simultaneous measurements of fluorescein tear-breakup area (TBA) and ocular-surface temperature (OST). By accounting for disruption of the tear-film lipid layer (TFLL), we report evaporation rates through lipid-covered tear. The modified heat-transfer model provides new insights into evaporative dry eye. A quantitative analysis is presented to assess human aqueous tear evaporation rate (TER) through intact TFLLs from simultaneous in vivo measurement of time-dependent infrared OST and fluorescein TBA. We interpret simultaneous OST and TBA measurements using an extended heat-transfer model. We hypothesize that TBAs are ineffectively insulated by the TFLL and therefore exhibit higher TER than does that for a well-insulting TFLL-covered tear. As time proceeds, TBAs increase in number and size, thereby increasing the cornea area-averaged TER and decreasing OST. Tear-breakup areas were assessed from image analysis of fluorescein tear-film-breakup video recordings and are included in the heat-transfer description of OST. Model-predicted OSTs agree well with clinical experiments. Percent reductions in TER of lipid-covered tear range from 50 to 95% of that for pure water, in good agreement with literature. The physical picture of noninsulating or ruptured TFLL spots followed by enhanced evaporation from underlying cooler tear-film ruptures is consistent with the evaporative-driven mechanism for local tear rupture. A quantitative analysis is presented of in vivo TER from simultaneous clinical measurement of transient OST and TBA. The new heat-transfer model accounts for increased TER through expanding TBAs. Tear evaporation rate varies strongly across the cornea because lipid is effectively missing over tear-rupture troughs. The result is local faster evaporation compared with nonruptured, thick lipid-covered tear. Evaporative-driven tear-film ruptures deepen to a thickness where fluorescein quenching commences and local

Duplex Tear Film Evaporation Analysis.

PubMed

Stapf, M R; Braun, R J; King-Smith, P E

2017-12-01

Tear film thinning, hyperosmolarity, and breakup can cause irritation and damage to the human eye, and these form an area of active investigation for dry eye syndrome research. Recent research demonstrates that deficiencies in the lipid layer may cause locally increased evaporation, inducing conditions for breakup. In this paper, we explore the conditions for tear film breakup by considering a model for tear film dynamics with two mobile fluid layers, the aqueous and lipid layers. In addition, we include the effects of osmosis, evaporation as modified by the lipid, and the polar portion of the lipid layer. We solve the system numerically for reasonable parameter values and initial conditions and analyze how shifts in these cause changes to the system's dynamics.

Diet, nutraceuticals and the tear film.

PubMed

Jalbert, Isabelle

2013-12-01

Nutrition disorders and their correlates such as obesity are increasingly prevalent worldwide. A number of studies to date have suggested numerous potential associations between diet and tear film health; this paper will provide a summary of the available literature. The tear film is characterized through its protein and lipid content and through clinical measurements of characteristics such as osmolarity, volume and stability. Malnutrition, protein and vitamin-A deficiencies are extremely deleterious to tear film health and supplementation with oral vitamin A in this setting is of clear benefit. The relative impact of diet on tear film within what would be considered normal ranges of consumption is less clear. A number of population studies have suggested that hyperlipidemia and a diet low in omega-3 fatty acids are risks factor for dry eye disease. Numerous studies have investigated the effectiveness of oral supplementation with antioxidants, omega-3 (e.g. fish oil and linseed oil) and omega-6 (e.g. evening primrose oil) fatty acids in the last 10 years. Taken together, these suggest a small benefit of oral supplementation on tear film volume, stability and decreased ocular symptoms in patients previously diagnosed with diseases involving the ocular surface (e.g. Sjögren's syndrome, meibomian gland dysfunction, dry eye disease) and contact lens wearers suffering from dry eye. More research is required to determine the exact composition, dosage and indications for their use and to fully characterize how these nutraceuticals modulate the tear film. Copyright © 2013 Elsevier Ltd. All rights reserved.

The effect of benoxinate on the tear stability of Hong Kong-Chinese.

PubMed

Cho, P; Brown, B

1995-07-01

We conducted a series of experiments to examine the effect of local anaesthetic instillation on tear stability measurements. All experiments were conducted with the examiner masked with respect to treatments. We measured tear break-up time (TDUT) and non-invasive tear break-up time (NITBUT) 30s after instillation of benoxinate (0.4%) in a single masked experiment and found that NITBUT was significantly increased while TBUT was unaffected. In separate experiments tear stability was assessed 5 min after instillation of benoxinate and there was no significant effect on either TBUT or NITBUT measurements. In a control experiment to examine the effect of instilling a drop of liquid into the eye, neither TBUT nor NITBUT were affected 30s after the instillation of saline. No corneal staining was observed in any of the subjects after instillation of benoxinate. The results suggest that benoxinate does not affect the stability of the precorneal tear film, and that tear stability can be assessed after the instillation of unpreserved benoxinate.

Effects of tear film dynamics on quality of vision.

PubMed

Koh, Shizuka; Tung, Cynthia I; Inoue, Yasushi; Jhanji, Vishal

2018-06-15

The precorneal tear film is maintained by blinking and exhibits different phases in the tear cycle. The tear film serves as the most anterior surface of the eye and plays an important role as a first refractive component of the eye. Alterations in tear film dynamics may cause both vision-related and ocular surface-related symptoms. Although the optical quality associated with the tear film dynamics previously received little attention, objective measurements of optical quality using wavefront sensors have enabled us to quantify optical aberrations induced by the tear film. This has provided an objective method for assessing reduced optical quality in dry eye; thus, visual disturbances were included in the definition of dry eye disease in the 2007 Dry Eye Workshop report. In addition, sequential measurements of wavefront aberrations have provided us with valuable insights into the dynamic optical changes associated with tear film dynamics. This review will focus on the current knowledge of the mechanisms of wavefront variations that are caused by different aspects of tear film dynamics: specifically, quality, quantity and properties of the tear film, demonstrating the respective effects of dry eye, epiphora and instillation of eye drops on the quality of vision. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Evaluating tear clearance rate with optical coherence tomography.

PubMed

Garaszczuk, Izabela K; Mousavi, Maryam; Cervino Exposito, Alejandro; Bartuzel, Maciej M; Montes-Micó, Robert; Iskander, D Robert

2018-02-01

To assess the early-phase of tear clearance rate (TCR) with anterior segment optical coherence tomography (OCT) and to determine the association between TCR and other clinical measures of the tear film in a group of young subjects with different levels of tear film quality. TCR was classified as the percentage decrease of subject's inferior tear meniscus height 30s after instillation of 5μl 0.9% saline solution. Fifty subjects (32F and 18M) aged (mean±standard deviation) 25.5±4.3 years volunteered for the study. It consisted of a review of medical history, Ocular Surface Disease Index (OSDI) questionnaire, tear film osmolarity measurements, slit lamp examination and TCR estimation based on dynamic measurements of the lower tear meniscus with OCT. Estimates of TCR were contrasted against subject age and tear film measures commonly used for dry eye diagnosis, which includes OSDI score, fluorescein tear film break-up time (FBUT), tear meniscus height (TMH), blinking frequency, tear film osmolarity and corneal staining. The group mean TCR was 29±13% and 36±19% respectively after 30 and 60s margin after saline solution instillation. Statistically significant correlations were found between TCR and FBUT (r 2 =0.319, p<0.001), blinking frequency (r 2 =0.138, p<0.01), tear film osmolarity (r 2 =0.133, p<0.01) and subject's age (r 2 =0.095, p<0.05). Anterior segment optical coherence tomography allows following changes of tear meniscus morphology post saline solution instillation and evaluating the TCR. OCT based TCR might be used as additional measure of the lacrimal functional unit. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

In vivo tear film thickness measurement and tear film dynamics visualization using spectral domain OCT and an efficient delay estimator

NASA Astrophysics Data System (ADS)

Aranha dos Santos, Valentin; Schmetterer, Leopold; Gröschl, Martin; Garhofer, Gerhard; Werkmeister, René M.

2016-03-01

Dry eye syndrome is a highly prevalent disease of the ocular surface characterized by an instability of the tear film. Traditional methods used for the evaluation of tear film stability are invasive or show limited repeatability. Here we propose a new noninvasive approach to measure tear film thickness using an efficient delay estimator and ultrahigh resolution spectral domain OCT. Silicon wafer phantoms with layers of known thickness and group index were used to validate the estimator-based thickness measurement. A theoretical analysis of the fundamental limit of the precision of the estimator is presented and the analytical expression of the Cramér-Rao lower bound (CRLB), which is the minimum variance that may be achieved by any unbiased estimator, is derived. The performance of the estimator against noise was investigated using simulations. We found that the proposed estimator reaches the CRLB associated with the OCT amplitude signal. The technique was applied in vivo in healthy subjects and dry eye patients. Series of tear film thickness maps were generated, allowing for the visualization of tear film dynamics. Our results show that the central tear film thickness precisely measured in vivo with a coefficient of variation of about 0.65% and that repeatable tear film dynamics can be observed. The presented method has the potential of being an alternative to breakup time measurements (BUT) and could be used in clinical setting to study patients with dry eye disease and monitor their treatments.

Evaluation of the Effects of Conjunctivochalasis Excision on Tear Stability and Contrast Sensitivity

PubMed Central

Qiu, Weiqiang; Zhang, Mingzhou; Xu, Ting; Liu, Ziyuan; Lv, Huibin; Wang, Wei; Li, Xuemin

2016-01-01

Conjunctivochalasis (CCh) disrupts tear flow and damages tear film stability. This study sought to evaluate the tear stability and contrast sensitivity of patients with CCh on whom CCh excision was performed. The study included 39 eyes from 39 patients; all patients had eyes with grade 2 or 3 CCh, underwent CCh excision, and were evaluated before and three months after the surgery. The evaluated variables included the ocular surface disease index (OSDI), the tear break-up time (TBUT), corneal fluorescein staining, corneal surface irregularity, Schirmer’s I test, the tear meniscus area (TMA), and contrast sensitivity. A follow-up of three months was achieved in 36 eyes for 36 patients. All parameters improved significantly after surgery (p < 0.05), except Schirmer’s I test, thus suggesting that CCh excision is an effective method for reconstructing the lower tear meniscus and improving both tear film stability and corneal surface irregularity. The results further demonstrated a simultaneous increase in contrast sensitivity after surgery. PMID:27892479

On tear film breakup (TBU): dynamics and imaging.

PubMed

Braun, Richard J; Driscoll, Tobin A; Begley, Carolyn G; King-Smith, P Ewen; Siddique, Javed I

2018-06-13

We report the results of some recent experiments to visualize tear film dynamics. We then study a mathematical model for tear film thinning and tear film breakup (TBU), a term from the ocular surface literature. The thinning is driven by an imposed tear film thinning rate which is input from in vivo measurements. Solutes representing osmolarity and fluorescein are included in the model. Osmolarity causes osmosis from the model ocular surface, and the fluorescein is used to compute the intensity corresponding closely to in vivo observations. The imposed thinning can be either one-dimensional or axisymmetric, leading to streaks or spots of TBU, respectively. For a spatially-uniform (flat) film, osmosis would cease thinning and balance mass lost due to evaporation; for these space-dependent evaporation profiles TBU does occur because osmolarity diffuses out of the TBU into the surrounding tear film, in agreement with previous results. The intensity pattern predicted based on the fluorescein concentration is compared with the computed thickness profiles; this comparison is important for interpreting in vivo observations. The non-dimensionalization introduced leads to insight about the relative importance of the competing processes; it leads to a classification of large vs small TBU regions in which different physical effects are dominant. Many regions of TBU may be considered small, revealing that the flow inside the film has an appreciable influence on fluorescence imaging of the tear film.

Expression of Lipid Peroxidation Markers in the Tear Film and Ocular Surface of Patients with Non-Sjogren Syndrome: Potential Biomarkers for Dry Eye Disease.

PubMed

Choi, Won; Lian, Cui; Ying, Li; Kim, Ga Eon; You, In Cheon; Park, Soo Hyun; Yoon, Kyung Chul

2016-09-01

To investigate the expression of lipid peroxidation markers in the tear film and ocular surface and their correlation with disease severity in patients with dry eye disease. The concentrations of hexanoyl-lysine (HEL), 4-hydroxy-2-nonenal (HNE), and malondialdehyde (MDA) were measured with enzyme-linked immunosorbent assays in tears obtained from 44 patients with non-Sjogren syndrome dry eye and 33 control subjects. The correlations between the marker levels and the tear film and ocular surface parameters, including tear film break-up time (BUT), Schirmer tear value, tear clearance rate, keratoepitheliopathy scores, corneal sensitivity, conjunctival goblet cell density, and symptom score, were analyzed. The expression of the lipid peroxidation markers HEL, 4-HNE, and MDA in the conjunctiva was evaluated using immunohistochemistry. The concentrations of HEL, 4-HNE, and MDA were 279.84 ± 69.98 nmol/L, 0.02 ± 0.01 μg/mL, and 3.80 ± 1.05 pmol/mg in control subjects and 283.21 ± 89.67 nmol/L (p = 0.97), 0.20 ± 0.03 μg/mL (p < 0.01), and 13.32 ± 4.03 pmol/mg (p < 0.01) in dry eye patients. 4-HNE and MDA levels significantly correlated with BUT, Schirmer tear value, tear clearance rate, keratoepitheliopathy scores, conjunctival goblet cell density, and symptom score (p < 0.05), whereas HEL levels did not correlate with these parameters. Staining intensities for 4-HNE and MDA increased in dry eye patients. The expression of late lipid peroxidation markers, 4-HNE and MDA, increases in the tear film and ocular surface of patients with dry eye. The levels correlate with various tear film and ocular surface parameters and may reflect the severity of dry eye disease.

Polyimide Film of Increased Tear Strength

NASA Technical Reports Server (NTRS)

St. Clair, A. K.; Hinkley, J. A.; Ezzell, S. A.

1986-01-01

High-temperature linear aromatic polyimide with improved resistance to tearing made by new process that incorporates elastomer into polyimide. Linear aromatic condensation polyimides are materials of prime choice for use as films and coatings on advanced spacecraft and aircraft where durability at temperatures in range of 200 to 300 degree C required. Elastomer-containing polyimide film with improved toughness proves useful for applications where resistance to tearing and long-term thermal stability necessary. Desired resistance to tearing achieved by careful control of amount and chemical composition of added elastomer.

Water-evaporation reduction by duplex films: application to the human tear film.

PubMed

Cerretani, Colin F; Ho, Nghia H; Radke, C J

2013-09-01

Water-evaporation reduction by duplex-oil films is especially important to understand the physiology of the human tear film. Secreted lipids, called meibum, form a duplex film that coats the aqueous tear film and purportedly reduces tear evaporation. Lipid-layer deficiency is correlated with the occurrence of dry-eye disease; however, in-vitro experiments fail to show water-evaporation reduction by tear-lipid duplex films. We review the available literature on water-evaporation reduction by duplex-oil films and outline the theoretical underpinnings of spreading and evaporation kinetics that govern behavior of these systems. A dissolution-diffusion model unifies the data reported in the literature and identifies dewetting of duplex films into lenses as a key challenge to obtaining significant evaporation reduction. We develop an improved apparatus for measuring evaporation reduction by duplex-oil films including simultaneous assessment of film coverage, stability, and temperature, all under controlled external mass transfer. New data reported in this study fit into the larger body of work conducted on water-evaporation reduction by duplex-oil films. Duplex-oil films of oxidized mineral oil/mucin (MOx/BSM), human meibum (HM), and bovine meibum (BM) reduce water evaporation by a dissolution-diffusion mechanism, as confirmed by agreement between measurement and theory. The water permeability of oxidized-mineral-oil duplex films agrees with those reported in the literature, after correction for the presence of mucin. We find that duplex-oil films of bovine and human meibum at physiologic temperature reduce water evaporation only 6-8% for a 100-nm film thickness pertinent to the human tear film. Comparison to in-vivo human tear-evaporation measurements is inconclusive because evaporation from a clean-water surface is not measured and because the mass-transfer resistance is not characterized. Copyright © 2013 Elsevier B.V. All rights reserved.

A new, specular reflection-based, precorneal tear film stability measurement technique in a rabbit model: viscoelastic increases tear film stability.

PubMed

Nankivil, Derek; Gonzalez, Alex; Arrieta, Esdras; Rowaan, Cornelis; Aguilar, Mariela C; Sotolongo, Krystal; Cabot, Florence A; Yoo, Sonia H; Parel, Jean-Marie A

2014-06-19

To develop a safe, noninvasive, noncontact, continuous in vivo method to measure the dehydration rate of the precorneal tear film and to compare the effectiveness of a viscoelastic agent in maintaining the precorneal tear film to that of a balanced salt solution. Software was designed to analyze the corneal reflection produced by the operating microscope's coaxial illumination. The software characterized the shape of the reflection, which became distorted as the precorneal tear film evaporated; characterization was accomplished by fitting an ellipse to the reflection and measuring its projected surface area. Balanced salt solution Plus (BSS+) and a 2% hydroxypropylmethylcellulose viscoelastic were used as the test agents. The tear film evaporation rate was characterized and compared over a period of 20 minutes in 20 eyes from 10 New Zealand white rabbits. The ellipse axes ratio and surface area were found to decrease initially after each application of either viscoelastic or BSS+ and then to increase linearly as the tear film began to evaporate (P < 0.001) for eyes treated with BSS+ only. Eyes treated with BSS+ required 7.5 ± 2.7 applications to maintain sufficient corneal hydration during the 20-minute test period, whereas eyes treated with viscoelastic required 1.4 ± 0.5 applications. The rates of evaporation differed significantly (P < 0.043) between viscoelastic and BSS+. The shape and surface area of the corneal reflection are strongly correlated with the state of the tear film. Rabbits' corneas treated with viscoelastic remained hydrated significantly longer than corneas treated with BSS+. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Dynamic interfacial properties of human tear-lipid films and their interactions with model-tear proteins in vitro.

PubMed

Svitova, Tatyana F; Lin, Meng C

2016-07-01

This review summarizes the current state of knowledge regarding interfacial properties of very complex biological colloids, specifically, human meibum and tear lipids, and their interactions with proteins similar to the proteins found in aqueous part of human tears. Tear lipids spread as thin films over the surface of tear-film aqueous and play crucial roles in tear-film stability and overall ocular-surface health. The vast majority of papers published to date report interfacial properties of meibum-lipid monolayers spread on various aqueous sub-phases, often containing model proteins, in Langmuir trough. However, it is well established that natural human ocular tear lipids exist as multilayered films with a thickness between 30 and 100nm, that is very much disparate from 1 to 2nm thick meibum monolayers. We employed sessile-bubble tensiometry to study the dynamic interfacial and rheological properties of reconstituted multilayered human tear-lipid films. Small amounts (0.5-1μg) of human tear lipids were deposited on an air-bubble surface to produce tear-lipid films in thickness range 30-100nm corresponding to ocular lipid films. Thus, we were able to overcome major Langmuir-trough method limitations because ocular tear lipids can be safely harvested only in minute, sub-milligram quantities, insufficient for Langmuir through studies. Sessile-bubble method is demonstrated to be a versatile tool for assessing conventional synthetic surfactants adsorption/desorption dynamics at an air-aqueous solution interface. (Svitova T., Weatherbee M., Radke C.J. Dynamics of surfactant sorption at the air/water interface: continuous-flow tensiometry. J. Colloid Interf. Sci. 2003;261:1170-179). The augmented flow-sessile-bubble setup, with step-strain relaxation module for dynamic interfacial rheological properties and high-precision syringe pump to generate larger and slow interfacial area expansions-contractions, was developed and employed in our studies. We established that

Shifting the IGF-axis: An age-related decline in human tear IGF-1 correlates with clinical signs of dry eye.

PubMed

Patel, Roshni; Zhu, Meifang; Robertson, Danielle M

2018-06-01

The human corneal epithelium expresses both the insulin-like growth factor type 1 receptor (IGF-1R) and the IGF-1R/insulin receptor (INSR) hybrid. Despite the previous identification of IGF-1 in human tear fluid, little is known regarding the regulation of IGF-1 in tear fluid and its role in corneal epithelial homeostasis. In the present study, we investigated the impact of biological parameters on the concentration of human tear levels of IGF-1. Tear levels of IGF-1 were measured in 41 healthy, human volunteers without any reported symptoms of dry eye. All volunteers underwent standard biomicroscopic examination of the cornea and tear film. In a subgroup of volunteers, corneal staining with sodium fluorescein, tear film break up time and tear production using a Schirmer's test strip were measured to assess clinical signs of dry eye. Tears were collected from the inferior tear meniscus using glass microcapillary tubes and IGF-1 levels were measured using a solid phase sandwich ELISA. Tear levels of IGF-1 were highest in young adults and significantly decreased in older adults (P = 0.003). There were no differences in tear IGF-1 between males and females (P = 0.628). Tear IGF-1 levels were correlated with tear film break up time (R = 0.738) and tear production (R = 0.826). These data indicate that there is a progressive decline in tear IGF-1 due to aging that is associated with clinical signs of dry eye. This effect is likely due to age-related changes in the lacrimal gland. Copyright © 2018 Elsevier Ltd. All rights reserved.

Goldmann tonometry tear film error and partial correction with a shaped applanation surface.

PubMed

McCafferty, Sean J; Enikov, Eniko T; Schwiegerling, Jim; Ashley, Sean M

2018-01-01

The aim of the study was to quantify the isolated tear film adhesion error in a Goldmann applanation tonometer (GAT) prism and in a correcting applanation tonometry surface (CATS) prism. The separation force of a tonometer prism adhered by a tear film to a simulated cornea was measured to quantify an isolated tear film adhesion force. Acrylic hemispheres (7.8 mm radius) used as corneas were lathed over the apical 3.06 mm diameter to simulate full applanation contact with the prism surface for both GAT and CATS prisms. Tear film separation measurements were completed with both an artificial tear and fluorescein solutions as a fluid bridge. The applanation mire thicknesses were measured and correlated with the tear film separation measurements. Human cadaver eyes were used to validate simulated cornea tear film separation measurement differences between the GAT and CATS prisms. The CATS prism tear film adhesion error (2.74±0.21 mmHg) was significantly less than the GAT prism (4.57±0.18 mmHg, p <0.001). Tear film adhesion error was independent of applanation mire thickness ( R 2 =0.09, p =0.04). Fluorescein produces more tear film error than artificial tears (+0.51±0.04 mmHg; p <0.001). Cadaver eye validation indicated the CATS prism's tear film adhesion error (1.40±0.51 mmHg) was significantly less than that of the GAT prism (3.30±0.38 mmHg; p =0.002). Measured GAT tear film adhesion error is more than previously predicted. A CATS prism significantly reduced tear film adhesion error bŷ41%. Fluorescein solution increases the tear film adhesion compared to artificial tears, while mire thickness has a negligible effect.

Interferometer for measuring the dynamic surface topography of a human tear film

NASA Astrophysics Data System (ADS)

Primeau, Brian C.; Greivenkamp, John E.

2012-03-01

The anterior refracting surface of the eye is the thin tear film that forms on the surface of the cornea. Following a blink, the tear film quickly smoothes and starts to become irregular after 10 seconds. This irregularity can affect comfort and vision quality. An in vivo method of characterizing dynamic tear films has been designed based upon a near-infrared phase-shifting interferometer. This interferometer continuously measures light reflected from the tear film, allowing sub-micron analysis of the dynamic surface topography. Movies showing the tear film behavior can be generated along with quantitative metrics describing changes in the tear film surface. This tear film measurement allows analysis beyond capabilities of typical fluorescein visual inspection or corneal topography and provides better sensitivity and resolution than shearing interferometry methods. The interferometer design is capable of identifying features in the tear film much less than a micron in height with a spatial resolution of about ten microns over a 6 mm diameter. This paper presents the design of the tear film interferometer along with the considerations that must be taken when designing an interferometer for on-eye diagnostics. Discussions include eye movement, design of null optics for a range of ocular geometries, and laser emission limits for on-eye interferometry.

Tear film proteome in age-related macular degeneration.

PubMed

Winiarczyk, Mateusz; Kaarniranta, Kai; Winiarczyk, Stanisław; Adaszek, Łukasz; Winiarczyk, Dagmara; Mackiewicz, Jerzy

2018-06-01

Age-related macular degeneration (AMD) is the main reason for blindness in elderly people in the developed countries. Current screening protocols have limitations in detecting the early signs of retinal degeneration. Therefore, it would be desirable to find novel biomarkers for early detection of AMD. Development of novel biomarkers would help in the prevention, diagnostics, and treatment of AMD. Proteomic analysis of tear film has shown promise in this research area. If an optimal set of biomarkers could be obtained from accessible body fluids, it would represent a reliable way to monitor disease progression and response to novel therapies. Tear films were collected on Schirmer strips from a total of 22 patients (8 with wet AMD, 6 with dry AMD, and 8 control individuals). 2D electrophoresis was used to separate tear film proteins prior to their identification with matrix-assisted laser desorption/ionization time of flight spectrometer (MALDI-TOF/TOF) and matching with functional databases. A total of 342 proteins were identified. Most of them were previously described in various proteomic studies concerning AMD. Shootin-1, histatin-3, fidgetin-like protein 1, SRC kinase signaling inhibitor, Graves disease carrier protein, actin cytoplasmic 1, prolactin-inducible protein 1, and protein S100-A7A were upregulated in the tear film samples isolated from AMD patients and were not previously linked with this disease in any proteomic analysis. The upregulated proteins supplement our current knowledge of AMD pathogenesis, providing evidence that certain specific proteins are expressed into the tear film in AMD. As far we are aware, this is the first study to have undertaken a comprehensive in-depth analysis of the human tear film proteome in AMD patients.

Tear film aberration dynamics and vision-related quality of life in patients with dry eye disease.

PubMed

Denoyer, Alexandre; Rabut, Ghislaine; Baudouin, Christophe

2012-09-01

Corneal and ocular wavefront aberrations were recorded together with clinical examination results and patient-reported vision-related quality-of-life evaluation results to define the relevance of dynamic optical analysis of the eye in dry eye disease (DED). Prospective and comparative clinical study. Forty DED patients and 40 age- and gender-matched control subjects. Serial measurements of ocular and corneal higher-order aberrations (HOAs) after blink were performed for 10 seconds using the KR-1 aberrometer (Topcon, Clichy, France). Vision-related health-targeted quality of life was evaluated using the Ocular Surface Disease Index (OSDI) questionnaire. The clinical examination included tear film assessment (tear film break-up time and Schirmer I test), ocular surface damage assessment with the Oxford and van Bijsterveld indexes, and Meibomian dysfunction grading. Tear osmolarity also was measured. The time course of HOAs and modulation transfer function (MTF) was compared between groups and was analyzed in comparison with the OSDI and clinical data in DED patients. The root mean square of ocular and corneal total HOAs, particularly third-order aberrations, significantly increased over the 10-second period in DED patients, whereas no change occurred in controls. Analysis of MTF revealed progressive degradation of ocular optical quality resulting from loss of contrast at intermediate and high spatial frequencies in DED patients compared with controls. The progression index for corneal HOAs was correlated with the subjective index of patient-reported visual outcomes and with objective clinical findings of tear film and ocular surface damage. Objective measurement of the time course of HOAs may constitute a new single instrument to evaluate and manage patients with DED because it reliably reflects the completeness of the disease. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

[The correlations between corneal sensation, tear meniscus volume, and tear film osmolarity after femtosecond laser-assisted LASIK].

PubMed

Zhang, Luyan; Sun, Xiyu; Yu, Ye; Xiong, Yan; Cui, Yuxin; Wang, Qinmei; Hu, Liang

2016-01-01

To investigate the correlations between corneal sensation, tear meniscus volume, and tear film osmolarity after femtosecond laser-assisted LASIK (FS-LASIK) surgery. In this prospective clinical study, 31 patients undergoing FS-LASIK for myopia were recruited. The upper and lower tear meniscus volumes (UTMV and LTMV) were measured by customized anterior segment optical coherence tomography, tear film osmolarity was measured by a TearLab Osmolarity test device, central corneal sensation was measured by a Cochet-Bonner esthesiometer preoperatively, at 1 week, 1 and 3 months postoperatively. Repeated measures analysis of variance was used to evaluate whether the tear film osmolarity, tear meniscus volume, and corneal sensation were changed after surgery. The correlations between these variables were analyzed by the Pearson correlation analysis. The tear film osmolarity was (310.03 ± 16.48) mOsms/L preoperatively, (323.51 ± 15.92) mOsms/L at 1 week, (319.93 ± 14.27) mOsms/L at 1 month, and (314.97±12.91) mOsms/L at 3 months. The UTMV was (0.42±0.15), (0.25± 0.09), (0.30±0.11), and (0.35±0.09) μL, respectively; the LTMV was (0.60±0.21),(0.37±0.08), (0.44± 0.14), and (0.52±0.17) μL, respectively. The tear film osmolarity was significantly higher at 1 week and 1 month postoperatively compared with the baseline (P=0.001, 0.004), and reduced to the preoperative level at 3 months (P=0.573). The UTMV, LTMV, and corneal sensation values presented significant decreases at all postoperative time points (all P<0.05). The Pearson correlation analysis showed the postoperative UTMV had a weak relationship with corneal sensation at 1 week after surgery (r=0.356,P=0.005). There were significant correlations between the preoperative LTMV and corneal sensation at 1 week, 1 and 3 months (respectively, r=0.422, 0.366, 0.352;P=0.001, 0.004, 0.006). No significant correlations were found between the tear film osmolarity, tear meniscus volume, and corneal sensation after surgery

Ocular Pharmacology of Tear Film, Dry Eye, and Allergic Conjunctivitis.

PubMed

Gulati, Shilpa; Jain, Sandeep

2017-01-01

Dry Eye Disease (DED) is "a multifactorial disease of the tears and ocular surface that results in symptoms of discomfort, visual disturbance, and tear-film instability with potential damage to the ocular surface." DED comprises two etiologic categories: aqueous-deficient dry eye (ADDE) and evaporative dry eye (EDE). Diagnostic workup of DED should include clinical history, symptom questionnaire, fluorescein TBUT, ocular surface staining grading, Schirmer I/II, lid and meibomian pathology, meibomian expression, followed by other available tests. New diagnostic tests employ the Oculus Keratograph, which performs non-invasive tear-film analysis and a bulbar redness (BR). The TearLab Osmolarity Test enables rapid clinical evaluation of tear osmolarity. Lipiview is a recently developed diagnostic tool that uses interferometry to quantitatively evaluate tear-film thickness. In DED, epithelial and inflammatory cells produce a variety of inflammatory mediators. A stagnant tear film and decreased concentration of mucin result in the accumulation of inflammatory factors that can penetrate tight junctions and cause epithelial cell death. DED treatment algorithms are based on severity of clinical signs and symptoms, and disease etiology. Therapeutic approaches include lubricating artificial tears and immunomodulatory agents.

Effects of topical cyclosporine a plus artificial tears versus artificial tears treatment on conjunctival goblet cell density in dysfunctional tear syndrome.

PubMed

Demiryay, Elvan; Yaylali, Volkan; Cetin, Ebru Nevin; Yildirim, Cem

2011-09-01

The aim was to compare the effects of topical cyclosporine A and artificial tears combination with artificial tears alone in patients with dysfunctional tear syndrome (DTS). Forty-two eyes of 42 patients with DTS were enrolled in the study. The inclusion criteria for the study were Schirmer I (without anesthesia) scores below 10 mm/5 min and tear film break-up time (BUT) below 10 sec. The patients were randomly divided into two groups. The study group (22 patients) underwent 0.05% cyclosporine A treatment twice a day and preservative-free artificial tears for four times a day for 4 months. The control group (20 patients) was administered only preservative-free artificial tears four times a day for 4 months. The BUT, Schirmer test scores, corneal fluorescein staining, conjunctival lissamine green staining, and goblet cell density derived by impression cytology were recorded before and after treatment in each group. In the study group, all parameters improved statistically significantly after treatment at the 4-month follow-up compared with the pretreatment values (P<0.001 for all). In the control group, corneal fluorescein staining (P<0.001) and conjunctival lissamine green staining (P=0.014) improved, but BUT and Schirmer scores did not change significantly after treatment. At the end of the 4-month follow-up, the study group demonstrated statistically significantly better BUT (P=0.020), Schirmer scores (P=0.002), goblet cell density (P=0.006), corneal fluorescein staining (P=0.003), and conjunctival lissamine green staining (P=0.017) scores than did the control group. Topical cyclosporine A and artificial tears treatment significantly increases goblet cell density, decreases the signs of DTS, and improves ocular surface health.

Effects of the rigid gas permeable contact lense use on tear and ocular surface among keratoconus patients.

PubMed

Yuksel Elgin, Cansu; Iskeleli, Guzin; Aydin, Ovgu

2018-06-01

To investigate changes in tear and ocular surface of patients with keratoconus using rigid gas permeable contact lenses (RGPCL) and compare them against keratoconus patients who were not using lenses as well as a control group of healthy subjects. 24 keratoconus patients using RGPCL (Group 1) 22 patients who were not using lenses (Group 3) and 21 healthy subjects (Group 3) were included in the study. Subjective complaints about the subjects' eyes have been investigated using the ocular-surface disease index (OSDI). After the control of best-corrected visual acuity, anterior chamber and fundus examinations were performed. Schirmer (p-value=0.01) and tear break up mean comparison tests (p-value=0.002) revealed significant differences across different groups but tear osmolarity analysis did not (p-value >0.05). Oxford and OSDI scores were compatible with Schirmer and tear break up test comparisons. (for both p-value=0.001) Moreover, no statistical differences were seen in impression cytology measures between groups. (p-value >0.05) CONCLUSIONS: The erosion in the tear film stability is in line with the erosion in the ocular surface epithelium. Taking into account the statistical indifference between the impression cytology measures across groups, the break up time differences may be attributed to the collagen destruction in tear. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Effect of preserved and preservative-free timolol eye drops on tear film stability in healthy Africans

PubMed Central

Ilechie, Alex; Abokyi, Samuel; Boateng, Gifty; Koffuor, George Asumeng

2016-01-01

Background: Preserved versus nonpreserved formulations for ophthalmic use have been well described in the literature although not specifically in the African population where beta blockers are frequently used as the first-line therapy due to economic and availability issues. This study sought to determine the effect of preserved and preservative-free Timolol eye drops on tear film stability in healthy black Africans. Materials and Methods: Sixty healthy nondry eye subjects aged 19–25 years were randomly assigned into four groups (n = 15) and differently treated with eye drops of phosphate buffered saline (PBS), preservative-free timolol (PFT), benzalkonium chloride (BAK) only, and BAK-preserved timolol (BPT). Noninvasive tear break-up time (NITBUT) was measured using the keratometer at baseline and 30, 60, and 90 min after drop application. Results: No significant decline in NITBUT was observed following treatment with PFT and PBS. However, BAK treatment showed a positive time-dependent significant decline in NITBUT (P < 0.001) while a significant decline in the BPT-treated group was only found at 90 min (−3.52 s; P < 0.001). In comparison to the PFT-treated group, treatment with BAK and BPT showed significantly lower NITBUT (P < 0.001). Conclusion: BPT is associated with a significant decline in tear film stability in black Africans. This finding has implications in the management of glaucoma in patients with high-risk of dry eyes in this population. PMID:27226684

[Immunoassay for matrix metalloproteinase-9 in the tear film of patients with pseudoexfoliation syndrome - a pilot study].

PubMed

Zimmermann, N; Erb, C

2013-08-01

Matrix-metalloproteinases (MMPs) are proteolytic enzymes released by irritated epithelial cells of the ocular surface. It has been established that the subtype MMP-9 can serve as an inflammatory marker within the tear film. MMP-9 is also attributed to have an effect on the PEX-glaucoma development. Recently, a rapid immunoassay for detection of MMP-9 in the tear film was developed to estimate inflammatory extent during dry eye disease. The aim of this study was to analyse the MMP-9 concentration in tear film in PEX-syndrome. In addition, an assessment of the feasibility, reliability and readability of the test was done. We randomly selected 10 patients with PEX-syndrome and 10 healthy control patients and measured tear film MMP-9 of one eye with the RPS InflammaDry Detector™ (Rapid Pathogen Screening Inc., USA). We detected increased levels of MMP-9 in tear film in PEX-syndrome. 80 % of the PEX-patients and 20 % of the controls showed a positive test result (>or= 40 ng/mL MMP-9) indicating a test specificity and sensitivity of 80 %. This corresponds approximately to the published values for the dry eye (sensitivity 87 %, specificity: 92 %). The performance of the test is simple. The patients tolerated the inclusion of the test strips well. However, it is difficult to estimate whether enough tear film was used and in many cases, the intensity of the "indicator line" was weak. The rapid MMP-9-immunoassay is a novel, meaningful approach for the detection of inflammatory activity of the ocular surface. We have shown an up-regulation of the non-specific inflammatory marker MMP-9 in tear film in PEX-syndrome and suggest an association with a tear film disorder. However, an improvement in the estimation of the amount of collected tears and readability is desirable. Georg Thieme Verlag KG Stuttgart · New York.

[Epidemiologic study of tear film lipid layer thickness measurement in the population of Taishitun Community in Beijing].

PubMed

Liang, Q F; Du, X H; Su, Y D; Wang, N L; Wei, Z J; Labbé, Antoine

2017-07-11

Objective: To investigate the distribution of tear film lipid layer thickness (LLT) and the relationship between symptoms and signs of dry eye and tear film LLT in the population of Taishitun Community in Beijing. Methods: A cross-sectional study. From May 2016 to August 2016, three streets of Taishitun Community were randomly selected as survey districts and 540 persons were taken as investigation subjects. Every participant completed 6 items of dry eye examinations as follows: questionnaire (Ocular Surface Disease Index, OSDI), measurement of tear film LLT, tear film break-up time (TBUT), corneal and conjunctival staining, SchirmerⅠtest and the infrared meibomian photography. According to their age, all participants were divided into four groups: junior group (<18 years old), youth group (18 to 40 years old), middle-aged group (41 to 59 years old) and the elderly group (over 60 years old). With the OSDI criteria, no dry eye symptom group (score, <12 points), mild to moderate dry eye symptom group (score, 12 to 32) and severe dry eye symptom group (score, 33-100) were included. With the statistical methods of variance analysis and multivariate Logistic regression analysis, distribution of the variables of LLT and the relationship between dry eye symptoms and LLT were studied. Results: A total of 473 residents finally participated in this study, and the response ratio was 87.6%. The values of LLT were normally distributed. The average LLT was (59.87±18.50) nm [(60.16±19.15) nm in males and (59.67±18.57) nm in females], and the comparison of LLT with different genders was not statistically significant ( t= 0.198, P= 0.843). The tear film LLT of four different age groups had statistical significance ( F= 15.092, P< 0.05), and increased with age [(56.10±18.33) nm in the junior group, (54.60±16.29) nm in the youth group, (60.61±19.18) nm in the middle-aged group and (73.25±14.58) nm in the elderly group]. The LLT was inversely proportional to the severity of

Biophysical characterization of monofilm model systems composed of selected tear film phospholipids.

PubMed

Patterson, Matthew; Vogel, Hans J; Prenner, Elmar J

2016-02-01

The tear film protects the eye from foreign particles and pathogens, prevents excess evaporation, provides lubrication, and maintains a high quality optical surface necessary for vision. The anterior layer of tear film consists of polar and non-polar lipid layers. The polar lipids form a monolayer on the aqueous subphase, acting as surfactants for the non-polar lipid multilayer. A tear film polar lipid biomimetic consisting of dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylethanolamine (DPPE), palmitoyl glucosylceramide (PGC), and palmitoyl sphingomyelin (PSM) was characterized using Langmuir monolayers and Brewster angle microscopy (BAM). Lipid combinations formed very stable monolayers, especially those containing DPPC or PSM. Surface experiments and elasticity analyses revealed that PGC resulted in more condensed and rigid mixed monolayers. DPPE provided resistance to large changes in lipid ordering over a wide surface pressure range. Ternary mixtures containing DPPE and PGC with either DPPC or PSM experienced the greatest lipid ordering within the natural tear film surface pressure range suggesting that these lipids are important to maintain tear film integrity during the inter-blink period. Finally, BAM images revealed unique structures within monolayers of DPPC, DPPE, and PGC at the natural tear film surface pressure. 3D analysis of these domains suggested either the formation of multilayers or outward protrusions at surface pressures far below the point of irreversible collapse as seen on the isotherm. This entails that the polar lipids of tear film may be capable of multilayer formation or outward folding as a mechanism to prevent rupture of the tear film during a blink. Copyright © 2015 Elsevier B.V. All rights reserved.

Symptoms, visual function, and mucin expression of eyes with tear film instability.

PubMed

Shimazaki-Den, Seika; Dogru, Murat; Higa, Kazunari; Shimazaki, Jun

2013-09-01

We examined symptoms, tear stability, visual function, and conjunctival cytology in eyes with an unstable tear film (UTF), expressed as a short tear film breakup time without epithelial damage or low tear secretion, and compared the results with those from eyes with aqueous deficiency (AD) associated with epithelial damage, and healthy eyes. We divided the patients with ocular discomfort into 2 groups according to the breakup time, Schirmer value, and epithelial staining score: UTF group (≤5 seconds, >5 mm, and <3 points; 21 eyes of 21 patients) and AD group (≤5 seconds, ≤5 mm, and ≥3 points; 21 eyes of 21 patients). We examined all patients and 17 healthy subjects for symptoms, tear functions, tear film stability by tear film lipid layer interferometry and tear film analysis system, and functional visual acuity. Conjunctival impression cytology was performed to investigate changes in goblet cell density, squamous metaplasia, and messenger RNA expression of MUC5AC and MUC16. The symptom scores, tear film analysis system index, and functional visual acuity testing were significantly worse in the UTF and AD groups compared with those in the control group (P < 0.05). The messenger RNA expression levels of MUC5AC and MUC16 were significantly lower in UTF and AD eyes compared with those in the control eyes (P < 0.0001). An UTF itself can cause dry eye symptoms and visual disturbance comparable with those of AD dry eyes.

Ocular surface and tear film status among contact lens wearers and non-wearers who use VDT at work: comparing three different lens types.

PubMed

Tauste, Ana; Ronda, Elena; Baste, Valborg; Bråtveit, Magne; Moen, Bente E; Seguí Crespo, María-Del-Mar

2018-04-01

To analyze differences in the ocular surface appearance and tear film status of contact lens wearers and non-wearers in a group of visual display terminals (VDT) workers and additionally to assess differences between lens materials. Cross-sectional study of 236 office workers, of whom 92 were contact lens wearers. Workers provided information on their contact lenses (conventional hydrogel, silicone hydrogel or rigid gas permeable lenses) and exposure to VDT at work. Ocular surface and tear film status were determined by the presence of bulbar, limbal and lid redness, lid roughness and corneal staining type, and by Schirmer's and tear break-up time tests (TBUT). A generalized linear model was used to calculate the crude (cRR) and age- and sex-adjusted (aRR) relative risk to measure the association between ocular surface and tear film abnormalities and contact lens use and type. The aRR of ocular surface abnormalities was higher in contact lens wearers compared to non-wearers: bulbar redness (aRR 1.69; 95% CI 1.25-2.30), limbal redness (aRR 2.87; 1.88-4.37), lid redness (aRR 2.53; 1.35-4.73) and lid roughness (aRR 7.03; 1.31-37.82). VDT exposure > 4 h/day increased wearers' risk of limbal and lid redness. Conventional hydrogel wearers had the highest risk of ocular surface abnormalities, followed by silicone hydrogel wearers. Both contact and non-contact lens wearers had a high prevalence of altered TBUT (77.3 and 75.7% respectively) and Schirmer (51.8 and 41.3%). Regular contact lens use during VDT exposure at work increases risk of bulbar, limbal and lid redness, and lid roughness, especially in soft contact lens wearers. The high prevalence of altered TBUT and Schirmer's results in all participants suggests that VDT use greatly affects tear film characteristics.

Correlations among ocular surface temperature difference value, the tear meniscus height, Schirmer's test and fluorescein tear film break up time.

PubMed

Su, Tai Yuan; Ho, Wei Ting; Lu, Chien Yi; Chang, Shu Wen; Chiang, Huihua Kenny

2015-04-01

To report the use of a thermographer for measuring ocular surface temperature, and to evaluate the correlation among the obtained temperature difference values (TDVs) and dry eye parameters (tear meniscus height (TMH); Schirmer's test results; fluorescent tear breakup time (FTBUT)). Forty-three participants (age 40.2±14.7 years; range 21-67 years) from Far Eastern Memorial Hospital, Taiwan were recruited for the study. The surface temperature was measured at the centre of the ocular surface for 4 s after blinking. TDV was defined as the change in corneal surface temperature relative to that of the preceding eye opening, where TDV01, TDV02, TDV03, and TDV04 represent the values obtained 1, 2, 3, and 4 s after blinking, respectively. Anterior segment optical coherence tomography (AS-OCT) was employed to measure the lower TMH. Schirmer's test with topical anaesthetic was conducted to measure the basal tear secretion. The FTBUT was recorded using a digital camera. TDV measurement exhibited high reliability (intraclass correlation coefficient=0.91). TDV03 exhibited the highest significance and strongest positive correlation with the TMH (r=0.52, p=0.0003) and Schirmer's test value (r=0.39, p=0.008), whereas the TDV03-FTBUT correlation was non-significant. Age correlated negatively and significantly with the TDV (r= -0.35, p=0.021), TMH (r= -0.33, p=0.031), and Schirmer's test value (r= -0.31, p=0.044). TDV03 remained significantly correlated with the TMH and Schirmer's test value after adjustment for age. The thermographer was effective in capturing temperature changes in the ocular surface. The temperature difference 3 s after blinking appears to be correlated with lower TMH and Schirmer test values. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Assessing tear film on soft contact lenses with lateral shearing interferometry.

PubMed

Szczesna, Dorota H

2011-11-01

Evaluating precorneal tear film is one of important clinical measurements for assessing health of anterior eye. Contact lens wear is known to influence the quality of tear film. The aim was to evaluate the applicability of lateral shearing interferometry technique in the noninvasive assessment of the effects of contact lens replacement modality and its water content on tear film stability. Sixteen regular soft contact lens wearers took place in the study. Lateral shearing interferometry measurements, in suppressed blinking conditions, were taken in the mornings and afternoons, after a minimum of 5 hours of lens wear for the daily lenses, and after 2 weeks and 1 month for the fortnightly and monthly lens replacement modalities, respectively. Significant differences (paired bootstrap-based Behrens-Fisher test, P < 0.05) in the tear film surface quality were found between all considered pairs of replacement modalities except for the daily and fortnightly lenses measured in the afternoon of the first day of wear. Significant worsening (paired bootstrap-based Behrens-Fisher test, P < 0.001) of tear film quality was found for the low water content materials. Lateral shearing interferometry is a powerful method for the noninvasive assessment of tear film surface quality on soft contact lenses that may find, in future, its use in the clinical assessment of anterior eye's health.

Plate break-up geometry in SE-Afar

NASA Astrophysics Data System (ADS)

Geoffroy, Laurent; Le Gall, Bernard; Daoud, Mohamed

2014-05-01

New structural data acquired in Djibouti strongly support the view of a magma-rich to magma-poor pair of conjugate margins developed in SE Afar since at least 9 Ma. Our model is illustrated by a crustal-scale transect that emphasizes the role of a two-stage extensional detachment fault system, with opposing senses of motion through time. The geometry and kinematics of this detachment fault pattern are mainly documented from lavas and fault dip data extracted from remote sensing imagery (Landsat ETM+, and corresponding DEM), further calibrated by field observations. Although expressed by opposite fault geometries, the two successive extensional events evidenced here are part of a two-stage continental extensional tear-system associated with the ongoing propagation of the Aden-Tadjoura oceanic axis to the NW. A flip-flop evolution of detachment faults accommodating lithosphere divergence has recently been proposed for the development of the Indian Ocean and continental margins (Sauter et al., 2013). However, the SE Afar evolution further suggests a radical and sudden change in lithosphere behavior during extension, from a long-term and widespread magmatic stage to a syn-sedimentary break-up stage where mantle melting concentrates along the future oceanic axis. Of special interest is the fact that a late and rapid stage of non-magmatic extension led to break-up, whose geometry triggered the location of the break-up axis and earliest oceanic accretion. New structural data acquired in Djibouti strongly support the view of a magma-rich to magma-poor pair of conjugate margins developed in SE Afar since at least 9 Ma. Our model is illustrated by a crustal-scale transect that emphasizes the role of a two-stage extensional detachment fault system, with opposing senses of motion through time. The geometry and kinematics of this detachment fault pattern are mainly documented from lavas and fault dip data extracted from remote sensing imagery (Landsat ETM+, and corresponding

Dynamics and function of the tear film in relation to the blink cycle.

PubMed

Braun, R J; King-Smith, P E; Begley, C G; Li, Longfei; Gewecke, N R

2015-03-01

Great strides have recently been made in quantitative measurements of tear film thickness and thinning, mathematical modeling thereof and linking these to sensory perception. This paper summarizes recent progress in these areas and reports on new results. The complete blink cycle is used as a framework that attempts to unify the results that are currently available. Understanding of tear film dynamics is aided by combining information from different imaging methods, including fluorescence, retroillumination and a new high-speed stroboscopic imaging system developed for studying the tear film during the blink cycle. During the downstroke of the blink, lipid is compressed as a thick layer just under the upper lid which is often released as a narrow thick band of lipid at the beginning of the upstroke. "Rippling" of the tear film/air interface due to motion of the tear film over the corneal surface, somewhat like the flow of water in a shallow stream over a rocky streambed, was observed during lid motion and treated theoretically here. New mathematical predictions of tear film osmolarity over the exposed ocular surface and in tear breakup are presented; the latter is closely linked to new in vivo observations. Models include the effects of evaporation, osmotic flow through the cornea and conjunctiva, quenching of fluorescence, tangential flow of aqueous tears and diffusion of tear solutes and fluorescein. These and other combinations of experiment and theory increase our understanding of the fluid dynamics of the tear film and its potential impact on the ocular surface. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dynamics and function of the tear film in relation to the blink cycle

PubMed Central

Braun, R.J.; King-Smith, P.E.; Begley, C.G.; Li, Longfei; Gewecke, N.R.

2014-01-01

Great strides have recently been made in quantitative measurements of tear film thickness and thinning, mathematical modeling thereof and linking these to sensory perception. This paper summarizes recent progress in these areas and reports on new results. The complete blink cycle is used as a framework that attempts to unify the results that are currently available. Understanding of tear film dynamics is aided by combining information from different imaging methods, including fluorescence, retroillumination and a new high-speed stroboscopic imaging system developed for studying the tear film during the blink cycle. During the downstroke of the blink, lipid is compressed as a thick layer just under the upper lid which is often released as a narrow thick band of lipid at the beginning of the upstroke. “Rippling” of the tear film/air interface due to motion of the tear film over the corneal surface, somewhat like the flow of water in a shallow stream over a rocky streambed, was observed during lid motion and treated theoretically here. New mathematical predictions of tear film osmolarity over the exposed ocular surface and in tear breakup are presented; the latter is closely linked to new in vivo observations. Models include the effects of evaporation, osmotic flow through the cornea and conjunctiva, quenching of fluorescence, tangential flow of aqueous tears and diffusion of tear solutes and fluorescein. These and other combinations of experiment and theory increase our understanding of the fluid dynamics of the tear film and its potential impact on the ocular surface. PMID:25479602

Ocular Surface and Tear Film Changes in Older Women Working with Computers.

PubMed

Ribelles, Alfredo; Galbis-Estrada, Carmen; Parras, Maria A; Vivar-Llopis, Bárbara; Marco-Ramírez, Carla; Diaz-Llopis, Manuel

2015-01-01

The aim of this work is to investigate changes in the ocular surface (OS) and tear film (TF) by means of questionnaire-based subjective symptoms, TF break-up time, Schirmer test, and TF analysis in women working with computers and to analyze the effects of the oral supplementation with antioxidants/omega 3 fatty acids (A/ω3) in the OS outcomes. Women aged 40-65 years (n = 148) were recruited at the Administrative Offices of Valencia (Spain) and distributed into two age groups, 40-52 years (AGE1; n = 87) and 53-65 years (AGE2; n = 61), and then subdivided according to being (or not) computer users (CUG; NCUG) during the workday. Homogeneous subgroups were randomly assigned (or not) to the daily intake of three pills of A/ω3 for three months. At baseline and at the end of follow-up, personalized interviews and ocular examination were done. Reflex tear samples were collected from the inferior meniscus and processed for a multiplexed particle-based flow cytometry assay to measure proinflammatory molecules. Statistics were performed using the SPSS 15.0 program. The OS pathology was clinically evident in the AGE1-CUG (33%) versus the AGE2-CUG (64%) of women. Significantly higher interleukins-1β and -6 tear levels were found in the AGE1 versus the AGE2 women employees (P = 0.006 and P = 0.001, resp.), as well as in the CUG versus the NCUG (P = 0.001 and P = 0.000, resp.). Supplementation with A/ω3 positively influenced the OS pathology as manifested by the amelioration of the clinical signs/symptoms related to computer uses. Strategies involving a safe environment and oral micronutrient supplements may be managed within eye-care standards in older women.

Ocular Surface and Tear Film Changes in Older Women Working with Computers

PubMed Central

Ribelles, Alfredo; Parras, Maria A.; Vivar-Llopis, Bárbara; Marco-Ramírez, Carla; Diaz-Llopis, Manuel

2015-01-01

The aim of this work is to investigate changes in the ocular surface (OS) and tear film (TF) by means of questionnaire-based subjective symptoms, TF break-up time, Schirmer test, and TF analysis in women working with computers and to analyze the effects of the oral supplementation with antioxidants/omega 3 fatty acids (A/ω3) in the OS outcomes. Women aged 40–65 years (n = 148) were recruited at the Administrative Offices of Valencia (Spain) and distributed into two age groups, 40–52 years (AGE1; n = 87) and 53–65 years (AGE2; n = 61), and then subdivided according to being (or not) computer users (CUG; NCUG) during the workday. Homogeneous subgroups were randomly assigned (or not) to the daily intake of three pills of A/ω3 for three months. At baseline and at the end of follow-up, personalized interviews and ocular examination were done. Reflex tear samples were collected from the inferior meniscus and processed for a multiplexed particle-based flow cytometry assay to measure proinflammatory molecules. Statistics were performed using the SPSS 15.0 program. The OS pathology was clinically evident in the AGE1-CUG (33%) versus the AGE2-CUG (64%) of women. Significantly higher interleukins-1β and -6 tear levels were found in the AGE1 versus the AGE2 women employees (P = 0.006 and P = 0.001, resp.), as well as in the CUG versus the NCUG (P = 0.001 and P = 0.000, resp.). Supplementation with A/ω3 positively influenced the OS pathology as manifested by the amelioration of the clinical signs/symptoms related to computer uses. Strategies involving a safe environment and oral micronutrient supplements may be managed within eye-care standards in older women. PMID:26557673

The effects of 2% rebamipide ophthalmic solution on the tear functions and ocular surface of the superoxide dismutase-1 (sod1) knockout mice.

PubMed

Ohguchi, Takeshi; Kojima, Takashi; Ibrahim, Osama M; Nagata, Taeko; Shimizu, Takahiko; Shirasawa, Takuji; Kawakita, Tetsuya; Satake, Yoshiyuki; Tsubota, Kazuo; Shimazaki, Jun; Ishida, Susumu

2013-11-21

To investigate the efficacy of 2% rebamipide ophthalmic solution on the tear functions and ocular surface status of the superoxide dismutase-1(Sod1(-/-)) mice. Two percent Rebamipide ophthalmic solution was applied to 40-week-old male Sod1(-/-) and wild-type (WT) mice four times a day for 2 weeks. We examined the cytokine concentrations in the tear fluid (by CytoBead assay), tear film break-up time, amount of tear production, and expressions of mucins 1, 4, and 5AC, by RT-PCR. We also performed vital staining of the ocular surface, PAS staining for muc5AC, and immunohistochemical stainings for 4-hydroxy-2-nonenal (4-HNE), 8-hydroxy-2'-deoxyguanosine (8-OHdG), in the conjunctiva to compare the results before and after rebamipide instillations. The tear functions and ocular surface epithelial damage scores were significantly worse in the Sod1(-/-) than in the WT mice. Application of 2% rebamipide for 2 weeks significantly improved the tear film break-up time, the amount of tear production, and the corneal epithelial damage scores, which also significantly increased the conjunctival goblet cell density and muc5 mRNA expression, in the Sod1(-/-) mice. The mean IL-6, IL-17, TNF-α, and IFN-γ levels in the tear fluid were reduced significantly along with a significant decrease in the density of cells positive for 4-HNE and 8-OHdG in the conjunctiva. Two percent Rebamipide ophthalmic solution significantly improved the tear stability and corneal epithelial damage, and enhanced the expression of muc5 mRNA on the ocular surface. We also observed anti-inflammatory effects in the tear film together with antioxidative effects in the conjunctiva, suggesting the efficacy of rebamipide in age-related dry eye disease attributable to SOD1 knockout.

The brilliant beauty of the eye: light reflex from the cornea and tear film.

PubMed

Goto, Eiki

2006-12-01

Light reflex from the cornea and tear film as contributors to beautiful eyes ("eye sparkling") are reviewed. A systematic literature review was conducted using "Purkinje-Sanson image," "corneal light reflex," "corneal topography," "corneal wavefront aberration," and "tear interference image" as search terms. Articles on corneal surface regularity and stability and tear interferometry of the precorneal tear lipid layer were reviewed. PS-1 image, that is light reflex from the cornea and tear film, is widely used in practical ophthalmic examination. To achieve a brilliant beauty of the eye ("eye sparkling"), it is important that the tear film (aqueous layer) surface is smooth and stable with adequate tear volume and that the tear lipid layer is present in adequate thickness.

Organization of Lipids in the Tear Film: A Molecular-Level View

PubMed Central

Wizert, Alicja; Iskander, D. Robert; Cwiklik, Lukasz

2014-01-01

Biophysical properties of the tear film lipid layer are studied at the molecular level employing coarse grain molecular dynamics (MD) simulations with a realistic model of the human tear film. In this model, polar lipids are chosen to reflect the current knowledge on the lipidome of the tear film whereas typical Meibomian-origin lipids are included in the thick non-polar lipids subphase. Simulation conditions mimic those experienced by the real human tear film during blinks. Namely, thermodynamic equilibrium simulations at different lateral compressions are performed to model varying surface pressure, and the dynamics of the system during a blink is studied by non-equilibrium MD simulations. Polar lipids separate their non-polar counterparts from water by forming a monomolecular layer whereas the non-polar molecules establish a thick outermost lipid layer. Under lateral compression, the polar layer undulates and a sorting of polar lipids occurs. Moreover, formation of three-dimensional aggregates of polar lipids in both non-polar and water subphases is observed. We suggest that these three-dimensional structures are abundant under dynamic conditions caused by the action of eye lids and that they act as reservoirs of polar lipids, thus increasing stability of the tear film. PMID:24651175

Interaction of lysozyme with a tear film lipid layer model: A molecular dynamics simulation study.

PubMed

Wizert, Alicja; Iskander, D Robert; Cwiklik, Lukasz

2017-12-01

The tear film is a thin multilayered structure covering the cornea. Its outermost layer is a lipid film underneath of which resides on an aqueous layer. This tear film lipid layer (TFLL) is itself a complex structure, formed by both polar and nonpolar lipids. It was recently suggested that due to tear film dynamics, TFLL contains inhomogeneities in the form of polar lipid aggregates. The aqueous phase of tear film contains lachrymal-origin proteins, whereby lysozyme is the most abundant. These proteins can alter TFLL properties, mainly by reducing its surface tension. However, a detailed nature of protein-lipid interactions in tear film is not known. We investigate the interactions of lysozyme with TFLL in molecular details by employing coarse-grained molecular dynamics simulations. We demonstrate that lysozyme, due to lateral restructuring of TFLL, is able to penetrate the tear lipid film embedded in inverse micellar aggregates. Copyright © 2017 Elsevier B.V. All rights reserved.

Changes in Tear Volume after 3% Diquafosol Treatment in Patients with Dry Eye Syndrome: An Anterior Segment Spectral-domain Optical Coherence Tomography Study.

PubMed

Lee, Kwan Bok; Koh, Kyung Min; Kwon, Young A; Song, Sang Wroul; Kim, Byoung Yeop; Chung, Jae Lim

2017-08-01

To evaluate changes in the tear meniscus area and tear meniscus height over time in patients with dry eye syndrome, using anterior segment spectral-domain optical coherence tomography after the instillation of 3% diquafosol ophthalmic solution. Sixty eyes from 30 patients with mild to moderate dry eye syndrome were included. Tear meniscus images acquired by anterior segment spectral-domain optical coherence tomography were analyzed using National Institutes of Health's image-analysis software (ImageJ 1.44p). Tear meniscus area and tear meniscus height were measured at baseline, 5 minutes, 10 minutes, and 30 minutes after instillation of a drop of diquafosol in one eye and normal saline in the other eye. Changes in ocular surface disease index score, tear film break-up time, corneal staining score by Oxford schema, and meibomian expressibility were also evaluated at baseline, and after 1 week and 1 month of a diquafosol daily regimen. Sixty eyes from 30 subjects (mean age, 29.3 years; 8 men and 22 women) were included. In eyes receiving diquafosol, tear volume was increased at 5 and 10 minutes compared with baseline. It was also higher than saline instilled eyes at 5, 10, and 30 minutes. Changes in tear volume with respect to baseline were not statistically different after the use of diquafosol for 1 month. Ocular surface disease index score, tear film break-up time, and Oxford cornea stain score were significantly improved after 1 week and 1 month of daily diquafosol instillation, but meibomian expressibility did not change. Topical diquafosol ophthalmic solution effectively increased tear volume for up to 30 minutes, compared to normal saline in patients with dry eye syndrome. © 2017 The Korean Ophthalmological Society

Changes in the tear film and ocular surface from dry eye syndrome.

PubMed

Johnson, Michael E; Murphy, Paul J

2004-07-01

Dry eye syndrome (DES) refers to a spectrum of ocular surface diseases with diverse and frequently multiple aetiologies. The common feature of the various manifestations of DES is an abnormal tear film. Tear film abnormalities associated with DES are tear deficiency, owing to insufficient supply or excessive loss, and anomalous tear composition. These categorizations are artificial, as in reality both often coexist. DES disrupts the homeostasis of the tear film with its adjacent structures, and adversely affects its ability to perform essential functions such as supporting the ocular surface epithelium and preventing microbial invasion. In addition, whatever the initial trigger, moderate and severe DES is characterized by ocular surface inflammation, which in turn becomes the cause and consequence of cell damage, creating a self-perpetuating cycle of deterioration. Progress has been made in our understanding of the aetiology and pathogenesis of DES, and these advances have encouraged a proliferation of therapeutic options. This article aims to amalgamate prevailing ideas of DES development, and to assist in that, relevant aspects of the structure, function, and production of the tear film are reviewed. Additionally, a synopsis of therapeutic strategies for DES is presented, detailing treatments currently available, and those in development.

Behavior of sphingomyelin and ceramide in a tear film lipid layer model.

PubMed

Olżyńska, Agnieszka; Cwiklik, Lukasz

2017-03-01

Tear film lipid layer is a complex lipid mixture forming the outermost interface between eye and environment. Its key characteristics, such as surface tension and structural stability, are governed by the presence of polar lipids. The origin of these lipids and exact composition of the mixture are still elusive. We focus on two minor polar lipid components of the tear film lipid later: sphingomyelin and ceramide. By employing coarse grain molecular dynamics in silico simulations accompanied by Langmuir balance experiments we provide molecular-level insight into behavior of these two lipids in a tear film lipid layer model. Sphingomyelin headgroups are significantly exposed at the water-lipids boundary while ceramide molecules are incorporated between other lipids frequently interacting with nonpolar lipids. Even though these two lipids increase surface tension of the film, their molecular-level behavior suggests that they have a stabilizing effect on the tear film lipid layer. Copyright © 2016 Elsevier GmbH. All rights reserved.

The Effect of Ambient Ozone on Unsaturated Tear Film Wax Esters.

PubMed

Paananen, Riku O; Rantamäki, Antti H; Parshintsev, Jevgeni; Holopainen, Juha M

2015-12-01

Tear film lipid layer (TFLL) is constantly exposed to reactive ozone in the surrounding air, which may have detrimental effects on ocular health. Behenyl oleate (BO), a representative tear film wax ester, was used to study the reaction with ozone at the air-water interface. Time-dependent changes in mean molecular area of BO monolayers were measured at different ozone concentrations and surface pressures. In addition, the effect of ascorbic acid on the reaction rate was determined. Reaction was followed using thin-layer chromatography and reaction products were identified using liquid chromatography-electrospray ionization mass spectrometry (LC-MS). Tear fluid samples from healthy subjects were analyzed with LC-MS for any ozonolysis reaction products. Behenyl oleate was found to undergo rapid ozonolysis at the air-water interface at normal indoor ozone concentrations. The reaction was observed as an initial expansion followed by a contraction of the film area. Ascorbic acid was found to decrease the rate of ozonolysis. Main reaction products were identified as behenyl 9-oxononanoate and behenyl 8-(5-octyl-1,2,4-trioxolan-3-yl)octanoate. Similar ozonolysis products were not detected in the tear fluid samples. At the air-water interface, unsaturated wax esters react readily with ozone in ambient air. However, no signs of ozonolysis products were found in the tear fluid. This is most likely due to the antioxidant systems present in tear fluid. Last, the results show that ozonolysis needs to be controlled in future surface chemistry studies on tear film lipids.

Adsorption of human tear lipocalin to human meibomian lipid films.

PubMed

Millar, Thomas J; Mudgil, Poonam; Butovich, Igor A; Palaniappan, Chendur K

2009-01-01

Tear lipocalin (Tlc) is a major lipid binding protein in tears and is thought to have an important role in stabilizing the Meibomian lipid layer by transferring lipids to it from the aqueous layer or ocular surface, or by adsorbing to it directly. These possible roles have been investigated in vitro using human Tlc. Tlc was purified from human tears by size exclusion chromatography followed by ion exchange chromatography. Three additional samples of the Tlc were prepared by lipidation, delipidation, and relipidation. The lipids extracted from the purified Tlc were analyzed by HPLC-MS followed by fragmentation. Adsorption of these different forms of Tlc to a human Meibomian lipid film spread on the surface of an artificial tear buffer in a Langmuir trough were observed by recording changes in the pressure with time (Pi-T profile) and monitoring the appearance of the film microscopically. These results were compared with similar experiments using a bovine Meibomian lipid film. The results indicated that Tlc binds slowly to a human Meibomian lipid film compared with lysozyme or lactoferrin, even at 37 degrees C. The adsorption of Tlc to a human Meibomian lipid film was very different from its adsorption to a bovine Meibomian lipid film, indicating the nature of the lipids in the film is critical to the adsorption process. Similarly, the different forms of Tlc had quite distinct adsorption patterns, as indicated both by changes in Pi-T profiles and the microscopic appearance of the films. It was concluded that human Tlc was capable of adsorbing to and penetrating into a Meibomian lipid layer, but this process is very complex and depends on both the types of lipids bound to Tlc and the lipid complement comprising the Meibomian lipid film.

Adsorption of Human Tear Lipocalin to Human Meibomian Lipid Films

PubMed Central

Millar, Thomas J.; Mudgil, Poonam; Butovich, Igor A.; Palaniappan, Chendur K.

2009-01-01

Purpose Tear lipocalin (Tlc) is a major lipid binding protein in tears and is thought to have an important role in stabilizing the Meibomian lipid layer by transferring lipids to it from the aqueous layer or ocular surface, or by adsorbing to it directly. These possible roles have been investigated in vitro using human Tlc. Methods Tlc was purified from human tears by size exclusion chromatography followed by ion exchange chromatography. Three additional samples of the Tlc were prepared by lipidation, delipidation, and relipidation. The lipids extracted from the purified Tlc were analyzed by HPLC-MS followed by fragmentation. Adsorption of these different forms of Tlc to a human Meibomian lipid film spread on the surface of an artificial tear buffer in a Langmuir trough were observed by recording changes in the pressure with time (∏-T profile) and monitoring the appearance of the film microscopically. These results were compared with similar experiments using a bovine Meibomian lipid film. Results The results indicated that Tlc binds slowly to a human Meibomian lipid film compared with lysozyme or lactoferrin, even at 37°C. The adsorption of Tlc to a human Meibomian lipid film was very different from its adsorption to a bovine Meibomian lipid film, indicating the nature of the lipids in the film is critical to the adsorption process. Similarly, the different forms of Tlc had quite distinct adsorption patterns, as indicated both by changes in ∏-T profiles and the microscopic appearance of the films. Conclusions It was concluded that human Tlc was capable of adsorbing to and penetrating into a Meibomian lipid layer, but this process is very complex and depends on both the types of lipids bound to Tlc and the lipid complement comprising the Meibomian lipid film. PMID:18757516

Examination of tear film smoothness on corneae after refractive surgeries using a noninvasive interferometric method

NASA Astrophysics Data System (ADS)

Szczesna, Dorota H.; Kulas, Zbigniew; Kasprzak, Henryk T.; Stenevi, Ulf

2009-11-01

A lateral shearing interferometer was used to examine the smoothness of the tear film. The information about the distribution and stability of the precorneal tear film is carried out by the wavefront reflected from the surface of tears and coded in interference fringes. Smooth and regular fringes indicate a smooth tear film surface. On corneae after laser in situ keratomileusis (LASIK) or radial keratotomy (RK) surgery, the interference fringes are seldom regular. The fringes are bent on bright lines, which are interpreted as tear film breakups. The high-intensity pattern seems to appear in similar location on the corneal surface after refractive surgery. Our purpose was to extract information about the pattern existing under the interference fringes and calculate its shape reproducibility over time and following eye blinks. A low-pass filter was applied and correlation coefficient was calculated to compare a selected fragment of the template image to each of the following frames in the recorded sequence. High values of the correlation coefficient suggest that irregularities of the corneal epithelium might influence tear film instability and that tear film breakup may be associated with local irregularities of the corneal topography created after the LASIK and RK surgeries.

Effects of wearing a daily disposable lens on tear film: a randomised controlled trial.

PubMed

Chong, Pamela Qin Yi; Yeo, Sharon; Too, Cheah Loon; Boo, Cynthia; Tong, Louis

2016-05-01

Contact lens-induced dry eye is commonly encountered, although its extent is not well documented with daily disposable lenses. A novel type of contact lens system incorporating moisturising agent (alginic acid) has been developed. The aim of this study was to evaluate the effect of wearing daily 2-hydroxyethyl methacrylate disposable contact lenses for seven days on tear stability, conjunctival and limbal redness and dry eye symptoms. Then, we aimed to determine whether lens solutions containing alginic acid had any influence on tear parameters. This was a seven-day parallel group double-masked clinical trial of previous contact lens wearers, where participants were randomly assigned to wearing SEED 1dayPure moisture contact lenses with (n = 15) or without alginic acid (n = 15). Tear lipid layer thickness (LLT), non-invasive tear break-up time (NIBUT), conjunctival redness, corneal fluorescein staining, tear break-up time and Schirmer I readings were measured. Symptom severity and frequency were evaluated and combined using a global score from visual analogue scales. The mean age and standard deviation of the participants was 25 ± 3.8 years. There were 24 females and six males. After reintroduction of contact lens wear for one week, there was significant improvement in the global symptom score; however, this may not be clinically significant. There were small and clinically insignificant changes in limbal and conjunctival hyperaemia but no significant changes in lipid layer thickness, Schirmer I and NIBUT in overall participants. The use of alginic acid in lens solutions did not affect these parameters compared to control lenses (p > 0.05). After seven days of wearing a modern daily disposable lens, there was no significant deterioration of tear function in a group of young contact lens wearers. In this short-term study, there was no evidence of significant benefit of lens solutions containing alginic acid used with HEMA lenses. © 2016 The Authors Clinical and

Coupling Osmolarity Dynamics within Human Tear Film on an Eye-Shaped Domain

NASA Astrophysics Data System (ADS)

Li, Longfei; Braun, R. J.; Driscoll, T. A.; Henshaw, W. D.; Banks, J. W.; King-Smith, P. E.

2013-11-01

The concentration of ions in the tear film (osmolarity) is a key variable in understanding dry eye symptoms and disease. We derived a mathematical model that couples osmolarity (treated as a single solute) and fluid dynamics within the tear film on a 2D eye-shaped domain. The model concerns the physical effects of evaporation, surface tension, viscosity, ocular surface wettability, osmolarity, osmosis and tear fluid supply and drainage. We solved the governing system of coupled nonlinear PDEs using the Overture computational framework developed at LLNL, together with a new hybrid time stepping scheme (using variable step BDF and RKC) that was added to the framework. Results of our numerical simulations show good agreement with existing 1D models (for both tear film and osmolarity dynamics) and provide new insight about the osmolarity distribution over the ocular surface during the interblink.

Corneal sensitivity, ocular surface health and tear film stability after punctal plug therapy of aqueous deficient dry eye

PubMed Central

Said, Azza Mohamed Ahmed; Farag, Mona Elsayed; Abdulla, Tarek Mohamed; Ziko, Othman Ali Othman; Osman, Wesam Mohamed

2016-01-01

AIM To evaluate the effect of punctal occlusion using thermosensitive (smart plug) versus silicone plug for management of aqueous deficient dry eye on corneal sensitivity, ocular surface health and tear film stability. METHODS A comparative prospective interventional case study included 45 patients with bilateral severe form of aqueous deficient dry eye. In each patient, the smart plug was inserted in the lower punctum of the right eye which was considered as study group 1 and silicone plug was inserted in the lower punctum of the left eye of the same patient which was considered as study group 2. All patients were subjected to careful history taking and questionnaire for subjective assessment of severity of symptoms. Corneal sensitivity, corneal fluorescein, rose bengal staining, Schirmer's I test, tear film break up time and conjunctival impression cytology were performed pre and 1, 3 and 6mo post plug insertion. RESULTS A statistically significant improvement in subjective and objective manifestations occurred following treatment with both types of plugs (P<0.01). The thermosensitive plug caused significant overall improvement, decrease in frequency of application of tear substitutes and improvement of conjunctival impression cytology parameters in the inserted side (P<0.01). Canaliculitis was reported in two eyes (4.4%) following punctal occlusion using thermosensitive plug (study group 1). Spontaneous plug loss occurred in 21 eyes (46.6%) in the silicone plug group (study group 2). CONCLUSION Improvement of subjective and objective manifestations of aqueous deficient dry eye occurs following punctal plug occlusion. Thermosensitive plug has good patient's compliance with fewer complications and lower rates of loss compared to the silicone plug. PMID:27990362

Dynamics of a pre-lens tear film after a blink: Model, evolution, and rupture

NASA Astrophysics Data System (ADS)

Usha, R.; Anjalaiah, Sanyasiraju, Y. V. S. S.

2013-11-01

A mathematical model is developed to investigate the dynamics and rupture of a pre-lens tear film on a contact lens. The contact lens is modeled as a saturated porous medium of constant, finite thickness and is described by the Darcy-Brinkman equations with stress-jump condition at the interface. The model incorporates the influence of capillarity, gravitational drainage, contact lens properties such as the permeability, the porosity, and the thickness of the contact lens on the evolution and rupture of a pre-lens tear film, when the eyelid has opened after a blink. Two models are derived for the evolution of a pre-lens tear film thickness using lubrication theory and are solved numerically; the first uses shear-free surface condition and the second, the tangentially immobile free surface condition. The results reveal that life span of a pre-lens tear film is longer on a thinner contact lens for all values of permeability and porosity parameter considered. An increase in permeability of contact lens, porosity or stress-jump parameter increases the rate of thinning of the film and advances the rupture time. The viscous-viscous interaction between the porous contact lens and the pre-lens tear film increases the resistance offered by the frictional forces to the rate of thinning of pre-lens tear film. This slows down the thinning process and hence delays the rupture of the film as compared to that predicted by the models of Nong and Anderson [SIAM. J. Appl. Math. 70, 2771-2795 (2010)] derived in the framework of Darcy model.

Dynamic changes in ocular Zernike aberrations and tear menisci measured with a wavefront sensor and an anterior segment OCT.

PubMed

Xu, Jingjing; Bao, Jinhua; Deng, Jun; Lu, Fan; He, Ji C

2011-07-29

To measure dynamic change characteristics of spatial and temporal variations in the post-blink tear film of normal eyes. A wavefront sensor was used to measure dynamic changes in wavefront aberrations, up to the seventh order, for 10 seconds in a group of 33 normal young adults. Tear menisci were imaged with an anterior segment optical coherence tomography (AS-OCT) system and tear film break-up times (TFBUTs) were determined. Systematic changes in main axis astigmatism (R(2) = 0.933, P < 0.0001), vertical coma (R(2) = 0.935, P < 0.0001) and spherical aberrations (R(2) = 0.879, P = 0.0002) occurred during the 10-second post-blink period. Both lower tear meniscus height and area increased by 10 seconds compared with the initial levels (P < 0.0001 for each). The change of vertical coma had significant correlation with the increase of lower tear meniscus areas during the 10-second post-blink period (R(2) = 0.181, P = 0.014). Subjects with TFBUTs < 15 seconds had significantly increased main axis astigmatism, vertical coma, and spherical aberrations by 10 seconds. Subjects with longer TFBUTs did not have any significant wavefront aberrations during that period. Systematic changes in some Zernike aberrations after blinking are associated with the changes in tear menisci and TFBUT. There was a substantial individual variation in dynamic changes of Zernike aberrations, suggesting the necessity to explore individual differences in tear quality and tear performance. Dynamic wavefront measurement combined with anterior segment optical coherence tomography could provide a useful tool to understand spatial and temporal processes of the tear film in clinical practice.

Advances in thickness measurements and dynamic visualization of the tear film using non-invasive optical approaches.

PubMed

Bai, Yuqiang; Nichols, Jason J

2017-05-01

The thickness of tear film has been investigated under both invasive and non-invasive methods. While invasive methods are largely historical, more recent noninvasive methods are generally based on optical approaches that provide accurate, precise, and rapid measures. Optical microscopy, interferometry, and optical coherence tomography (OCT) have been developed to characterize the thickness of tear film or certain aspects of the tear film (e.g., the lipid layer). This review provides an in-depth overview on contemporary optical techniques used in studying the tear film, including both advantages and limitations of these approaches. It is anticipated that further developments of high-resolution OCT and other interferometric methods will enable a more accurate and precise measurement of the thickness of the tear film and its related dynamic properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

The efficacy, sensitivity, and specificity of strip meniscometry in conjunction with tear function tests in the assessment of tear meniscus.

PubMed

Ibrahim, Osama M A; Dogru, Murat; Ward, Samantha K; Matsumoto, Yukihiro; Wakamatsu, Tais Hitomi; Ishida, Katsushi; Tsuyama, Atsushi; Kojima, Takashi; Shimazaki, Jun; Tsubota, Kazuo

2011-04-06

To evaluate the specificity and sensitivity of strip meniscometry (SM) testing in conjunction with tear function tests in the diagnosis of dry eye (DE) disease and to investigate the effect of SM on reflex tearing. One hundred seven left eyes of 107 patients with definite DE disease according to the Japanese DE diagnostic criteria and 68 left eyes of 68 age- and sex-matched control subjects were studied. Tear meniscus height (TMH) measurements, fluorescein tear film break-up time (FTBUT), fluorescein (F) and rose bengal (RB) staining, and Schirmer's test-1 (ST) were also performed. The assessment of reflex tearing before and after SM application was assessed with a graticule scale at the slit lamp and by optical coherence tomography. The sensitivity and specificity of SM alone and in combination with tear function tests were also sought. The SM scores, TMH measurements, FTBUTs, and STs were significantly lower in dry eye patients than in the controls (P < 0.001). The RB and F staining scores were significantly higher in the dry eye group than in the control group (P < 0.001). The meniscometry strips did not induce significant changes in relation to reflex tearing. SM had an acceptable sensitivity and specificity. SM is a swift, noninvasive, promising method of assessing tear meniscus volume. The combined SM and FTBUT examination appears to be a sensitive approach to the assessment of dry eye disease.

Punctal plugs versus artificial tears for treating dry eye: a comparative observation of their effects on contrast sensitivity.

PubMed

Qiu, Weiqiang; Liu, Ziyuan; Zhang, Zhihong; Ao, Mingxin; Li, Xuemin; Wang, Wei

2012-01-01

This study aimed to compare the effects of treatment with punctal plugs versus artificial tears on visual function and tear film stability for dry eye. A total of 56 consecutive eyes of 28 dry eye patients observed at our clinic from May to October in 2009 were divided into two groups. One group (32 eyes of 16 patients) was treated with artificial tears, and punctal plugs were used in the other group (24 eyes of 12 patients). A questionnaire was used in these patients before treatment and was repeated 2 weeks after treatment. Fluorescent staining for tear film break-up time (BUT), the Schirmer test I (STI), and contrast sensitivity was performed at the same time. The questionnaire indicated that all patients complained about the uncomfortable symptoms associated with dry eye. These symptoms were relieved after the application of artificial tears or punctal plugs, and there was no significant difference between these two groups. We found that the corneal fluorescent staining disappeared after treatment. The BUT was improved significantly after treatment in both groups, but the improvement was greater in patients who received punctal plugs than those that received artificial tears. There was no remarkable change in the STI in the artificial tears group, but a significant change was observed in the punctal plugs group. The contrast sensitivities were greatly improved in simulated daylight, night, and glare disability conditions after treatment with artificial tears and punctal plugs. However, the changes in contrast sensitivity did not significantly differ between groups. Both artificial tears and punctal plugs relieved dry eye symptoms, repaired corneal lesions, enhanced tear film stability, and improved contrast sensitivity. Punctal plugs could improve tear film stability and elongate the BUT better than artificial tears.

Determination of loss tangent of human tear film at 9.8 GHz

NASA Astrophysics Data System (ADS)

Bansal, Namita; Dhaliwal, A. S.; Mann, K. S.

2015-08-01

Basal (non-stimulated) tears that are produced by accessory lacrimal glands located in conjunctiva of human eye, form tear film which in turn keeps the eye moist and lubricate; nourishes the eye; protects the eye from dust, bacterial infection and shear forces generated during eye movements and blinking; and provides a refractive surface on the corneal epithelium. Film is known to contain water, mucin, lipids, lysozyme, glucose, urea, sodium etc. In present communication, loss tangent of human tear film has been determined at 9.8 GHz microwaves by employing cavity perturbation technique at a temperature of 37°C. The basal tears from a small population comprising six subjects were collected and average value of loss tangent is reported. Slater's technique was used to reduce the error caused in measuring the volume of sample. The determined values are useful to study the biological effects of microwaves on tear film as well as other parts of human eye such as eye lens and lens epithelial cells. To the best of author's knowledge, no such study is available in literature at any radio as well as microwave frequencies; therefore present determinations are first of its kind.

The effect of repeated lateral compression and expansions mimicking blinking on selected tear film polar lipid monofilms.

PubMed

Patterson, Matthew; Vogel, Hans J; Prenner, Elmar J

2017-03-01

The tear film lipid layer is formed on the anterior surface of the eye, functioning as a barrier to excess evaporation and foreign particles, while also providing stability to the tear film. The lipid layer is organized into a polar lipid layer consisting of phospholipids, ceramides, and free fatty acids that act as a surfactant to a non-polar multilayer of wax and cholesterol esters. Due to shear forces from eye movement and the compression and expansion of blinking, the tear lipids are under constant stress. However, tear film is able to resist immediate rupture and remains intact over multiple blinks. This work aimed to better understand the lateral organization of selected tear film polar lipids. The polar lipid biomimetic studied here consisted of dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylethanolamine (DPPE), palmitoyl glucosylceramide (PGC), and palmitoyl sphingomyelin (PSM). Surface pressure-area isocycles mimicked blinking and films were visualized by Brewster angle microscopy (BAM). All lipid systems formed relatively reversible films as indicated by limited hysteresis. However, pure DPPC and PSM films experienced greater changes in lipid packing upon compression and expansion compared to pure PGC and DPPE. This suggests that the driving force behind maintaining the lateral organization of the polar lipids from tear film may be the hydrogen bonding propensities of the head groups. Additionally, isocycles of films containing DPPC, DPPE, and PGC mixtures exhibited evidence for reversible multilayer formation or folding. This was supported by 3D analysis of structures that formed during compression but reintegrated back into the bulk lipid film during expansion near the in vitro tear film surface pressure of the open eye. Therefore, the polar lipids of tear film may be directly involved in preventing film rupture during a blink. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of the tear film instability in children with allergic diseases.

PubMed

Dogru, Mahmut; Gunay, Murat; Celik, Gokhan; Aktas, Alev

2016-03-01

The presence of dry eye syndrome (DES) in ocular allergic diseases was evaluated in several studies. Despite this, little exists about the tear film instability in atopic children including patients with allergic rhinitis (AR), allergic conjunctivitis (AC) and asthma. This is a study which presents intriguing findings regarding the relationship of tear film instability with clinical aspects in atopic children. To determine the tear film instability in children with AR, AC and asthma. One hundred and thirty-five consecutive children with AR, AC and asthma as study group and 45 children without any systemic and ocular abnormality as control group were included in the study. Skin prick tests, measurement of tear film breakup time (TFBUT), serum immunoglobulin E and eosinophil counts were performed in all patients. Also four subgroups of patients were designated as AR group (Group I), AC group (Group II), asthma group (Group III) and control group (Group IV). Socio-demographic characteristics were similar except for family atopy between the groups (p > 0.05). The mean TFBUT was significantly lower in the study group (15.5 ± 4.4 s) than the control group (18.4 ± 2.9 s; p = 0.000). Also, there was no significant differences in the percentage of the patients who has TFBUT<10 s (p = 0.066). In logistic regression analysis, atopy was found to be the determinant of lower TFBUT (OR = 16.33, 95%; CI = 1.17 to 228.05, p = 0.03). The presence of tear film instability was higher in children with AC, AR and asthma. This finding should be taken in consideration in atopic children.

Evidence for the major contribution of evaporation to tear film thinning between blinks.

PubMed

Kimball, Samuel H; King-Smith, P Ewen; Nichols, Jason J

2010-12-01

To determine the contribution of evaporation to the thinning of the precorneal tear film between blinks. The rate of tear film thinning after a blink was measured using spectral interferometry from the right eyes of 37 subjects. Data were obtained under two different conditions: free air and air-tight goggles. The mean (±SD) tear film thinning rates for subjects was 3.22 ± 4.27 μm/min in free air and -0.16 ± 1.78 μm/min (i.e., a slight but not significant thickening) for the same subjects wearing air-tight goggles; this reduction in thinning rates was significant (P < 0.0001). The large reduction in thinning rate caused by wearing goggles indicates that evaporation is the major cause of thinning between blinks. The mean thinning rate in free air is greater than reported evaporation rates; it is argued that the preocular chambers used in evaporimeters restrict movement of air over the tear film and reduce evaporation compared to our free air condition.

Effect of periocular humidity on the tear film lipid layer.

PubMed

Korb, D R; Greiner, J V; Glonek, T; Esbah, R; Finnemore, V M; Whalen, A C

1996-03-01

The purpose of this study was to determine the relationship between the tear film and humidity by examining whether alterations in periocular humidity influence the thickness of the tear film lipid layer. Thirteen dry eye subjects presenting with a baseline lipid layer thickness of < or = 60 nm were fitted with modified swim goggles in which the right eye (OD) was exposed to conditions of high humidity and the left eye (OS) remained exposed to ambient room conditions. The lipid layer was monitored over a 60-min time course with goggles on and for an additional 60 min following goggle removal. The OD lipid layer increased significantly in thickness within 5 min of exposure to conditions of high humidity (p < 0.0001), reaching a maximum increase of 66.4 nm after 15 min of goggle wear (p < 0.0001). This maximum increase to a lipid layer thickness of 120.5 nm was maintained at the 30- and 60-min goggle time points. No significant change was detected OS. Following goggle removal, OD values declined but remained significantly elevated over the OS lipid layer thickness throughout the 60-min postgoggle period. Moderate to total relief of dry eye symptoms was reported during goggle wear and generally persisted at a reduced level for 1-3 h following goggle removal. Increased periocular humidity results in an increase in tear film lipid layer thickness, possibly by providing an environment that is more conducive to the spreading of meibomian lipid and its incorporation into the tear film.

Tear Film Osmolarity in Subjects with Acute Allergic Rhinoconjunctivitis

PubMed Central

NITODA, EIRINI; LAVARIS, ANASTASIOS; LAIOS, KONSTANTINOS; ANDROUDI, SOPHIA; KALOGEROPOULOS, CHRIS D; TSATSOS, MICHAEL; DAMASKOS, CHRISTOS; GARMPIS, NIKOLAOS; MOSCHOS, MARILITA M

2018-01-01

Background/Aim: Acute allergic rhinoconjuctivitis is the most common form of ocular allergies. The pathogenetic mechanisms are based on an immunoglobulin E (IgE)-mediated hypersensitivity reaction. On the other hand, tear osmolarity has been suggested to be an index of ocular surface damage and inflammation. These data were the motive to investigate the levels of tear osmolarity in subjects with acute allergic rhinoconjuctivitis, before and after administration of artificial tears. Patients and Methods: Forty-five subjects with acute allergic rhinoconjuctivitis were randomly divided into three groups, based on the type of artificial tears that they received: Group A (Thera tears), Group B (Wet therapy) and Group C (Tears Naturale free). The eye drops were administered six times a day for 60 days and all subjects underwent grading of subjective symptoms and clinical examination at baseline and at the end of the treatment. Results: The diagnosis of severe eye disease, which was based on ocular surface disease index (OSDI; Allergan, Inc, Irvine, CA, USA) and tear osmolarity values, concerned all patients at baseline. Although the administration of artificial tears significantly ameliorated the symptoms and the ocular variables in all groups, the results were better in the first group. Tear osmolarity was strongly and negatively correlated with tear film breakup time (BUT) and Schirmer I test at 2 months. Contrariwise, symptoms were eliminated, when tear osmolarity was decreased. Conclusion: Acute allergic rhinoconjuctivitis is characterized by tear hyperosmolarity, which can be rehabilitated with the administration of hypotonic artificial tears. PMID:29475928

Tear Film Osmolarity in Subjects with Acute Allergic Rhinoconjunctivitis.

PubMed

Nitoda, Eirini; Lavaris, Anastasios; Laios, Konstantinos; Androudi, Sophia; Kalogeropoulos, Chris D; Tsatsos, Michael; Damaskos, Christos; Garmpis, Nikolaos; Moschos, Marilita M

2018-01-01

Acute allergic rhinoconjuctivitis is the most common form of ocular allergies. The pathogenetic mechanisms are based on an immunoglobulin E (IgE)-mediated hypersensitivity reaction. On the other hand, tear osmolarity has been suggested to be an index of ocular surface damage and inflammation. These data were the motive to investigate the levels of tear osmolarity in subjects with acute allergic rhinoconjuctivitis, before and after administration of artificial tears. Forty-five subjects with acute allergic rhinoconjuctivitis were randomly divided into three groups, based on the type of artificial tears that they received: Group A (Thera tears), Group B (Wet therapy) and Group C (Tears Naturale free). The eye drops were administered six times a day for 60 days and all subjects underwent grading of subjective symptoms and clinical examination at baseline and at the end of the treatment. The diagnosis of severe eye disease, which was based on ocular surface disease index (OSDI; Allergan, Inc, Irvine, CA, USA) and tear osmolarity values, concerned all patients at baseline. Although the administration of artificial tears significantly ameliorated the symptoms and the ocular variables in all groups, the results were better in the first group. Tear osmolarity was strongly and negatively correlated with tear film breakup time (BUT) and Schirmer I test at 2 months. Contrariwise, symptoms were eliminated, when tear osmolarity was decreased. Acute allergic rhinoconjuctivitis is characterized by tear hyperosmolarity, which can be rehabilitated with the administration of hypotonic artificial tears. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Surface Properties of Squalene/Meibum Films and NMR Confirmation of Squalene in Tears

PubMed Central

Ivanova, Slavyana; Tonchev, Vesselin; Yokoi, Norihiko; Yappert, Marta C.; Borchman, Douglas; Georgiev, Georgi As.

2015-01-01

Squalene (SQ) possesses a wide range of pharmacological activities (antioxidant, drug carrier, detoxifier, hydrating, emollient) that can be of benefit to the ocular surface. It can come in contact with human meibum (hMGS; the most abundant component of the tear film lipid layer) as an endogenous tear lipid or from exogenous sources as eyelid sebum or pharmaceuticals. The aims of this study were to determine (i) if SQ is in tear lipids and (ii) its influence on the surface properties of hMGS films. Heteronuclear single quantum correlation NMR confirmed 7 mol % SQ in Schirmer’s strips extracts. The properties of SQ/hMGS pseudo-binary films at the air/water interface were studied with Langmuir surface balance, stress-relaxation dilatational rheology and Brewster angle microscopy. SQ does not possess surfactant properties. When mixed with hMGS squalene (i) localized over the layers’ thinner regions and (ii) did not affect the film pressure at high compression. Therefore, tear SQ is unlikely to instigate dry eye, and SQ can be used as a safe and “inert” ingredient in formulations to protect against dry eye. The layering of SQ over the thinner film regions in addition to its pharmacological properties could contribute to the protection of the ocular surface. PMID:26370992

Phototoxic effects of an operating microscope on the ocular surface and tear film.

PubMed

Hwang, Hyung Bin; Kim, Hyun Seung

2014-01-01

We evaluated light exposure-induced dry eye syndrome by investigating the phototoxic effects of an operating microscope on the ocular surface and tear film in rabbits. Sixty eyes of 30 rabbits were divided into 3 groups based on the intensity of light exposure received from an operating microscope: Control group, no exposure to light; group A, 40,000-lx intensity for 30 minutes; and group B, 100,000-lx intensity for 30 minutes. To evaluate the potential damage to the ocular surface and tear film, Schirmer tests, rose bengal staining, and conjunctival impression cytology were performed before the light exposure and at 1, 3, and 5 days afterward. In addition, the expression of interleukin 1-beta was analyzed in tear samples. The expression of mucin 5AC was evaluated using immunofluorescence staining, and periodic acid-Schiff staining was conducted on conjunctival tissues. Corneal and conjunctival tissues were observed by means of electron microscopy. Potential damage to the ocular surface and tear film was found in the light-exposed groups as evidenced by decreased aqueous tear production, devitalized corneal and conjunctival epithelial cells, squamous metaplasia of conjunctival epithelial cells, decreased conjunctival goblet cell density, decreased expression of mucin 5AC, ultrastructural cellular damage to corneal and conjunctival tissues, and increased interleukin 1-beta expression in tears. This damage was more noticeable in group B than in group A (P < 0.05). Light exposure from an operating microscope had phototoxic effects on the ocular surface and tear film in this in vivo experiment. These changes seemed to intensify as the intensity of the light increased. Therefore, excessive light exposure during ophthalmic procedures could be a pathogenic factor in dry eye syndrome after a surgery is performed.

Dry eye symptoms align more closely to non-ocular conditions than to tear film parameters.

PubMed

Galor, Anat; Felix, Elizabeth R; Feuer, William; Shalabi, Nabeel; Martin, Eden R; Margolis, Todd P; Sarantopoulos, Constantine D; Levitt, Roy C

2015-08-01

To evaluate the relationship between dry eye symptoms, non-ocular conditions and tear film parameters. Cross-sectional study. The study population consisted of patients who were seen in the Miami Veterans Affairs eye clinic. Patients filled out standardised questionnaires assessing dry eye symptoms (dry eye questionnaire 5 (DEQ5) and ocular surface disease index (OSDI)), non-ocular pain, depression and post-traumatic stress disorder (PTSD), and also underwent measurement of tear film parameters. Correlations between dry eye symptoms and non-ocular conditions as compared with tear film parameters. 136 patients with a mean age of 65 (SD 11) years participated in the study. All correlations between the dry eye questionnaire scores (DEQ5 and OSDI) and (A) self-reported non-ocular pain measures (numerical rating scale and pain history), (B) depression and (C) PTSD were significant and moderate in strength (Pearson's coefficient 0.24 to 0.60, p<0.01 for all). All correlations between the dry eye questionnaires and tear film measures were weak (Pearson's coefficient -0.10 to 0.18) and most were not significant. Multivariable linear regression analyses revealed that PTSD and non-ocular pain more closely associated with dry eye symptoms than did tear film parameters. Specifically, non-ocular pain and PTSD accounted for approximately 36% of the variability in DEQ5 scores (R=0.60) and approximately 40% of variability in OSDI scores (R=0.64). Of note, none of the tear parameters remained significantly associated with dry eye symptoms in either model. Dry eye symptoms more closely align to non-ocular pain, depression and PTSD than to tear film parameters. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

The ocular surface and tear film and their dysfunction in dry eye disease.

PubMed

Rolando, M; Zierhut, M

2001-03-01

The ocular surface, tear film, lacrimal glands, and eyelids act as a functional unit to preserve the quality of the refractive surface of the eye and to resist injury and protect the eye against changing bodily and environmental conditions. Events that disturb the homeostasis of this functional unit can result in a vicious cycle of ocular surface disease. The tear film is the most dynamic structure of the functional unit, and its production and turnover is essential to maintaining the health of the ocular surface. Classically, the tear film is reported to be composed of three layers: the mucin, aqueous, and lipid layers. The boundaries and real thickness of such layers is still under discussion. A dysfunction of any of these layers can result in dry eye disease.

Tearing as a test for mechanical characterization of thin adhesive films

NASA Astrophysics Data System (ADS)

Hamm, Eugenio; Reis, Pedro; Leblanc, Michael; Roman, Benoit; Cerda, Enrique

2008-05-01

Thin adhesive films have become increasingly important in applications involving packaging, coating or for advertising. Once a film is adhered to a substrate, flaps can be detached by tearing and peeling, but they narrow and collapse in pointy shapes. Similar geometries are observed when peeling ultrathin films grown or deposited on a solid substrate, or skinning the natural protective cover of a ripe fruit. Here, we show that the detached flaps have perfect triangular shapes with a well-defined vertex angle; this is a signature of the conversion of bending energy into surface energy of fracture and adhesion. In particular, this triangular shape of the tear encodes the mechanical parameters related to these three forms of energy and could form the basis of a quantitative assay for the mechanical characterization of thin adhesive films, nanofilms deposited on substrates or fruit skin.

Tearing as a test for mechanical characterization of thin adhesive films.

PubMed

Hamm, Eugenio; Reis, Pedro; LeBlanc, Michael; Roman, Benoit; Cerda, Enrique

2008-05-01

Thin adhesive films have become increasingly important in applications involving packaging, coating or for advertising. Once a film is adhered to a substrate, flaps can be detached by tearing and peeling, but they narrow and collapse in pointy shapes. Similar geometries are observed when peeling ultrathin films grown or deposited on a solid substrate, or skinning the natural protective cover of a ripe fruit. Here, we show that the detached flaps have perfect triangular shapes with a well-defined vertex angle; this is a signature of the conversion of bending energy into surface energy of fracture and adhesion. In particular, this triangular shape of the tear encodes the mechanical parameters related to these three forms of energy and could form the basis of a quantitative assay for the mechanical characterization of thin adhesive films, nanofilms deposited on substrates or fruit skin.

In-vivo measurements of the tear film on a cornea and a contact lens by use of interferometry

NASA Astrophysics Data System (ADS)

Licznerski, Tomasz J.; Kasprzak, Henryk T.; Kowalik, Waldemar

1996-12-01

The tear film fulfills several important functions in the eye. Apart of its physiologic functions like maintaining a moist environment for the epithelial cells of the cornea and conjunctiva, bacterial properties, transporting metabolic products etc., this film causes that the corneal surface has the optical quality. This smooth surface allows to apply interferometry for measurements. The paper presents tear's layer distribution on the soft contact lens and the cornea in comparison. Tv frame speed registration in the Twyman- Green interferometer was used to observe an unstable biomedical objects like the eye. The proposed method has the advantage of being noncontact and applies the low energy laser beam in interferometric set-up. This provides non- invasive testing of human cornea in vivo and enables observation the kinetics of its tear layer deterioration. The evaluation of non-invasive tear breakup time is possible by use of proposed setup. Further analysis of recorded interferograms helps to examine the matter of the breakup process and can be used for detection of the 'dry eye' symptoms.

Computed tear film and osmolarity dynamics on an eye-shaped domain

PubMed Central

Li, Longfei; Braun, Richard J.; Driscoll, Tobin A.; Henshaw, William D.; Banks, Jeffrey W.; King-Smith, P. Ewen

2016-01-01

The concentration of ions, or osmolarity, in the tear film is a key variable in understanding dry eye symptoms and disease. In this manuscript, we derive a mathematical model that couples osmolarity (treated as a single solute) and fluid dynamics within the tear film on a 2D eye-shaped domain. The model includes the physical effects of evaporation, surface tension, viscosity, ocular surface wettability, osmolarity, osmosis and tear fluid supply and drainage. The governing system of coupled non-linear partial differential equations is solved using the Overture computational framework, together with a hybrid time-stepping scheme, using a variable step backward differentiation formula and a Runge–Kutta–Chebyshev method that were added to the framework. The results of our numerical simulations provide new insight into the osmolarity distribution over the ocular surface during the interblink. PMID:25883248

Comparative Analysis of Tear Film Levels of Inflammatory Mediators in Contact Lens Users.

PubMed

Yüksel Elgin, Cansu; İskeleli, Güzin; Talaz, Serap; Akyol, Sibel

2016-04-01

To compare tear films levels of various inflammatory cytokines in asymptomatic contact lens (CL) users. CL users of rigid gas-permeable CLs (RGPCL) (group 1) or silicone hydrogel CLs (SiHCL) (group 2) were compared with non-CL-using healthy subjects (group 3). Tear samples were collected from subjects in each group after ensuring that there were no complications secondary to CL wear in the CL-wearing participants. Tear-film levels of interleukins (ILs)-1β, -6, and -8; granulocyte-macrophage colony-stimulating factor (GM-CSF) (using the Luminex method); and leukotriene B4 (LTB4) (using the ELISA method) were determined. Cytokine levels were compared among the three groups using analysis-of-variance (ANOVA) and Kruskall-Wallis tests. There were significant differences in concentrations of IL-1β, GM-CSF and LTB4 among the three groups (p = 0.002, p = 0.021 and p = 0.009, respectively), as shown by the Kruskall-Wallis test comparing all three groups for the three cytokines. There were no significant differences for IL-6 and IL-8 (p = 0.079 and 0.094, respectively) when all three groups were compared. There were substantial statistically significant differences between RGPCL users, SiHCL users and control subjects in levels of tear film cytokines. Although CL users were asymptomatic, changes in tear-film levels of several important inflammatory mediators revealed that a chronic inflammatory process occurs during CL wear.

Ocular surface inflammation, and nerve growth factor level in tears in active thyroid-associated ophthalmopathy.

PubMed

Yoon, Jin Sook; Choi, Soo Hyun; Lee, Joon H; Lee, Sung Jun; Lee, Sang Yeul

2010-02-01

To measure tear nerve growth factor (NGF) concentrations in cases of active thyroid-associated ophthalmopathy (TAO) before and after glucocorticoid treatment, and to correlate NGF levels with disease inflammatory activity and thyroid autoantibody concentration. The study involved 20 patients with active TAO and 20 age- and gender-matched controls. Tear break-up time (BUT) was obtained, the Schirmer test was performed, and tear NGF/total protein ratio was measured in control subjects and patients with active TAO before, and 2 and 4 weeks after, steroid treatment. Tear BUT and Schirmer values significantly increased after 2 and 4 weeks of steroid treatment (p < 0.001 and p = 0.004 respectively). Baseline tear NGF/total protein ratio was higher in patients with active TAO than in control subjects, and the ratio significantly decreased after 2 and 4 weeks of steroid treatment (p < 0.001). Tear NGF/total protein ratio did not correlate with inflammatory activity score, exophthalmos value and thyroid binding inhibiting immunoglobulin (TBII) level (p > 0.05). Tear NGF may have a specific role in ocular surface inflammation, which protects against ocular surface damage in patients with active TAO. Anti-inflammatory treatment significantly reduced the level of NGF in tears, increased tear film stability and production, and decreased congestive symptoms.

[Clinical study of the effectiveness of a dexpanthenol containing artificial tears solution (Siccaprotect) in treatment of dry eyes].

PubMed

Göbbels, M; Gross, D

1996-01-01

In this controlled, randomized, double-masked study the effect of dexpanthenol-containing artificial tears (Siccaprotect) on patients with dry eyes was examined. 50 patients applied either dexpanthenol-containing artificial tears (Siccaprotect) or the identical, but free of dexpanthenol, eye drops five times daily into the conjunctival sac. No other ophthalmics were administered. The corneal epithelial permeability was measured by fluorophotometry and Schirmer-Test, Rose Bengal staining, tear film break-up time and the patients' subjective complaints were determined before and after 6 weeks of treatment. The dexpanthenol-containing artificial tears (Siccaprotect) improved disturbances of the corneal epithelial permeability significantly in comparison to the dexpanthenol-free eyes drops. The other parameters didn't show relevant differences. These data suggest that, in dry eyes, treatment with dexpanthenol-containing eye drops leads to a favorable and comparing with dexpanthenol-free eye drops superior improvement in disturbances of corneal epithelium permeability.

Tear film concentrations of doxycycline following oral administration in ophthalmologically normal dogs.

PubMed

Collins, Sean P; Labelle, Amber L; Dirikolu, Levent; Li, Zhong; Mitchell, Mark A; Hamor, Ralph E

2016-09-01

OBJECTIVE To determine tear film concentrations of doxycycline in ophthalmologically normal dogs following oral doxycycline administration. DESIGN Crossover study. ANIMALS 10 privately owned dolichocephalic or mesaticephalic dogs free of ophthalmic disease. PROCEDURES Dogs were randomly assigned to receive doxycycline hyclate first at 5 mg/kg (2.3 mg/lb) or 10 mg/kg (4.5 mg/lb), PO, every 12 hours for 5 days, beginning on day 1. Doxycycline was administered 1 hour prior to feeding. Tear samples were collected from days 1 through 10 approximately 3 hours after the morning dose was administered. Following a 3-week washout period, dogs received the alternative dose in the same conditions. Doxycycline concentration in tear samples from 1 eye (same eye used for both sessions) was measured via liquid chromatography-mass spectrometry and compared between the 2 doxycycline doses. RESULTS Doxycycline was detected in tear samples of all dogs from days 1 through 10 for both doxycycline doses. Median peak doxycycline concentrations for the 5 mg/kg and 10 mg/kg doses were 2.19 ng/mL on day 3 and 4.32 ng/mL on day 4, respectively. Concentrations differed significantly with time, but this difference was not influenced by dose, dose order, or eye. A significant positive correlation was identified between doxycycline concentration and body weight (r = 0.22). CONCLUSIONS AND CLINICAL RELEVANCE Detectable doxycycline concentrations were achieved in the tear film of ophthalmologically normal dogs following oral administration of doxycycline at 5 or 10 mg/kg, every 12 hours. Dose had no significant effect on tear film concentration of the drug.

Influence of interfacial rheology on stabilization of the tear film

NASA Astrophysics Data System (ADS)

Bhamla, M. Saad; Fuller, Gerald G.

2014-11-01

The tear film that protecting the ocular surface is a complex, thin film comprised of a collection of proteins and lipids that come together to provide a number of important functions. Of particular interest in this presentation is meibum, an insoluble layer that is spread from glands lining our eyelids. Past work has focussed on the role of this layer in reducing evaporation, although conflicting evidence on its ability to reduce evaporative loss has been published. We present here the beneficial effects that are derived through the interfacial viscoelasticity of the meibomian lipid film. This is a duplex film is comprised of a rich mixture of phospholipids, long chain fatty esters, and cholesterol esters. Using interfacial rheology measurements, meibum has been shown to be highly viscoelastic. By measuring the drainage and dewetting dynamics of thin aqueous films from hemispherical surfaces where those films are laden with insoluble layers of lipids at controlled surface pressure, we offer evidence that these layers strongly stabilize the films because of their ability to support surface shearing stresses. This alternative view of the role of meibum can help explain the origin of meibomian gland dysfunction, or dry eye disease, where improper compositions of this lipid mixture do not offer the proper mechanical resistance to breakage and dewetting of the tear film.

The effects of 2 week senofilcon-A silicone hydrogel contact lens daily wear on tear functions and ocular surface health status.

PubMed

Dogru, Murat; Ward, Samantha K; Wakamatsu, Tais; Ibrahim, Osama; Schnider, Cristina; Kojima, Takashi; Matsumoto, Yukihiro; Ogawa, Junko; Shimazaki, Jun; Tsubota, Kazuo

2011-04-01

To prospectively investigate the effects of 2 week senofilcon A contact lens (CL) daily wear on the functional visual acuity (VA), ocular surface and tear film. Seventeen right eyes of 17 senofilcon A CL wearers without any ocular or systemic diseases were examined before and 2 weeks after lens wear. Visual acuity measurements, tear evaporation rate, ELISA for tear cytokines, strip meniscometry, tear lipid layer interferometry, tear film break-up time (BUT), in vivo confocal microscopy, corneal sensitivity, ocular surface vital staining, Schirmer I test and brush cytology for MUC5AC mRNA expression were performed before and after CL wear. The best corrected Landolt VA, functional VA parameters, the mean lipid layer interferometry grades, tear evaporation rates, Schirmer test values, vital staining scores and in vivo confocal microscopy parameters did not show any significant differences after 2 weeks of CL wear. The tear film BUT showed a significant decrease together with a significant down regulation of MUC5 AC mRNA expression after CL wear. A statistically significant elevation in the mean tear interleukin (IL)-6 concentration was also observed after 2 weeks of CL wear. Two week senofilcon A daily CL wear seems to be associated with tear instability, a decrease in MUC5AC expression, and elevation of IL-6 in tears without significant alterations in epithelial damage scores or in the morphology or density of in vivo keratoconjunctival cells and nerves. Alterations associated with long term wear and patients with dry eye disease need to be studied in future trials. Copyright © 2010 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Assessment of tear osmolarity and other dry eye parameters in post-LASIK eyes.

PubMed

Hassan, Ziad; Szalai, Eszter; Berta, Andras; Modis, Laszlo; Nemeth, Gabor

2013-07-01

To assess the tear osmolarity using the TearLab device after laser in situ keratomileusis (LASIK) and to compare the values with those obtained by traditional tear film tests before and after the procedure. Thirty eyes of 15 refractive surgery candidates (5 men and 10 women of mean age: 30.55 ± 11.79 years) were examined. Using a special questionnaire (Ocular Surface Disease Index), subjective dry eye complaints were evaluated, and then, the tear osmolarity was measured with the TearLab system (TearLab Corporation) and conventional dry eye tests were carried out. Examinations were performed preoperatively and at 1, 30, and 60 days after the surgery. The mean value of tear osmolarity was 303.62 ± 12.29 mOsm/L before the surgery and 303.58 ± 20.14 mOsm/L at 60 days after the treatment (P = 0.69). Mean lid parallel conjunctival folds value was 0.68 ± 0.68 before the procedure and 0.58 ± 0.65 subsequent to surgery (P = 0.25). Meibomian gland dysfunction was not detected. No significant deviation was observed in the values of Schirmer test, corneal staining, tear break-up time, and lid parallel conjunctival folds when compared with postoperatively obtained values during the follow-up period (P > 0.05). During LASIK flap creation, intact corneal innervation is damaged, and the ocular surface lacrimal functional unit can be impaired. In our study, no abnormal dry eye test results were observed before or after the procedure. Based on our results, LASIK treatment is safe for dry eye involving the administration of adequate artificial tears for a minimum of 3 months.

Surface Chemistry Interactions of Cationorm with Films by Human Meibum and Tear Film Compounds

PubMed Central

Georgiev, Georgi As.; Yokoi, Norihiko; Nencheva, Yana; Peev, Nikola; Daull, Philippe

2017-01-01

Cationorm® (CN) cationic nanoemulsion was demonstrated to enhance tear film (TF) stability in vivo possibly via effects on tear film lipid layer (TFLL). Therefore the interactions of CN with human meibum (MGS) and TFLL in vitro and in vivo deserve special study. MGS and CN were spread at the air/water interface of a Langmuir surface balance to ensure a range of MGS/CN oil phase ratios: 20/1, 10/1, 5/1, 3/1, 2/1 and 1/1. The films capability to reorganize during dynamic area changes was evaluated via the surface pressure-area compression isotherms and step/relaxation dilatational rheology studies. Films structure was monitored with Brewster angle microscopy. CN/TFLL interactions at the ocular surface were monitored with non-contact specular microscopy. The in vitro studies of MGS/CN layers showed that (i) CN inclusion (at fixed MGS content) increased film elasticity and thickness and that (ii) CN can compensate for moderate meibum deficiency in MGS/CN films. In vivo CN mixed with TFLL in a manner similar to CN/MGS interactions in vitro, and resulted in enhanced thickness of TFLL. In vitro and in vivo data complement each other and facilitated the study of the composition-structure-function relationship that determines the impact of cationic nanoemulsions on TF. PMID:28718823

Tear film and ocular surface assessment in psoriasis.

PubMed

Aragona, Emanuela; Rania, Laura; Postorino, Elisa Imelde; Interdonato, Alberto; Giuffrida, Roberta; Cannavò, Serafinella Patrizia; Puzzolo, Domenico; Aragona, Pasquale

2018-03-01

Psoriasis is a skin disease with also systemic involvement: its impact on the eye is not well established and often clinically underestimated. Aim of this study was to investigate the presence of ocular discomfort symptoms and of ocular surface changes in a population of patients with psoriasis. For this cross-sectional, comparative study, 66 patients with psoriasis were subdivided according to the presence of arthritis and to the use of biological therapy. All patients underwent clinical evaluation with the following tests: Ocular Surface Disease Index Questionnaire, Tearscope examination, meibometry, tear film breakup time, corneal and conjunctival fluorescein staining, Schirmer I test, corneal aesthesiometry, meibomian gland dysfunction (MGD) assessment and conjunctival impression cytology. 28 healthy subjects were also enrolled and treated with the same clinical tests. A statistical analysis of the results was performed. Patients with psoriasis showed a significant deterioration of the ocular surface tests, if compared with healthy subjects, demonstrated by tear film lipid layer alteration, tear film instability, corneal and conjunctival epithelial suffering and mild squamous metaplasia at impression cytology. No differences were found in ocular surface test results of the psoriatic group when patients were divided according to the presence of arthritis, whereas the anti-inflammatory treatment with biological drugs demonstrated a significant improvement of corneal stain and MGD. Our findings suggest that the ocular surface involvement in patients with psoriasis indicates the need of periodic ophthalmological examinations to diagnose the condition and allow a proper treatment, so contributing to the amelioration of patients' quality of life. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Analysis of Th17-associated cytokines in tears of patients with dry eye syndrome.

PubMed

Tan, X; Sun, S; Liu, Y; Zhu, T; Wang, K; Ren, T; Wu, Z; Xu, H; Zhu, L

2014-05-01

To determine the levels of Th17-associated cytokines, particularly interleukin (IL)-17 and IL-22 in tears of patients with dry eye syndrome. Tear samples were collected from 20 healthy volunteers, 20 dry eye (DE) patients with non-Sjögren's syndrome (NSSDE) and 20 DE patients with Sjögren's syndrome (SSDE). Symptom questionnaire was self-administered and multiple dry eye disease (DED)-related clinical tests were performed. The levels of IL-17 and IL-22 in tears were measured by enzyme-linked immunosorbent assay. The levels of IL-17 and IL-22 were significantly increased in tears of DE patients compared with those of controls and also higher in SSDE patients compared with those of NSSDE patients (P<0.05). Moreover, the levels of IL-17 and IL-22 were positively correlated with questionnaire score and keratopathy score but negatively correlated with tear film break-up time and Schirmer I test in both NSSDE and SSDE patients (P<0.05). The levels of IL-17 and IL-22 in tears were significantly increased in DE patients, which were associated with the disease severity. Therefore, Th17 cell-associated cytokines, particularly IL-17 and IL-22, may have important roles in the immunopathogenesis of the DED.

Parallel definition of tear film maps on distributed-memory clusters for the support of dry eye diagnosis.

PubMed

González-Domínguez, Jorge; Remeseiro, Beatriz; Martín, María J

2017-02-01

The analysis of the interference patterns on the tear film lipid layer is a useful clinical test to diagnose dry eye syndrome. This task can be automated with a high degree of accuracy by means of the use of tear film maps. However, the time required by the existing applications to generate them prevents a wider acceptance of this method by medical experts. Multithreading has been previously successfully employed by the authors to accelerate the tear film map definition on multicore single-node machines. In this work, we propose a hybrid message-passing and multithreading parallel approach that further accelerates the generation of tear film maps by exploiting the computational capabilities of distributed-memory systems such as multicore clusters and supercomputers. The algorithm for drawing tear film maps is parallelized using Message Passing Interface (MPI) for inter-node communications and the multithreading support available in the C++11 standard for intra-node parallelization. The original algorithm is modified to reduce the communications and increase the scalability. The hybrid method has been tested on 32 nodes of an Intel cluster (with two 12-core Haswell 2680v3 processors per node) using 50 representative images. Results show that maximum runtime is reduced from almost two minutes using the previous only-multithreaded approach to less than ten seconds using the hybrid method. The hybrid MPI/multithreaded implementation can be used by medical experts to obtain tear film maps in only a few seconds, which will significantly accelerate and facilitate the diagnosis of the dry eye syndrome. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The Changes of Tear Status after Conventional and Wavefront-Guided IntraLASIK

PubMed Central

Foo, Say Kiang; Kaur, Sharanjeet; Abd Manan, Faudziah; Low, Aloysius Joseph

2011-01-01

Background: IntraLASIK is a LASIK surgery that involved IntraLase femtosecond laser for the corneal flap creating. The objective of this research was to investigate and compare the changes in tear status at 1 and 3 months after undergoing conventional IntraLASIK with Bausch & Lomb PlanoScan (PS) algorithm, Bausch & Lomb Zyoptix Tissue Saving (ZTS) algorithm, and wavefront-guided (WG) IntraLASIK with VISX CustomVue. Methods: Tear status of 36 patients who were divided into 3 groups depending on the type of IntraLASIK they underwent (PS, n = 13; ZTS, n = 9; WG, n = 14) was evaluated. Tear status was determined by classifying the category of the thickness of pre-corneal tear lipid layer, non-invasive tear break-up time, and tear meniscus height. Repeated measures analysis of variance (ANOVA) and one way ANOVA were used for the statistical analyses. Results: The category of the thickness of tear lipid layer, non-invasive tear break up time and tear meniscus height were neither significantly changed after IntraLASIK for all groups nor showed significant difference among groups at 1 and 3 months post-IntraLASIK (P > 0.05). Blinking rate and palpebral aperture also had no significant changed after IntraLASIK. Conclusion: Both conventional (PS and ZTS) and WG IntraLASIK did not affect tear status up to 3 months post-IntraLASIK. WG IntraLASIK did not show superiority in preserving tear status 1 and 3 months post-surgery compared with conventional IntraLASIK. PMID:22135584

Crystalline desiccation patterns and film break up from evaporating drops on hydrophobic oxide surfaces

NASA Astrophysics Data System (ADS)

McBride, Samantha; Dash, Susmita; Khan, Sami; Varanasi, Kripa

2017-11-01

Solute-laden sessile drops evaporating on a substrate will often force crystallization of the solute at the triple phase contact line between the drop, substrate, and air in an effect similar to the ``coffee-ring'' deposition of particles from a particle-laden drop. We report new observations of ring-shaped desiccation patterns of gypsum crystals on hydrophobic oxide substrates; ceria, erbia, and silica. These surfaces have similar contact angles ( 105 degrees), and evaporation of sessile drops proceeds at the same rate and without contact angle hysteresis on all three substrates. However, despite the apparent similarity, the patterns of crystal deposits exhibit large differences across the substrates. The supersaturation and elapsed time at the onset of crystallization also varied across substrates, despite overall evaporation rates being identical. The differences in patterns can be explained in light of the position and morphology of the crystals just prior to completion of evaporation when the sessile drop has transitioned to a thin film spread over the deposit area. Break-up of this film occurs very differently on the different surfaces, and is simultaneously influenced by existing crystals while also influencing final crystalline patterns. This work was supported by the NSF GRFP.

Effects of oral sea buckthorn oil on tear film Fatty acids in individuals with dry eye.

PubMed

Järvinen, Riikka L; Larmo, Petra S; Setälä, Niko L; Yang, Baoru; Engblom, Janne Rk; Viitanen, Matti H; Kallio, Heikki P

2011-09-01

Evaporative dry eye is associated with meibomian gland dysfunction and abnormalities of the tear film lipids. Dry eye is known to be affected positively by intake of linoleic and γ-linolenic acids and n-3 fatty acids. Oral sea buckthorn (Hippophaë rhamnoides) (SB) oil, which contains linoleic and α-linolenic acids and antioxidants, has shown beneficial effects on dry eye. The objective was to investigate whether supplementation with SB oil affects the composition of the tear film fatty acids in individuals reporting dry eye. One hundred participants were randomized to this parallel, double-blind, placebo-controlled study, which 86 of them completed. The participants daily consumed 2 g of SB or placebo oil for 3 months. Tear film samples were collected at the beginning, during, and at the end of the intervention and 1 to 2 months later. Tear film fatty acids were analyzed as methyl esters by gas chromatography. There were no group differences in the changes in fatty acid proportions during the intervention (branched-chain fatty acids: P = 0.49, saturated fatty acids: P = 0.59, monounsaturated fatty acids: P = 0.53, and polyunsaturated fatty acids: P = 0.16). The results indicate that the positive effects of SB oil on dry eye are not mediated through direct effects on the tear film fatty acids. Carotenoids and tocopherols in the oil or eicosanoids produced from the fatty acids of the oil may have a positive effect on inflammation and differentiation of the meibomian gland cells.

Effects of a warm compress containing menthol on the tear film in healthy subjects and dry eye patients

NASA Astrophysics Data System (ADS)

Arita, Reiko; Morishige, Naoyuki; Sakamoto, Ichiro; Imai, Natsuko; Shimada, Yuko; Igaki, Michihito; Suzuki, Atsushi; Itoh, Kouzo; Tsubota, Kazuo

2017-04-01

Menthol is thought to stimulate lacrimation via activation of cold-sensitive primary afferent neurons in the cornea. We evaluated a warm compress containing menthol as a potential treatment for dry eye by examining its effects on the tear film in healthy subjects (n = 20) and dry eye patients (n = 35). Disposable eyelid-warming steamers that either did (MH) or did not (HO) contain menthol were applied to one eye of each subject either once only for 10 min or repeatedly over 2 weeks. Single application of MH significantly increased tear meniscus volume (P = 8.6 × 10-5, P = 1.3 × 10-5) and tear film breakup time (P = 0.006, P = 0.002) as well as improved meibum condition in healthy subjects and dry eye patients, respectively. Repeated application of MH significantly increased tear meniscus volume (P = 0.004, P = 1.7 × 10-4) and tear film breakup time (P = 0.037, P = 0.010) in healthy subjects and dry eye patients, respectively. Repeated application of MH thus induced persistent increases in tear fluid volume and tear film stability in dry eye patients, suggesting that repeated use of a warm compress containing menthol is a potential novel treatment for dry eye disease.

A MODEL FOR THE TEAR FILM AND OCULAR SURFACE TEMPERATURE FOR PARTIAL BLINKS

PubMed Central

Deng, Quan; Braun, R. J.; Driscoll, T. A.; King-Smith, P. E.

2015-01-01

In this paper, we investigate the dynamics of tear film and the associated temperature variation for partial blinks. We investigate the mechanism of fluid supply during partial blink cycles, and compare the film thickness with observation in vivo. We find that varying the thickness of the fluid layer beneath the moving upper lid improves the agreement for the in vivo measurement of tear film thickness after a half blink. By examining the flux of the fluid, we provide an explanation of this assumption. We also investigate the temperature dynamics both at the ocular surface and inside the simulated anterior chamber. Our simulation results suggest that the ocular surface temperature readjusts rapidly to normal temperature distribution after partial blinks. PMID:25635242

Solute Dynamics and Imaging in the Tear Film on an Eye-shaped Domain

NASA Astrophysics Data System (ADS)

Braun, R. J.; Li, Longfei; Henshaw, William; Driscoll, Tobin; King-Smith, P. E.

2015-11-01

The concentration of ions in the tear film (osmolarity) is a key variable in understanding dry eye symptoms and disease, yet its global distribution is not available; direct measurements are restricted to a region near the temporal canthus. It has been suggested that imaging methods that use solutes such as fluorescein can be used as a proxy for estimating the osmolarity. The concentration of fluorescein is not measured directly either but the intensity as a function of concentration and thickness of the film is well established. We derived a mathematical model that couples multiple solutes and fluid dynamics within the tear film on a 2D eye-shaped domain. The model includes the physical effects of evaporation, surface tension, viscosity, ocular surface wettability, osmolarity, osmosis, fluorescence and tear fluid supply and drainage. We solved the governing system of coupled nonlinear PDEs using the Overture computational framework developed at LLNL, together with a hybrid time stepping scheme (using variable step BDF and RKC). Results of our numerical simulations provide new insight about the osmolarity distribution and its connection with images obtained in vivo over the whole ocular surface and in local regions of tear thinning due to evaporation and other effects. This work was supported in part by NSF grants 1022706 and 1412085, and NIH grant 1R01EY021794.

Efficacy of 3 different artificial tears for the treatment of dry eye in frequent computer users and/or contact lens users.

PubMed

Calvão-Santos, Gil; Borges, Cristina; Nunes, Sandrina; Salgado-Borges, José; Duarte, Lilianne

2011-01-01

To compare the efficacy of 3 different artificial tears (AT) acting primarily in one of the 3 tear film layers (Tears Again®, lipidic; Opticol®, aqueous; Optive®, mucin) in recovering the tear film changes in patients with dry eye symptoms due to external causes. A total of 27 patients, with dry eye symptoms associated with extra hours of computer or contact lenses use, were randomized to 4 treatment groups: A received Tears Again®; B received Optive®; C received Opticol®; D received no treatment (control). Patients were observed in 3 visits: day 0, day 7, and day 30. Tear break-up time (TBUT) and Schirmer tests and the Ocular Surface Disease Index were performed. Data analysis was performed. There were no significant differences between the groups. From day 0 to day 30, there was a decrease in the number of eyes with abnormal TBUT (not significant) and Schirmer (significant in A, B, D; p<0.031). There was an increase in the average TBUT for all groups (significant in A, C; p<0.001) and a decrease in the average Schirmer value in groups B, C, and D (not significant) and an increase in group A (p = 0.002). There was a decrease in the average Ocular Surface Disease Index value in all groups (p<0.045). All AT were efficient at recovering the tear film, but those acting primarily on the internal and intermediate layer led to a mild decline on lachrymal production. An association of different kinds of AT acting on each layer can be the best treatment for corneal surface diseases affecting eye lubrication.

Iris colour and the influence of local anaesthetics on pre-corneal tear film stability.

PubMed

Patel, S; Laidlaw, S; Mathewson, L; McCallum, L; Nicholson, C

1991-06-01

Using non-invasive methods we report here that the stability of the pre-corneal tear film is lower in the brown eye than in the blue eye. The average stability in the blue eye is 15.8 sec (SD +/- 5.8) and in the brown eye it is 12.3 sec (SD +/- 2.9). On average, instillation of topical anaesthetics, benoxinate hydrochloride (0.4%) or amethacaine hydrochloride (0.5%), depress the stability of the pre-corneal tear film in blue eyes but not in brown eyes.

Tear film dynamics with evaporation, wetting, and time-dependent flux boundary condition on an eye-shaped domain

PubMed Central

Li, Longfei; Braun, R. J.; Maki, K. L.; Henshaw, W. D.; King-Smith, P. E.

2014-01-01

We study tear film dynamics with evaporation on a wettable eye-shaped ocular surface using a lubrication model. The mathematical model has a time-dependent flux boundary condition that models the cycles of tear fluid supply and drainage; it mimics blinks on a stationary eye-shaped domain. We generate computational grids and solve the nonlinear governing equations using the OVERTURE computational framework. In vivo experimental results using fluorescent imaging are used to visualize the influx and redistribution of tears for an open eye. Results from the numerical simulations are compared with the experiment. The model captures the flow around the meniscus and other dynamic features of human tear film observed in vivo. PMID:24926191

Modelling the evaporation of a tear film over a contact lens.

PubMed

Talbott, Kevin; Xu, Amber; Anderson, Daniel M; Seshaiyer, Padmanabhan

2015-06-01

A contact lens (CL) separates the tear film into a pre-lens tear film (PrLTF), the fluid layer between the CL and the outside environment, and a post-lens tear film (PoLTF), the fluid layer between the CL and the cornea. We examine a model for evaporation of a PrLTF on a modern permeable CL allowing fluid transfer between the PrLTF and the PoLTF. Evaporation depletes the PrLTF, and continued evaporation causes depletion of the PoLTF via fluid loss through the CL. Governing equations include Navier-Stokes, heat and Darcy's equations for the fluid flow and heat transfer in the PrLTF and porous layer. The PoLTF is modelled by a fixed pressure condition on the posterior surface of the CL. The original model is simplified using lubrication theory for the PrLTF and CL applied to a sagittal plane through the eye. We obtain a partial differential equation (PDE) for the PrLTF thickness that is first-order in time and fourth-order in space. This model incorporates evaporation, conjoining pressure effects in the PrLTF, capillarity and heat transfer. For a planar film, we find that this PDE can be reduced to an ordinary differential equation (ODE) that can be solved analytically or numerically. This reduced model allows for interpretation of the various system parameters and captures most of the basic physics contained in the model. Comparisons of ODE and PDE models, including estimates for the loss of fluid through the lens due to evaporation, are given. © The Authors 2014. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

Antibody Protein Array Analysis of the Tear Film Cytokines

PubMed Central

Li, Shimin; Sack, Robert; Vijmasi, Trinka; Sathe, Sonal; Beaton, Ann; Quigley, David; Gallup, Marianne; McNamara, Nancy A.

2013-01-01

Purpose Many bioactive proteins including cytokines are reported to increase in dry eye disease although the specific profile and concentration of inflammatory mediators varies considerably from study to study. In part this variability results from inherent difficulties in quantifying low abundance proteins in a limited sample volume using relatively low sensitivity dot ELISA methods. Additional complexity comes with the use of pooled samples collected using a variety of techniques and intrinsic variation in the diurnal pattern of individual tear proteins. The current study describes a recent advance in the area of proteomics that has allowed the identification of dozens of low abundance proteins in human tear samples. Methods Commercially available stationary phase antibody protein arrays were adapted to improve suitability for use in small volume biological fluid analysis with particular emphasis on tear film proteomics. Arrays were adapted to allow simultaneous screening for a panel of inflammatory cytokines in low volume tear samples collected from individual eyes. Results A preliminary study comparing tear array results in a small population of Sjögren’s syndrome patients was conducted. The multiplex microplate array assays of cytokines in tear fluid present an unanticipated challenge due to the unique nature of tear fluid. The presence of factors that exhibit an affinity for plastic, capture antibodies and IgG and create a complex series of matrix effects profoundly impacting the reliability of dot ELISA, including with elevated levels of background reactivity and reduction in capacity to bind targeted protein. Conclusions Preliminary results using tears collected from patients with Sjögren’s syndrome reveal methodological advantages of protein array technology and support the concept that autoimmune-mediated dry eye disease has an inflammatory component. They also emphasize the inherent difficulties one can face when interpreting the results of micro

The tear film and ocular mucins.

PubMed

Davidson, Harriet J; Kuonen, Vanessa J

2004-01-01

Abstract The trilaminar tear film, composed of the lipid, aqueous and mucin layers, has many functions including defending the ocular surface. The aqueous layer has several soluble antimicrobial factors that protect the ocular surface. Ocular mucins have recently been studied with regard to their role in the defense of the eye as well as in dry eye syndromes. To date, 15 mucin genes have been identified, and six of these mucin genes are localized to or secreted by ocular glands or epithelia. Understanding the production, secretion and function of ocular mucins will aid in the treatment of dry eye syndromes and ocular surface microbial infections.

Management of the ocular surface and tear film before, during, and after laser in situ keratomileusis.

PubMed

Albietz, Julie M; Lenton, Lee M

2004-01-01

To identify evidence-based, best practice strategies for managing the ocular surface and tear film before, during, and after laser in situ keratomileusis (LASIK). After a comprehensive review of relevant published literature, evidence-based recommendations for best practice management strategies are presented. Symptoms of ocular irritation and signs of dysfunction of the integrated lacrimal gland/ocular surface functional gland unit are common before and after LASIK. The status of the ocular surface and tear film before LASIK can impact surgical outcomes in terms of potential complications during and after surgery, refractive outcome, optical quality, patient satisfaction, and the severity and duration of dry eye after LASIK. Before LASIK, the health of the ocular surface should be optimized and patients selected appropriately. Dry eye before surgery and female gender are risk factors for developing chronic dry eye after LASIK. Management of the ocular surface during LASIK can minimize ocular surface damage and the risk of adverse outcomes. Long-term management of the tear film and ocular surface after LASIK can reduce the severity and duration of dry eye symptoms and signs. Strategies to manage the integrated ocular surface/lacrimal gland functional unit before, during, and after LASIK can optimize outcomes. As problems with the ocular surface and tear film are relatively common, attention should focus on the use and improvement of evidence-based management strategies.

Objective categorization of interferential tear film lipid layer pattern: validation of the technique

NASA Astrophysics Data System (ADS)

García-Resúa, C.; Giráldez, M. J.; Barreira, N.; Penedo, M. G.; Yebra-Pimentel, E.

2011-05-01

Purpose: The lipid layer of the tear film limits evaporation during the inter-blink interval and also affects tear stability. This study was designed to validate a new software application designed to characterize the tear film lipid layer through texture and colour pattern recognition. Methods: Using the Tearscope-plus (slit lamp magnification 200X), the lipid layer was examined in 105 healthy young adults and interference photographs acquired with a Topcon DV-3 digital camera. The photographs were classified by the new software and by 2 further observers (observer 1 and observer 2) with experience in examining the eye surface. Results: Strong correlation was detected between the categories determined by the new application, observer 1 and observer 2 (Cramer's V, from 0.81 to 0.87, p<0.001). Best agreement (96.2%) was noted between the new method and observers 1 and 2 for recognizing meshwork patterns, whereas observers 1 and 2 showed greatest correspondence when classifying colour fringe patterns. Conclusions: The new application can objectively categorize LLPs using the Tearscope-plus.

Comparative study on fractal analysis of interferometry images with application to tear film surface quality assessment.

PubMed

Szyperski, Piotr D

2018-06-01

The purpose of this research was to evaluate the applicability of the fractal dimension (FD) estimators to assess lateral shearing interferometric (LSI) measurements of tear film surface quality. Retrospective recordings of tear film measured with LSI were used: 69 from healthy subjects and 41 from patients diagnosed with dry eye syndrome. Five surface quality descriptors were considered, four based on FD and a previously reported descriptor operating in a spatial frequency domain (M 2 ), presenting temporal kinetics of post-blink tear film. A set of 12 regression parameters has been extracted and analyzed for classification purposes. The classifiers are assessed in terms of receiver operating characteristics and areas under their curves (AUC). Also, the computational loads are estimated. The maximum AUC of 82.4% was achieved for M 2 , closely followed by the binary box-counting (BBC) FD estimator with AUC=78.6%. For all descriptors, statistically significant differences between the subject groups were found (p<0.05). The BBC FD estimator was characterized with the highest empirical computational efficiency that was about 30% faster than that of M 2 , while that based on the differential box-counting exhibited the lowest efficiency (4.5 times slower than the best one). Concluding, FD estimators can be utilized for quantitative assessment of tear film kinetics. They provide a viable alternative to previously used spectral counter parameters, and at the same time allow higher computational efficiency.

Super-resolved thickness maps of thin film phantoms and in vivo visualization of tear film lipid layer using OCT

PubMed Central

dos Santos, Valentin Aranha; Schmetterer, Leopold; Triggs, Graham J.; Leitgeb, Rainer A.; Gröschl, Martin; Messner, Alina; Schmidl, Doreen; Garhofer, Gerhard; Aschinger, Gerold; Werkmeister, René M.

2016-01-01

In optical coherence tomography (OCT), the axial resolution is directly linked to the coherence length of the employed light source. It is currently unclear if OCT allows measuring thicknesses below its axial resolution value. To investigate spectral-domain OCT imaging in the super-resolution regime, we derived a signal model and compared it with the experiment. Several island thin film samples of known refractive indices and thicknesses in the range 46 – 163 nm were fabricated and imaged. Reference thickness measurements were performed using a commercial atomic force microscope. In vivo measurements of the tear film were performed in 4 healthy subjects. Our results show that quantitative super-resolved thickness measurement can be performed using OCT. In addition, we report repeatable tear film lipid layer visualization. Our results provide a novel interpretation of the OCT axial resolution limit and open a perspective to deeper extraction of the information hidden in the coherence volume. PMID:27446696

Dataset of tear film cytokine levels in dry eye disease (DED) patients with and without HIV infection.

PubMed

Balne, Praveen Kumar; Agrawal, Rupesh; Au, Veonice Bijin; Lee, Bernett; Loo, Eileen; Tong, Louis; Ghosh, Arkasubhra; Teoh, Stephen C; Connolly, John; Tan, Petrina

2017-02-01

The tear film cytokine profiling data in this article was obtained from a prospective case-control study with a sample size of 34 dry eye disease (DED) patients with HIV infection and 32 DED patients without HIV infection, see "A distinct cytokines profile in tear film of dry eye disease (DED) patients with HIV infection" (R. Agrawal, P.K. Balne, A. Veerappan, V.B. Au, B. Lee, E. Loo, A. Ghosh, L. Tong, S.C. Teoh, J. Connolly, P. Tan, 2016) [1]. Tear samples were collected from all the subjects using Schirmer׳s strips and cytokine profiling was done using the Luminex bead based multiplex assay with a panel of 41 analytes. The cytokine level differences in each group of subjects were analyzed using logistic regression models.

Diagnosis of dry eye disease and emerging technologies

PubMed Central

Zeev, Maya Salomon-Ben; Miller, Darby Douglas; Latkany, Robert

2014-01-01

Dry eye is one of the most commonly encountered problems in ophthalmology. Signs can include punctate epithelial erosions, hyperemia, low tear lakes, rapid tear break-up time, and meibomian gland disease. Current methods of diagnosis include a slit-lamp examination with and without different stains, including fluorescein, rose bengal, and lissamine green. Other methods are the Schirmer test, tear function index, tear break-up time, and functional visual acuity. Emerging technologies include meniscometry, optical coherence tomography, tear film stability analysis, interferometry, tear osmolarity, the tear film normalization test, ocular surface thermography, and tear biomarkers. Patient-specific considerations involve relevant history of autoimmune disease, refractive surgery or use of oral medications, and allergies or rosacea. Other patient considerations include clinical examination for lid margin disease and presence of lagophthalmos or blink abnormalities. Given a complex presentation and a variety of signs and symptoms, it would be beneficial if there was an inexpensive, readily available, and reproducible diagnostic test for dry eye. PMID:24672224

Analysis of Factors Associated With the Tear Film Lipid Layer Thickness in Normal Eyes and Patients With Dry Eye Syndrome.

PubMed

Jung, Ji Won; Park, Si Yoon; Kim, Jin Sun; Kim, Eung Kweon; Seo, Kyoung Yul; Kim, Tae-Im

2016-08-01

To determine the effects of clinical variables, including age, sex, history of refractive or cataract surgery, contact lens use, and ocular surface and meibomian gland parameters on the lipid layer thickness (LLT) in normal subjects and patients with dry eye syndrome (DES). A total of 64 normal subjects and 326 patients with DES were enrolled, and they underwent measurements of LLT with a LipiView interferometer and tear meniscus height using optical coherence tomography, tear film break-up time (TBUT) determination, ocular surface staining, Schirmer's test, examination of the lid margins and meibomian glands, and assessment using the Ocular Surface Disease Index (OSDI). In normal subjects, the median (range) LLT was 67 (33-100) nm, and age was the only factor that was significantly associated with LLT (β = 0.678, P = 0.028). In patients with DES, the median (range) LLT was 84 (20-100) nm, and 79.0% of the participants fulfilled the diagnostic criteria for meibomian gland dysfunction (MGD). In a multivariate analysis, increased age and female sex were significantly related to increased LLT (β = 0.282, P = 0.005 and β = 11.493, P < 0.001), and hypersecretory MGD and lid margin inflammation were independently associated with increased LLT (β = 11.299, P = 0.001 and β = 12.747, P = 0.001). Lipid layer thickness measurements using a new interferometer are significantly affected by demographic factors such as age, sex, ocular surgical history, and MGD type. Therefore, all of these factors must be considered in the diagnosis of ocular surface diseases.

Effects of punctal occlusion on global tear proteins in patients with dry eye.

PubMed

Tong, Louis; Zhou, Lei; Beuerman, Roger; Simonyi, Susan; Hollander, David A; Stern, Michael E

2017-10-01

To investigate effects of punctal occlusion on global tear protein levels in patients with dry eye. In this prospective, longitudinal, single-center study, nonabsorbable punctal plugs were inserted bilaterally into the lower punctum of 30 patients with moderate dry eye. Dry eye symptoms, fluorescein corneal staining, Schirmer I test, tear film break-up time, and safety were assessed in the more severely affected eye. Tear proteins at weeks 1 and 3 were quantified by iTRAQ relative to baseline preocclusion levels. Of 29 patients who completed the study, 23 (mean age 49.8 years) had sufficient tear samples for analysis. After 3 weeks, punctal occlusion significantly upregulated tear proteins, including glutathione synthase (mean of 1.6-fold, P = 0.01) and interleukin-1 receptor antagonist (1.7-fold, P = 0.032) and downregulated cholinergic receptor (neuronal) alpha-7 (0.79-fold, P = 0.039) and lymphocyte cytosolic protein-1 (0.66-fold, P = 0.012). Clustering analysis of global tear proteins revealed two clear profile changes; the first group of patients (cluster 1, n = 10) had a reduction in the inflammatory proteins (e.g., S100A8) and rise in lacrimal proteins supporting the ocular surface (e.g., lysozyme), whereas the second group (cluster 2, n = 13) had an increase in inflammatory proteins and a decrease in lacrimal proteins. Logistic regression analysis revealed that cluster 1 patients had significantly (P = 0.006) lower Schirmer scores at baseline (mean [standard deviation]: 4.3 [4.3] mm) than cluster 2 (6.8 [2.6] mm). Punctal plugs produced a beneficial pattern of tear protein change in patients with relatively low Schirmer scores within 3 weeks of punctal occlusion. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Supercontinent break-up: Causes and consequences

NASA Astrophysics Data System (ADS)

Li, Z. X.

2014-12-01

Supercontinent break-up has most commonly been linked to plume or superplume events, and/or supercontinent thermal insulation, but precise mechanisms are yet to be worked out. Even less know is if and what roles other factors may play. Key factors likely include gravitational force due to the continental superswell driven by both the lower-mantle superplume and continental thermal insulation, mental convention driven by the superplume and individual plumes atop the superplume, assisted by thermal/magmatic weakening of the supercontinent interior (both plume heat and thermal insulation heat). In addition, circum-supercontinent slab downwelling may not only drive the formation of the antipodal superplumes (thus the break-up of the supercontinent), the likely roll-back of the subduction system would also create extension within the supercontinent, facilitating supercontinent break-up. Consequences of supercontinent break-up include long-term sea-level rise, climatic changes due to changes in ocean circulation pattern and carbon cycle, and biodiversification. It has long been demonstrated that the existence of the supercontinent Pangea corresponds to a long-term sea-level drop, whereas the break-up of the supercontinent corresponds to a long-term sea-level rise (170 m higher than it is today). A recent analysis of Neoproterozoic sedimentary facies illustrates that the time of Neoproterozoic supercontinent Rodinia corresponds to a low in the percentage of deep marine facies occurrence, whereas the time of Rodinia break-up corresponds to a significantly higher percentage of deep marine facies occurrence. The long-tern sea-level drop during supercontinent times were likely caused by both plume/superplume dynamic topography and an older mean age of the oceanic crust, whereas long-tern sea-level rise during supercontinent break-up (720-580 Ma for Rodinia and Late Jurassic-Cretaceous for Pangea) likely corresponds to an younger mean age of the oceanic crust, massive plume

Long-term follow-up after submandibular gland transplantation in severe dry eyes secondary to cicatrizing conjunctivitis.

PubMed

Borrelli, Maria; Schröder, Christina; Dart, John K G; Collin, John Richard O; Sieg, Peter; Cree, Ian A; Matheson, Melville A; Tiffany, John M; Proctor, Gordon; van Best, Jaap; Hyde, Nick; Geerling, Gerd

2010-12-01

To evaluate the long-term results of autologous submandibular gland transplantation in eyes with cicatrizing conjunctivitis and to determine biomechanical and biochemical features of the resulting salivary tear film. Prospective, observational case series. Fifteen eyes with cicatrizing conjunctivitis with a viable autologous submandibular gland transplantation were compared with 10 eyes with cicatrizing conjunctivitis and a failed submandibular gland transplantation or no submandibular gland transplantation. Best-corrected visual acuity, frequency of tear substitute instillation, severity of dry eye discomfort, lid margin erythema, conjunctival hyperemia, corneal epithelial edema, tear film break-up time, Schirmer test results, and corneal fluorescein and conjunctival Rose Bengal staining were evaluated. In a subgroup central corneal thickness and sensitivity, corneal epithelial barrier function, conjunctival and lid margin flora, and conjunctival impression cytologic analysis results were evaluated. In 3 patients, preoperative and postoperative tear samples were analyzed for viscosity, surface tension, and presence of mucins. Submandibular gland autotransplantation resulted in long-term improvement of subjective, objective, and some ocular surface parameters. Salivary mucins were detectable in salivary tears after submandibular gland transplantation. The viscosity of salivary tears was more similar to normal saliva and the surface tension was intermediate between the 2 original secretions. Submandibular gland autotransplantation provides long-term relief from pain and reduces the need for frequent installation of lubricants. Copyright © 2010 Elsevier Inc. All rights reserved.

Can the optimum artificial tear treatment for dry eye disease be predicted from presenting signs and symptoms?

PubMed

Essa, Laika; Laughton, Deborah; Wolffsohn, James S

2018-02-01

To assess dry eye treatment with four preservative-free dry eye artificial tear treatments to facilitate evidence-based prescribing. A randomised, single masked crossover trial of Clinitas Soothe, Hyabak, Tears Again and TheraTears artificial tears was conducted on 50 symptomatic dry eye patients, aged 60.8±14.2years. At baseline and after trialling each treatment for 4 weeks, signs and symptoms were assessed using the Ocular Surface Disease Index (OSDI), non-invasive tear break-up time, fluorescein tear break-up time, tear meniscus height (TMH), Phenol Red test, lid-parallel conjunctival folds (LIPCOF), ocular surface staining, and lipid layer grading and osmolarity (baseline visit only). OSDI (p=0.002), LIPCOF (p=0.014) and conjunctival staining (p<0.001) significantly improved from baseline, however, the impact of each dry eye treatment on ocular symptoms and signs was similar. Clinitas Soothe and Hyabak were preferred by 34%/30% of participants, but only subjective comparison with the other drops influenced this choice. TheraTears was preferred (by 24%) by those with a lower baseline tear volume (p=0.01) and Tears Again (by 12%) by those with a thinner baseline lipid layer (p=0.04). The treatment that afforded the greatest improvement in clinical signs did not consistently match each individual's preferred treatment. If prescribed to a general dry eye population, the artificial tears performed similarly, improving symptoms and conjunctival signs. However, osmolarity balanced artificial tears were the preferred treatment in individuals with low baseline tear volume and lipisomal spray for individuals with a baseline lipid layer deficiency. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Evaluation of point-of-care test for elevated tear matrix metalloproteinase 9 in post-LASIK dry eyes.

PubMed

Chan, Tommy C Y; Ye, Cong; Chan, Kwok Ping; Chu, Kai On; Jhanji, Vishal

2016-09-01

To evaluate the performance of a point-of-care test for detection of matrix metalloproteinase 9 (MMP-9) levels in post-laser-assisted in situ keratomileusis (LASIK) dry eyes. A comparative study between patients with mild to moderate post-LASIK dry eyes and age-matched normal subjects was conducted. Ocular surface disease index (OSDI), tear break-up time (TBUT), and tear film MMP-9 and total protein levels were compared between the two groups. A point-of-care test device (RPS InflammaDry, Sarasota, Florida, USA) was utilised to confirm elevated MMP-9 levels in tear film. Fourteen post-LASIK dry eyes and 34 normal eyes were included. There was no significant difference in age and gender between both groups (p>0.175). The OSDI was significantly higher (25.5±7.7 vs 7.4±2.5; p<0.001) and TBUT levels were significantly lower (5.4±0.9 vs 13.5±2.3; p<0.001) in patients with dry eye compared with normal subjects. The tear film MMP-9 levels were 52.7±32.5 ng/mL in dry eyes and 4.1±2.1 ng/mL in normal eyes (p<0.001). MMP-9 levels were >40 ng/mL in 7/14 (50.0%) post-LASIK dry eyes. The InflammaDry was positive in 8/14 (57.1%) post-LASIK eyes. All positive cases had tear film MMP-9 levels ≥38.03 ng/mL. Agreement between InflammaDry and MMP-9 was excellent with Cohen κ value of 0.857 in post-LASIK dry eyes. Only half of post-LASIK dry eyes were found to have significant inflammation associated with elevated MMP-9. The OSDI is useful to non-specifically identify patients with symptomatic dry eye while the InflammaDry determined which patients with dry eye were associated with significant inflammation that may guide therapeutic management decisions. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

The Relationship between Metabolic Syndrome, Its Components, and Dry Eye: A Cross-Sectional Study.

PubMed

Erdur, Sevil Karaman; Aydin, Rukiye; Ozsutcu, Mustafa; Olmuscelik, Oktay; Eliacik, Mustafa; Demirci, Goktug; Kocabora, Mehmet Selim

2017-08-01

The aim of this study was to evaluate tear osmolarity and tear film function and ocular surface changes in patients with metabolic syndrome. 108 eyes of 64 patients with metabolic syndrome (group 1) and 110 eyes of 55 healthy individuals (group 2) were included in this cross-sectional study. All participants were evaluated using the Ocular Surface Disease Index (OSDI) questionnaire, Schirmer I test, tear film break-up time (TBUT), and tear osmolarity. Main outcome measures were Ocular Surface Disease Index (OSDI) questionnaire, Schirmer I test, tear film break-up time (TBUT), and tear osmolarity values. Tear osmolarity values and OSDI scores were significantly higher in group 1 (314.4 ± 19.1 mOsm and 38.9 ± 1.1, respectively) compared with group 2 (295 ± 14.3 mOsm and 18.69 ± 17.2, respectively) (p = 0.01 for both). The Schirmer test values and TBUT in group 1 (10 ± 3.7 mm and 14.8 ± 3.6 sec, respectively) were significantly lower compared with group 2 (16.8 ± 2.6 mm and 18.1 ± 0.5 sec, respectively) (p < 0.001 for both). There was significant correlation between tear osmolarity versus waist circumference and fasting blood glucose in the study group (r = 0.364, p = 0.04; and r = 0.542, p ≤ 0.001, respectively). This study showed that metabolic syndrome can influence tear osmolarity and tear film function. Patients with metabolic syndrome showed tear hyperosmolarity and tear film dysfunction.

Simultaneous measurement of lipid and aqueous layers of tear film using optical coherence tomography and statistical decision theory

NASA Astrophysics Data System (ADS)

Huang, Jinxin; Clarkson, Eric; Kupinski, Matthew; Rolland, Jannick P.

2014-03-01

The prevalence of Dry Eye Disease (DED) in the USA is approximately 40 million in aging adults with about $3.8 billion economic burden. However, a comprehensive understanding of tear film dynamics, which is the prerequisite to advance the management of DED, is yet to be realized. To extend our understanding of tear film dynamics, we investigate the simultaneous estimation of the lipid and aqueous layers thicknesses with the combination of optical coherence tomography (OCT) and statistical decision theory. In specific, we develop a mathematical model for Fourier-domain OCT where we take into account the different statistical processes associated with the imaging chain. We formulate the first-order and second-order statistical quantities of the output of the OCT system, which can generate some simulated OCT spectra. A tear film model, which includes a lipid and aqueous layer on top of a rough corneal surface, is the object being imaged. Then we further implement a Maximum-likelihood (ML) estimator to interpret the simulated OCT data to estimate the thicknesses of both layers of the tear film. Results show that an axial resolution of 1 μm allows estimates down to nanometers scale. We use the root mean square error of the estimates as a metric to evaluate the system parameters, such as the tradeoff between the imaging speed and the precision of estimation. This framework further provides the theoretical basics to optimize the imaging setup for a specific thickness estimation task.

Conjunctival impression cytology versus routine tear function tests for dry eye evaluation in contact lens wearers.

PubMed

Kumar, Prachi; Bhargava, Rahul; Arora, Yogesh C; Kaushal, Sidharth; Kumar, Manjushri

2015-01-01

Prolonged contact lens wear is often accompanied by dryness of the eyes. The aim of this study was to compare conjunctival impression cytology (CIC) and tear film tests such as tear film break up time (TBUT) and Schirmer test for dry eye evaluation in contact lens wearers and measure their correlation with dry eye symptoms. A case control study was done at three referral eye centers. The eyes of 230 contact lens users were compared to 250 eyes of age- and sex-matched controls. Participants were recruited based on their response to a questionnaire of dry eye symptoms, (Dry Eye Scoring System, DESS(©)) and measurements of TBUT, Schirmer test, and CIC was done. A correlation analysis between symptom severity and tear film tests was performed. Pearson's coefficient, R(2) > 0.5 was considered significant. As compared to controls (r (2) = 0.010), Nelson grade correlated significantly with dry eye symptoms (r (2) = 0.765), among cases. However, there was moderate correlation between dry eye symptoms, Schirmer test, and TBUT (r (2) = 0.557 and 0.530, respectively) among cases and a weak correlation among controls (r (2) = 0.130 and 0.054, respectively). The sensitivity of TBUT was 86.4%, specificity was 82.4%, positive likelihood ratio (LR) was 4.50 [95% confidence interval (CI) 3.46-5.85)], and negative LR was 0.09. The sensitivity of the Schirmer test was 48.2%, specificity 88%, LR 2.12 (95% CI 1.48-2.96), and negative LR 0.83. CIC correlates better than Schirmer and TBUT with dry eye symptoms. It may be the most appropriate test for dry-eye evaluation in contact lens wearers.

Adsorption of apo- and holo-tear lipocalin to a bovine Meibomian lipid film.

PubMed

Mudgil, Poonam; Millar, Thomas J

2008-04-01

Adsorption of apo- and holo-tear lipocalin (Tlc) to bovine Meibomian lipid film was studied. A Langmuir trough was used for these studies and the adsorption of protein was observed by recording changes in the pressure with time (pi-T profile). The films were photographed at different stages of adsorption by doping Meibomian lipids with a fluorescently tagged lipid. The results indicated that apo-Tlc adsorbed much more quickly than holo-Tlc to the Meibomian lipid film. Contrary to the expectation that holo-Tlc would release lipids to the surface and surface pressure would be higher, it was found that the surface pressure was higher with the adsorption of apo-Tlc to the surface. Photography of the films showed that apo- and holo-Tlc interacted differently with the Meibomian lipid layer. Adsorption of holo-Tlc resulted in big bright patches and adsorption of apo-Tlc resulted in many small patches along with the big patches. Both forms of Tlc produced a more stable film as indicated by decreased movement of the protein adsorbed films, and a higher maximum surface pressure upon compression of these films compared with Meibomian lipid films alone. Isocyles of apo-Tlc adsorbed films gave a higher surface pressure than that of holo-Tlc. From these results, it is concluded that both apo- and holo-Tlc adsorbed to the Meibomian lipid layer and the delivery of the lipids from Tlc to the outer lipid layer could not be detected by our techniques. Its scavenging role to remove lipids from the corneal surface and bind with them might be beneficial for increasing tear viscosity but whether those lipids are delivered to the outermost lipid layer still remains unclear.

Clinical correlations of dry eye syndrome and allergic conjunctivitis in Korean children.

PubMed

Kim, Tae Hyung; Moon, Nam Ju

2013-01-01

Clinical patterns in pediatric patients with dry eye syndrome and allergic conjunctivitis were investigated. Children aged 6 to 15 years with dry eye symptoms were included. Slit-lamp examinations including tear film break-up time, Schirmer's test, and fluorescent staining were performed, and subjective symptoms were investigated. Patients with allergic conjunctivitis were subjected to skin prick tests. Tear film break-up time was shorter and the number of symptoms related to dry eyes was higher in pediatric patients with allergic conjunctivitis than in those without allergic conjunctivitis. Patients with allergic conjunctivitis who had higher numbers of positive allergens on the skin prick test also had shorter tear film break-up time. Because pediatric patients with dry eye syndrome tend to complain less about their symptoms than adult patients, dry eye syndrome is commonly overlooked. This study showed that dry eyes tended to be more severe with the presence of allergic conjunctivitis; the more allergens present, the more severe the dry eyes. More attention should be paid to the treatment of pediatric patients with dry eyes accompanied by allergies. Copyright 2013, SLACK Incorporated.

Tear film thickness after treatment with artificial tears in patients with moderate dry eye disease.

PubMed

Schmidl, Doreen; Schmetterer, Leopold; Witkowska, Katarzyna J; Unterhuber, Angelika; dos Santos, Valentin Aranha; Kaya, Semira; Nepp, Johannes; Baar, Carina; Rosner, Peter; Werkmeister, René M; Garhofer, Gerhard

2015-04-01

This study was designed to investigate the effect of a single-drop instillation of different lacrimal substitutes on tear film thickness (TFT) assessed with optical coherence tomography in patients with mild to moderate dry eye disease. The study was performed in a randomized, double-masked, controlled parallel group design. Patients received a single dose of either unpreserved trehalose 30 mg/mL and sodium hyaluronate 1.5 mg/mL (TH-SH, Thealoz Duo), unpreserved sodium hyaluronate, 0.15% (HA, Hyabak) or sodium chloride, 0.9% (NaCl, Hydrabak) eye drops. Sixty patients finished the study according to the protocol. TFT was measured with a custom-built ultrahigh-resolution Fourier domain optical coherence tomography system providing a resolution of 1.2 μm. The mean TFT before treatment was 2.5 ± 0.4 μm. Ten minutes after instillation, TFT significantly increased in the TH-SH group from 2.4 ± 0.4 to 3.1 ± 0.9 μm (P < 0.01) and in the HA group from 2.4 ± 0.3 to 2.9 ± 0.5 μm (P < 0.01), whereas no significant change was observed in the NaCl group (from 2.6 ± 0.4 to 2.7 ± 0.4 μm, P = 0.76). The increase in TFT remained statistically significant up to 240 minutes after administration of TH-SH. In contrast, the increase in TFT after administration of HA was only statistically significant at 10, 20, and 40 minutes after drop instillation. The findings of this study indicate that single instillation of TH-SH and HA eye drops increases TFT in patients with dry eye disease. The data also indicate longer corneal residence of the TH-containing eye drops. The effect of multiple instillation and long-term use of artificial tears on TFT warrants further investigation.

Ocular surface and tear functions after topical cyclosporine treatment in dry eye patients with chronic graft-versus-host disease.

PubMed

Wang, Y; Ogawa, Y; Dogru, M; Kawai, M; Tatematsu, Y; Uchino, M; Okada, N; Igarashi, A; Kujira, A; Fujishima, H; Okamoto, S; Shimazaki, J; Tsubota, K

2008-02-01

We investigated the effect of 0.05% topical cyclosporine (Cys) on the ocular surface and tear functions in dry eye patients with chronic GVHD (cGVHD) in a prospective comparative study. Thirty eyes of 15 patients refractory to baseline treatment were recruited and the patients assigned for topical Cys treatment group (14 eyes of 7 patients) and control group (12 eyes of 6 patients) respectively. Two patients dropped out because of intolerable irritation while using topical Cys eye drops. Visual analog scale symptom scores, corneal sensitivity, Schirmer I test value, tear film break-up time (TBUT), tear evaporation rate and ocular surface vital staining scores were recorded at baseline and at the end of the following one month. Conjunctival impression and brush cytology were performed before and after the treatment. After topical Cys treatment, significant improvements were found in symptom scores, corneal sensitivity, tear evaporation rate, TBUT, vital staining scores, goblet cells density, conjunctival squamous metaplasia grade, inflammatory cell numbers and the MUC5AC expression. Our study suggests that 0.05% topical Cys may be an effective treatment for dry eye patients with cGVHD. The improvements in the ocular surface and tear functions resulted presumably from the decreased inflammation, increased goblet cell density and MUC5AC mRNA expression. Bone Marrow Transplantation (2008) 41, 293-302; doi:10.1038/sj.bmt.1705900; published online 5 November 2007.

[Assessment of lipid layer thickness of tear film in the diagnosis of dry-eye syndrome in children after the hematopoietic stem cell transplantation].

PubMed

Kurpińska, Małgorzata; Gorczyńska, Ewa; Owoc-Lempach, Joanna; Bernacka, Aleksandra; Misiuk-Hojło, Marta; Chybicka, Alicja

2011-01-01

Dry eye syndrome (DES), also known as keratoconjunctivitis sicca (KCS) is recognized as the most frequent ocular complication after allogeneic stem cell transplantation (allo-SCT). KCS can appear either due to insufficient tear production or excessive tear evaporation, both resulting in tears hyperosmolarity that leads to ocular damage. The evaporation rate and better film stability is determined primarily by the status of the lipid layer. Observation and classification of tear film lipid layer interference patterns in normal and dry eyes in patients after allogeneic stem cell transplantation with a follow-up time of 6 months-5 years (median 26.54 months). Investigation of the relation between the lipid layer interference patterns in normal and dry eyes and the results of other dry eye examinations and complaints. Relation between DES and conditioning regimes, including total body irradiation and high-dose chemotherapy, immunosuppressive drugs, the time after allogeneic stem cell transplantation and chronic graft-versus-host disease. Precorneal tears lipid layer interference patterns, were examined in 114 eyes in treatment group with the Tearscope-plus. Patient with dry eye were identified on the basis of Schirmer test scores and/or tear breakup time, and positive lissamine and/or fluorescein staining. 42 of 114 eyes (36.8%) developed DES after allo-SCT A significant correlation between thickness of lipid layer and BUT, Schirmer test, lissamine green and fluorescein staining was found in the treatment group. A significant association was found between present chronic GVHD and DES in children. DES was not associated with TBI, corticosteroids, immunosuppressive drugs and the time in the present study. Tears lipid layer interference patterns are highly correlated with the diagnosis of DES. Tears lipid layer interference patterns ( noninvasive method), can be used to diagnose early DES in children after allo-SCT. Chronic GVHD play a major role in development of DES

[Abnormal of tear lipid layer and recent advances in clinical study of dry eye].

PubMed

Xiao, Xin-Ye; Liu, Zu-Guo

2012-03-01

Dry eye is a common disease in the ophthalmological clinic, which is related to the dysfunction of tear film. The tear film is composed of lipid layer, aqueous layer and mucin layer (or lipid layer, aqueous/mucin layer). The lipid of the outmost layer derived from Meibomian gland and distributed on the tear film after blinking can decrease the evaporation and stabilize the tear film. The thickness, quality, and distribution of lipid layer are impaired in many dry eye patients, hence restoring the physiological function of lipid layer may be crucial for the treatment of this kind of dry eye. The lipid artificial tears manifest great effects on increasing lipid layer thickness, stabilizing tear film, improving Meibomian gland dysfunction, and promoting tear film distribution.

Tear thinning time and topical anesthesia as assessed using the HIRCAL grid and the NCCA.

PubMed

Blades, K J; Murphy, P J; Patel, S

1999-03-01

The literature contains conflicting reports of the effects of topical anesthetics on tear film stability, with some consensus that unpreserved topical anesthetics are less likely to reduce tear film stability than preserved preparations. This experiment investigated the effect of unpreserved 0.4% benoxinate hydrochloride on tear thinning time (TTT), in parallel with "real time" corneal sensitivity assessment. Tear film stability was assessed (HIRCAL grid) in parallel with real time assessment of the pharmacological activity (NCCA) of unpreserved 0.4% benoxinate hydrochloride in normal eyes. The anesthetic used did not significantly affect tear film stability. This finding is in agreement with previous investigators. Unpreserved 0.4% benoxinate hydrochloride could be used to facilitate tear film stability assessment. The experimental protocol used could also be applied to investigate the temporal relationship between anesthesia and tear film stability with preserved topical anesthetics that have been found to decrease tear film stability.

24 CFR 982.315 - Family break-up.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Family break-up. 982.315 Section... SECTION 8 TENANT BASED ASSISTANCE: HOUSING CHOICE VOUCHER PROGRAM Leasing a Unit § 982.315 Family break-up. (a) The PHA has discretion to determine which members of an assisted family continue to receive...

24 CFR 982.315 - Family break-up.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Family break-up. 982.315 Section... SECTION 8 TENANT BASED ASSISTANCE: HOUSING CHOICE VOUCHER PROGRAM Leasing a Unit § 982.315 Family break-up. (a)(1) The PHA has discretion to determine which members of an assisted family continue to receive...

Tear Film Lipids

PubMed Central

Butovich, Igor A.

2013-01-01

Human meibomian gland secretions (MGS, or meibum) are formed from a complex mixture of lipids of different classes such as wax esters, cholesteryl esters, (O-acyl)-ω-hydroxy fatty acids (OAHFA) and their esters, acylglycerols, diacylated diols, free fatty acids, cholesterol, and a smaller amount of other polar and nonpolar lipids, whose chemical nature and the very presence in MGS have been a matter of intense debates. The purpose of this review is to discuss recent results that were obtained using different experimental techniques, estimate limitations of their usability, and discuss their biochemical, biophysical, and physiological implications. To create a lipid map of MGS and tears, the results obtained in the author’s laboratory were integrated with available information on chemical composition of MGS and tears. The most informative approaches that are available today to researchers, such as HPLC-MS, GC-MS, and proton NMR, are discussed in details. A map of the meibomian lipidome (as it is seen in reverse phase liquid chromatography/mass spectrometry experiments) is presented. Directions of future efforts in the area are outlined. PMID:23769846

Tears of Wine

NASA Astrophysics Data System (ADS)

Rathore, Prerana; Sharma, Vivek

`Tears of wine' refer to the rows of wine-drops that spontaneously emerge within a glass of strong wine. Evaporation-driven Marangoni flows near the meniscus of water-alcohol mixtures drive liquid upward forming a thin liquid film, and a rim or ridge forms near the moving contact line. Eventually the rim undergoes an instability forming drops, that roll back into bulk reservoir forming so called tears or legs of wine. Most studies in literature argue the evaporation of more volatile, lower surface tension component (alcohol) results in a concentration-dependent surface tension gradient that drives the climbing flow within the thin film. Though it is well-known that evaporative cooling can create temperature gradients that could provide additional contribution to the climbing flows, the role of thermocapillary flows is less well-understood. Furthermore, the patterns, flows and instabilities that occur near the rim, and determine the size and periodicity of tears, are not well-studied. Using experiments and theory, we visualize and analyze the formation and growth of tears of wine. The sliding drops, released from the rim towards the bulk reservoir, show oscillations and a cascade of fascinating flows that are analyzed for the first time.

Corneal Nerve Morphology and Tear Film Substance P in Diabetes.

PubMed

Markoulli, Maria; You, Jingjing; Kim, Juno; Duong, Carmen L; Tolentino, Jonathan B; Karras, Joshua; Lum, Edward

2017-07-01

This work aims to characterize the relationship between tear film neuropeptide substance P and the structural integrity of the sub-basal nerve plexus in diabetes. Seventeen healthy control participants and nine participants with diabetes were recruited in this cross-sectional study. Total protein content and substance P concentrations were determined in the flush tears of participants. Corneal nerve morphology was assessed by capturing the corneal sub-basal nerve plexus using the Heidelberg Retinal Tomograph II with the Rostock Corneal Module (Heidelberg Engineering GmbH, Heidelberg, Germany) in the central cornea. Corneal nerve fiber density (CNFD) was measured using ACCMetrics (M.A. Dabbah, Imaging Science and Biomedical Engineering, Manchester, UK) on eight captured images. Comparisons between groups were made using independent samples t-tests. Correlations between parameters were analyzed using Pearson's correlations. Substance P concentrations were significantly higher in the tears of the control group compared to participants with diabetes (4150 ± 4752 and 1473 ± 1671 pg/mL, respectively, P = .047). There was no significant difference in total protein content between the groups (3.4 ± 1.8 and 2.6 ± 1.7 mg/mL in the control and diabetes groups, respectively, P = .262). CNFD was significantly lower in the participants with diabetes compared to the control group (16.1 ± 5.7 and 21.5 ± 7.0 mm/mm, respectively, P = .041). There was a moderate correlation between substance P and CNFD (r = 0.48, P = .01). Substance P is expressed at a significantly lower level in the tears of people with diabetes compared with healthy controls. The positive correlation between substance P and corneal nerve density indicates that substance P may be a potential biomarker for corneal nerve health.

The relation of functional visual acuity measurement methodology to tear functions and ocular surface status.

PubMed

Kaido, Minako; Ishida, Reiko; Dogru, Murat; Tsubota, Kazuo

2011-09-01

To investigate the relation of functional visual acuity (FVA) measurements with dry eye test parameters and to compare the testing methods with and without blink suppression and anesthetic instillation. A prospective comparative case series. Thirty right eyes of 30 dry eye patients and 25 right eyes of 25 normal subjects seen at Keio University School of Medicine, Department of Ophthalmology were studied. FVA testing was performed using a FVA measurement system with two different approaches, one in which measurements were made under natural blinking conditions without topical anesthesia (FVA-N) and the other in which the measurements were made under the blink suppression condition with topical anesthetic eye drops (FVA-BS). Tear function examinations, such as the Schirmer test, tear film break-up time, and fluorescein and Rose Bengal vital staining as ocular surface evaluation, were performed. The mean logMAR FVA-N scores and logMAR Landolt visual acuity scores were significantly lower in the dry eye subjects than in the healthy controls (p < 0.05), while there were no statistical differences between the logMAR FVA-BS scores of the dry eye subjects and those of the healthy controls. There was a significant correlation between the logMAR Landolt visual acuities and the logMAR FVA-N and logMAR FVA-BS scores. The FVA-N scores correlated significantly with tear quantities, tear stability and, especially, the ocular surface vital staining scores. FVA measurements performed under natural blinking significantly reflected the tear functions and ocular surface status of the eye and would appear to be a reliable method of FVA testing. FVA measurement is also an accurate predictor of dry eye status.

Phospholipid transfer protein is present in human tear fluid.

PubMed

Jauhiainen, Matti; Setälä, Niko L; Ehnholm, Christian; Metso, Jari; Tervo, Timo M T; Eriksson, Ove; Holopainen, Juha M

2005-06-07

The human tear fluid film consists of a superficial lipid layer, an aqueous middle layer, and a hydrated mucin layer located next to the corneal epithelium. The superficial lipid layer protects the eye from drying and is composed of polar and neutral lipids provided by the meibomian glands. Excess accumulation of lipids in the tear film may lead to drying of the corneal epithelium. In the circulation, phospholipid transfer protein (PLTP) and cholesteryl ester transfer protein (CETP) mediate lipid transfers. To gain insight into the formation of tear film, we investigated whether PLTP and CETP are present in human tear fluid. Tear fluid samples were collected with microcapillaries. The presence of PLTP and CETP was studied in tear fluid by Western blotting, and the PLTP concentration was determined by ELISA. The activities of the enzymes were determined by specific lipid transfer assays. Size-exclusion and heparin-affinity chromatography assessed the molecular form of PLTP. PLTP is present in tear fluid, whereas CETP is not. Quantitative assessment of PLTP by ELISA indicated that the PLTP concentration in tear fluid, 10.9 +/- 2.4 microg/mL, is about 2-fold higher than that in human plasma. PLTP-facilitated phospholipid transfer activity in tears, 15.1 +/- 1.8 micromol mL(-)(1) h(-)(1), was also significantly higher than that measured in plasma. Inactivation of PLTP by heat treatment (+58 degrees C, 60 min) or immunoinhibition abolished the phospholipid transfer activity in tear fluid. Size-exclusion chromatography of tear fluid indicated that PLTP eluted in a position corresponding to a size of 160-170 kDa. Tear fluid PLTP was quantitatively bound to Heparin-Sepharose and could be eluted as a single peak by 0.5 M NaCl. These data indicate that human tear fluid contains catalytically active PLTP protein, which resembles the active form of PLTP present in plasma. The results suggest that PLTP may play a role in the formation of the tear film by supporting phospholipid

Oral sea buckthorn oil attenuates tear film osmolarity and symptoms in individuals with dry eye.

PubMed

Larmo, Petra S; Järvinen, Riikka L; Setälä, Niko L; Yang, Baoru; Viitanen, Matti H; Engblom, Janne R K; Tahvonen, Raija L; Kallio, Heikki P

2010-08-01

Dry eye is a common condition that can severely impair the quality of life. We aimed to find out whether oral sea buckthorn (SB) oil, containing (n-3) and (n-6) fatty acids and antioxidants, affects dry eye. In this double-blind, randomized, parallel trial, 20- to 75-y-old women and men experiencing dry eye symptoms consumed 2 g of SB or placebo oil daily for 3 mo from fall to winter. One hundred participants were recruited and 86 completed the study. Clinical dry eye tests and symptom follow-ups were performed. Tear film hyperosmolarity is a focal factor in dry eye. There was a general increase in the osmolarity from baseline to the end of the intervention. Compared with the placebo group, the increase was significantly less in the SB group when all participants were included [intention to treat (ITT), P = 0.04] and when only participants consuming the study products for at least 80% of the intervention days were included [per protocol (PP), P = 0.02]. The maximum intensities of redness and burning tended to be lower in the SB group. In the ITT participants, the group difference was significant for redness (P = 0.04) but not for burning (P = 0.05). In the PP participants, the group difference was significant for burning (P = 0.04) but not for redness (P = 0.11). In conclusion, SB oil attenuated the increase in tear film osmolarity during the cold season and positively affected the dry eye symptoms.

Dysfunctional tear syndrome: dry eye disease and associated tear film disorders - new strategies for diagnosis and treatment.

PubMed

Milner, Mark S; Beckman, Kenneth A; Luchs, Jodi I; Allen, Quentin B; Awdeh, Richard M; Berdahl, John; Boland, Thomas S; Buznego, Carlos; Gira, Joseph P; Goldberg, Damien F; Goldman, David; Goyal, Raj K; Jackson, Mitchell A; Katz, James; Kim, Terry; Majmudar, Parag A; Malhotra, Ranjan P; McDonald, Marguerite B; Rajpal, Rajesh K; Raviv, Tal; Rowen, Sheri; Shamie, Neda; Solomon, Jonathan D; Stonecipher, Karl; Tauber, Shachar; Trattler, William; Walter, Keith A; Waring, George O; Weinstock, Robert J; Wiley, William F; Yeu, Elizabeth

2017-01-01

Dysfunctional tear syndrome (DTS) is a common and complex condition affecting the ocular surface. The health and normal functioning of the ocular surface is dependent on a stable and sufficient tear film. Clinician awareness of conditions affecting the ocular surface has increased in recent years because of expanded research and the publication of diagnosis and treatment guidelines pertaining to disorders resulting in DTS, including the Delphi panel treatment recommendations for DTS (2006), the International Dry Eye Workshop (DEWS) (2007), the Meibomian Gland Dysfunction (MGD) Workshop (2011), and the updated Preferred Practice Pattern guidelines from the American Academy of Ophthalmology pertaining to dry eye and blepharitis (2013). Since the publication of the existing guidelines, new diagnostic techniques and treatment options that provide an opportunity for better management of patients have become available. Clinicians are now able to access a wealth of information that can help them obtain a differential diagnosis and treatment approach for patients presenting with DTS. This review provides a practical and directed approach to the diagnosis and treatment of patients with DTS, emphasizing treatment that is tailored to the specific disease subtype as well as the severity of the condition.

Tears of Wine

ERIC Educational Resources Information Center

Gugliotti, Marcos

2004-01-01

The unique occurrence of the upward motion of a thin film of wine, and its formation into drops inside the wall of a wine glass is explained. Evaporation of alcohol generates a surface tension gradient, moving the film of wine upwards on the internal sides of a wine glass, where it collects and forms into drops or tears.

Dysfunctional tear syndrome: dry eye disease and associated tear film disorders – new strategies for diagnosis and treatment

PubMed Central

Milner, Mark S.; Beckman, Kenneth A.; Luchs, Jodi I.; Allen, Quentin B.; Awdeh, Richard M.; Berdahl, John; Boland, Thomas S.; Buznego, Carlos; Gira, Joseph P.; Goldberg, Damien F.; Goldman, David; Goyal, Raj K.; Jackson, Mitchell A.; Katz, James; Kim, Terry; Majmudar, Parag A.; Malhotra, Ranjan P.; McDonald, Marguerite B.; Rajpal, Rajesh K.; Raviv, Tal; Rowen, Sheri; Shamie, Neda; Solomon, Jonathan D.; Stonecipher, Karl; Tauber, Shachar; Trattler, William; Walter, Keith A.; Waring, George O.; Weinstock, Robert J.; Wiley, William F.; Yeu, Elizabeth

2017-01-01

Dysfunctional tear syndrome (DTS) is a common and complex condition affecting the ocular surface. The health and normal functioning of the ocular surface is dependent on a stable and sufficient tear film. Clinician awareness of conditions affecting the ocular surface has increased in recent years because of expanded research and the publication of diagnosis and treatment guidelines pertaining to disorders resulting in DTS, including the Delphi panel treatment recommendations for DTS (2006), the International Dry Eye Workshop (DEWS) (2007), the Meibomian Gland Dysfunction (MGD) Workshop (2011), and the updated Preferred Practice Pattern guidelines from the American Academy of Ophthalmology pertaining to dry eye and blepharitis (2013). Since the publication of the existing guidelines, new diagnostic techniques and treatment options that provide an opportunity for better management of patients have become available. Clinicians are now able to access a wealth of information that can help them obtain a differential diagnosis and treatment approach for patients presenting with DTS. This review provides a practical and directed approach to the diagnosis and treatment of patients with DTS, emphasizing treatment that is tailored to the specific disease subtype as well as the severity of the condition. PMID:28099212

Tear osmolarity measurements in dry eye related to primary Sjögren's syndrome.

PubMed

Utine, Canan Asli; Bıçakçıgil, Müge; Yavuz, Sule; Çiftçi, Ferda

2011-08-01

To evaluate the tear osmolarity in patients with dry eye syndrome related to primary Sjögren's Syndrome (SS). Twenty eyes of 10 patients with dry eye and primary SS (Group 1) and 20 eyes of 20 subjects who do not have dry eye syndrome (Group 2) were included in this cross-sectional study. In all eyes, ophthalmic examination was performed in the same order: International Ocular Surface Disease Index survey, visual acuity assessment, conjunctival hyperemia scoring, tear osmolarity measurement with TearLab(™) Osmolarity System, tear film break-up time assessment, corneal fluorescein staining scoring, ocular surface Lissamine Green staining scoring, anesthetized Schirmer test. Dry eye severity was graded according to Dry Eye Workshop (DEWS) classification system. Four eyes with grade 1, four eyes with grade 2, seven eyes with grade 3, and five eyes with grade 4 dryness, according to DEWS system, were included. The mean tear osmolarity value was 301.9 ± 11.40 mOsm/L (range: 290-328) in Group 1, and 294.85 ± 8.33 mOsm/L (range: 283-311) in Group 2 (p = 0.03). In Group 1, tear osmolarity values were positively correlated with OSDI scores (r(18) = 0.55, r(2) = 0.31, p = 0.01), DEWS classification grades (r(18) = 0.73, r(2) = 0.54, p < 0.01), temporal and total corneal staining scores (r(18) = 0.67, r(2) = 0.44, p < 0.01, and r(18) = 0.51, r(2) = 0.26, p = 0.02, respectively), temporal conjunctival staining scores (r(18) = 58, r(2) = 0.34, p < 0.01); and negatively correlated with anesthetized Schirmer test results (r(18) = -0.62, r(2) = 0.38, p < 0.01) and TFBUT (r(18) = -0.50, r(2) = 0.25, p = 0.02). Tear osmolarity values were found to be greater in patients with dry eye syndrome related to primary SS compared to control subjects, and positively correlated with the severity of dry eye.

Adsorption of lysozyme to phospholipid and meibomian lipid monolayer films.

PubMed

Mudgil, Poonam; Torres, Margaux; Millar, Thomas J

2006-03-15

It is believed that a lipid layer forms the outer layer of the pre-ocular tear film and this layer helps maintain tear film stability by lowering its surface tension. Proteins of the aqueous layer of the tear film (beneath the lipid layer) may also contribute to reducing surface tension by adsorbing to, or penetrating the lipid layer. The purpose of this study was to compare the penetration of lysozyme, a tear protein, into films of meibomian lipids and phospholipids held at different surface pressures to determine if lysozyme were part of the surface layer of the tear film. Films of meibomian lipids or phospholipids were spread onto the surface of a buffered aqueous subphase. Films were compressed to particular pressures and lysozyme was injected into the subphase. Changes in surface pressure were monitored to determine adsorption or penetration of lysozyme into the surface film. Lysozyme penetrated a meibomian lipid film at all pressures tested (max=20 mN/m). It also penetrated phosphatidylglycerol, phosphatidylserine or phosphatidylethanolamine lipid films up to a pressure of 20 mN/m. It was not able to penetrate a phosphatidylcholine film at pressures >or=10 mN/m irrespective of the temperature being at 20 or 37 degrees C. However, it was able to penetrate it at very low pressures (<10 mN/m). Epifluorescence microscopy showed that the protein either adsorbs to or penetrates the lipid layer and the pattern of mixing depended upon the lipid at the surface. These results indicate that lysozyme is present at the surface of the tear film where it contributes to decreasing the surface tension by adsorbing and penetrating the meibomian lipids. Thus it helps to stabilize the tear film.

Tear film inflammatory mediators in patients with keratoconus.

PubMed

Sorkhabi, Rana; Ghorbanihaghjo, Amir; Taheri, Nazli; Ahoor, Mohammad Hosein

2015-08-01

To determine the concentration of inflammatory mediators in the tear film of patients with keratoconus. Basal tears from patients with keratoconus and from normal controls were collected using a capillary tube. Patients with keratoconus were examined in a routine fashion, and keratometric readings were also taken from corneal topographic maps .The concentration of cytokines including Interleukin 6,10,1b and Interferon-γ was measured by enzyme-linked immunoadsorbent assay. Seventy-two subjects were enrolled in the study including 42 patients with keratoconus and 30 normals. Patients with keratoconus had significantly higher levels of Interlukin 6,1b and Interferon-γ (17.49 ± 1.92 pg/ml), (8.58 ± 1.15 pg/ml), and (33.33 ± 7.57 pg/ml) compared with control subjects (13.81 ± 1.71 pg/ml), (4.98 ± 0.52 pg/ml), and (22.99 ± 4.68 pg/ml), (P = 0.0001, P = 0.0001, and P = 0.0001). But the level of Interlukin-10 in keratoconus patients was significantly lower (6.07 ± 1.35 pg/ml) than controls (8.99 ± 0.70 pg/ml) (P = 0.0001). We realized that the proinflammatory markers (Interlukin-6,1-b and Interferon-γ) are over expressed, whereas the anti-inflammatory marker (Interlukin-10) is under expressed, indicating that the pathogenesis of keratoconus may involve complex chronic inflammatory events. Additional future studies will reveal the exact molecular and biochemical mechanisms that are required to better manage the disease and halt its progression.

A novel technique of contrast-enhanced optical coherence tomography imaging in evaluation of clearance of lipids in human tears.

PubMed

Napoli, Pietro Emanuele; Coronella, Franco; Satta, Giovanni Maria; Fossarello, Maurizio

2014-01-01

The aim of this work was to gather preliminary data in different conditions of healthy eyes, aqueous tear deficient dry eyes, obstructive meibomian gland disease (MGD) and non-obvious obstructive MGD (NOMGD) individuals, using a new, contrast-enhanced optical coherence tomography (OCT) imaging method to evaluate the clearance of lipids in human tears. Eighty-two adult patients presenting with complaints of ocular irritation were studied for abnormalities of the ocular surface and classified as healthy (n = 21), aqueous tear deficient dry eyes (n = 20), obstructive MGD (n = 15) and NOMGD (n = 26) individuals. A lipid-based tracer, containing an oil-in-water emulsion, was used to obtain an enhanced OCT imaging of the lower tear meniscus. After instillation, a dramatic initial increase of reflectivity of the lower tear meniscus was detected by OCT, followed by a decay back to baseline values over time. Based on this finding, the clearance of lipids was measured in real-time by Fourier-domain anterior segment OCT. The differences in the clearance of lipids among the four groups as well as the correlations between symptom questionnaire score, standardized visual scale test, fluorescein break-up time, ocular surface fluorescein staining score, Schirmer I test scores were found to be statistically significant. The individual areas under the curve of the clearance of lipids calculated by the receiver operating characteristic curve technique ranged from 0.66 to 0.98, suggesting reliable sensitivity and specificity of lipid-enhanced OCT imaging. This new technique of contrast-enhanced OCT imaging of the tear film following lipid-based tracer instillation provides a measure of the clearance of lipids. The quantitative values found are in agreement with other methods of evaluation of the lacrimal system. An improvement of the clinician's ability in the diagnosis and understanding of abnormalities of the ocular surface may be achieved by this simple approach.

Tear progression of symptomatic full-thickness and partial-thickness rotator cuff tears as measured by repeated MRI.

PubMed

Kim, Yang-Soo; Kim, Sung-Eun; Bae, Sung-Ho; Lee, Hyo-Jin; Jee, Won-Hee; Park, Chang Kyun

2017-07-01

The purpose of this study was to analyse the natural course of symptomatic full-thickness and partial-thickness rotator cuff tears treated non-operatively and to identify risk factors affecting tear enlargement. One hundred and twenty-two patients who received non-surgical treatment for a partial- or full-thickness supraspinatus tear were included in this study. All rotator cuff tears were diagnosed with magnetic resonance imaging (MRI), and the same modality was used for follow-up studies. Follow-up MRI was performed after at least a 6-month interval. We evaluated the correlation between tear enlargement and follow-up duration. Eleven risk factors were analysed by both univariate and multivariate analyses to identify factors that affect enlargement of rotator cuff tears. The mean follow-up period was 24.4 ± 19.5 months. Out of 122 patients, 34 (27.9%) patients had an initial full-thickness tear and 88 (72.1%) patients had a partial-thickness tear. Considering all patients together, tear size increased in 51/122 (41.8%) patients, was unchanged in 65/122 (53.3%) patients, and decreased in 6/122 (4.9%) patients. Tear size increased for 28/34 (82.4%) patients with full-thickness tears and 23/88 (26.1%) patients with partial-thickness tears. From the two groups which were followed over 12 months, a higher rate of enlargement was observed in full-thickness tears than in partial-thickness tears (6-12 months, n.s.; 12-24 months, P = 0.002; over 24 months, P < 0.001). Logistic regression revealed that having a full-thickness tear was the most reliable risk factor for tear progression (P < 0.001). This study found that 28/34 (82.4%) of symptomatic full-thickness rotator cuff tears and 23/88 (26.1%) of symptomatic partial-thickness tears increased in size over a follow-up period of 6-100 months. Full-thickness tears showed a higher rate of enlargement than partial-thickness tears regardless of the follow-up duration. Univariate and multivariate analyses

Modelling wave-induced sea ice break-up in the marginal ice zone

NASA Astrophysics Data System (ADS)

Montiel, F.; Squire, V. A.

2017-10-01

A model of ice floe break-up under ocean wave forcing in the marginal ice zone (MIZ) is proposed to investigate how floe size distribution (FSD) evolves under repeated wave break-up events. A three-dimensional linear model of ocean wave scattering by a finite array of compliant circular ice floes is coupled to a flexural failure model, which breaks a floe into two floes provided the two-dimensional stress field satisfies a break-up criterion. A closed-feedback loop algorithm is devised, which (i) solves the wave-scattering problem for a given FSD under time-harmonic plane wave forcing, (ii) computes the stress field in all the floes, (iii) fractures the floes satisfying the break-up criterion, and (iv) generates an updated FSD, initializing the geometry for the next iteration of the loop. The FSD after 50 break-up events is unimodal and near normal, or bimodal, suggesting waves alone do not govern the power law observed in some field studies. Multiple scattering is found to enhance break-up for long waves and thin ice, but to reduce break-up for short waves and thick ice. A break-up front marches forward in the latter regime, as wave-induced fracture weakens the ice cover, allowing waves to travel deeper into the MIZ.

Tear clearance implications for ocular surface health.

PubMed

de Paiva, Cintia Sade; Pflugfelder, Stephen C

2004-03-01

Tear clearance/turnover provides a global assessment of the function of the lacrimal functional unit and of tear exchange on the ocular surface. It is an indirect measure of dry eye induced inflammation on the ocular surface. It shows better correlation with the severity of ocular irritation symptoms and corneal epithelial disease in dry eye than the Schirmer 1 test. Delayed tear clearance may prove to be the best measure for identifying patients with tear film disorders who may respond to anti-inflammatory therapy.

Partial repair in irreparable rotator cuff tear: our experience in long-term follow-up.

PubMed

Di Benedetto, E D; Di Benedetto, Paolo; Fiocchi, Andrea; Beltrame, Alessandro; Causero, Araldo

2017-10-18

Massive rotator cuff tears are a common source of shoulder pain and dysfunction, especially in middle age patient; these lesions represent about 20% of all rotator cuff tears and 80% of recurrent tears. Some lesions are not repairable or should not be repaired: in this case, a rotator cuff partial repair should be recommended. The aim of the study is to evaluate the outcome of rotator cuff partial repair in irreparable rotator cuff massive tear at medium and long-term follow-up. We have evaluated 74 consecutive patients treated with functional repair of rotator cuff by the same surgeon between 2006 and 2014. We divided patients into 2 groups, obtaining 2 average follow-up: at about 6,5 (group A) and 3 years (group B). In December 2015, we evaluated in every patient ROM and Constant Score. We analyzed difference between pre-operatory data and the 2 groups.  Results: We found statistical significant difference in ROM and in Constant Score between pre-operatory data and group A and group B. Between group A and group B there is relevant difference in Constant Score but not in ROM. Partial repair can give good results in a medium follow-up, in terms of pain relief and improvement of ROM, as well as in quality of life. Difference in ROM and Constant Score between group A and group B may indicate the begin of partial repair failure; according to our data, 6-7 years may be the time limit for this surgery technique.

Trace elements and diabetes: Assessment of levels in tears and serum.

PubMed

Cancarini, A; Fostinelli, J; Napoli, L; Gilberti, M E; Apostoli, P; Semeraro, F

2017-01-01

Tear film is critical for the well-being and homeostasis of the ocular surface. Although the composition of the tear film is well known, the composition of metallic elements have yet to be analysed. Despite trace elements metabolism has been reported to play a role in the pathogenesis of diabetes mellitus, a metabolic disease that affects several aspects of homeostasis, little is known in the literature regarding concentration and possible variation of metallic elements in tear film. We studied the concentrations of several essential and non-essential metallic elements in the tear fluid and serum of patients with type II diabetes mellitus and a group of non-diabetic controls. Serum and tear fluid were collected from 97 patients: 47 type II diabetic patients and 50 non-diabetic controls. Regarding tear film, there were statistically significant differences in Zinc, Chrome, Cobalt, Manganese, Barium, and Lead between groups; the values of all metallic elements were found to be statistically significant higher in patients with mellitus type II diabetes. Regarding serum values there was a statistically significant difference in Chrome, Cobalt, and Selenium values; the concentrations of Chrome and Cobalt were higher in the control group, while Selenium concentration was higher in diabetic patients. In patients with type II diabetes, metal elements with higher concentrations in tears compared to serum were: Lead, Barium, Manganese, Cobalt, and Chrome. In the control group, the metal elements with the highest concentration in tear film compared to serum were Chrome, Manganese, Barium, and Lead. In this study, we attempted to evaluate the possible effect of a disease, such as diabetes, on the metabolism of metallic elements. Although our evidence was very interesting, it is probably limited in its accuracy due to the fact that individuals in the control group harboured ocular pathologies. This work lays the foundation for future studies. Copyright © 2016 Elsevier Ltd. All

Modelling wave-induced sea ice break-up in the marginal ice zone

PubMed Central

Squire, V. A.

2017-01-01

A model of ice floe break-up under ocean wave forcing in the marginal ice zone (MIZ) is proposed to investigate how floe size distribution (FSD) evolves under repeated wave break-up events. A three-dimensional linear model of ocean wave scattering by a finite array of compliant circular ice floes is coupled to a flexural failure model, which breaks a floe into two floes provided the two-dimensional stress field satisfies a break-up criterion. A closed-feedback loop algorithm is devised, which (i) solves the wave-scattering problem for a given FSD under time-harmonic plane wave forcing, (ii) computes the stress field in all the floes, (iii) fractures the floes satisfying the break-up criterion, and (iv) generates an updated FSD, initializing the geometry for the next iteration of the loop. The FSD after 50 break-up events is unimodal and near normal, or bimodal, suggesting waves alone do not govern the power law observed in some field studies. Multiple scattering is found to enhance break-up for long waves and thin ice, but to reduce break-up for short waves and thick ice. A break-up front marches forward in the latter regime, as wave-induced fracture weakens the ice cover, allowing waves to travel deeper into the MIZ. PMID:29118659

Modelling wave-induced sea ice break-up in the marginal ice zone.

PubMed

Montiel, F; Squire, V A

2017-10-01

A model of ice floe break-up under ocean wave forcing in the marginal ice zone (MIZ) is proposed to investigate how floe size distribution (FSD) evolves under repeated wave break-up events. A three-dimensional linear model of ocean wave scattering by a finite array of compliant circular ice floes is coupled to a flexural failure model, which breaks a floe into two floes provided the two-dimensional stress field satisfies a break-up criterion. A closed-feedback loop algorithm is devised, which (i) solves the wave-scattering problem for a given FSD under time-harmonic plane wave forcing, (ii) computes the stress field in all the floes, (iii) fractures the floes satisfying the break-up criterion, and (iv) generates an updated FSD, initializing the geometry for the next iteration of the loop. The FSD after 50 break-up events is unimodal and near normal, or bimodal, suggesting waves alone do not govern the power law observed in some field studies. Multiple scattering is found to enhance break-up for long waves and thin ice, but to reduce break-up for short waves and thick ice. A break-up front marches forward in the latter regime, as wave-induced fracture weakens the ice cover, allowing waves to travel deeper into the MIZ.

High melt strength, tear resistant blown film based on poly(lactic acid)

NASA Astrophysics Data System (ADS)

Edmonds, Neil R.; Plimmer, Peter N.; Tanner, Chris

2015-05-01

A major problem associated with the commercial manufacture of thin films from PLA is inferior processing characteristics on blown film lines compared to low density polyethylene. PLA has poor melt strength (leading to bubble instability) and develops a permanent crease in the flattened film as it exits the tower of the film line. In addition, the thin film product has poor tear strength and an unacceptable `noise' level when converted into flexible packaging. Furthermore, fabricated articles based on PLA are known to show an unattractive tendency toward dimensional instability. This behaviour is associated with `cold crystallization', a phenomenon which also causes exudation of any plasticizer added for improving flexibility. Blow moulded articles based on PLA also exhibit dimensional sensitivity above 60°C. All of these issues have been overcome by the technology described in this paper. This has been accomplished without loss of the valuable compostability characteristic of PLA; this was confirmed by evaluation of film in a commercial composting operation. These results have been achieved through novel reactive compounding technology which: (a) Creates a PLA-rich structure containing long chain crosslinks, (b) generates a low glass transition temperature phase covalently bonded to the PLA structure, and (c) provides a material which performs like LDPE in a blown film manufacturing operation. The technology developed is covered by NZ Patent 580231 (3). The patent is held by UniServices Ltd, The University of Auckland, New Zealand.

Ply-tear webbing energy absorber

NASA Technical Reports Server (NTRS)

Stevens, G. W. H.

1972-01-01

Ply-tear webbing is essentially two plain webbings that are bound together by a portion of the warps and that can be torn apart and do work by breaking the binders. Nylon webbing were woven to range in tear force from 1 to 10 kilonewtons. This force is substantially independent of speed, which was as high as 100 m/sec in some cases. A specific energy absorption of 90 J/g was achieved in the dry state. However, lower rated webbings that absorb approximately 40 J/g are recommended for use in practice where it is acceptable.

Assessment of tear film osmolarity using the TearLab™ osmometer in normal dogs and dogs with keratoconjunctivitis sicca.

PubMed

Sebbag, Lionel; Park, Shin Ae; Kass, Philip H; Maggs, David J; Attar, Mayssa; Murphy, Christopher J

2017-07-01

To evaluate repeatability and reproducibility of tear osmolarity measured using the TearLab ™ osmometer in normal dogs and to assess its diagnostic potential in dogs with keratoconjunctivitis sicca (KCS). Beagle dogs; six normal and five with KCS. Tear osmolarity and Schirmer tear test-1 (STT-1) values were obtained at various times. Normal dogs were assessed for diurnal variation and repeatability and reproducibility of measurements. Dogs with KCS were evaluated before and after 5 months' topical twice-daily therapy with 2% cyclosporine. Mean ± SD tear osmolarity (mOsm/L) was significantly higher in normal dogs (337.4 ± 16.2) than in dogs with KCS before therapy (306.2 ± 18.0; P < 0.0001), but not following therapy with 2% cyclosporine (330.5 ± 13.7; P = 1.00). Osmolarity readings lower than 325.5 mOsm/L were suggestive of KCS (84.8% sensitivity and 87.1% specificity). In normal dogs, tear osmolarity readings were stable during the daytime (P = 0.99). Repeated measurements revealed high variability and typically poor-to-moderate repeatability and reproducibility, although this was improved by taking three successive measurements at each session. Considering combined data from all dogs, a positive correlation existed between STT-1 and tear osmolarity measurements (Pearson's correlation test, P = 0.04, r = 0.62). Canine tear osmolarity as determined by TearLab ™ osmometer was variable, required multiple readings to be informative, and differed from values reported for humans. Dogs with KCS had a lower tear osmolarity than did normal dogs, and this increased following cyclosporine therapy. © 2016 American College of Veterinary Ophthalmologists.

Tear exchange and contact lenses: A review

PubMed Central

Muntz, Alex; Subbaraman, Lakshman N.; Sorbara, Luigina; Jones, Lyndon

2015-01-01

Tear exchange beneath a contact lens facilitates ongoing fluid replenishment between the ocular surface and the lens. This exchange is considerably lower during the wear of soft lenses compared with rigid lenses. As a result, the accumulation of tear film debris and metabolic by-products between the cornea and a soft contact lens increases, potentially leading to complications. Lens design innovations have been proposed, but no substantial improvement in soft lens tear exchange has been reported. Researchers have determined post-lens tear exchange using several methods, notably fluorophotometry. However, due to technological limitations, little remains known about tear hydrodynamics around the lens and, to-date, true tear exchange with contact lenses has not been shown. Further knowledge regarding tear exchange could be vital in aiding better contact lens design, with the prospect of alleviating certain adverse ocular responses. This article reviews the literature to-date on the significance, implications and measurement of tear exchange with contact lenses. PMID:25575892

Numerical models for continental break-up: Implications for the South Atlantic

NASA Astrophysics Data System (ADS)

Beniest, A.; Koptev, A.; Burov, E.

2017-03-01

We propose a mechanism that explains in one unified framework the presence of continental break-up features such as failed rift arms and high-velocity and high-density bodies that occur along the South Atlantic rifted continental margins. We used 2D and 3D numerical models to investigate the impact of thermo-rheological structure of the continental lithosphere and initial plume position on continental rifting and break-up processes. 2D experiments show that break-up can be 1) "central", mantle plume-induced and directly located above the centre of the mantle anomaly, 2) "shifted", mantle plume-induced and 50 to 200 km shifted from the initial plume location or 3) "distant", self-induced due to convection and/or slab-subduction/delamination and 300 to 800 km off-set from the original plume location. With a 3D, perfectly symmetrical and laterally homogeneous setup, the location of continental break-up can be shifted hundreds of kilometres from the initial position of the mantle anomaly. We demonstrate that in case of shifted or distant continental break-up with respect to the original plume location, multiple features can be explained. Its deep-seated source can remain below the continent at one or both sides of the newly-formed ocean. This mantle material, glued underneath the margins at lower crustal levels, resembles the geometry and location of high velocity/high density bodies observed along the South Atlantic conjugate margins. Impingement of vertically up-welled plume material on the base of the lithosphere results in pre-break-up topography variations that are located just above this initial anomaly impingement. This can be interpreted as aborted rift features that are also observed along the rifted margins. When extension continues after continental break-up, high strain rates can relocalize. This relocation has been so far attributed to rift jumps. Most importantly, this study shows that there is not one, single rift mode for plume-induced crustal break-up.

Antimicrobial Compounds in Tears

PubMed Central

McDermott, Alison M.

2013-01-01

The tear film coats the cornea and conjunctiva and serves several important functions. It provides lubrication, prevents drying of the ocular surface epithelia, helps provide a smooth surface for refracting light, supplies oxygen and is an important component of the innate defense system of the eye providing protection against a range of potential pathogens. This review describes both classic antimicrobial compounds found in tears such as lysozyme and some more recently identified such as members of the cationic antimicrobial peptide family and surfactant protein-D as well as potential new candidate molecules that may contribute to antimicrobial protection. As is readily evident from the literature review herein, tears, like all mucosal fluids, contain a plethora of molecules with known antimicrobial effects. That all of these are active in vivo is debatable as many are present in low concentrations, may be influenced by other tear components such as the ionic environment, and antimicrobial action may be only one of several activities ascribed to the molecule. However, there are many studies showing synergistic/additive interactions between several of the tear antimicrobials and it is highly likely that cooperativity between molecules is the primary way tears are able to afford significant antimicrobial protection to the ocular surface in vivo. In addition to effects on pathogen growth and survival some tear components prevent epithelial cell invasion and promote the epithelial expression of innate defense molecules. Given the protective role of tears a number of scenarios can be envisaged that may affect the amount and/or activity of tear antimicrobials and hence compromise tear immunity. Two such situations, dry eye disease and contact lens wear, are discussed here. PMID:23880529

Dry eye evaluation and correlation analysis between tear film stability and corneal surface regularity after small incision lenticule extraction.

PubMed

Zhang, Hui; Wang, Yan

2017-09-22

To investigate the dry eye after small incision lenticule extraction (SMILE) and explore the correlations between changes in the tear film stability, the tear secretion and the corneal surface regularity. Sixty-two eyes of 22 men and 13 women who underwent SMILE were included in this study. Corneal topography was measured to assess the index of surface variance (ISV) and the index of vertical asymmetry (IVA). Dry eye tests including subjective symptom questionnaire, tear breakup time (TBUT), corneal fluorescein staining and Schirmer's test (ST) were evaluated before and at 1 and 6 months postoperatively. TBUT was found to be significantly decreased from 9.8 ± 3.4 s preoperatively to 7.4 ± 3.8 s at 1 month and 6.5 ± 3.6 s at 6 months (both P < 0.001). There was a significant decrease in ST at 1 month postoperatively (P = 0.012); however, ST returned to baseline by 6 months (P = 0.522). Both ISV and IVA significantly increased after the surgery (all P < 0.001). In addition, the changes in TBUT were negatively correlated with the increases in ISV and IVA (r = -0.343, P = 0.006 and r = -0.311, P = 0.014, respectively). Patients undergoing SMILE might develop a short-TBUT type of dry eye. Corneal surface regularity indices might be helpful in the assessment of tear film stability following SMILE procedure.

[Alterations in tears aqueous layer during cytostatics treatment].

PubMed

Wojciechowska, Katarzyna; Wieckowska-Szakiel, Marzena; Rózalska, Barbara; Jurowski, Piotr

2013-01-01

The aim of the study was to evaluate tears secretion, pH and lysozyme activity in tears aqueous layer during chemotherapy in lung, breast and bowel cancer. 36 patients were enrolled to the study. Depending on the type of cancer and type of chemotherapy patients were divided into three groups. Group I (12 patients) diagnosed with non-small-cell lung cancer treated with PE schema (cisplatin, etoposide), Group II (12 patients) with breast cancer treated with FAC schema (fluorouracil, doxorubicin, cyclophosphamide), Group III (12 patients) with bowel cancer treated with FU/LV schema (fluorouracil, leucovorin). In all the patients: Schirmer's I test, pH measurements and lysozyme test were performed. Patients were examined before chemotherapy, after 2nd, 4th, 6th cycle. In group I and II lowering of tears secretion (p < 0.001) was revealed. In group III there was higher tears secretion (p < 0.001). PH was lowered after 2nd chemotherapy course in group I and II. In further treatment pH value were in the same lower level as after the second course. In group III there was higher pH--more alkaline (p < 0.001) after 2nd cycle of treatment and it was on the same level to the end of the examination process. Lowering of lysozyme activity in the tears film in all groups (p < 0.001) was established. The higher alterations of the lysozyme activity were observed in group treated with FAC schema. Cytostatic treatment has major influence on tears aqueous layer causing alterations of tears secretions. PH alterations depending on type of chemotherapy was observed. Lowering of lysozyme activity in tears was observed. All the deteriorations aggravate with duration of chemotherapy. Alterations of tears film parameters during chemotherapy may influence upon eye surface homeostasis and infectious complication. tears aqueous layer, Schirmer's test, lysozyme activity, tears pH.

Fluorophotometric measurement of the buffering action of human tears in vivo.

PubMed

Yamada, M; Kawai, M; Mochizuki, H; Hata, Y; Mashima, Y

1998-10-01

The buffering action of human tears is thought to be important to keep its pH constant. We measured the change in pH in the precorneal tear film in vivo when the acidic solution is challenged, using a fluorophotometric technique. Twelve eyes from 6 healthy subjects were entered in this study. Each subject was pretreated with either one drop of 0.4% oxybuprocaine for once (light anesthesia), three times (deep anesthesia), or none (controls). The measurement was initiated by instilling 20 microl of 0.067 M phosphate buffer at pH 5.5 containing 2 mM bis-carboxyethyl-carboxyfluorescein free acid, a pH sensitive dye, into the subject's eye. The pH was determined by the ratio of fluorescent intensities at two excitation wavelengths (490 and 430 nm). pH recovery time (PHRT) as defined by the time required for pH to reach 95% of pH at equilibrium was used for the marker of tear buffering action. Tear turnover rate was also determined using the fluorescent decay curve at 430 nm, which was independent of pH, but dependent on dye concentration. Immediately after the instillation, the pH value in the tear film was around 6.0-6.5 in all cases. The tear film rapidly became more alkaline, reaching its normal value in 2.3 +/- 0.5 min in untreated eyes. The pretreatment with 0.4% oxybuprocaine retarded the neutralization process. A single regression analysis revealed that the PHRT had a significant negative correlation with the tear turnover rate (r = -0.78). Our results suggest that the neutralization process of tears largely depends on the tear turnover rate. The buffering action of tears in vivo consists of the tear turnover as well as its chemical buffering capacity.

Effects of phytoestrogen supplementation in postmenopausal women with dry eye syndrome: a randomized clinical trial.

PubMed

Scuderi, Gianluca; Contestabile, Maria Teresa; Gagliano, Caterina; Iacovello, Daniela; Scuderi, Luca; Avitabile, Teresio

2012-12-01

To evaluate the correlation between tear osmolarity and blood levels of 17-β estradiol, estrone, and testosterone in postmenopausal women with dry eye syndrome, and to assess the efficacy and safety of oral supplementation with phytoestrogens, lipoic acid, and eicosapentaenoic acid in this population. Cross-sectional study including 66 postmenopausal women with dry eye syndrome. Sixty-six postmenopausal women with dry eye syndrome were enrolled in a randomized, double-blind, placebo-controlled, crossover study. Patients were divided into 2 groups (groups A and B) and treated, respectively, with phytoestrogen (Bioos, Montegiorgio, Italy) tablets or placebo tablets for 30 days. The 2 treatment periods were separated by a 30-day washout. Patients were examined on days 0 and 30 of each period. Assessments included blood levels of sex hormones, the Schirmer test for tear production, and measurement of tear osmolarity and tear film break-up time. At baseline, all patients had low sex hormone levels, which were correlated with high tear film osmolarity values (r = -0.59,-0.61,-0.58, respectively). After 30 days of therapy, the group treated with Lacrisek® (Bioos) had significantly decreased tear osmolarity (P<0.005) and significantly increased tear production evaluated with the Schirmer test and tear film break-up time values (P<0.001) compared with the placebo-treated group. Our study confirms that steroid hormones play an important role in ocular surface equilibrium and functions. Consequently, reduced blood levels of these hormones can produce changes at the ocular surface. Phytoestrogen supplementation can significantly improve the signs and symptoms of dry eye syndrome in postmenopausal women. Copyright © 2012 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

Monitoring ice break-up on the Mackenzie River using MODIS data

NASA Astrophysics Data System (ADS)

Muhammad, P.; Duguay, C.; Kang, K.-K.

2016-03-01

The aim of this study was to develop an approach for estimating ice break-up dates on the Mackenzie River (MR) using more than a decade of MODIS Level 3 500 m snow products (MOD/MYD10A1), complemented with 250 m Level 1B radiance products (MOD/MYD02QKM) from the Terra and Aqua satellite platforms. The analysis showed break-up began on average between days of year (DOYs) 115 and 125 and ended between DOYs 145 and 155 over 13 ice seasons (2001-2013), resulting in an average melt duration of ca. 30-40 days. Thermal processes were more important in driving ice break-up south of the MR confluence with the Liard River, while dynamically driven break-up was more important north of the Liard. A comparison of the timing of ice disappearance with snow disappearance from surrounding land areas of the MR with MODIS Level 3 snow products showed varying relationships along the river. Ice-off and snow-off timing were in sync north of the MR-Liard River confluence and over sections of the MR before it enters the Mackenzie Delta, but ice disappeared much later than snow on land in regions where thermal ice break-up processes dominated. MODIS observations revealed that channel morphology is a more important control of ice break-up patterns than previously believed with ice runs on the MR strongly influenced by channel morphology (islands and bars, confluences and channel constriction). Ice velocity estimates from feature tracking were able to be made in 2008 and 2010 and yielded 3-4-day average ice velocities of 1.21 and 1.84 m s-1 respectively, which is in agreement with estimates from previous studies. These preliminary results confirm the utility of daily MODIS data for monitoring ice break-up processes along the Mackenzie River. The addition of optical and synthetic aperture radar data from recent and upcoming satellite missions (e.g. Sentinel-1/2/3 and RADARSAT Constellation) would improve the monitoring of ice break-up in narrower sections of the MR.

Hard Break-Up of Two-Nucleons and QCD Dynamics of NN Interaction

NASA Astrophysics Data System (ADS)

Sargsian, Misak; Granados, Carlos

2009-05-01

We investigate hard photodisintegration of two nucleons from ^3He nucleus within the framework of hard rescattering model (HRM). In HRM a quark of one nucleon knocked-out by incoming photon rescatters with a quark of the other nucleon leading to the production of two nucleons with high relative momentum. HRM allows to express the amplitude of two-nucleon break-up reaction through the convolution of photon-quark scattering, NN hard scattering amplitude and nuclear spectral function which can be calculated using nonrelativistic ^3He wave function. HRM predicts several specific features for hard break-up reaction. First, the cross section will approximately scale as s-11. Also one predicts comparable or larger cross section for pp break up as compared to that of pn break-up, which is opposite to what is observed in low energy kinematics. Another result is the prediction of different spectator momentum dependencies of pp and pn break-up cross sections. This is due to the fact that same-helicity pp-component is strongly suppressed in the ground state wave function of ^3He. Due to this suppression HRM predicts significantly different asymmetries for the cross section of polarization transfer NN break-up reactions for circularly polarized photons. For the pp break-up this asymmetry is predicted to be zero while for the pn it is close to 23.

A Clinical Study of Subtype-based Prevalence of Dry Eye.

PubMed

Rege, Aditya; Kulkarni, Varsha; Puthran, Neelam; Khandgave, Tejaswini

2013-10-01

Dry Eye is a multifactorial disease of the tearfilm and the ocular surface which may be due to reduced tear production or excessive tear evaporation resulting in discomfort, visual disturbance, and tear film instability with a potential damage to the ocular surface. Various population-based studies have been done to find out the prevalence and the magnitude of the problem. Women Health Study reported prevalence of 7.8% after screening 36995 subjects above 49 years by interview. The prevalence reported by Blue Mountain Study was 15.3% .The Beaver Dam Study and Shiphai Eye studies are other studies reporting prevalence of 14.5% and 33.7% respectively. McMonnies questionnaire is a widely used screening instrument for Dry-Eye syndromes with sensitivity reportedly varying between 87% and 98% and specificity between 87% and 97%. Prevalence studies use McMonnie's questionnaire for screening individuals for Dry Eye, whereafter tests like Schirmer's test, Tear Film Break Up Time test, Rose Bengal test, Lissamine Green test and Meibomian Gland Dysfunction test are useful for further evaluation. While these tests help to differentiate the subtypes of Dry Eye such as Lipid Anomaly Dry Eye, Aqueous Tear Deficiency and Mucin Layer Deficiency, however, their sensitivity and specificity has not been widely studied. Additionally, very few studies have reported the prevalence of the various subtypes of Dry Eye. To determine the subtype-based prevalence of Dry Eye, to study the specificity and sensitivity of clinical tests for Dry Eye and to correlate McMonnies questionnaire with Dry Eye tests results. A prospective, cross-sectional, observational study, duly approved by the Institutional Ethics Committee, was conducted from October 2010 to April 2012. A total of 4750 subjects above 18 yrs of age were screened by the McMonnies questionnaire. Respondents having a score greater than 14.5 were subjected to clinical Dry Eye tests. The data obtained was analyzed using chi-square test. p

Extensive characterization of human tear fluid collected using different techniques unravels the presence of novel lipid amphiphiles1[S

PubMed Central

Lam, Sin Man; Tong, Louis; Duan, Xinrui; Petznick, Andrea; Wenk, Markus R.; Shui, Guanghou

2014-01-01

The tear film covers the anterior eye and the precise balance of its various constituting components is critical for maintaining ocular health. The composition of the tear film amphiphilic lipid sublayer, in particular, has largely remained a matter of contention due to the limiting concentrations of these lipid amphiphiles in tears that render their detection and accurate quantitation tedious. Using systematic and sensitive lipidomic approaches, we validated different tear collection techniques and report the most comprehensive human tear lipidome to date; comprising more than 600 lipid species from 17 major lipid classes. Our study confers novel insights to the compositional details of the existent tear film model, in particular the disputable amphiphilic lipid sublayer constituents, by demonstrating the presence of cholesteryl sulfate, O-acyl-ω-hydroxyfatty acids, and various sphingolipids and phospholipids in tears. The discovery and quantitation of the relative abundance of various tear lipid amphiphiles reported herein are expected to have a profound impact on the current understanding of the existent human tear film model. PMID:24287120

The Fate of Meniscus Tears Left in situ at the time of Anterior Cruciate Ligament Reconstruction: A 6-year Follow-up Study from the MOON Cohort

PubMed Central

Duchman, Kyle R.; Westermann, Robert W.; Spindler, Kurt P.; Reinke, Emily K.; Huston, Laura J.; Amendola, Annunziato; Wolf, Brian R.

2016-01-01

Background The management of meniscus tears identified at the time of primary ACL reconstruction is highly variable and includes repair, meniscectomy, and non-treatment. Hypothesis/Purpose The purpose of this study is to determine the reoperation rate for meniscus tears left untreated at the time of ACL reconstruction with minimum follow-up of 6 years. We hypothesize that small, peripheral tears identified at the time of ACL reconstruction managed with “no treatment” will have successful clinical outcomes. Study Design Retrospective study of a prospective cohort; Level of Evidence, 3 Methods Patients with meniscus tears left untreated at the time of primary ACL reconstruction were identified from a multicenter study group with minimum 6-year follow-up. Patient, tear, and reoperation data were obtained for analysis. Need for reoperation was used as the primary endpoint, with analysis performed to determine patient and tear characteristics associated with reoperation. Results There were 194 patients with 208 meniscus tears (71 medial; 137 lateral) left in situ without treatment with complete follow-up for analysis. Of these, 97.8% of lateral and 94.4% of medial untreated tears required no reoperation. Sixteen tears (7.7%) left in situ without treatment underwent subsequent reoperation: 9 tears (4.3%) underwent reoperation in the setting of revision ACL reconstruction and 7 tears (3.4%) underwent reoperation for isolated meniscus pathology. Patient age was significantly lower in patients requiring reoperation, while tears measuring ≥ 10 mm more frequently required reoperation. Conclusions Lateral and medial meniscus tears left in situ at the time of ACL reconstruction did not require reoperation at minimum 6-year follow-up for 97.8% and 94.4% of tears, respectively. These findings reemphasize the low reoperation rate following non-treatment of small, peripheral lateral meniscus tears while noting less predictable results for medial meniscus tears left without

The Fate of Meniscus Tears Left In Situ at the Time of Anterior Cruciate Ligament Reconstruction: A 6-Year Follow-up Study From the MOON Cohort.

PubMed

Duchman, Kyle R; Westermann, Robert W; Spindler, Kurt P; Reinke, Emily K; Huston, Laura J; Amendola, Annunziato; Wolf, Brian R

2015-11-01

The management of meniscus tears identified at the time of primary anterior cruciate ligament (ACL) reconstruction is highly variable and includes repair, meniscectomy, and nontreatment. The purpose of this study was to determine the reoperation rate for meniscus tears left untreated at the time of ACL reconstruction with a minimum follow-up of 6 years. The hypothesis was that small peripheral tears identified at the time of ACL reconstruction managed with "no treatment" would have successful clinical outcomes. Cohort study; Level of evidence, 3. Patients with meniscus tears left untreated at the time of primary ACL reconstruction were identified from a multicenter study group with a minimum 6-year follow-up. Patient, tear, and reoperation data were obtained for analysis. The need for reoperation was used as the primary endpoint, with analysis performed to determine patient and tear characteristics associated with reoperation. There were 194 patients with 208 meniscus tears (71 medial, 137 lateral) left in situ without treatment with a complete follow-up for analysis. Of these, 97.8% of lateral and 94.4% of medial untreated tears required no reoperation. Sixteen tears (7.7%) left in situ without treatment underwent subsequent reoperation: 9 tears (4.3%) underwent reoperation in the setting of revision ACL reconstruction, and 7 tears (3.4%) underwent reoperation for an isolated meniscus injury. The patient age was significantly lower in patients requiring reoperation, while tears measuring ≥10 mm more frequently required reoperation. Lateral and medial meniscus tears left in situ at the time of ACL reconstruction did not require reoperation at a minimum 6-year follow-up for 97.8% and 94.4% of tears, respectively. These findings re-emphasize the low reoperation rate after the nontreatment of small, peripheral lateral meniscus tears while noting less predictable results for medial meniscus tears left without treatment. © 2015 The Author(s).

Antimicrobial compounds in tears.

PubMed

McDermott, Alison M

2013-12-01

The tear film coats the cornea and conjunctiva and serves several important functions. It provides lubrication, prevents drying of the ocular surface epithelia, helps provide a smooth surface for refracting light, supplies oxygen and is an important component of the innate defense system of the eye providing protection against a range of potential pathogens. This review describes both classic antimicrobial compounds found in tears such as lysozyme and some more recently identified such as members of the cationic antimicrobial peptide family and surfactant protein-D as well as potential new candidate molecules that may contribute to antimicrobial protection. As is readily evident from the literature review herein, tears, like all mucosal fluids, contain a plethora of molecules with known antimicrobial effects. That all of these are active in vivo is debatable as many are present in low concentrations, may be influenced by other tear components such as the ionic environment, and antimicrobial action may be only one of several activities ascribed to the molecule. However, there are many studies showing synergistic/additive interactions between several of the tear antimicrobials and it is highly likely that cooperativity between molecules is the primary way tears are able to afford significant antimicrobial protection to the ocular surface in vivo. In addition to effects on pathogen growth and survival some tear components prevent epithelial cell invasion and promote the epithelial expression of innate defense molecules. Given the protective role of tears a number of scenarios can be envisaged that may affect the amount and/or activity of tear antimicrobials and hence compromise tear immunity. Two such situations, dry eye disease and contact lens wear, are discussed here. Copyright © 2013 Elsevier Ltd. All rights reserved.

Tear exchange and contact lenses: a review.

PubMed

Muntz, Alex; Subbaraman, Lakshman N; Sorbara, Luigina; Jones, Lyndon

2015-01-01

Tear exchange beneath a contact lens facilitates ongoing fluid replenishment between the ocular surface and the lens. This exchange is considerably lower during the wear of soft lenses compared with rigid lenses. As a result, the accumulation of tear film debris and metabolic by-products between the cornea and a soft contact lens increases, potentially leading to complications. Lens design innovations have been proposed, but no substantial improvement in soft lens tear exchange has been reported. Researchers have determined post-lens tear exchange using several methods, notably fluorophotometry. However, due to technological limitations, little remains known about tear hydrodynamics around the lens and, to-date, true tear exchange with contact lenses has not been shown. Further knowledge regarding tear exchange could be vital in aiding better contact lens design, with the prospect of alleviating certain adverse ocular responses. This article reviews the literature to-date on the significance, implications and measurement of tear exchange with contact lenses. Copyright © 2014 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Ten-year clinical and anatomic follow-up after repair of anterosuperior rotator cuff tears: influence of the subscapularis.

PubMed

Nové-Josserand, Laurent; Collin, Philippe; Godenèche, Arnaud; Walch, Gilles; Meyer, Nicolas; Kempf, Jean-Francois

2017-10-01

Anterosuperior rotator cuff tears are more frequent than expected. We report the results of a 10-year follow-up study after repair. Our hypothesis was that the extent of the subscapularis tear influenced the prognosis. The study population consisted of all 138 patients who underwent surgery in 14 participating centers in 2003 for full-thickness tears of the rotator cuff with lesions in the subscapularis and supraspinatus tendons. The patients were divided into 2 groups, depending on whether the subscapularis lesion affected only the superior half of the tendon (group A) or extended into the lower half (group B). Ninety-two patients (56 ± 7 years; 71 in group A and 21 in group B) were available for follow-up after 10 years (127 ± 16 months) with magnetic resonance imaging to evaluate tendon healing and muscle condition. The mean Constant scores were 59 ± 16 before surgery and 77 ± 14 at follow-up (P = 1.7 × 10 -12 ). The retear rates were 25% for the supraspinatus and 13.5% for the subscapularis tendon. The clinical results for group A patients were better than those for group B. Severe fatty infiltration was observed more frequently in the subscapularis than in the supraspinatus muscle (27% vs. 12% of cases). Supraspinatus healing influenced subscapularis healing and fatty infiltration. Repair of anterosuperior rotator cuff tears is satisfactory at 10 years, particularly if the subscapularis tear is not extensive. An extensive subscapularis tear is a negative prognosis factor. Postoperatively, fatty infiltration of the subscapularis muscle was frequently observed despite tendon healing. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Spectral-domain optical coherence tomography study on dynamic changes of human tears after instillation of artificial tears.

PubMed

Napoli, Pietro Emanuele; Satta, Giovanni Maria; Coronella, Franco; Fossarello, Maurizio

2014-07-01

To analyze in vivo the dynamic changes induced by different artificial tears (ATs) in the precorneal tear film (PCTF) and lower tear meniscus (LTM) by using spectral-domain (SD) anterior segment optical coherence tomography (OCT). We prospectively examined 42 normal human eyes by using SD-OCT imaging. On the day before OCT imaging, all enrolled subjects were evaluated for abnormalities of ocular surface. All tear film images were obtained before and after instillation of three different types of ATs (mucomimetic, lipid-based, and saline) in five serial scans: immediately (within 30 seconds), at the first, fifth, 10th, and 20th minute. Subjects received a drop of 35 μL in one randomly selected eye. All examinations were conducted in the same conditions of temperature, brightness, humidity, and time of day. Changes in the morphological pattern of both LTM and PCTF were associated with the type of artificial tear instilled on the ocular surface. Similarly, the radius of curvature (rc), the height (h), and the depth (d) showed dynamic variations depending on treatment. Although by the 20th minute, both h and d returned to baseline values in all groups, a significant difference in rc (compared with baseline) was detected for mucomimetic ATs (P = 0.04) and lipid ATs (P = 0.02). Spectral-domain OCT imaging has preliminarily proved to be a noninvasive tool to evaluate, in real time, the different changes induced by ATs instillation. An important stride in understanding the clinical response to various tear substitutes can be achieved by this objective and quantitative approach. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

[Clinical characteristics of short tear film breakup time (BUT) -type dry eye].

PubMed

Yamamoto, Yuji; Yokoi, Norihiko; Higashihara, Hisayo; Inagaki, Kayoko; Sonomura, Yukiko; Komuro, Aoi; Kinoshita, Shigeru

2012-12-01

To evaluate the clinical characteristics and management of short tear film breakup time (BUT) -type dry eye. Clinical background and post-treatment changes of symptoms in 77 patients with short BUT -type dry eye were investigated. Treatment consisted of artificial-tear eye-drop instillation and, if necessary, the addition of a low-density-level steroid, hyaluronic acid, a low-density-level cyclopentolate prepared by ourselves and punctal plugs inserted into the upper and lower lacrimal puncta. There were three times more women than men among the patients, and the peak age of occurrence was in the twenties in the men and in the sixties in the women. Our findings show that visual display terminal (VDT) work, contact lens (CL) wear, and changes in the sex hormones may initiate subjective symptoms. Some patients had simultaneous conjunctivochalasis, allergic conjunctivitis, and meibomian gland dysfunction. Nineteen patients (24.7%) were effectively treated with eye-drop instillation alone. Thirty-seven patients (48.1%) required punctal-plug insertion, which was completely effective in only 8 of them (21.6%). Mainly young men and menopausal women contract short BUT -type dry eye. Changes in sex hormones, VDT work and CL wear may be causal, and the disease cannot be controlled by eyedrop and punctal-plug treatment alone.

A mass and solute balance model for tear volume and osmolarity in the normal and the dry eye.

PubMed

Gaffney, E A; Tiffany, J M; Yokoi, N; Bron, A J

2010-01-01

Tear hyperosmolarity is thought to play a key role in the mechanism of dry eye, a common symptomatic condition accompanied by visual disturbance, tear film instability, inflammation and damage to the ocular surface. We have constructed a model for the mass and solute balance of the tears, with parameter estimation based on extensive data from the literature which permits the influence of tear evaporation, lacrimal flux and blink rate on tear osmolarity to be explored. In particular the nature of compensatory events has been estimated in aqueous-deficient (ADDE) and evaporative (EDE) dry eye. The model reproduces observed osmolarities of the tear meniscus for the healthy eye and predicts a higher concentration in the tear film than meniscus in normal and dry eye states. The differential is small in the normal eye, but is significantly increased in dry eye, especially for the simultaneous presence of high meniscus concentration and low meniscus radius. This may influence the interpretation of osmolarity values obtained from meniscus samples since they need not fully reflect potential damage to the ocular surface caused by tear film hyperosmolarity. Interrogation of the model suggests that increases in blink rate may play a limited role in compensating for a rise in tear osmolarity in ADDE but that an increase in lacrimal flux, together with an increase in blink rate, may delay the development of hyperosmolarity in EDE. Nonetheless, it is predicted that tear osmolarity may rise to much higher levels in EDE than ADDE before the onset of tear film breakup, in the absence of events at the ocular surface which would independently compromise tear film stability. Differences in the predicted responses of the pre-ocular tears in ADDE compared to EDE or hybrid disease to defined conditions suggest that no single, empirically-accessible variable can act as a surrogate for tear film concentration and the potential for ocular surface damage. This emphasises the need to measure

Atomic physics effects on tokamak edge drift-tearing modes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hahm, T.S.

1993-03-01

The effects of ionization and charge exchange on the linear stability of drift-tearing modes are analytically investigated. In particular, the linear instability threshold {Delta}{sup Th}, produced by ion sound wave coupling is modified. In the strongly collisional regime, the ionization breaks up the near cancellation of the perturbed electric field and the pressure gradient along the magnetic field, and increases the threshold. In the semi-collisional regime, both ionization and charge exchange act as drag on the ion parallel velocity, and consequently decrease the threshold by reducing the effectiveness of ion sound wave propagation.

Atomic physics effects on tokamak edge drift-tearing modes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hahm, T.S.

1993-03-01

The effects of ionization and charge exchange on the linear stability of drift-tearing modes are analytically investigated. In particular, the linear instability threshold [Delta][sup Th], produced by ion sound wave coupling is modified. In the strongly collisional regime, the ionization breaks up the near cancellation of the perturbed electric field and the pressure gradient along the magnetic field, and increases the threshold. In the semi-collisional regime, both ionization and charge exchange act as drag on the ion parallel velocity, and consequently decrease the threshold by reducing the effectiveness of ion sound wave propagation.

Corneal Sensitivity in Tear Dysfunction and its Correlation with Clinical Parameters and Blink Rate

PubMed Central

Rahman, Effie Z.; Lam, Peter K.; Chu, Chia-Kai; Moore, Quianta; Pflugfelder, Stephen C.

2015-01-01

Purpose To compare corneal sensitivity in tear dysfunction due to a variety of causes using contact and non-contact esthesiometers and to evaluate correlations between corneal sensitivity, blink rate and clinical parameters. Design Comparative observational case series. Methods Ten normal and 33 subjects with tear dysfunction [meibomian gland disease (n = 11), aqueous tear deficiency (n = 10) - without (n = 7) and with (n = 3) Sjögren syndrome (SS) and conjunctivochalasis (n = 12)] were evaluated. Corneal sensitivity was measured with Cochet-Bonnet and air jet esthesiometers and blink rate by electromyelography. Eye irritation symptoms, tear meniscus height, tear break-up time (TBUT), and corneal and conjunctival dye staining were measured. Between group means were compared and correlations calculated. Results Compared with control (Cochet-Bonnet 5.45 mm, air esthesiometer 3.62 mg), mean sensory thresholds were significantly higher in aqueous tear deficiency using either Cochet-Bonnet (3.6 mm; P = 0.003) or air (11.7 mg; P = 0.046) esthesiometers, but were not significantly different in the other groups. Reduced corneal sensitivity significantly correlated with more rapid TBUT and blink rate, and greater irritation and ocular surface dye staining with one or both esthesiometers. Mean blink rates were significantly higher in both aqueous tear deficiency and conjunctivochalasis compared with control. Among all subjects, blink rate positively correlated with ocular surface staining and irritation and inversely correlated with TBUT. Conclusion Amongst conditions causing tear dysfunction, reduced corneal sensitivity is associated with greater irritation, tear instability, ocular surface disease and blink rate. Rapid blinking is associated with worse ocular surface disease and tear stability. PMID:26255576

Nebraska to Break Up Omaha District

ERIC Educational Resources Information Center

Archer, Jeff

2006-01-01

Nebraska lawmakers the week of April 10, 2006 approved a hotly debated bill to break up the Omaha Public Schools--largely along racial and ethnic lines--under a plan that critics say amounts to state-sanctioned segregation and that likely will face a legal challenge. Passed April 13, 2006 in the last hours of the legislative session and signed the…

Human tear serotonin levels correlate with symptoms and signs of dry eye

PubMed Central

Chhadva, Priyanka; Lee, Tinthu; Sarantopoulos, Constantine D.; Hackam, Abigail S.; McClellan, Allison L.; Felix, Elizabeth R.; Levitt, Roy C.; Galor, Anat

2015-01-01

Purpose Serotonin, a neurotransmitter known to be involved in nociceptor sensitization, is present in human tears. The purpose of this study was to correlate tear serotonin levels, as a marker of nociceptor sensitization, to facets of dry eye (DE) including symptoms and signs. Design Cross-sectional study Participants Sixty-two patients with normal eyelid and corneal anatomy were prospectively recruited from a Veterans Administration Ophthalmology Clinic over 11 months. Methods DE symptoms (Ocular Surface Disease Index [OSDI]), signs (tear break-up time [TBUT], corneal staining, and Schirmer’s score), and clinical descriptors of neuropathic ocular pain (NOP) (sensitivity to light and/or sensitivity to wind) were assessed. For tear analysis, each patient’s tears were collected after instilling 50µl of sterile saline to the lower cul-de-sac of each eye and using capillary action microcaps to collect the ocular wash. Tear serotonin levels were measured using enzyme-linked immunosorbent assay. Main Outcomes Measured Correlations between tear serotonin concentrations and DE symptoms and signs. Results The mean age of the population was 61±14 years and 84% (n=52) of the patients were male. Serotonin concentrations negatively correlated with Schirmer’s scores (r=−0.28; p=0.02), but did not correlate with other DE parameters, such as OSDI scores, sensitivity to light or wind, TBUT, or staining. According to our hypothesis, we divided patients into groups based on both DE symptoms and aqueous tear production; serotonin concentrations were found to be significantly higher in DE group 1 (OSDI≥6 and Schirmer’s<8) compared to both DE group 2 (OSDI≥6 and Schirmer’s≥8) and controls (OSDI<6 and Schirmer’s≥8). Patients in the DE group 2 more frequently complained of sensitivity to light (64%) and wind (67%) compared to the DE group 1 (40% and 60%, respectively) and controls (8% and 17%, respectively). Conclusion Patients with DE symptoms and aqueous tear

Comparative role of 20% cord blood serum and 20% autologous serum in dry eye associated with Hansen's disease: a tear proteomic study.

PubMed

Mukhopadhyay, Somnath; Sen, Swarnali; Datta, Himadri

2015-01-01

To compare the role of topically applied serum therapy with preservative-free artificial tear (AT) drops in patients with moderate to severe dry eye in Hansen's disease along with change in tear protein profile. 144 consecutive patients were randomly divided into three groups. After a baseline examination of clinical parameters, each of the patients received designated modality of topical therapy six times a day for 6 weeks. Post-treatment documentation of clinical parameters was done at 6 weeks, and then at 12 weeks after discontinuation of topical therapy. Analysis of three tear proteins using gel electrophoresis (sodium dodecyl sulfate polyacrylamide gel electrophoresis) was done at baseline, at the first and second post-treatment visits. In the cord blood serum (CBS) group, except for McMonnies score and staining score, all other clinical parameters showed continued improvement in the first and second post-treatment analyses. In the autologous serum (ALS) group, all the clinical parameters except Schirmer's I showed significant improvement in the first post-treatment analysis .This was sustained at a significant level in the second analysis except for tear film break-up time (TBUT) and conjunctival impression cytology grading. In the AT group, all the parameters improved at a non-significant level except for TBUT in the first analysis. In the next analysis, apart from McMonnies score and TBUT, other clinical parameters did not improve. In the ALS and CBS groups, tear lysozyme, lactoferrin levels improved in both post-treatment measurements (statistically insignificant).Total tear protein continued to increase at statistically significant levels in the first and second post-treatment analyses in the CBS group and at a statistically insignificant level in the ALS group. In the AT group, the three tear proteins continued to decrease in both the analyses. In moderate to severe dry eye in Hansen's disease, serum therapy in comparison with AT drops, improves

Effect of breaking up sedentary time with callisthenics on endothelial function.

PubMed

Carter, Sophie E; Gladwell, Valerie F

2017-08-01

Periods of prolonged sitting impairs endothelial function in lower limb conduit arteries, which is attenuated with physical activity breaks. The effect of activity breaks on upper limb arteries has not been examined. This study assessed changes in brachial artery endothelial function following either a prolonged sitting period or breaking up this sedentary time by performing sets of callisthenics exercises. Ten healthy participants (6 men) completed 2 conditions in a counterbalanced order: (a) 1-h 26-min sitting, or (b) breaking up this period every 20 min by performing a set of 5 callisthenics exercises. Brachial artery endothelial function was assessed via ultrasound using the flow-mediated dilation (FMD) technique prior to and following each condition, while brachial shear rate (SR) was acquired after each set of callisthenics. There was no significant change in FMD over time (P = 0.09) or between conditions (P = 0.12). Compared to sitting, brachial SR increased following each set of callisthenics, with a significant difference after the third break (Sit: 33.94 ± 12.79 s -1 ; Callisthenics: 57.16 ± 30.48 s -1 , P = 0.02). Alterations in SR in the upper limbs suggest callisthenics may be an effective intervention to break up sedentary time and attenuate the potentially deleterious effects of prolonged sitting on cardiovascular health.

Elastic and break-up of the 1n-halo 11Be nucleus

NASA Astrophysics Data System (ADS)

Di Pietro, A.; Moro, A. M.; Acosta, L.; Amorini, F.; Borge, M. J. G.; Figuera, P.; Fisichella, M.; Fraile, L. M.; Gomez-Camacho, J.; Jeppesen, H.; Lattuada, M.; Martel, I.; Milin, M.; Musumarra, A.; Papa, M.; Pellegriti, M. G.; Perez-Bernal, F.; Raabe, R.; Randisi, G.; Rizzo, F.; Scuderi, V.; Tengblad, O.; Torresi, D.; Vidal, A. Maira; Voulot, D.; Wenander, F.; Zadro, M.

2014-03-01

The elastic and break-up angular distributions of the 10,11Be+64Zn reactions measured at Ec.m.≈1.4 VC have been analysed within the CCDC and O.M. frameworks. The suppression of the Coulomb-nuclear interference, observed in the 11Be scattering case with respect to the 10Be, has been interpreted as due to a long range absorption owing to the coupling with the break-up (Coulomb and nuclear) channels. The presence of 10Be events on the 11Be experiment data have been explained as due mainly to break-up processes.

Reducing Short-Wavelength Blue Light in Dry Eye Patients with Unstable Tear Film Improves Performance on Tests of Visual Acuity.

PubMed

Kaido, Minako; Toda, Ikuko; Oobayashi, Tomoo; Kawashima, Motoko; Katada, Yusaku; Tsubota, Kazuo

2016-01-01

To investigate whether suppression of blue light can improve visual function in patients with short tear break up time (BUT) dry eye (DE). Twenty-two patients with short BUT DE (10 men, 12 women; mean age, 32.4 ± 6.4 years; age range, 23-43 years) and 18 healthy controls (10 men, 8 women; mean age, 30.1 ± 7.4 years; age range, 20-49 years) underwent functional visual acuity (VA) examinations with and without wearing eyeglasses with 50% blue light blocked lenses. The functional VA parameters were starting VA, functional VA, and visual maintenance ratio. The baseline mean values (logarithm of the minimum angle of resolution, logMAR) of functional VA and the visual maintenance ratio were significantly worse in the DE patients than in the controls (P < 0.05), while no significant difference was observed in the baseline starting VA (P > 0.05). The DE patients had significant improvement in mean functional VA and visual maintenance ratio while wearing the glasses (P < 0.05), while there were no significant changes with and without the glasses in the control group (P > 0.05). Protecting the eyes from short-wavelength blue light may help to ameliorate visual impairment associated with tear instability in patients with DE. This finding represents a new concept, which is that the blue light exposure might be harmful to visual function in patients with short BUT DE.

Reducing Short-Wavelength Blue Light in Dry Eye Patients with Unstable Tear Film Improves Performance on Tests of Visual Acuity

PubMed Central

Kaido, Minako

2016-01-01

Purpose To investigate whether suppression of blue light can improve visual function in patients with short tear break up time (BUT) dry eye (DE). Methods Twenty-two patients with short BUT DE (10 men, 12 women; mean age, 32.4 ± 6.4 years; age range, 23–43 years) and 18 healthy controls (10 men, 8 women; mean age, 30.1 ± 7.4 years; age range, 20–49 years) underwent functional visual acuity (VA) examinations with and without wearing eyeglasses with 50% blue light blocked lenses. The functional VA parameters were starting VA, functional VA, and visual maintenance ratio. Results The baseline mean values (logarithm of the minimum angle of resolution, logMAR) of functional VA and the visual maintenance ratio were significantly worse in the DE patients than in the controls (P < 0.05), while no significant difference was observed in the baseline starting VA (P > 0.05). The DE patients had significant improvement in mean functional VA and visual maintenance ratio while wearing the glasses (P < 0.05), while there were no significant changes with and without the glasses in the control group (P > 0.05), Conclusions Protecting the eyes from short-wavelength blue light may help to ameliorate visual impairment associated with tear instability in patients with DE. This finding represents a new concept, which is that the blue light exposure might be harmful to visual function in patients with short BUT DE. PMID:27045760

High Energy Break-Up of Few-Nucleon Systems

NASA Astrophysics Data System (ADS)

Sargsian, Misak

2008-03-01

We discus recent developments in theory of high energy two-body break-up reactions of few-nucleon systems. The characteristics of these reactions are such that the hard two-body quasielastic subprocess can be clearly separated from the accompanying soft subprocesses. We discuss in details the hard rescattering model (HRM) in which hard photodisintegration develops in two stages. At first, photon knocks-out an energetic quark which rescatters subsequently with a quark of the other nucleon. The latter provides a mechanism of sharing the initial high momentum of the photon by the outgoing two nucleons. Within HRM we discuss hard break-up reactions involving 2D and 3He targets. Another development of HRM is the prediction of new helicity selection mechanism for hard two-body reactions, which was apparently confirmed in the recent JLab experiment.

Does partial tear repair of adjacent tendons improve the outcome of supraspinatus tendonfull-thickness tear reinsertion?

PubMed

Nich, C; Dhiaf, N; Di Schino, M; Augereau, B

2014-11-01

Partial tearing of the infraspinatus and/or subscapularis tendon(s) is frequently associated with supraspinatus full-thickness tears. However, limited data regarding its influence on supraspinatus surgical repair is available. Our aim was to assess the functional and anatomical outcomes of open repair of supraspinatus full-thickness tears combined with adjacent partial tearing, comparatively to a control. We retrospectively identified 22 patients (22 shoulders) with a partial tear, most of them being a delamination tear, of the infraspinatus and/or subscapularis tendons associated with a complete detachment of the supraspinatus tendon. Twenty-seven patients (27 shoulders) treated for an isolated complete detachment of the supraspinatus tendon by open repair served as controls. The mean age was 58 years. A proximalized trans-osseous reinsertion of the supraspinatus tendon was combined with a curettage-closure of the delamination tear. Patients were evaluated with standardized MRI at last follow-up. At a mean of 75-month follow-up, the presence of a partial tear of either infraspinatus or subscapularis, or both, did not influence function and healing rates of supraspinatus tendon repair. Conversely to the control, when a retear occurred, the functional score tended to worsen. Preoperatively, fatty muscular degeneration was more pronounced when a partial tear was present. Fatty degeneration worsened regardless of repair healing. Open reinsertion of a supraspinatus full-thickness tear associated with a thorough treatment of partial tear of adjacent tendons led to optimal functional and anatomical mid term outcomes. Our results suggest the presence of a partial tear of adjacent tendons could be associated with poorer function in case of supraspinatus tendon re-rupture. Level III case-control study. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

SFTA3 - a novel surfactant protein of the ocular surface and its role in corneal wound healing and tear film surface tension.

PubMed

Schicht, Martin; Garreis, Fabian; Hartjen, Nadine; Beileke, Stephanie; Jacobi, Christina; Sahin, Afsun; Holland, Detlef; Schröder, Henrik; Hammer, Christian M; Paulsen, Friedrich; Bräuer, Lars

2018-06-28

The study aimed to characterize the expression and function of SFTA3 at the ocular surface and in tears. Ocular tissues, conjunctival (HCjE) and human corneal (HCE) epithelial cell lines as well as tearfilm of patients suffering from different forms of dry eye disease (DED) were analyzed by means of RT-PCR, western blot, immunohistochemistry, and ELISA. A possible role of recombinant SFTA3 in corneal wound healing was investigated performing in vitro scratch assays. Tear film regulatory properties were analyzed with the spinning drop method and the regulation of SFTA3 transcripts was studied in HCE and HCjE after incubation with proinflammatory cytokines as well as typical ocular pathogens by real-time RT-PCR and ELISA. The results reveal that human ocular tissue as well as tears of healthy volunteers express SFTA3 whereas tears from patients with DED showed significantly increased SFTA3 levels. In vitro wounding of HCE cell cultures that had been treated with recombinant SFTA3 demonstrated a significantly increased wound closure rate and rSFTA3 reduced the surface tension of tear fluid. The results indicate that SFTA3 at the ocular surface seemed to be involved in wound healing and the reduction of surface tension.

Effects of amino acids enriched tears substitutes on the cornea of patients with dysfunctional tear syndrome.

PubMed

Aragona, Pasquale; Rania, Laura; Roszkowska, Anna M; Spinella, Rosaria; Postorino, Elisa; Puzzolo, Domenico; Micali, Antonio

2013-09-01

To evaluate the effect of aminoacid enriched artificial tears on the ocular surface of patients with dysfunctional tear syndrome (DTS). Forty patients were divided into two groups: group 1 treated for 90 days with sodium hyaluronate (SH) 0.15% 1 drop × 5 times/day; group 2 treated for 90 days with SH 0.15% + aminoacids mixture 1 drop × 5 times/day. Symptom score questionnaire, tear break-up time (TBUT), corneal fluorescein stain, Shirmer's I test and confocal microscopy were performed at baseline and after 30 and 90 days. Confocal images underwent morphometric analysis. Both treatments improved symptoms after 1 month. Group 2 patients showed at 1 month an improvement of TBUT and corneal stain, maintained throughout the study. Also Shirmer's I test improved after 3 months. In group 1, an improvement of TBUT and corneal stain was observed after 3 months. The morphometric analysis of confocal images demonstrated at month 1 an improvement of nerve tortuosity in group 2; after 3 months both groups showed a significant improvement versus baseline. The epithelium showed, in both groups, a reduction in hyperreflective large cells starting from 1 month; the area of the cells was significantly reduced after 3 months, with a significant higher reduction in group 2. The perineural stromal opacity was significantly increased after 3 months, particularly in group 2. This is the first study addressing corneal changes after amino acids administration in a DTS population. The treatment with amino acids enriched SH can be considered a useful tool in the treatment of DTS. © 2013 The Authors Acta Ophthalmologica © 2013 Acta Ophthalmologica Scandinavica Foundation. Published by Blackwell Publishing Ltd.

Effects of artificial tear treatment on corneal epithelial thickness and corneal topography findings in dry eye patients.

PubMed

Çakır, B; Doğan, E; Çelik, E; Babashli, T; Uçak, T; Alagöz, G

2018-05-01

To investigate the effects of artificial tear treatment on central corneal epithelial thickness, and central, mid-peripheral and peripheral corneal thicknesses in patients with dry eye disease (DED). Patients with DED underwent ocular examinations, including Schirmer-2 test, slit lamp examination for tear break-up time (BUT), corneal topography (CT) for measuring mean central, mid-peripheral and peripheral corneal thickness values and anterior segment optic coherence tomography (AS-OCT) for obtaining central corneal epithelial thickness. After artificial tear treatment (carboxymethylcellulose and sodium hyaluronate formulations) for one month, patients were examined again at a second visit and the results were compared. Sixty-one eyes of 33 female dry eye patients (mean age: 38.3±5.7 years) were enrolled. The mean follow-up time was 36.4±3.3 days. The mean tear BUT and Schirmer-1 tests revealed significant improvement after treatment (P=0.000, P=0.000, respectively). Central corneal epithelium and mean mid-peripheral corneal thicknesses measured significantly higher after treatment (P=0.001, P=0.02). Changes in central and peripheral corneal thicknesses were not statistically significant. Artificial tear treatment in dry eye patients seems to increase central corneal epithelial and mid-peripheral corneal thicknesses. Measurement of corneal epithelial thickness can be a useful tool for evaluation of treatment response in dry eye patients. Further long-term prospective studies are needed to investigate this item. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

The presence and significance of polar meibum and tear lipids.

PubMed

Pucker, Andrew D; Haworth, Kristina M

2015-01-01

The ocular tear film is a complex structure composed of a number of elements. While all of these components serve valuable functional and structural roles, the external lipid layer has been a focus because it is known to play a critical role in dry eye. Traditionally, meibomian gland phospholipids have been considered to be the vital amphiphilic molecules needed to create an interphase between the outer nonpolar lipid layer and inner aqueous layers, yet recent work has called this theory into question. The purpose of this review is to clarify the current understanding of the origins, identity, and significance of polar tear lipids. Studies indicate that both phospholipids and ω-hydroxy fatty acids likely play a critical role in tear film stability. Studies also indicate that polar lipids likely originate from multiple sources and that they are integrally involved in ocular surface disease. Additional studies are needed to fully understand the origins and significance of polar tear lipids, because to date only correlational evidence has described their hypothesized origins and functions. Copyright © 2015 Elsevier Inc. All rights reserved.

Amphiphilic nanoparticles suppress droplet break-up in a concentrated emulsion flowing through a narrow constriction

PubMed Central

Gai, Ya; Kim, Minkyu; Pan, Ming; Tang, Sindy K. Y.

2017-01-01

This paper describes the break-up behavior of a concentrated emulsion comprising drops stabilized by amphiphilic silica nanoparticles flowing in a tapered microchannel. Such geometry is often used in serial droplet interrogation and sorting processes in droplet microfluidics applications. When exposed to high viscous stresses, drops can undergo break-up and compromise their physical integrity. As these drops are used as micro-reactors, such compromise leads to a loss in the accuracy of droplet-based assays. Here, we show droplet break-up is suppressed by replacing the fluoro-surfactant similar to the one commonly used in current droplet microfluidics applications with amphiphilic nanoparticles as droplet stabilizer. We identify parameters that influence the break-up of these drops and demonstrate that break-up probability increases with increasing capillary number and confinement, decreasing nanoparticle size, and is insensitive to viscosity ratio within the range tested. Practically, our results reveal two key advantages of nanoparticles with direct applications to droplet microfluidics. First, replacing surfactants with nanoparticles suppresses break-up and increases the throughput of the serial interrogation process to 3 times higher than that in surfactant system under similar flow conditions. Second, the insensitivity of break-up to droplet viscosity makes it possible to process samples having different composition and viscosities without having to change the channel and droplet geometry in order to maintain the same degree of break-up and corresponding assay accuracy. PMID:28652887

[A study on the diagnostic value of tear film objective scatter index in dry eye].

PubMed

Su, Y D; Liang, Q F; Wang, N L; Antoine, Labbè

2017-09-11

Objective: To study the sensitivity and specificity of tear film objective scatter index to the diagnosis dry eye disease (DED). Methods: A prospective case-controlled study. Fifty-three patients with DED and 32 healthy age- and sex-matched control subjects were included from July to October 2016. All subjects underwent the examinations sequentially as follows: evaluation of ocular surface disease symptoms using the Ocular Surface Disease Index, optical quality detection, lipid layer thickness, tear film breakup time and SchirmerⅠtest. With Optical Quality Analysis SystemⅡ, the values of modulation transfer function cut off, basic objective scatter index (OSI) and total OSI were measured. To eliminate the influence of other refractive media, the tear film OSI (TF-OSI) was calculated, and the difference in TF-OSI between two groups was analyzed with the independent-samples t test. Spearman's correlation analysis was used to detect the correlation of each parameter in the DED group. With the receiver operating characteristic curve and the area under the curve (AUC), the specificity and sensitivity of TF-OSI and other parameters were described to differentiate DED from normal eyes. Results: In the dry eye group, the value of modulation transfer function cut off (32.07±11.95) was significantly lower than the normal group (39.38±9.44, t=- 3.096, P= 0.003) , and the mean value and dispersion of TF-OSI (0.50±0.43, 0.52±0.81) were higher than the normal group (0.21±0.16, 0.12±0.01) ( t= 4.300, P= 0.000, t= 3.546, P= 0.001) . The mean value of TF-OSI had a positive correlation with lipid layer thickness ( r= 0.365, P= 0.007) and dispersion of TF-OSI ( r= 0.581, P= 0.000), and a negative correlation with MTF cut off ( r=- 0.368, P= 0.007). To the diagnostic value of DED, the mean value of TF-OSI had a sensitivity of 0.736, a specificity of 0.762, and the AUC was 0.764. The dispersion of TF-OSI had a sensitivity of 0.811 and a specificity of 0.810, and the AUC was 0

Isotretinoin in lacrimal gland fluid and tears.

PubMed

Rismondo, V; Ubels, J L

1987-03-01

Isotretinoin (13-cis-retinoic acid) is used in the treatment of severe cystic acne. Adverse ocular reactions, including blepharoconjunctivitis and dry eye symptoms, are frequent side effects of this drug. Our previous observation that retinol is present in tears and lacrimal gland fluid suggests that isotretinoin may also be secreted by the lacrimal gland. Rabbits were treated with isotretinoin, and lacrimal gland fluid was collected from the cannulated lacrimal gland duct. Tears were collected from patients who were being treated with isotretinoin. Lacrimal gland fluid and tears were analyzed by reverse-phase high-pressure liquid chromatography and a peak eluted from each sample, which was identified as isotretinoin. We conclude that the lacrimal gland is able to secrete isotretinoin in addition to retinol and that, in animals and patients treated systemically with isotretinoin, the ocular surface is exposed to the drug via the tear film.

Effect of benzalkonium chloride on the stability of the precorneal tear film in rabbit and man.

PubMed Central

Wilson, W. S.; Duncan, A. J.; Jay, J. L.

1975-01-01

Benzalkonium chloride, a surface-active preservative commonly used in eyedrop preparations, has been shown to hasten the drying of the precorneal tear film. In the rabbit, 0.01 per cent benzalkonium (the concentration usually employed as a preservative) shortened the time required for the appearance of dry spots on the corneal surface by a factor of about four. In man, an approximately twofold hastening was demonstrated. This effect is thought to preclude the use of this substance as a preservative in eyedrop preparations for use as local anaesthetics. PMID:1203224

Conjunctival Tear Layer Temperature, Evaporation, Hyperosmolarity, Inflammation, Hyperemia, Tissue Damage, and Symptoms: A Review of an Amplifying Cascade.

PubMed

McMonnies, Charles W

2017-12-01

This review examines the evidence for and significance of pre-conjunctival tear temperature being higher than central pre-corneal temperature with associated more rapid evaporation of warmer pre-conjunctival tears in normal eyes but especially in hyperemic dry eye disease. PubMed searches using the terms "evaporative dry eye," "conjunctival tear evaporation," "tear evaporation," and "dry eye conjunctival hyperemia" indicated 157, 49, 309, and 96 potentially relevant papers, respectively. Selections from these lists were the basis for examining the significance of the evidence relevant to pre-conjunctival tear layer temperature and evaporation. There is evidence supporting an amplifying inflammatory and para-inflammatory hyperemia dry eye cascade, which increases pre-conjunctival tear temperature and the risk of accelerated pre-conjunctival tear evaporation with exacerbated osmolarity elevation and inflammation. Dry eye cascade amplification is consistent with increases in symptoms and inflammatory as well as para-inflammatory hyperemia toward the end of the waking day. Apart from age-related conjunctivochalasis, dry eye-related conjunctival epithelial cell pathology including reduced goblet cell numbers and associated mucin deficiency, squamous metaplasia, and increased separation of cell layers could help to destabilize tears and facilitate evaporation as part of an amplifying cascade. Greater difficulty in assessing conjunctival tear break up may contribute to an underestimation of a role for faster evaporation of pre-conjunctival tears in dry eye disease and help explain any non-correspondence between symptoms and corneal signs of dry eye disease. Success with anti-inflammatory therapies for dry eye disease may be at least partly due to reductions in conjunctival hyperemia and deamplification of evaporative cascades. Conjunctival inflammatory hyperemia in other diseases may contribute to accelerated pre-conjunctival tear evaporation and the risk of tear

Break-up of droplets in a concentrated emulsion flowing through a narrow constriction

NASA Astrophysics Data System (ADS)

Kim, Minkyu; Rosenfeld, Liat; Tang, Sindy; Tang Lab Team

2014-11-01

Droplet microfluidics has enabled a wide range of high throughput screening applications. Compared with other technologies such as robotic screening technology, droplet microfluidics has 1000 times higher throughput, which makes the technology one of the most promising platforms for the ultrahigh throughput screening applications. Few studies have considered the throughput of the droplet interrogation process, however. In this research, we show that the probability of break-up increases with increasing flow rate, entrance angle to the constriction, and size of the drops. Since single drops do not break at the highest flow rate used in the system, break-ups occur primarily from the interactions between highly packed droplets close to each other. Moreover, the probabilistic nature of the break-up process arises from the stochastic variations in the packing configuration. Our results can be used to calculate the maximum throughput of the serial interrogation process. For 40 pL-drops, the highest throughput with less than 1% droplet break-up was measured to be approximately 7,000 drops per second. In addition, the results are useful for understanding the behavior of concentrated emulsions in applications such as mobility control in enhanced oil recovery.

The influence of humidity, temperature, and oral contraceptive in tear

NASA Astrophysics Data System (ADS)

Sousa, Raul A. R. C.; Ribeiro, Tânia L. C.; Moreira, Sandra M. B.; Baptista, António M. G.

2013-11-01

The aim of this study is to ascertain whether the quantity and quality of tear and eye subjective comfort are influenced by the temperature, humidity and oral Contraceptives Taking or Non-taking (CTNT). Forty-one students, females, from the University of Minho, Braga, Portugal, aged (mean+/-1standard deviation) of 21.51+/-1.85 years, ranging from 20 to 30 years, participated in this study. The McMonnies Questionnaire (MMQ), Break Up Time (BUT) and Phenol Red Test (PRT) were accessed between 14-17 hours in four sets of visits throughout the year: Visit 1, Visit 2, Visit 3 and Visit 4. The PRT and BUT values (mean+/-1standard deviation) for Visit 1, Visit 2, Visit 3 and Visit 4 were respectively 23.88+/-6.50mm, 22.29+/-8.00mm, 23.61+/-6.75mm, 22.88+/-7.00mm and 6.02+/-1.58s, 5.62+/-1.22s, 5.23+/-0.88s, 5.53+/-1. 42s. The MMQ scores for Visit 1, Visit 2, Visit 3 and Visit 4 ranged from 2-13, 2-15, 1-14 and 2-14 with medians of 6, 7, 6 and 6, respectively. The influence of temperature, humidity and CTNT on PRT, BUT and MMQ were evaluated using generalized linear mixed model. For BUT and MMQ statistical significant effects were found regarding temperature and humidity. The temperature and humidity influenced the tear quality and subjective comfort but did not influence the tear quantity. The CTNT did not influence tear quantity, quality or subjective eye comfort.

Diadenosine polyphosphates in the tears of aniridia patients.

PubMed

Peral, Assumpta; Carracedo, Gonzalo; Pintor, Jesús

2015-08-01

To quantify diadenosine polyphosphate levels in tears of congenital aniridia patients to estimate the ocular surface changes associated with congenital aniridia compared to normal individuals. Fifteen patients diagnosed with congenital aniridia and a control group of forty volunteers were studied. Tears were collected to quantify the levels of diadenosine polyphosphates Ap4 A and Ap5 A by high-performance liquid chromatography (H.P.L.C). Break-up time (BUT), corneal staining, McMonnies questionnaire and the Schirmer I test were applied to both groups. Dinucleotides in congenital aniridia patients were higher than in control subjects. For the congenital aniridia group, under 15 years old, the values were 0.77 ± 0.01 μm and 0.17 ± 0.02 μm for Ap4 A and Ap5 A, respectively. The group aged from 15 to 40 years old provided concentrations of 4.37 ± 0.97 μm and 0.46 ± 0.05 μm for Ap4 A and Ap5 A, the group over 40 gave concentrations of 11.17 ± 5.53 μm and 0.68 ± 0.17 μm for Ap4 A and Ap5 A. Dinucleotide concentrations increased with age, being statistically significant different among the three age groups (p < 0.05). Congenital aniridia patients showed a normal tear secretion and no dry eye McMonnies scores, except for the group over 40 years old. BUT values decreased and corneal staining increased with age and correlated with the levels of diadenosine polyphosphates (p < 0.05). The levels of dinucleotides in tears increase in aniridia patients compared with healthy subjects, and they seem to be related with the progression of corneal disorders in aniridia patients, both of which increase with ageing. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Long-term follow-up after latissimus dorsi transfer for irreparable posterosuperior rotator cuff tears.

PubMed

El-Azab, Hossam Mahmoud; Rott, Olaf; Irlenbusch, Ulrich

2015-03-18

Irreparable posterosuperior rotator cuff tears are treated in several ways. Transfer of the latissimus dorsi is an alternative with acceptable mid-term results, but long-term results have rarely been published. The cases of 108 consecutive patients with 115 shoulders treated with latissimus dorsi transfer between 2000 and 2005 were reviewed clinically and radiographically. Ninety-three shoulders in eighty-six patients were included in the follow-up analysis. The mean duration of follow-up was 9.3 years (range, 6.6 to 11.7 years), and the mean age at the operation was fifty-six years (range, forty to seventy-two years). Outcome measures included the Constant-Murley score (Constant score), American Shoulder and Elbow Surgeons (ASES) index, and visual analog scale (VAS) for pain. The progress of cuff tear arthropathy was determined with radiographic evaluation according to the system described by Hamada et al. The mean relative Constant score improved from 44% preoperatively to 71% at the time of follow-up (p < 0.0001, effect size = 0.6), excluding the clinical failures. Similarly, the mean ASES index improved from 30 to 70 (p < 0.0001, effect size = 0.7), and the mean VAS score decreased from 7.8 to 2.4 (p < 0.0001, effect size = 0.8). A pain-free outcome was reported in only eighteen shoulders (19%). Active shoulder movement improved significantly (p < 0.05). The mean Hamada radiographic grade of cuff tear arthropathy increased from 1.7 (range, 0 to 2) preoperatively to 2.2 (range, 1 to 5) (p < 0.0001, effect size = 0.2). The rate of clinical failure of latissimus dorsi transfer was 10%, and the rate of shoulder prosthetic replacement after latissimus dorsi transfer was 4%. Pain relief and improvement of shoulder function were maintained a mean of 9.3 years after latissimus dorsi transfer for irreparable posterosuperior cuff defects. The younger the patient, the better the outcome. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

Photon correlation spectroscopy applied to tear analysis.

PubMed

Picarazzi, S; Lecchi, M; Pastori, V; D'Arienzo, M; Scotti, R; Tavazzi, S

2017-09-01

This study aims to deepen the knowledge on tear film properties by the development of a protocol for analyses of Photon Correlation Spectroscopy (PCS) on human tears and by the comparison between PCS results obtained on tears of contact lens wearers and non-wearers. Tears (5μL) were collected by a glass capillary. The analyses provide the hydrodynamic diameter of tear components by analyzing intensity fluctuations in time of scattered light. PCS appears a promising technique for studying tear features and for shedding light on specific eye conditions, such as on the clinical effects of CL wear. In fact, statistical difference (p<0.001) was found between the measured mean hydrodynamic diameter of tear components of wearers and non-wearers, the resulting value significantly higher for CL wearers. The scenario does not substantially change after (25±5)min from the CL removal. The difference is attributed to changes in the interactions between tear constituents due to CL wear. In order to get deeper insights on the influence of CL wear on aggregation and structure of tear components, a preliminary Electron Spin Resonance (ESR) investigation was performed, monitoring Fe 3+ species. ESR spectra on tears of both CL wearers and non-wearers showed the presence of intense signals, probably associated to iron (III) centers in proteins such as lactoferrin, and a weaker resonance attributable to Fe 3+ species interacting with S-S bridges of lysozyme. Differences in ESR spectra between CL wearers and non-wearers were detected and tentatively ascribed to changes in coordination or in local environment of Fe 3+ centers connected to aggregation phenomena induced by CL wear, which promote their interaction with other neighboring iron species. Copyright © 2017. Published by Elsevier B.V.

River-ice break-up/freeze-up: a review of climatic drivers, historical trends and future predictions

NASA Astrophysics Data System (ADS)

Prowse, T. D.; Bonsal, B. R.; Duguay, C. R.; Lacroix, M. P.

2007-10-01

River ice plays a fundamental role in biological, chemical and physical processes that control freshwater regimes of the cold regions. Moreover, it can have enormous economic implications for river-based developments. All such activities and processes can be modified significantly by any changes to river-ice thickness, composition or event timing and severity. This paper briefly reviews some of the major hydraulic, mechanical and thermodynamic processes controlling river-ice events and how these are influenced by variations in climate. A regional and temporal synthesis is also made of the observed historical trends in river-ice break-up/freeze-up occurrence from the Eurasian and North American cold regions. This involves assessment of several hydroclimatic variables that have influenced past trends and variability in river-ice break-up/freeze-up dates including air-temperature indicators (e.g. seasonal temperature, 0°C isotherm dates and various degree-days) and large-scale atmospheric circulation patterns or teleconnections. Implications of future climate change on the timing and severity of river-ice events are presented and discussed in relation to the historical trends. Attention is drawn to the increasing trends towards the occurrence of mid-winter break-up events that can produce especially severe flood conditions but prove to be the most difficult type of event to model and predict.

Fluorophotometric measurement of pH of human tears in vivo.

PubMed

Yamada, M; Mochizuki, H; Kawai, M; Yoshino, M; Mashima, Y

1997-05-01

To measure the pH in the precorneal tear film of humans in vivo using a pH-sensitive fluorescent dye, bis-carboxyethyl-carboxyfluorescein (BCECF). The measurement was initiated by instilling 1 microliter of 2 mM BCECF solution into the subject's eye. The pH was calculated by measuring the ratio of fluorescent intensities at two excitation wavelengths (490/430 ratio), which was dependent on pH, but independent of the dye concentration and other variables. The tears of the same subject were then collected and loaded on to a micro pH-meter to ensure the accuracy of the measurement. The mean pH values of 40 eyes from 20 healthy volunteers was 7.50 (SD +/- 0.23), which corresponded well with those measured by the micro pH-meter. The method described was useful in measuring the pH of the precorneal tear film of humans with minimal invasion.

Lipid peroxidation is increased in tears from the elderly.

PubMed

Benlloch-Navarro, Soledad; Franco, Ilenia; Sánchez-Vallejo, Violeta; Silvestre, Dolores; Romero, Francisco Javier; Miranda, María

2013-10-01

We describe a procedure in which tears, obtained from Schirmer strips, are used to measure a marker of lipid peroxidation, malondialdehyde (MDA). We also compared the levels of proteins and MDA in tears from two groups of people: young adults (18-30 years old) and elderly adults (65-85 years old), because the data related to total protein concentration of human tears vary widely and because the majority of people over the age of 65 experience some symptoms of dry eyes and this condition has been recognized as an oxidative stress-induced disease. Our results show a significant difference in the protein concentration of the tears taken from the two age categories, younger adults (18-30 years old) and older adults (65-85 years old). Herein, we report for the first time an increase in MDA concentrations determined by HPLC in human tears based on age. It is possible that alterations in the tear lipid layer may lead to an increase in lipid peroxidation. Further studies are needed to understand the nature and function of tear film and stability in order to obtain new methods to analyze tears in patients with different diseases. In this sense, it would be interesting to compare MDA concentration in tears from control subjects and from people with meibomian gland dysfunction. Copyright © 2013 Elsevier Ltd. All rights reserved.

Break-up dynamics of fluctuating liquid threads

PubMed Central

Petit, Julien; Rivière, David; Kellay, Hamid; Delville, Jean-Pierre

2012-01-01

The thinning dynamics of a liquid neck before break-up, as may happen when a drop detaches from a faucet or a capillary, follows different rules and dynamic scaling laws depending on the importance of inertia, viscous stresses, or capillary forces. If now the thinning neck reaches dimensions comparable to the thermally excited interfacial fluctuations, as for nanojet break-up or the fragmentation of thermally annealed nanowires, these fluctuations should play a dominant role according to recent theory and observations. Using near-critical interfaces, we here fully characterize the universal dynamics of this thermal fluctuation-dominated regime and demonstrate that the cross-over from the classical two-fluid pinch-off scenario of a liquid thread to the fluctuation-dominated regime occurs at a well-defined neck radius proportional to the thermal length scale. Investigating satellite drop formation, we also show that at the level of the cross-over between these two regimes it is more probable to produce monodisperse droplets because fluctuation-dominated pinch-off may allow the unique situation where satellite drop formation can be inhibited. Nonetheless, the interplay between the evolution of the neck profiles from the classical to the fluctuation-dominated regime and the satellites’ production remains to be clarified. PMID:23090994

Contact lens physical properties and lipid deposition in a novel characterized artificial tear solution

PubMed Central

Heynen, Miriam; Kay, Lise M.M.; Dominici, Claudia Yvette; Khan, Warda; Ng, Wendy W.S.; Jones, Lyndon

2011-01-01

Purpose To characterize various properties of a physiologically-relevant artificial tear solution (ATS) containing a range of tear film components within a complex salt solution, and to measure contact lens parameters and lipid deposition of a variety of contact lens materials after incubation in this ATS. Methods A complex ATS was developed that contains a range of salts, proteins, lipids, mucin, and other tear film constituents in tear-film relevant concentrations. This ATS was tested to confirm that its pH, osmolality, surface tension, and homogeneity are similar to human tears and remain so throughout the material incubation process, for up to 4 weeks. To confirm that silicone hydrogel and conventional hydrogel contact lens materials do not alter in physical characteristics beyond what is allowed by the International Organization for Standardization (ISO) 18369–2. The diameter, center thickness, and calculated base curve were measured for five different lens materials directly out of the blister pack, after a rinse in saline and then following a two week incubation in the modified ATS. To test the ATS and the effect of its composition on lipid deposition, two lens materials were incubated in the ATS and a modified version for several time points. Both ATS solutions contained trace amounts of carbon-14 cholesterol and phosphatidylcholine, such that deposition of these specific lipids could be quantified using standard methods. Results This ATS is a complex mixture that remains stable at physiologically relevant pH (7.3–7.6), osmolality (304–306 mmol/kg), surface tension (40–46 dynes/cm) and homogeneity over an incubation period of three weeks or more. The physical parameters of the lenses tested showed no changes beyond that allowed by the ISO guidelines. Incubations with the ATS found that balafilcon A lenses deposit significantly more cholesterol and phosphatidylcholine than omafilcon A lenses (p<0.05) and that removing lactoferrin and immunoglobulin G

Electronic enhancement of tear secretion

NASA Astrophysics Data System (ADS)

Brinton, Mark; Lim Chung, Jae; Kossler, Andrea; Kook, Koung Hoon; Loudin, Jim; Franke, Manfred; Palanker, Daniel

2016-02-01

Objective. To study electrical stimulation of the lacrimal gland and afferent nerves for enhanced tear secretion, as a potential treatment for dry eye disease. We investigate the response pathways and electrical parameters to safely maximize tear secretion. Approach. We evaluated the tear response to electrical stimulation of the lacrimal gland and afferent nerves in isofluorane-anesthetized rabbits. In acute studies, electrical stimulation was performed using bipolar platinum foil electrodes, implanted beneath the inferior lacrimal gland, and a monopolar electrode placed near the afferent ethmoid nerve. Wireless microstimulators with bipolar electrodes were implanted beneath the lacrimal gland for chronic studies. To identify the response pathways, we applied various pharmacological inhibitors. To optimize the stimulus, we measured tear secretion rate (Schirmer test) as a function of pulse amplitude (1.5-12 mA), duration (0.1-1 ms) and repetition rate (10-100 Hz). Main results. Stimulation of the lacrimal gland increased tear secretion by engaging efferent parasympathetic nerves. Tearing increased with stimulation amplitude, pulse duration and repetition rate, up to 70 Hz. Stimulation with 3 mA, 500 μs pulses at 70 Hz provided a 4.5 mm (125%) increase in Schirmer score. Modulating duty cycle further increased tearing up to 57%, compared to continuous stimulation in chronically implanted animals (36%). Ethmoid (afferent) nerve stimulation increased tearing similar to gland stimulation (3.6 mm) via a reflex pathway. In animals with chronically implanted stimulators, a nearly 6 mm increase (57%) was achieved with 12-fold less charge density per pulse (0.06-0.3 μC mm-2 with 170-680 μs pulses) than the damage threshold (3.5 μC mm-2 with 1 ms pulses). Significance. Electrical stimulation of the lacrimal gland or afferent nerves may be used as a treatment for dry eye disease. Clinical trials should validate this approach in patients with aqueous tear deficiency, and

Improving Cardiometabolic Health with Diet, Physical Activity, and Breaking Up Sitting: What about Sleep?

PubMed Central

Vincent, Grace E.; Jay, Sarah M.; Sargent, Charli; Vandelanotte, Corneel; Ridgers, Nicola D.; Ferguson, Sally A.

2017-01-01

Cardiometabolic disease poses a serious health and economic burden worldwide and its prevalence is predicted to increase. Prolonged sitting, lack of physical activity, poor diet, and short sleep duration are ubiquitous behaviors in modern society, and all are independent risk factors in the development of cardiometabolic disease. Existing evidence demonstrates that breaking up prolonged periods of sitting is beneficial for cardiometabolic health, however, studies have not controlled for prior sleep duration. This article examines how prolonged sitting and short sleep duration independently contribute to cardiometabolic risk, and how breaking up sitting and obtaining adequate sleep may reduce this risk. We suggest that as prolonged sitting and short sleep duration influence the same cardiometabolic parameters, there is potential for short sleep to attenuate the positive impact of breaking up prolonged sitting with physical activity. Likewise, breaking up prolonged sitting and obtaining adequate sleep together could improve predictors of cardiometabolic disease, i.e., the combined effect may be stronger than either alone. To explore these perspectives, we propose a research agenda to investigate the relationship between breaking up prolonged sitting with physical activity and short sleep duration. This will provide an evidence-base for informing the design of interventions to reduce the burden of cardiometabolic disease on communities worldwide. PMID:29167645

The effect of Meibomian lipids and tear proteins on evaporation rate under controlled in vitro conditions.

PubMed

Herok, George Henryk; Mudgil, Poonam; Millar, Thomas James

2009-07-01

The lipid layer of the tear film is associated with preventing evaporative loss. The ability of human Meibomian lipids to reduce evaporation in vitro was tested. Films of human or animal Meibomian lipids or mixtures of cholesterol and phosphatidylcholine were spread on the surface of either artificial buffer or on whole tears and placed on a mass balance that was enclosed in a sealed chamber. The temperature was adjusted to 37 degrees C and gas flow was controlled. Increasing the amounts of Meibomian lipids gave a very small reduction in evaporation. It was concluded from these in vitro experiments that prevention of evaporation from the tear film is not due to the Meibomian lipids alone, but is more likely to be due to a complex interaction between components of the aqueous and the Meibomian lipids.

4A syndrome: ocular surface investigation in an Italian young patient.

PubMed

Aragona, Pasquale; Rania, Laura; Roszkowska, Anna Maria; Puzzolo, Domenico; Micali, Antonio; Pisani, Antonina; Salzano, Giuseppina; Messina, Maria Francesca

2014-12-08

Allgrove's 4A syndrome determines ocular surface changes. This is the first report providing an up-to-dated analysis of the ocular surface in an affected patient. An 18-years-old male Caucasian patient, with a complex progressive gait disorder and adrenal insufficiency, was referred for ophthalmic evaluation, as part of the clinical assessment. He underwent the following tests: best corrected visual acuity, tear osmolarity, tear film break-up time (BUT), corneal fluorescein staining, Schirmer's I test, lid margin assessment, corneal sensitivity, in vivo corneal confocal microscopy, conjunctival impression cytology, tonometry and fundus exam. A dry eye condition was documented by the Schirmer's I test of 0 mm/5' in both eyes, accompanied by tear hyperosmolarity, mild meibomian gland dysfunction, reduced BUT, mucus filaments in the tear film and conjunctival epithelium metaplasic changes. The corneal confocal microscopy showed the presence of activated keratocytes, while the nerve pattern was normal. The dry eye in this patient appears to be due to tear aqueous deficiency and can be considered as part of the 4A syndrome. The decreased tear production, resulting from a deterioration of the autonomic innervation of the lacrimal glands rather than an impaired corneal innervation, can be considered as part of the systemic autonomic dysfunction present in this disease.

Breaking Up is Hard to do: The Impact of Unmarried Relationship Dissolution on Mental Health and Life Satisfaction

PubMed Central

Rhoades, Galena K.; Kamp Dush, Claire M.; Atkins, David C.; Stanley, Scott M.; Markman, Howard J.

2011-01-01

This study was the first to examine the impact of unmarried relationship break-up on psychological distress and life satisfaction using a within-subjects design. Among unmarried 18 to 35-year olds (N = 1295), 36.5% had one or more break-ups over a 20-month period. Experiencing a break-up was associated with an increase in psychological distress and a decline in life satisfaction (from pre- to post-dissolution). In addition, several characteristics of the relationship or of the break-up were associated with the magnitude of the changes in life satisfaction following a break-up. Specifically, having been cohabiting and having had plans for marriage were associated with larger declines in life satisfaction while having begun to date someone new was associated with smaller declines. Interestingly, having higher relationship quality at the previous wave was associated with smaller declines in life satisfaction following a break-up. No relationship or break-up characteristics were significantly associated with the magnitude of changes in psychological distress after a break-up. Existing theories are used to explain the results. Implications for clinical work and future research on unmarried relationships are also discussed. PMID:21517174

Repeatability of a new method for measuring tear evaporation rates.

PubMed

Petznick, Andrea; Tan, Jen Hong; Boo, Shiao Khee; Lee, Sze Yee; Acharya, U Rajendra; Tong, Louis

2013-04-01

The purpose of this study was to evaluate the repeatability of tear evaporimetry based on infrared thermography in a clinical room setting and to test the effect of changing environmental humidity on ocular surface temperature (OST) and tear evaporation rates (TERs) in a controlled adverse environmental (CAE) chamber. Twenty-six healthy participants were enrolled, of whom 16 underwent repeatability measurements in a clinical room and 10 were exposed to a constant temperature of 30°C with a humidity of 45 and 65% in a CAE. Participants were acclimatized to each condition for at least 20 minutes before OSTs were taken. Tear film breakup time was assessed in the CAE only. Number of blinks and OSTs were continuously measured for 20 seconds for the cornea, conjunctiva, and overall ocular surface with an infrared camera; corresponding TERs were calculated. The OSTs and TERs showed acceptable strength of agreement between the first and second measurements. The coefficients of repeatability were 0.4°C for OST and 6.0 W m for TER. An increase in chamber humidity (from 45 to 65%) increased OST (p < 0.05). The TER was not changed significantly (p > 0.05). The tear film breakup time and number of blinks were not significantly affected by different humidity conditions. This technique has acceptable repeatability and has potential to document individual tear evaporation changes with time where humidity may differ by less than 20%.

Risk Factors for Tear Progression in Symptomatic Rotator Cuff Tears: A Prospective Study of 174 Shoulders.

PubMed

Yamamoto, Nobuyuki; Mineta, Mitsuyoshi; Kawakami, Jun; Sano, Hirotaka; Itoi, Eiji

2017-09-01

The risk factors for tear progression in symptomatic rotator cuff tears have not been clarified yet. It is important for orthopaedic surgeons to know the natural course of tear progression when nonoperative management is to be chosen. Tears in younger patients, high-activity patients, or heavy laborers would progress in size more than those in older patients, low-activity patients, or light laborers. Case-control study; Level of evidence, 3. Two hundred twenty-five consecutive patients with symptomatic rotator cuff tears visited our institute between 2009 and 2015. Of these, 174 shoulders of 171 patients (mean age, 66.9 years) who underwent at least 2 magnetic resonance imaging (MRI) examinations were prospectively enrolled. The mean follow-up was 19 months. Tear progression was defined as positive when the tear size increased by ≥2 mm. The demographic factors that were analyzed by multivariate analysis included age, sex, hand dominance, smoking, alcohol drinking, hypercholesterolemia, sports participation, job type, tear size, and tear type (full or partial thickness). Of the 174 shoulders, 82 shoulders (47%) showed tear progression. The mean (±SD) tear length and width in the progression group on final MRI were 23.1 ± 12.5 mm and 17.3 ± 9.6 mm, respectively; the tear size progressed by a mean 5.8 ± 5.6 mm in length and 3.1 ± 5.2 mm in width. The mean propagation speed was 3.8 mm/y in length and 2.0 mm/y in width. The size of full-thickness tears significantly increased compared with that of articular-sided partial-thickness tears ( P = .0215). The size of medium tears significantly increased compared with that of other tears ( P < .0001). According to the logistic regression analysis, smoking was significantly correlated with tear progression ( P = .026). Subgroup analyses showed that male sex, hand dominance, and trauma were correlated with tear progression. Age, alcohol drinking, hypercholesterolemia, sports participation, and job type did not show any

Do Ligamentum Teres Tears Portend Inferior Outcomes in Patients With Borderline Dysplasia Undergoing Hip Arthroscopic Surgery? A Match-Controlled Study With a Minimum 2-Year Follow-up.

PubMed

Chaharbakhshi, Edwin O; Perets, Itay; Ashberg, Lyall; Mu, Brian; Lenkeit, Christopher; Domb, Benjamin G

2017-09-01

Arthroscopic surgery in borderline dysplastic hips remains controversial, but the role of the ligamentum teres (LT) has not been studied in this setting. Borderline dysplastic patients with LT tears have worse short-term outcomes than those without LT tears. Cohort study; Level of evidence, 3. Data were prospectively collected on patients who underwent arthroscopic surgery between February 2008 and April 2014. The inclusion criteria were borderline dysplasia (lateral center-edge angle [LCEA], 18°-25°) and labral tears; arthroscopic treatments including labral preservation and capsular plication; and preoperative patient-reported outcome scores including the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score-Sport-Specific Subscale, and visual analog scale for pain. Patients were excluded for preoperative Tönnis osteoarthritis grade >0, workers' compensation claims, previous ipsilateral hip surgery and conditions, or frank dysplasia (LCEA <18°). Patients with LT tears were pair-matched to patients without tears for sex, age at surgery ±10 years, body mass index (<30 kg/m 2 vs ≥30 kg/m 2 ), labral treatment type, and microfracture. Of 68 eligible patients, 63 (93%) had a minimum 2-year follow-up, and 30 (48%) had LT tears. Twenty patients in each group were pair-matched. The mean follow-up time was 54.3 months (range, 24.2-83.8 months) for the LT tear group and 38.6 months (range, 24.6-70.6 months) for the control group ( P = .002). Ninety percent were female. There were no significant differences regarding demographics or intra-operative procedures. The LT tear group trended toward lower postoperative mHHS ( P = .09) and NAHS ( P = .09) values. Mean satisfaction was 8.1 for the LT tear group and 7.9 for the control group. Preoperative and follow-up scores were not significantly different between the groups. The LT tear group had 5 revisions, with 1 revision in the control group. Three patients (15%) in the LT tear group

Meniscal tears missed on MR imaging: relationship to meniscal tear patterns and anterior cruciate ligament tears.

PubMed

De Smet, A A; Graf, B K

1994-04-01

MR imaging of the knee is a valuable technique for diagnosing meniscal tears, but some tears found at arthroscopy are not shown on MR imaging. The purpose of this study was to determine whether or not tears were more frequently missed in the presence of an anterior cruciate ligament tear or when tears had certain locations or configurations. We reviewed the original MR reports and surgical records of 400 patients who had both an MR examination and arthroscopy of the knee. Using chi 2 analysis, we examined how the sensitivity for detecting meniscal tears varied with the presence of a tear of the anterior cruciate ligament, with the location of the tear within the meniscus, and among six configurations of meniscal tears. We also studied whether sensitivity decreased with an increasing delay between MR examination and arthroscopy. In the presence of a tear of the anterior cruciate ligament, the sensitivity decreased from 0.97 to 0.88 (p = .016) for medial meniscal tears and from 0.94 to 0.69 (p = .0005) for lateral tears. The overall sensitivity for lateral meniscal tears was significantly less for posterior (p = .001) and peripheral (p = .005) tears than for other tear locations or configurations. The sensitivities did not significantly differ between tear locations and configurations in the medial meniscus or with an increasing delay until arthroscopy. Patients with a torn anterior cruciate ligament were more likely to have peripheral tears of the medial meniscus (p = .00004) and posterior (p = .0004) and peripheral (p = .04) tears of the lateral meniscus. Because of their location and configuration, meniscal tears associated with an anterior cruciate ligament injury are more difficult to detect on MR images than are tears in knees with an intact ligament. If a tear of the anterior cruciate ligament is detected, special attention should be given to the subtle peripheral tears that may be present in either meniscus, but most commonly in the posterior horn of the

Mechanical, structural and physical aspects of chitosan-based films as antimicrobial dressings.

PubMed

Escárcega-Galaz, Ana A; Sánchez-Machado, Dalia I; López-Cervantes, Jaime; Sanches-Silva, Ana; Madera-Santana, Tomás J; Paseiro-Losada, Perfecto

2018-05-01

Chitosan is a biodegradable, non-toxic, and antimicrobial polymer. Chitosan films can be used as a dressing because they promote the healing of cutaneous ulcers. In this study, the mechanical, physical, and microbiological properties films of pure chitosan and films formulated with a glycerol-honey mixture were characterized. The films were smooth, homogenous, transparent, and porous, with no fractures or cracks. Additionally, it was found that all were resistant to breaking, that the tearing force was directly related to the chitosan concentration, and that the addition of honey and glycerol improved the elongation percentage. When evaluating the antimicrobial activity of the films against Pseudomonas aeruginosa and Klebsiella pneumoniae, the films were found to have an effect only by direct contact. In the films formulated with honey, the area of contact increased to 44%. The excellent color, structural, antimicrobial, and surface morphological properties of the newly developed films make them a promising alternative for use as a dressing for the healing of skin ulcers. Copyright © 2018 Elsevier B.V. All rights reserved.

Measurement of Tear Production in English Angora and Dutch Rabbits

PubMed Central

Rajaei, Seyed Mehdi; Rafiee, Siamak Mashhady; Ghaffari, Masoud Selk; Masouleh, Mohammad N; Jamshidian, Mahmoud

2016-01-01

The purpose of this study was to establish normal values for tear production tests in different breeds of domestic rabbits. Healthy adult rabbits (n = 60; 120 eyes) of 2 different breeds (English angora and Dutch; n = 15 of each sex and breed) were used in this study. Tear production was measured by using the 1-min Schirmer tear test (STT), phenol red thread test (PRTT), and endodontic absorbent paper point tear test (EAPTT). In addition, horizontal palpebral fissure length was evaluated as a measure of ocular adnexal dimensions. Tear production (mean ± 1 SD) in English angora rabbits was 5.4 ± 1.6 mm/min according to the STT, 25.0 ± 2.7 mm in 15 s for the PRTT, and 18.8 ± 2.1 mm/min by the EAPTT; in Dutch rabbits, these values were 4.6 ± 1.2 mm/min, 23.6 ± 2.3 mm in 15 s, and 16.9 ± 1.7 mm/min, respectively. Only the EAPTT revealed a significant difference in tear production between English Angora and Dutch rabbits. These results provide reference values for tear production in English Angora and Dutch rabbits according to 3 different quantitative tear film assessment methods. PMID:27025815

The tear turnover and tear clearance tests - a review.

PubMed

Garaszczuk, Izabela K; Montes Mico, Robert; Iskander, D Robert; Expósito, Alejandro Cerviño

2018-03-01

The aim is to provide a summary of methods available for the assessment of tear turnover and tear clearance rates. The review defines tear clearance and tear turnover and describes their implication for ocular surface health. Additionally, it describes main types of techniques for measuring tear turnover, including fluorescein tear clearance tests, techniques utilizing electromagnetic spectrum and tracer molecule and novel experimental techniques utilizing optical coherence tomography and fluorescein profilometry. Areas covered: Internet databases (PubMed, Science Direct, Google Scholar) and most frequently cited references were used as a principal resource of information on tear turnover rate and tear clearance rate, presenting methodologies and equipment, as well as their definition and implications for the anterior eye surface health and function. Keywords used for data-search were as follows: tear turnover, tear clearance, fluorescein clearance, scintigraphy, fluorophotometry, tear flow, drainage, tear meniscus dynamics, Krehbiel flow and lacrimal functional unit. Expert commentary: After decades, the topic of tear turnover assessment has been reintroduced. Recently, new techniques have been developed to propose less invasive, less time consuming and simpler methodologies for the assessment of tear dynamics that have the potential to be utilized in clinical practice.

Break-up of New Orleans Households after Hurricane Katrina

PubMed Central

Rendall, Michael S.

2011-01-01

Theory and evidence on disaster-induced population displacement have focused on individual and population-subgroup characteristics. Less is known about impacts on households. I estimate excess incidence of household break-up due to Hurricane Katrina by comparing a probability sample of pre-Katrina New Orleans resident adult household heads and non–household heads (N = 242), traced just over a year later, with a matched sample from a nationally representative survey over an equivalent period. One in three among all adult non–household heads, and one in two among adult children of household heads, had separated from the household head 1 year post-Katrina. These rates were, respectively, 2.2 and 2.7 times higher than national rates. A 50% higher prevalence of adult children living with parents in pre-Katrina New Orleans than nationally increased the hurricane’s impact on household break-up. Attention to living arrangements as a dimension of social vulnerability in disaster recovery is suggested. PMID:21709733

Tear Osmolarity and Correlation With Ocular Surface Parameters in Patients With Dry Eye.

PubMed

Mathews, Priya M; Karakus, Sezen; Agrawal, Devika; Hindman, Holly B; Ramulu, Pradeep Y; Akpek, Esen K

2017-11-01

To analyze the distribution of tear film osmolarity in patients with dry eye and its association with other ocular surface parameters. Tear osmolarity and other quantitative dry eye parameters were obtained from patients with 1) clinically significant dry eye (significant symptoms and ocular surface staining, n = 131), 2) symptoms-only dry eye (significant symptoms but no significant ocular surface staining, n = 52), and 3) controls (no significant symptoms or staining, n = 42). Tear osmolarity varied significantly across groups (P = 0.01), with patients with clinically significant dry eye having the highest tear osmolarity (312.0 ± 16.9 mOsm/L), control patients having the lowest tear osmolarity (305.6 ± 9.7 mOsm/L), and patients with symptoms-only dry eye falling in between (307.4 ± 5.6 mOsm/L). Patients with clinically significant dry eye also tended to have a greater intereye difference in osmolarity (12.0 ± 13.4) than did the individuals with symptoms-only dry eye (9.1 ± 12.4) and controls (9.0 ± 7.4) (P = 0.06). In multivariable regression models, higher tear osmolarity was associated with higher Ocular Surface Disease Index, discomfort subscore (P = 0.02), and higher corneal and conjunctival staining scores (P < 0.01 for both). Worse eye tear osmolarity was not correlated with the corresponding tear film breakup time or Schirmer test (P > 0.05 for both). Individuals with symptomatic dry eye that is not yet clinically significant seem to have higher and more variable osmolarity measurements than controls, potentially indicating that changes in osmolarity precede clinical findings.

Phospholipids and their degrading enzyme in the tears of soft contact lens wearers.

PubMed

Yamada, Masakazu; Mochizuki, Hiroshi; Kawashima, Motoko; Hata, Seiichiro

2006-12-01

Low tear phospholipids levels are associated with tear film instability in soft contact lens wearers. We assayed levels of phospholipids and their degrading enzyme secretory phospholipase A2 (sPLA2) both in tears and deposited on contact lenses composed of 2 hydrophilic materials after 1 day of routine use. Polymacon (Medalist; FDA group 1, low water/nonionic) and Etafilcon A (One Day Acuvue; group 4, high water/ionic) contact lenses were worn for 12 hours by 16 experienced contact lens wearers. Phospholipids in tear fluids and deposited on contact lenses were estimated by phosphorus determination with ammonium molybdate through enzymatic digestion. Double-antibody sandwich ELISA was used to determine group IIa sPLA2 concentrations, and sPLA2 activity was assayed using 1,2-diheptanoyl thio-phosphatidylcholine as substrate. Phospholipids concentrations in tears with Polymacon and Etafilcon A were 186 +/- 39 and 162 +/- 33 microg/mL, respectively. The latter concentration was significantly lower than that observed in the same subjects when not wearing contact lenses (P = 0.0023). In tears, both group IIa sPLA2 concentrations and enzymatic activity remained unchanged, regardless of lens wearing. However, Etafilcon A (0.57 +/- 0.09 microg/lens) showed more group IIa sPLA2 deposition than Polymacon (0.01 +/- 0.01 microg/lens; P < 0.001). Furthermore, group IIa sPLA2 deposited on Etafilcon A but not on Polymacon lenses retained its enzymatic activity. Significant differences of group IIa sPLA2 deposition were found in the 2 lenses tested. Such deposition might induce phospholipid hydrolysis in tears and thereby promote tear film instability in hydrophilic contact lens wearers.

Central Atlantic Break-up: A competition between CAMP Hotspot and thinning rate.

NASA Astrophysics Data System (ADS)

Sapin, F.; Maurin, T.

2017-12-01

The break-up of the Central Atlantic is known to have ended at about 190Myrs while the CAMP (Central Atlantic Magmatic Province) was still active. Several seismic lines, acquired recently in the deep offshore Senegal and Mauritanian domain, provide detailed images of continent-ocean transition and the oceanic crust architecture. Their interpretation is the opportunity to describe the progressive interaction between the hot spot activity, the architecture and timing of break up and the oceanic crust production. In the North, seismic data and gravity/magnetic inversions suggest an extremely thinned continental crust with possible mantle exhumation. In the South, the continental crust is thick and the transition to oceanic crust is sharp. In addition, three oceanic crust facies were described along the margin in an extremely slow spreading ridge setting ( 0.8cm/yr during the first 20Myrs): facies (1) with a poorly imaged Moho and a strongly faulted thin oceanic crust or exhumed mantle; facies (2) with an extensively faulted 6km thick oceanic crust; facies (3) with abnormally thick (9km) oceanic crust marked by SDR-type reflections. They are diachronous from North to South and the two first one disappear southwards and (facies 3) being younger toward the North. Only a single very thick oceanic crust (12-14km) remains in front of the Guinea Plateau. We concluded that, in the South, the break-up had been forced through a thick or thickened continental crust due to the remnant activity of the CAMP Hotspot. In the North, the magmatic pulse arrived far after the break-up during the spreading and the thinning of the continental crust could lead to hyper extension. This evolution emphasizes that the architecture, and thus processes leading to the break-up can vary a lot considering the influence of thermal vertical forces (mantle dynamics/hotspot/magmatism) and mechanical horizontal forces (plate movement/faulting/spreading), both of them being necessary for a rift to succeed.

Antioxidant content and ultraviolet absorption characteristics of human tears.

PubMed

Choy, Camus Kar Man; Cho, Pauline; Benzie, Iris F F

2011-04-01

tear film of the aging eye may help prevent or improve dry eye symptoms and promote ocular health.

Breaking into the Movies: Pedagogy and the Politics of Film.

ERIC Educational Resources Information Center

Giroux, Henry A.

2001-01-01

Proposes that in addition to entertaining, film offers up subject positions; mobilizes desires; influences its audience unconsciously; and helps construct the landscape of American culture. Notes that film can provide a pedagogical tool for offering students alternative views of the world. Concludes that as a form of public pedagogy, film combines…

Electrophoresis of tear proteins as a new diagnostic tool for two high risk groups for dry eye: computer users and contact lens wearers.

PubMed

Chiva, Andreea

2011-08-15

Dry eye is the most prevalent condition seen by the ophthalmologist, in particular in elderly. The identification of new common risk factors (computer use and contact lens wear) extends the disease among the young people. The early diagnosis of dry eye is essential, but difficult, because the biochemical changes in tear film usually occur before any detectable signs. Due its advantages, electrophoresis of tear proteins could be an important tool for diagnosis of tear film impairment in high risk groups for dry eye. The role of tear proteins electrophoresis in early diagnosis of dry eye related to computer use and contact lens wear, as well as the biochemical changes in these high risk groups are presented. This review will summarize the actual data concerning the electrophoretic changes of tear proteins in computer users and contact lens wearers, two common high risk groups for dry eye. Electrophoresis of tear proteins using automated system Hyrys-Hydrasys SEBIA France is an important tool for early diagnosis of tear film alterations and monitoring of therapy. The quantification of many proteins in a single analysis using a small quantity of unconcentrated reflex tears is the main advantage of this technique. Electrophoresis of tear proteins should became a prerequisite, in particular for computer users less than 3 h/day, as well as at prescribing contact lenses.

First order sea-level cycles and supercontinent break up

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heller, P.L.; Angevine, C.L.

1985-01-01

The authors have developed a model that successfully predicts the approximate magnitude and timing of long term sea-level change without relying on short term increases in global spreading rates. The model involves the following key assumptions. (1) Ocean basins have two types of area/age distributions; Pacific ocean basins are rimmed by subduction zones and have triangular distributions; and Atlantic ocean basins which open at constant rates, have no subduction, and so have rectangular distributions. (2) The total area of the global ocean is constant so that the Pacific basin must close as the Atlantic opens. These assumptions approximate modern globalmore » ocean basin conditions. The model begins with supercontinent break up. As the Atlantic begins to open, the mean age of the global ocean decreases, the mean depth of the sea floor shallows, and sea level, therefore, rises. Once the Atlantic occupies more than 8 to 10% of the global ocean area, the mean age and depth of the ocean floor increases resulting in a sea-level fall. The model can be applied to the mid-Cretaceous sea-level high stand which followed break up of Pangea by 80 to 100 Ma. Based on average Atlantic opening rates, sea level rises to a peak of 44 m at 80 Ma after opening began and then falls by 84 m to the present. Thus the model is capable of explaining approximately half of the total magnitude of the post-mid-Cretaceous eustatic fall without invoking short-term changes in global spreading rates. In addition, the model predicts the observed time lag between supercontinent break up and sea-level high stand for both Mesozoic as well as early Paleozoic time.« less

Breaking up with Deleuze: Desire and Valuing the Irreconcilable

ERIC Educational Resources Information Center

Tuck, Eve

2010-01-01

In this article, Eve Tuck grapples with Gilles Deleuze's conceptualization of desire, finding it simultaneously generative and unsatisfying. Recognizing that Deleuze will not "say" what Tuck wants him to say about desire--that it is smart, and constitutes expertise--Tuck reasons that there is only one thing she can do: break up with Deleuze. The…

Evaluation of the UP4FUN Intervention: A Cluster Randomized Trial to Reduce and Break Up Sitting Time in European 10-12-Year-Old Children

PubMed Central

Vik, Frøydis N.; Lien, Nanna; Berntsen, Sveinung; De Bourdeaudhuij, Ilse; Grillenberger, Monika; Manios, Yannis; Kovacs, Eva; Chinapaw, Mai J. M.; Brug, Johannes; Bere, Elling

2015-01-01

Background The UP4FUN intervention is a family-involved school-based intervention aiming at reducing and breaking up sitting time at home (with special emphasis on screen time), and breaking up sitting time in school among 10–12 year olds in Europe. The purpose of the present paper was to evaluate its short term effects. Methodology/Principal Findings A total of 3147 pupils from Belgium, Germany, Greece, Hungary and Norway participated in a school-randomized controlled trial. The intervention included 1–2 school lessons per week for a period of six weeks, along with assignments for the children and their parents. Screen time and breaking up sitting time were registered by self-report and total sedentary time and breaking up sitting time by accelerometry. The effect of the intervention on these behaviors was evaluated by multilevel regression analyses. All analyses were adjusted for baseline values and gender. Significance level was p≤0.01. No significant intervention effects were observed, neither for self-reported TV/DVD or computer/game console time, nor for accelerometer-assessed total sedentary time and number of breaks in sitting time. The intervention group, however, reported more positive attitudes towards (β = 0.25 (95% CI 0.11, 0.38)) and preferences/liking for (β = 0.20 (95% CI 0.08, 0.32)) breaking up sitting time than the control group. Conclusions/Significance No significant intervention effect on self-reported screen time or accelerometer-assessed sedentary time or breaks in sitting time was observed, but positive effects on beliefs regarding breaking up sitting time were found in favor of the intervention group. Overall, these results do not warrant wider dissemination of the present UP4FUN intervention. Trial Registration International Standard Randomized Controlled Trial Number Registry ISRCTN34562078 PMID:25826704

The UP4FUN Intervention Effect on Breaking Up Sedentary Time in 10- to 12-Year-Old Belgian Children: The ENERGY-Project.

PubMed

Verloigne, Maïté; Berntsen, Sveinung; Ridgers, Nicola D; Cardon, Greet; Chinapaw, Mai; Altenburg, Teatske; Brug, Johannes; Bere, Elling; De Bourdeaudhuij, Ilse; Van Lippevelde, Wendy; Maes, Lea

2015-05-01

There are currently no studies available reporting intervention effects on breaking up children's sedentary time. This study examined the UP4FUN intervention effect on objectively measured number of breaks in sedentary time, number of sedentary bouts (≥ 10 mins) and total and average amount of time spent in those sedentary bouts among 10- to 12-year-old Belgian children. The total sample included 354 children (mean age: 10.9 ± 0.7 years; 59% girls) with valid ActiGraph accelerometer data at pre- and posttest. Only few and small intervention effects were found, namely on total time spent in sedentary bouts immediately after school hours (4-6PM; β = -3.51mins) and on average time spent in sedentary bouts before school hours (6-8.30AM; β = -4.83mins) and immediately after school hours in favor of children from intervention schools (β = -2.71mins). Unexpectedly, girls from intervention schools decreased the number of breaks during school hours (8.30AM-4PM; β = -23.45breaks) and increased the number of sedentary bouts on a weekend day (β = +0.90bouts), whereas girls in control schools showed an increase in number of breaks and a decrease in number of bouts. In conclusion, UP4FUN did not have a consistent or substantial effect on breaking up children's sedentary time and these data suggest that more intensive and longer lasting interventions are needed.

Evaluation of inter-day and inter-individual variability of tear peptide/protein profiles by MALDI-TOF MS analyses

PubMed Central

González, Nerea; Iloro, Ibon; Durán, Juan A.; Elortza, Félix

2012-01-01

Purpose To characterize the tear film peptidome and low molecular weight protein profiles of healthy control individuals, and to evaluate changes due to day-to-day and individual variation and tear collection methods, by using solid phase extraction coupled to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) profiling. Methods The tear protein profiles of six healthy volunteers were analyzed over seven days and inter-day and inter-individual variability was evaluated. The bilaterality of tear film and the effect of tear collection methods on protein profiles were also analyzed in some of these patients. MALDI-TOF MS analyses were performed on tear samples purified by using a solid phase extraction (SPE) method based on C18 functionalized magnetic beads for peptide and low molecular weight protein enrichment, focusing spectra acquisition on the 1 to 20 kDa range. Spectra were analyzed using principal component analysis (PCA) with MultiExperiment Viewer (TMeV) software. Volunteers were examined in terms of tear production status (Schirmer I test), clinical assessment of palpebral lids and meibomian glands, and a subjective OSD questionnaire before tear collection by a glass micro-capillary. Results Analysis of peptides and proteins in the 1–20 kDa range showed no significant inter-day differences in tear samples collected from six healthy individuals during seven days of monitoring, but revealed subtle intrinsic inter-individual differences. Profile analyses of tears collected from the right and left eyes confirmed tear bilaterality in four healthy patients. The addition of physiologic serum for tear sample collection did not affect the peptide and small protein profiles with respect to the number of resolved peaks, but it did reduce the signal intensity of the peaks, and increased variability. Magnetic beads were found to be a suitable method for tear film purification for the profiling study. Conclusions No significant

Different modes of continental break-up triggered by a sole mantle plume: a 2D and 3D numerical study

NASA Astrophysics Data System (ADS)

Beniest, Anouk; Koptev, Alexander; Leroy, Sylvie; Burov, Evgueni

2017-04-01

We used 2D and 3D numerical models to investigate the impact of a single mantle plume on continental rifting and breakup processes. We varied the thermo-rheological structure of the continental lithosphere, its geometry and the initial plume position. Based on the results of our 2D experiments, three continental break-up modes can be distinguished: A) 'central' continental break-up, the break-up center is located directly above the original mantle anomaly position, B) 'shifted' break-up, the break-up center is 50 to 200 km displaced from the initial plume location and C) 'distant' break-up, due to convection and/or slab-subduction/delamination, the break-up center is considerably shifted (300 to 800 km) from the primary plume position. Our 3D model, with a laterally homogeneous initial setup also results in continental break-up with the axis of continental break-up hundreds of kilometers shifted from the original plume location. The model results show that the classical, 'central' view of mantle plume induced continental break-up is not the only mode of break-up. When considering a diversity of break-up styles, it is possible to explain a variety of observed geophysical and geological features. For example, the mantle material glued to the base of the lithosphere at shallower depths corresponds geometrically and location-wise to high-velocity/high-density bodies observed on seismic data below the thinned continental lithosphere and the transition zone of the South Atlantic domain. During migration, products of partial melting of the mantle material can move vertically to (shallow) lower crustal levels. They might resemble high density bodies observed at lower crustal levels inside continental crust with similar geometries observed with gravity modelling. Also, topographic variation form in the very early stages of rifting on the first impingement of upwelled plume material. These variations remain visible, as the final position of the spreading center is shifted

Evaporation and Hydrocarbon Chain Conformation of Surface Lipid Films

PubMed Central

Sledge, Samiyyah M.; Khimji, Hussain; Borchman, Douglas; Oliver, Alexandria; Michael, Heidi; Dennis, Emily K.; Gerlach, Dylan; Bhola, Rahul; Stephen, Elsa

2016-01-01

Purpose The inhibition of the rate of evaporation (Revap) by surface lipids is relevant to reservoirs and dry eye. Our aim was to test the idea that lipid surface films inhibit Revap. Methods Revap were determined gravimetrically. Hydrocarbon chain conformation and structure were measured using a Raman microscope. Six 1-hydroxyl hydrocarbons (11–24 carbons in length) and human meibum were studied. Reflex tears were obtained from a 62-year-old male. Results The Raman scattering intensity of the lipid film deviated by about 7 % for hydroxyl lipids and varied by 21 % for meibum films across the entire film at a resolution of 5 µm2. All of the surface lipids were ordered. Revap of the shorter chain hydroxyl lipids were slightly (7%) but significantly lower compared with the longer chain hydroxyl lipids. Revap of both groups was essentially similar to that of buffer. A hydroxyl lipid film did not influence Revap over an estimated average thickness range of 0.69 to >6.9 µm. Revap of human tears and buffer with and without human meibum (34.4 µm thick) was not significantly different. Revap of human tears was not significantly different from buffer. Conclusions Human meibum and hydroxyl lipids, regardless of their fluidity, chain length, or thickness did not inhibit Revap of buffer or tears even though they completely covered the surface. It is unlikely that hydroxyl lipids can be used to inhibit Revap of reservoirs. Our data do not support the widely accepted (yet unconfirmed) idea that the tear film lipid layer inhibits Revap of tears. PMID:27395776

The correlation between plasma osmolarity and tear osmolarity.

PubMed

Kobayashi, Maika; Igarashi, Tsutomu; Takahashi, Hisatomo; Fujimoto, Chiaki; Suzuki, Hisaharu; Takahashi, Hiroshi

2018-04-01

To the correlation between plasma osmolarity (Posm) and tear osmolarity (Tosm) in patients (54 patients, 88 eyes) who underwent cataract surgery was evaluated. Before cataract surgery, routine pre-operative biochemical tests were performed, and Posm was determined from blood samples. Also, Tosm was measured using the TearLab system, and objective signs including tear break-up time (BUT), fluorescein staining, lissamine green staining, and Schirmer's test were evaluated. Dry eye (DE) was diagnosed according to the Japanese criteria for DE. Of the 88 eyes, 4 were diagnosed as definite DE, 70 as probable DE, and 14 as normal. Since the number of definite DE was small, the eyes were divided into two groups: normal group (n = 14) and DE group (n = 74), which included definite DE (n = 4) and probable DE (n = 70). There was no correlation between Posm and Tosm, though Posm (293.32 mOsm/L) was significantly higher than Tosm (288.48 mOsm/L; p < 0.001). There was no significant difference in Tosm between the normal group (288.29 mOsm/L) and the DE group (288.51 mOsm/L). No patients had a Tosm higher than 310 mOsm/L even in the DE group. Correlations between Posm/Tosm and each DE sign value were not found. Of 54 patients, 18 were diabetic. Posm was significantly higher in diabetic (295.78 mOsm/L) than in non-diabetic (292.36 mOsm/L; p = 0.014) patients, while there was no significant difference in Tosm between diabetic and non-diabetic patients. The results suggest that Tosm is independent of Posm, and Tosm elevation in DE occurs by some local mechanisms.

Real-world assessment of diquafosol in dry eye patients with risk factors such as contact lens, meibomian gland dysfunction, and conjunctivochalasis: subgroup analysis from a prospective observational study

PubMed Central

Yamaguchi, Masahiko; Nishijima, Takeshi; Shimazaki, Jun; Takamura, Etsuko; Yokoi, Norihiko; Watanabe, Hitoshi; Ohashi, Yuichi

2015-01-01

Purpose To evaluate the efficacy and safety of diquafosol (DQS) ophthalmic solution in dry eye (DE) patients wearing contact lenses (CLs) or with concomitant meibomian gland dysfunction (MGD) or conjunctivochalasis in a real-world setting. Patients and methods From a cohort of patients enrolled in a prospective observational study, DE patients who met the Japanese diagnostic criteria and who received DQS as a monotherapy were extracted and stratified according to the presence or absence of CL use, MGD, and conjunctivochalasis. Corneal and conjunctival fluorescein staining score, tear film break-up time, total symptom score (12 DE-related subjective symptoms), patient-reported outcomes, and adverse reactions were investigated. Results DQS treatment resulted in significant improvement in total symptom score, corneal and conjunctival fluorescein staining score, and tear film break-up time without significant differences between patient subgroups with versus without CL use, MGD, or conjunctivochalasis. Comparable proportions of patients perceived symptomatic improvements in all subgroups. There were no adverse reactions specifically associated with the CL use or any comorbidity of MGD or conjunctivochalasis. Conclusion DQS can be used effectively and safely as a monotherapy for the treatment of DE patients wearing CLs or with concomitant MGD or conjunctivochalasis. PMID:26664039

Large-eddy simulation of cavitating nozzle flow and primary jet break-up

DOE Office of Scientific and Technical Information (OSTI.GOV)

Örley, F., E-mail: felix.oerley@aer.mw.tum.de; Trummler, T.; Mihatsch, M. S.

We employ a barotropic two-phase/two-fluid model to study the primary break-up of cavitating liquid jets emanating from a rectangular nozzle, which resembles a high aspect-ratio slot flow. All components (i.e., gas, liquid, and vapor) are represented by a homogeneous mixture approach. The cavitating fluid model is based on a thermodynamic-equilibrium assumption. Compressibility of all phases enables full resolution of collapse-induced pressure wave dynamics. The thermodynamic model is embedded into an implicit large-eddy simulation (LES) environment. The considered configuration follows the general setup of a reference experiment and is a generic reproduction of a scaled-up fuel injector or control valve asmore » found in an automotive engine. Due to the experimental conditions, it operates, however, at significantly lower pressures. LES results are compared to the experimental reference for validation. Three different operating points are studied, which differ in terms of the development of cavitation regions and the jet break-up characteristics. Observed differences between experimental and numerical data in some of the investigated cases can be caused by uncertainties in meeting nominal parameters by the experiment. The investigation reveals that three main mechanisms promote primary jet break-up: collapse-induced turbulent fluctuations near the outlet, entrainment of free gas into the nozzle, and collapse events inside the jet near the liquid-gas interface.« less

Tears Falling on Goosebumps: Co-occurrence of Emotional Lacrimation and Emotional Piloerection Indicates a Psychophysiological Climax in Emotional Arousal

PubMed Central

Wassiliwizky, Eugen; Jacobsen, Thomas; Heinrich, Jan; Schneiderbauer, Manuel; Menninghaus, Winfried

2017-01-01

This psychophysiological study is the first to examine the relationship between emotional tears and emotional piloerection (i.e., goosebumps). Although both phenomena have been related to peak states of being moved, details about their temporal occurrence and the associated levels of physiological arousal have remained unknown. In our study, we used emotionally powerful film scenes that were self-selected by participants. Our findings show that even within peak moments of emotional arousal, a gradation of intensity is possible. The overlap of tears and goosebumps signifies a maximal climax within peak moments. On the side of the stimulus, we found that displays of prosocial behavior play a crucial role in the elicitation of tears and goosebumps. Finally, based on the results of a formal film analysis of the tears-eliciting clips provided by our participants, as compared to randomly extracted, equally long control clips from the same films, we show how the technical and artistic making of the clips was optimized for the display of social interaction and emotional expressions. PMID:28223946

Contact geometry at the undersurface of the acromion with and without a rotator cuff tear.

PubMed

Lee, S B; Itoi, E; O'Driscoll, S W; An, K N

2001-04-01

The purpose of this study was to investigate the difference in contact geometry at the undersurface of acromion in shoulders with and without a rotator cuff (RC) tear. Case-control study. Forty fresh cadaveric shoulders (average age at death, 61 years) without gross osteoarthritic changes were divided into the intact RC group (n = 20) and the RC tear group (n = 20). Clinical impingement was simulated by compressing the humeral head and the intact portion of the RC against the coracoacromial arch with an axial compressive force of 25 kg while the humerus was held abducted 20 degrees in the scapular plane. The contact pattern between the acromion and the RC was measured with Fuji Prescale super low-pressure-sensitive film (Fuji Photo Film Co, Ltd, Tokyo, Japan). The imprint image was analyzed using Global Lab image software (Automatix, Marlboro, MA). The percentage of the maximum anteroposterior dimension of the imprint on Fuji film to the anteroposterior diameter of the acromial undersurface was 29% +/- 9% in intact RC shoulders, and 39% +/- 13% in shoulders with an RC tear (P >.05). The percentage of the maximum mediolateral dimension of the imprint to the mediolateral diameter of the corresponding part of the acromial undersurface was 27% +/- 12% in intact RC shoulders, and 48% +/- 11% in shoulders with an RC tear. This difference was statistically significant (P <.005). The contact geometry of the acromial undersurface with the underlying RC in the anteroposterior dimension, which might be related to the appearance in supraspinatus outlet view, was not significantly different between shoulders with and without an RC tear. These findings suggest that factors other than acromial shape play a significant role in the pathogenesis of RC tears. The implication regarding the role of acromioplasty remains to be clarified.

Aspergillus flavus induced alterations in tear protein profile reveal pathogen-induced host response to fungal infection.

PubMed

Kandhavelu, Jeyalakshmi; Demonte, Naveen Luke; Namperumalsamy, Venkatesh Prajna; Prajna, Lalitha; Thangavel, Chitra; Jayapal, Jeya Maheshwari; Kuppamuthu, Dharmalingam

2017-01-30

Aspergillus flavus and Fusarium sp. are primary causative agents of keratitis that results in corneal tissue damage leading to vision loss particularly in individuals from the tropical parts of the world. Proteins in the tear film collected from control and keratitis patients was profiled and compared. A total of 1873 proteins from control and 1400 proteins from patient tear were identified by mass spectrometry. While 847 proteins were found to be glycosylated in the patient tear, only 726 were glycosylated in control tear. And, some of the tear proteins showed alterations in their glycosylation pattern after infection. Complement system proteins, proteins specific for neutrophil extracellular traps and proteins involved in would healing were found only in the patient tear. The presence of these innate immune system proteins in the tear film of patients supports the previous data indicating the involvement of neutrophil and complement pathways in antifungal defense. High levels of wound healing proteins in keratitis patient tear implied activation of tissue repair during infection. The early appearance of the host defense proteins and wound healing response indicates that tear proteins could be used as an early marker system for monitoring the progression of pathogenesis. Identification of negative regulators of the above defense pathways in keratitis tear indicates an intricate balance of pro and anti-defense mechanisms operating in fungal infection of the eye. Tear proteins from control and mycotic keratitis patients were separated into glycoproteins and non-glycosylated proteins and then identified by mass spectrometry. Tear proteins from keratitis patients showed alteration in the glycosylation pattern indicating the alteration of glycosylation machinery due to infection. Neutrophil extracellular traps specific proteins, complement pathway proteins, as well as wound healing proteins, were found only in patient tear showing the activation of antifungal defense

Tear Film Steroid Profiling in Dry Eye Disease by Liquid Chromatography Tandem Mass Spectrometry

PubMed Central

Agnifili, Luca; Cicalini, Ilaria; Calienno, Roberta; Zucchelli, Mirco; Mastropasqua, Leonardo; Sacchetta, Paolo; Del Boccio, Piero; Rossi, Claudia

2017-01-01

Dry eye disease (DED) is a multifactorial disorder of the ocular surface unit resulting in eye discomfort, visual disturbance, and ocular surface damage; the risk of DED increases with age in both sexes, while its incidence is higher among females caused by an overall hormonal imbalance. The role of androgens has recently investigated and these hormones were considered to have a protective function on the ocular surface. In order to correlate DED to tear steroid levels, a robust, specific, and selective method for the simultaneous quantification of cortisol (CORT), corticosterone (CCONE), 11-deoxycortisol (11-DECOL), 4-androstene-3,17-dione (ADIONE), testosterone (TESTO), 17α-hydroxyprogesterone (17-OHP), and progesterone (PROG) was developed and applied for the analysis of tear samples. The method involves a simple extraction procedure of steroids from tears collected on Schirmer strips, followed by a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis. In total, tear samples from 14 DED female patients and 13 healthy female controls were analysed and, CORT, ADIONE, and 17-OHP response levels resulted significantly decreased in dry eye patients respect to controls. The receiver operating characteristic (ROC) curve obtained by the combination of these three steroids (AUC = 0.964) demonstrated the good diagnostic power of the differential tear steroids in identifying DED. In conclusion, the present method made it possible, for the first time, to study steroid profiling directly in tear fluid. PMID:28672794

JBP485 promotes tear and mucin secretion in ocular surface epithelia

PubMed Central

Nakamura, Takahiro; Hata, Yuiko; Nagata, Maho; Yokoi, Norihiko; Yamaguchi, Shumpei; Kaku, Taiichi; Kinoshita, Shigeru

2015-01-01

Dry eye syndrome (DES), a multifactorial disease of the tears and ocular surface, is one of the most common ocular disorders. Tear film contains ocular mucins and is essential for maintaining the homeostasis of the wet ocular surface. Since there are a limited number of clinical options for the treatment of DES, additional novel treatments are needed to improve the clinical results. In this study, we found that placental extract-derived dipeptide (JBP485) clearly promoted the expression and secretion of gel-forming mucin 5ac (Muc5ac) in rabbit conjunctival epithelium. JBP485 also elevated the expression level of cell surface-associated mucins (Muc1/4/16) in rabbit corneal epithelium. The Schirmer tear test results indicated that JBP485 induced tear secretion in the rabbit model. Moreover, JBP485 clinically improved corneal epithelial damage in a mouse dry eye model. Thus, our data indicate that JBP485 efficiently promoted mucin and aqueous tear secretion in rabbit ocular surface epithelium and has the potential to be used as a novel treatment for DES. PMID:25996902

JBP485 promotes tear and mucin secretion in ocular surface epithelia.

PubMed

Nakamura, Takahiro; Hata, Yuiko; Nagata, Maho; Yokoi, Norihiko; Yamaguchi, Shumpei; Kaku, Taiichi; Kinoshita, Shigeru

2015-05-21

Dry eye syndrome (DES), a multifactorial disease of the tears and ocular surface, is one of the most common ocular disorders. Tear film contains ocular mucins and is essential for maintaining the homeostasis of the wet ocular surface. Since there are a limited number of clinical options for the treatment of DES, additional novel treatments are needed to improve the clinical results. In this study, we found that placental extract-derived dipeptide (JBP485) clearly promoted the expression and secretion of gel-forming mucin 5ac (Muc5ac) in rabbit conjunctival epithelium. JBP485 also elevated the expression level of cell surface-associated mucins (Muc1/4/16) in rabbit corneal epithelium. The Schirmer tear test results indicated that JBP485 induced tear secretion in the rabbit model. Moreover, JBP485 clinically improved corneal epithelial damage in a mouse dry eye model. Thus, our data indicate that JBP485 efficiently promoted mucin and aqueous tear secretion in rabbit ocular surface epithelium and has the potential to be used as a novel treatment for DES.

Effect of Sn addition on hot tearing susceptibility of AXJ530 alloy

NASA Astrophysics Data System (ADS)

Hai-kuo, Dong; Feng, Wang; Zhi, Wang; Jin-kun, Liu; Zheng, Liu; Ping-li, Mao

2018-03-01

The effects of different Sn additions (0, 0.5, 1.0, and 2.0 wt%) on hot tearing susceptibility (HTS) of AXJ530 alloy were studied using ‘T-shaped’ hot tearing mold at a pouring temperature of 700 °C and a mold temperature of 200 °C and paraffin permeation method. The dendrite coherency temperature was obtained by means of differential thermal analysis (DTA), and phases evolution, microstructures and morphology of the crack zone of AXJ530-xSn alloys were also investigated by using x-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The experimental results show that the HTS of AXJ530-xSn alloys increases with Sn additions up to 1.0 wt%, and then exhibits a slight decrease with further Sn additions up to 2.0 wt%. The Sn additions into AXJ530 alloy can first form CaMgSn phase with high melting point, reduce amount of α-Mg+(Mg,Al)2Ca eutectic phase, increase the dendrite coherency temperature, decrease the thickness of liquid film and the feeding ability at the end of solidification, resulting in the rise of the HTS. However, the improvement in hot tearing resistance for AXJ530-2.0Sn alloy can be attributed to the grain refinement, lower dendrite coherency temperature and formation of the Mg17Al12 phase with a low melting point to feed more readily at the end of solidification, which improves the state of dendrite and the feeding channel.

Evaporation and Hydrocarbon Chain Conformation of Surface Lipid Films.

PubMed

Sledge, Samiyyah M; Khimji, Hussain; Borchman, Douglas; Oliver, Alexandria L; Michael, Heidi; Dennis, Emily K; Gerlach, Dylan; Bhola, Rahul; Stephen, Elsa

2016-10-01

The inhibition of the rate of evaporation (R evap ) by surface lipids is relevant to reservoirs and dry eye. Our aim was to test the idea that lipid surface films inhibit R evap . R evap were determined gravimetrically. Hydrocarbon chain conformation and structure were measured using a Raman microscope. Six 1-hydroxyl hydrocarbons (11-24 carbons in length) and human meibum were studied. Reflex tears were obtained from a 62-year-old male. The Raman scattering intensity of the lipid film deviated by about 7 % for hydroxyl lipids and varied by 21 % for meibum films across the entire film at a resolution of 5 μm 2 . All of the surface lipids were ordered. R evap of the shorter chain hydroxyl lipids were slightly (7%) but significantly lower compared with the longer chain hydroxyl lipids. R evap of both groups was essentially similar to that of buffer. A hydroxyl lipid film did not influence R evap over an estimated average thickness range of 0.69 to >6.9 μm. R evap of human tears and buffer with and without human meibum (34.4 μm thick) was not significantly different. R evap of human tears was not significantly different from buffer. Human meibum and hydroxyl lipids, regardless of their fluidity, chain length, or thickness did not inhibit R evap of buffer or tears even though they completely covered the surface. It is unlikely that hydroxyl lipids can be used to inhibit R evap of reservoirs. Our data do not support the widely accepted (yet unconfirmed) idea that the tear film lipid layer inhibits R evap of tears. Copyright © 2016 Elsevier Inc. All rights reserved.

Simulation of Thin Film Equations on an Eye-Shaped Domain with Moving Boundary

NASA Astrophysics Data System (ADS)

Brosch, Joseph; Driscoll, Tobin; Braun, Richard

During a normal eye blink, the upper lid moves, and during the upstroke the lid paints a thin tear film over the exposed corneal and conjunctival surfaces. This thin tear film may be modeled by a nonlinear fourth-order PDE derived from lubrication theory. A major stumbling block in the numerical simulation of this model is to include both the geometry of the eye and the movement of the eyelid. Using a pair of orthogonal and conformal maps, we transform a computational box into a rough representation of a human eye where we proceed to simulate the thin tear film equations. Although we give up some realism, we gain spectrally accurate numerical methods on the computational box. We have applied this method to the heat equation on the blinking domain with both Dirichlet and no-flux boundary conditions, in each case demonstrating at least 10 digits of accuracy.. We are able to perform these simulations very quickly (generally in under a minute) using a desktop version of MATLAB. This project was supported by Grant 1022706 (R.J.B., T.A.D., J.K.B.) from the NSF.

Comparison of camel tear proteins between summer and winter

PubMed Central

Chen, Ziyan; Shamsi, Farrukh A.; Li, Kaijun; Huang, Qiang; Al-Rajhi, Ali A.; Chaudhry, Imtiaz A.

2011-01-01

Purpose Proteins in the tear fluid have positive effects on maintaining the integrity and stabilization of the tear film, which is affected by several environmental factors. The aim of this study is to investigate seasonal variation of protein patterns in camel tears collected during the summer and winter season. Methods Tears from both eyes of 50 clinically normal camels (Camelus dromedarius) were collected in the summer (June – July) and in the winter (December – January) respectively. Pooled tear protein samples from two seasons were separated by SDS–PAGE and two-dimensional electrophoresis (2-DE). Protein spots of differential expression in two season gels were excised and subjected to in-gel digestion and identification by matrix assisted laser desorption/ionization-time of flight/time of flight-mass spectrum (MALDI-TOF/TOF-MS) analysis. Two differentially expressed proteins, lactoferrin (LF) and vitelline membrane outer layer protein 1 homolog (VMO1 homolog), were validated by western blotting. Results Thirteen well resolved bands were detected in SDS–PAGE gels of both summer and winter camel tears. By band densitometry, significantly higher intensities of band 6, 7, 11, and lower intensity of band 13 were observed in the summer group compared to the winter group. In 2-DE profiles of camel tears, four protein spots were found expressed differentially in two seasons. Further protein identification by MALDI-TOF/TOF-MS and confirmation by western blotting indicated that there was a significant decrease in LF (p=0.002) and an increase in VMO1 homolog (p=0.042) in tears in the summer compared to the winter. Conclusions The seasonal variation of camel tear fluids has been found in the composition of proteins, including LF and VMO1 homolog. This result will expand our knowledge of physiologic characteristics of tear fluids and establish a foundation for the mechanistic studies and clinical practices on ocular surface disorders. PMID:21293736

A Microscopic View of Oil Slick Break-Up and Emulsion Formation in Breaking Waves

NASA Astrophysics Data System (ADS)

Law, J.; Shahrokhi, H.; Shaw, J. M.

1996-11-01

The hydrodynamic behaviour of oil spills in breaking waves determines the appropriateness and effectiveness of remedial measures during clean-up operations. Oil slicks either disperse as fine drops or form water in oil emulsions when exposed to breaking waves. However, there is little agreement with respect to the controlling variables or mechanisms for emulsification or dispersion and predictions are unreliable. For example, predicted energy dissipation rates in breaking waves are too low to account for the drop sizes encountered experimentally[1]. In this paper, we assess the impact of hydrodynamics and physical properties on the formation of dispersions or emulsions. The maximum stable drop size for dispersions arising from oil slicks and water in oil emulsions are shown to be controlled by Raleigh-Taylor instability or the prevalent local shear stress. Data from four experimental studies[2-5], with a broad range of physical properties were fitted quantitatively. As high shear events are intermittent, stable water in oil emulsions can be formed by dispersion inversion near the water air interface or by water entrained by gas bubbles passing through oil slicks. 1) Li & Garrett, 19th AMOP, Calgary AB, 1, 185-198 (1996). 2) Lin et al., Report CG-D-54-78, U.S. Coast Guard, Washington D.C. (1978). 3) Buist, MASc Thesis, University of Toronto (1979). 4) Wallace et al., 9th AMOP, Edmonton AB, 2, 421-429, June 10-12 (1986). 5) Ross Environmental Research Ltd., Ottawa ON, Report EE-96, (1987).

Impact of wildfire smoke in Buenos Aires, Argentina, on ocular surface.

PubMed

Berra, Martin; Galperín, Gustavo; Dawidowski, Laura; Tau, Julia; Márquez, Isabel; Berra, Alejandro

2015-01-01

To evaluate the acute impact of the wildfire smoke episode in 2008 on the ocular surface of subjects living in the Metropolitan Area of Buenos Aires (MABA). A total of 86 subjects were evaluated: Group 1 comprised patients from a public ophthalmology hospital (N=35) and Group 2 comprised healthy volunteers (N=51). All subjects answered a questionnaire on ocular symptoms and underwent ophthalmologic examination [bulbar conjunctival hyperemia, corneal fluorescein staining, rose bengal vital staining, tear break-up time (TBUT), Schirmer I test, tear lysozyme, and impression cytology] during and after the acute episode. Concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), and particulate matter (PM) were measured before, during, and after the acute episode. Both groups showed a statically significant increase in ocular symptoms and bulbar conjunctival hyperemia and a statically significant decrease in tear break-up time during the acute episode. Group 1 showed more severe symptoms and a statistically significant increase in fluorescein and rose bengal staining intensities during the acute episode. We found a significant negative correlation between ocular symptoms and tear break-up time. During the episode, the levels of CO, NO2, and particulate matter in MABA were four times higher than the usual average levels for the same period in 2007 and 2009. Increased air pollution from the burning of biomass is associated with a decrease in the stability of the tear film (TBUT), generating areas of ocular surface exposure that may be the cause of the increased feeling of irritation. Group 1 was more affected by not having a healthy ocular surface, and thus consulted an ophthalmologist. Cytological changes in the conjunctiva were not observed, which could be due to the short duration of the episode.

Temporal Characteristics of Sodium Fluorescein in the Tear Meniscus.

PubMed

Markoulli, Maria; Isa, Nur Amalina M D; Papas, Eric B

2017-02-01

To observe the emission intensity profile of sodium fluorescein in the human tear film as a function of time and concentration. Twenty-two participants with no dry eye signs or symptoms were randomly allocated to receive 1 μL of either a 2 or 10% concentration of fluorescein to one eye. Images of the inferior tear meniscus were captured at regular intervals over 30 minutes and the process repeated for the other eye with the alternate concentration. Fluorescence intensity was quantified on the basis of the grayscale pixel values in the tear meniscus images. The fluorescein-decay profile over time and between concentrations was determined. Peak fluorescence intensity was reached in 3.9 ± 3.0 and 8.7 ± 4.4 minutes after instillation for the 2 and 10% concentrations, respectively. The 10% concentration of fluorescein maintained its peak fluorescence intensity longer than the 2% concentration (about 9 and 2 minutes, respectively). The peak fluorescence intensity was not significantly different between the higher and lower concentrations (44 ± 37 vs. 38 ± 32 units, P = .22). For both concentrations, the observed intensity did not return to baseline levels by the end of the 30-minute observation time. The fluorescence intensity of fluorescein in a clinical setting varies with time such that both the onset and duration of maximum brightness are concentration dependent. At low concentration (2%), maximum brightness occurs almost immediately after instillation and lasts about 2 minutes. With a higher concentration (10%), the effective working window is delayed for about 7 to 8 minutes. Irrespective of initial concentration, observable fluorescence remains in the tear film beyond 30 minutes post-instillation.

Arthroscopic pullout suture repair of posterior root tear of the medial meniscus: radiographic and clinical results with a 2-year follow-up.

PubMed

Lee, Ju Hong; Lim, Young Jin; Kim, Ki Bum; Kim, Kyu Hyung; Song, Ji Hun

2009-09-01

This study was undertaken to document the short-term clinical efficacy of arthroscopic pullout suture repair in treating posterior root tears of the medial meniscus. From March 2004 to August 2006, 26 patients (27 knees) with posterior root tears of the medial meniscus were treated with arthroscopic pullout suture repair surgery by the senior author. Of these, 20 consecutive patients (21 knees) with a minimum of 2 years' follow-up treated by arthroscopic pullout suture repair were analyzed. Clinical results by use of the Lysholm knee and Hospital for Special Surgery scores and radiographic grade were evaluated, both preoperatively and at final follow-up. In addition, the second-look arthroscopic findings for 10 knees were analyzed. A radiographic evaluation using the criteria of Kellgren and Lawrence at final follow-up showed an increase in radiographic grade by 1 grade in only 1 knee. On the second-look arthroscopies performed in 10 knees (47.6%), all repaired menisci had healed completely without additional chondral lesions in the knee. The mean Hospital for Special Surgery scores improved from 61.1 preoperatively to 93.8 at final follow-up (P < .0001), and the mean preoperative Lysholm knee scores improved from 57.0 to 93.1 at final follow-up (P < .0001). Retear was found in 1 knee at the 6-month follow-up, and reoperation was performed with the same procedure used for the index surgery. Arthroscopic pullout suture repair is an effective treatment for alleviating meniscal symptoms in patients with a symptomatic posterior root tear of the medial meniscus with degenerated articular cartilage of less than grade III. In addition, no discernable degenerative arthritic changes were found in terms of radiographic features with our limited short-term follow-up. Level IV, therapeutic case series.

Glenohumeral Instability Related to Special Conditions: SLAP Tears, Pan-labral Tears, and Multidirectional Instability.

PubMed

Van Blarcum, Gregory S; Svoboda, Steven J

2017-09-01

Glenohumeral instability is one of the more common conditions seen by sports medicine physicians, especially in young, active athletes. The associated anatomy of the glenohumeral joint (the shallow nature of the glenoid and the increased motion it allows) make the shoulder more prone to instability events as compared with other joints. Although traumatic dislocations or instability events associated with acute labral tears (ie, Bankart lesions) are well described in the literature, there exists other special shoulder conditions that are also associated with shoulder instability: superior labrum anterior/posterior (SLAP) tears, pan-labral tears, and multidirectional instability. SLAP tears can be difficult to diagnose and arthroscopic diagnosis remains the gold standard. Surgical treatment as ranged from repair to biceps tenodesis with varying reports of success. Along the spectrum of SLAP tears, pan-labral tears consist of 360-degree injuries to the labrum. Patients can present complaining of either anterior or posterior instability alone, making the physical examination and advanced imaging a crucial component of the work up of the patients. Arthroscopic labral repair remains a good initial option for surgical treatment of these conditions. Multidirectional instability remains one of the more difficult conditions for the sports medicine physician to diagnose and treat. Symptoms may only be reported as vague pain versus frank instability making the diagnoses particularly challenging, especially in a patient with overall joint laxity. Conservative management to include physical therapy is the mainstay initial treatment in patients without an identifiable structural abnormality. Surgical management of this condition has evolved from open to arthroscopic capsular shifts with comparable results.

Arthroscopic Repair of Full-Thickness Rotator Cuff Tears With and Without Acromioplasty: Randomized Prospective Trial With 2-Year Follow-up.

PubMed

Abrams, Geoffrey D; Gupta, Anil K; Hussey, Kristen E; Tetteh, Elizabeth S; Karas, Vasili; Bach, Bernard R; Cole, Brian J; Romeo, Anthony A; Verma, Nikhil N

2014-06-01

Acromioplasty is commonly performed during arthroscopic rotator cuff repair, but its effect on short-term outcomes is debated. To report the short-term clinical outcomes of patients undergoing arthroscopic repair of full-thickness rotator cuff tears with and without acromioplasty. Randomized controlled trial; Level of evidence, 2. Patients undergoing arthroscopic repair of full-thickness rotator cuff tears were randomized into acromioplasty or nonacromioplasty groups. The Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons (ASES) score, Constant score, University of California-Los Angeles (UCLA) score, and Short Form-12 (SF-12) health assessment were collected along with physical examination including range of motion and dynamometer strength testing. Intraoperative data including tear size, repair configuration, and concomitant procedures were recorded. Follow-up examination was performed at regular intervals up to 2 years. Preoperative imaging was reviewed to classify the acromial morphologic type, acromial angle, and lateral acromial angulation. A total of 114 patients were initially enrolled in the study, and 95 (83%; 43 nonacromioplasty, 52 acromioplasty) were available for a minimum 2-year follow-up. There were no significant differences in baseline characteristics, including number of tendons torn, repair configuration, concomitant procedures, and acromion type and angles. Within groups, there was a significant (P < .001) improvement in all functional outcome scores from preoperatively to all follow-up time points, including 2 years, for the nonacromioplasty and acromioplasty groups (ASES score: 55.1-91.5, 48.8-89.0; Constant score: 48.3-75.0, 51.9-78.7, respectively). There were no significant differences in functional outcomes between nonacromioplasty and acromioplasty groups or between subjects with different acromial features at any time point. The results of this study demonstrate no difference in clinical outcomes after rotator cuff repair

Early changes in ocular surface and tear inflammatory mediators after small-incision lenticule extraction and femtosecond laser-assisted laser in situ keratomileusis.

PubMed

Gao, Shaohui; Li, Saiqun; Liu, Liangping; Wang, Yong; Ding, Hui; Li, Lili; Zhong, Xingwu

2014-01-01

To characterize the early ocular-surface changes or tear inflammatory-mediators levels following small-incision lenticule extraction (ReLEx smile) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK). Forty-seven myopic subjects were recruited for this prospective study. Fifteen underwent ReLEx smile and thirty-two underwent FS-LASIK. Corneal fluorescein (FL) staining, tear break-up time (TBUT), Schirmer I test (SIT), ocular surface disease index (OSDI) and central corneal sensitivity were evaluated in all participants. Tears were collected and analyzed for interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), nerve growth factor (NGF) and intercellular adhesion molecule-1 (ICAM-1) levels using multiplex magnetic beads. All measurements were preformed preoperatively and 1 day, 1 week, 1 month and 3 months postoperatively. FL scores in ReLEx smile group were lower than those of FS-LASIK group 1 week postoperatively (P = 0.010). Compared to the FS-LASIK group, longer TBUT were observed in ReLEx smile group 1 month (P = 0.029) and 3 months (P = 0.045) postoperatively. No significant differences were found in tear secretion for the two groups (P>0.05). OSDI scores were higher in FS-LASIK group 1 month after surgery (P = 0.020). Higher central corneal sensitivity was observed in ReLEx smile group 1 week, 1 month and 3 months (P<0.05) postoperatively. Compared to FS-LASIK group, lower and faster recovery of IL-6 and NGF levels in tears was observed in ReLEx smile group postoperatively (P<0.05). Tears TNF-α and ICAM-1 concentrations were not significantly different between the two groups at any follow-up time (P>0.05). Moreover, IL-6 and NGF levels correlated with ocular surface changes after ReLEx smile or FS-LASIK. In the early postoperative period, ReLEx smile results in milder ocular surface changes than FS-LASIK. Furthermore, the tear inflammatory mediators IL-6 and NGF may play a crucial role in the ocular surface healing process following Re

Mass spectrometric identification of phospholipids in human tears and tear lipocalin.

PubMed

Dean, Austin W; Glasgow, Ben J

2012-04-02

The purpose of this article was to identify by mass spectrometry phosphocholine lipids in stimulated human tears and determine the molecules bound to tear lipocalin or other proteins. Tear proteins were separated isocratically from pooled stimulated human tears by gel filtration fast performance liquid chromatography. Separation of tear lipocalin was confirmed by SDS tricine gradient PAGE. Protein fractions were extracted with chloroform/methanol and analyzed with electrospray ionization MS/MS triple quadrupole mass spectrometry in precursor ion scan mode for select leaving groups. For quantification, integrated ion counts were derived from standard curves of authentic compounds of phosphatidylcholine (PC) and phosphatidylserine. Linear approximation was possible from integration of the mass spectrometrically obtained ion peaks at 760 Da for the PC standard. Tears contained 194 ng/mL of the major intact PC (34:2), m/z 758.6. Ten other monoisotopic phosphocholines were found in tears. A peak at 703.3 Da was assigned as a sphingomyelin. Four lysophosphatidylcholines (m/z 490-540) accounted for about 80% of the total integrated ion count. The [M+H](+) compound, m/z 496.3, accounted for 60% of the signal intensity. Only the tear lipocalin-bearing fractions showed phosphocholines (104 ng/mL). Although the intact phospholipids bound to tear lipocalin corresponded precisely in mass and relative signal intensity to that found in tears, we did not identify phosphocholines between m/z 490 and 540 in any of the gel-filtration fractions. Phospholipids, predominantly lysophospholipids, are present in tears. The higher mass intact PCs in tears are native ligands of tear lipocalin.

Changes in the evaporation rate of tear film after digital expression of meibomian glands in patients with and without dry eye.

PubMed

Arciniega, Juan Carlos; Wojtowicz, Jadwiga Cristina; Mohamed, Engy Mostafa; McCulley, James Parker

2011-08-01

To evaluate the effect of excess meibum on tear evaporation rate in patients with and without dry eye. Eleven healthy subjects and 16 patients with dry eye were tested. The dry eye group was divided into 2 subgroups: classic keratoconjunctivitis sicca (KCS) with clear and easily expressed meibum and KCS with meibomian gland dysfunction (MGD) with turbid secretions and difficult-to-express meibum. Evaporative measurements were performed at baseline and after digital expression of meibomian glands at 12, 24, 36, and 48 minutes. Two ranges of relative humidity were used, 25% to 35% and 35% to 45%. The data were expressed as microliters per square centimeter per minute. An increase in the evaporation rate of the tear film was noted for all measurements at both relative humidities in the classic KCS and KCS with MGD groups compared with healthy subjects (P < 0.05). The average evaporation rates at relative humidities of 25% to 35% and 35% to 45% were 0.056 ± 0.016 and 0.040 ± 0.008 for the classic KCS group; 0.055 ± 0.026 and 0.037 ± 0.019 for the KCS with MGD group and 0.033 ± 0.012 and 0.023 ± 0.008 for the healthy group. Also, a decrease in the evaporation rate was observed in the healthy and KCS with MGD groups between baseline and the first measurement after digital expression for both relative humidities (P < 0.05). The classic KCS group did not show any changes after expression. Classic KCS and KCS with MGD groups showed an increase in tear evaporation rates compared with the healthy group. Aqueous tear evaporation diminished in the healthy and KCS with MGD groups after expression of meibomian glands. However, this effect was transient and negligible after the second measurement.

Noninvasive Continuous Monitoring of Tear Glucose Using Glucose-Sensing Contact Lenses.

PubMed

Ascaso, Francisco J; Huerva, Valentín

2016-04-01

: The incidence of diabetes mellitus is dramatically increasing in the developed countries. Tight control of blood glucose concentration is crucial to diabetic patients to prevent microvascular complications. Self-monitoring of blood glucose is widely used for controlling blood glucose levels and usually performed by an invasive test using a portable glucometer. Many technologies have been developed over the past decades with the purpose of obtaining a continuous physiological glycemic monitoring. A contact lens is the ideal vehicle for continuous tear glucose monitoring of glucose concentration in tear film. There are several research groups that are working in the development of contact lenses with embedded biosensors for continuously and noninvasively monitoring tear glucose levels. Although numerous aspects must be improved, contact lens technology is one step closer to helping diabetic subjects better manage their condition, and these contact lenses will be able to measure the level of glucose in the wearer's tears and communicate the information to a mobile phone or computer. This article reviews studies on ocular glucose and its monitoring methods as well as the attempts to continuously monitor the concentration of tear glucose by using contact lens-based sensors.

The effect of reinforcement on the tear properties of flexible circuits

NASA Astrophysics Data System (ADS)

Acton, A. E.

The tear properties of Kapton flexible circuitry are very poor. To better understand the properties of flex circuits and how to reinforce them, four different reinforcing materials were applied to a typical flex circuit and the tear properties were measured. Teflon film, nylon fabric, glass fabric and Kevlar fabric were all laminated to a flex circuit with Pyralux (a Dupont tradename) adhesive. The fabrics were laminated in both a 0/90 and a + or - 45 configuration. Five tests wereperformed, Graves, crescent, trousers, tensile and single edge notch (SEN). Of the four materials used for reinforcement, Kevlar clearly showed the greatest overall improvement in tear properties. However, Kevlar also provided the greatest processing difficulties. All of the reinforced circuits had an increase in thickness which resulted in an unacceptable loss of flexibility.

Mass Spectrometric Identification of Phospholipids in Human Tears and Tear Lipocalin

PubMed Central

Dean, Austin W.; Glasgow, Ben J.

2012-01-01

Purpose. The purpose of this article was to identify by mass spectrometry phosphocholine lipids in stimulated human tears and determine the molecules bound to tear lipocalin or other proteins. Methods. Tear proteins were separated isocratically from pooled stimulated human tears by gel filtration fast performance liquid chromatography. Separation of tear lipocalin was confirmed by SDS tricine gradient PAGE. Protein fractions were extracted with chloroform/methanol and analyzed with electrospray ionization MS/MS triple quadrupole mass spectrometry in precursor ion scan mode for select leaving groups. For quantification, integrated ion counts were derived from standard curves of authentic compounds of phosphatidylcholine (PC) and phosphatidylserine. Results. Linear approximation was possible from integration of the mass spectrometrically obtained ion peaks at 760 Da for the PC standard. Tears contained 194 ng/mL of the major intact PC (34:2), m/z 758.6. Ten other monoisotopic phosphocholines were found in tears. A peak at 703.3 Da was assigned as a sphingomyelin. Four lysophosphatidylcholines (m/z 490–540) accounted for about 80% of the total integrated ion count. The [M+H]+ compound, m/z 496.3, accounted for 60% of the signal intensity. Only the tear lipocalin–bearing fractions showed phosphocholines (104 ng/mL). Although the intact phospholipids bound to tear lipocalin corresponded precisely in mass and relative signal intensity to that found in tears, we did not identify phosphocholines between m/z 490 and 540 in any of the gel-filtration fractions. Conclusions. Phospholipids, predominantly lysophospholipids, are present in tears. The higher mass intact PCs in tears are native ligands of tear lipocalin. PMID:22395887

Physical Changes in Human Meibum with Age as Measured by Infrared Spectroscopy

PubMed Central

Borchman, Douglas; Foulks, Gary N.; Yappert, Marta C.; Kakar, Shelly; Podoll, Nathan; Rychwalski, Paul; Schwietz, Eric

2010-01-01

Both lipids and mucins contribute to the stability of the tear film and lipids may inhibit tears from evaporating. Younger people have lower lipid viscosity, higher lipid volume, and a lower rate of tear evaporation. Since age-related changes in human meibum composition and conformation have never been investigated, as a basis for the study of lipid-associated changes with meibomian gland dysfunction, we used the power of infrared spectroscopy to characterize hydrocarbon chain conformation and packing in meibum from humans without dry eye symptoms in relation to age and sex. Meibum from normal human donors ranging in age from 3 to 88 years was studied. Meibum phase transitions were quantified by fitting them to a 4-parameter 2-state sigmoidal equation. Human meibum order and phase transition temperatures decrease with age and this trend may be attributed to lipid compositional changes. If meibum has the same thermodynamic properties on the surface of the tears as it does on the lid margin, a decrease in lipid-lipid interaction strength with increasing age could decrease the stability of tears since lipid-lipid interactions on the tear surface must be broken for the tear film to break up. This study also serves as a foundation to examine meibum conformational differences in meibum from people with meibomian gland dysfunction. PMID:20160464

Cytokine changes in tears and relationship to contact lens discomfort.

PubMed

Willcox, Mark D P; Zhao, Zhenjun; Naduvilath, Thomas; Lazon de la Jara, Percy

2015-01-01

To determine the reproducibility of a multiplex bead assay for measuring cytokines in tears and correlations between ocular discomfort with or without contact lens wear and the concentration of cytokines in tears. Ninety participants (divided into two groups) were enrolled in this prospective study. They were asked to rate their ocular comfort and collect their tears in the morning and just before sleep for 10 days with or without contact lenses. The participants collected their tears using a glass microcapillary tube for both stages. Galyfilcon A lenses were worn on a daily disposable basis during the contact lens stage, and comfort scores and tears were collected before lens insertion and prior to lens removal at the end of the day. Tears were analyzed for cytokine concentrations using a 27-plex multibead assay. Correlations were sought between cytokine concentrations and comfort. There was a significant (p<0.022) decrease in ocular comfort over the day with or without lens wear. The magnitude of ocular discomfort was significantly greater (p<0.009) with lens wear. The concentrations of 12 cytokines differed significantly between the groups; thus, these cytokines were not analyzed further. For the remaining 15 cytokines, interleukin-8 (IL-8) was the only cytokine that changed in both groups during the day without (reduced by >-0.5 Log pg/ml, p<0.001) or with lens wear (reduced by >-0.2 Log pg/ml, p<0.001). The change in the vascular endothelial growth factor (VEGF) concentration only in tears was correlated to ocular comfort, but this was not changed by contact lens wear. Ocular comfort during the day is magnified by contact lens wear. However, the increase in the change in comfort during lens wear was not associated with changes in 15 cytokines in the tear film.

Cytokine changes in tears and relationship to contact lens discomfort

PubMed Central

Zhao, Zhenjun; Naduvilath, Thomas; Lazon de la Jara, Percy

2015-01-01

Purpose To determine the reproducibility of a multiplex bead assay for measuring cytokines in tears and correlations between ocular discomfort with or without contact lens wear and the concentration of cytokines in tears. Methods Ninety participants (divided into two groups) were enrolled in this prospective study. They were asked to rate their ocular comfort and collect their tears in the morning and just before sleep for 10 days with or without contact lenses. The participants collected their tears using a glass microcapillary tube for both stages. Galyfilcon A lenses were worn on a daily disposable basis during the contact lens stage, and comfort scores and tears were collected before lens insertion and prior to lens removal at the end of the day. Tears were analyzed for cytokine concentrations using a 27-plex multibead assay. Correlations were sought between cytokine concentrations and comfort. Results There was a significant (p<0.022) decrease in ocular comfort over the day with or without lens wear. The magnitude of ocular discomfort was significantly greater (p<0.009) with lens wear. The concentrations of 12 cytokines differed significantly between the groups; thus, these cytokines were not analyzed further. For the remaining 15 cytokines, interleukin-8 (IL-8) was the only cytokine that changed in both groups during the day without (reduced by >-0.5 Log pg/ml, p<0.001) or with lens wear (reduced by >-0.2 Log pg/ml, p<0.001). The change in the vascular endothelial growth factor (VEGF) concentration only in tears was correlated to ocular comfort, but this was not changed by contact lens wear. Conclusions Ocular comfort during the day is magnified by contact lens wear. However, the increase in the change in comfort during lens wear was not associated with changes in 15 cytokines in the tear film. PMID:25814827

Visual Fatigue Induced by Viewing a Tablet Computer with a High-resolution Display.

PubMed

Kim, Dong Ju; Lim, Chi Yeon; Gu, Namyi; Park, Choul Yong

2017-10-01

In the present study, the visual discomfort induced by smart mobile devices was assessed in normal and healthy adults. Fifty-nine volunteers (age, 38.16 ± 10.23 years; male : female = 19 : 40) were exposed to tablet computer screen stimuli (iPad Air, Apple Inc.) for 1 hour. Participants watched a movie or played a computer game on the tablet computer. Visual fatigue and discomfort were assessed using an asthenopia questionnaire, tear film break-up time, and total ocular wavefront aberration before and after viewing smart mobile devices. Based on the questionnaire, viewing smart mobile devices for 1 hour significantly increased mean total asthenopia score from 19.59 ± 8.58 to 22.68 ± 9.39 (p < 0.001). Specifically, the scores for five items (tired eyes, sore/aching eyes, irritated eyes, watery eyes, and hot/burning eye) were significantly increased by viewing smart mobile devices. Tear film break-up time significantly decreased from 5.09 ± 1.52 seconds to 4.63 ± 1.34 seconds (p = 0.003). However, total ocular wavefront aberration was unchanged. Visual fatigue and discomfort were significantly induced by viewing smart mobile devices, even though the devices were equipped with state-of-the-art display technology. © 2017 The Korean Ophthalmological Society

Contact lens-related dry eye and ocular surface changes with mapping technique in long-term soft silicone hydrogel contact lens wearers.

PubMed

Sengor, Tomris; Aydin Kurna, Sevda; Ozbay, Nurver; Ertek, Semahat; Aki, Suat; Altun, Ahmet

2012-01-01

To evaluate ocular surface changes in long-term silicone hydrogel contact lens wearers. Thirty patients were included in this study. Twenty patients (40 eyes) using contact lenses constituted group 1 and 10 (20 eyes) volunteers constituted group 2. The duration of average contact lens usage was 7.74 ± 3.3 years. Ocular surface was evaluated by surface staining, tear film break-up time (TBUT), Schirmer I test, and conjunctival impression cytology with color-coded mapping technique and by the Ocular Surface Disease Index (OSDI). The mean break-up time was lower and staining scores were higher in group 1 (p<0.001) but Schirmer values were not significantly different from group 2 (p>0.05). The mean OSDI score was 34.59 ± 11.93 to 19.28 ± 6.7 in group 1 and 2. Increased metaplastic predominant changes of grade II and III were observed in the interpalpebral and perilimbal areas in group 1. Significant correlations were observed in TBUT, cornea staining, and grade II to grade III metaplasia ratios between duration of the lens usage and contact lens wear time in a day. Silicone hydrogel lenses produce significant changes on tear film and impression cytology of the ocular surface in long-term use.

Visual Fatigue Induced by Viewing a Tablet Computer with a High-resolution Display

PubMed Central

Kim, Dong Ju; Lim, Chi-Yeon; Gu, Namyi

2017-01-01

Purpose In the present study, the visual discomfort induced by smart mobile devices was assessed in normal and healthy adults. Methods Fifty-nine volunteers (age, 38.16 ± 10.23 years; male : female = 19 : 40) were exposed to tablet computer screen stimuli (iPad Air, Apple Inc.) for 1 hour. Participants watched a movie or played a computer game on the tablet computer. Visual fatigue and discomfort were assessed using an asthenopia questionnaire, tear film break-up time, and total ocular wavefront aberration before and after viewing smart mobile devices. Results Based on the questionnaire, viewing smart mobile devices for 1 hour significantly increased mean total asthenopia score from 19.59 ± 8.58 to 22.68 ± 9.39 (p < 0.001). Specifically, the scores for five items (tired eyes, sore/aching eyes, irritated eyes, watery eyes, and hot/burning eye) were significantly increased by viewing smart mobile devices. Tear film break-up time significantly decreased from 5.09 ± 1.52 seconds to 4.63 ± 1.34 seconds (p = 0.003). However, total ocular wavefront aberration was unchanged. Conclusions Visual fatigue and discomfort were significantly induced by viewing smart mobile devices, even though the devices were equipped with state-of-the-art display technology. PMID:28914003

Influence of Ophthalmic Solutions on Tear Components.

PubMed

Shigeyasu, Chika; Yamada, Masakazu; Akune, Yoko

2016-11-01

Tear fluids are a mixture of secretions derived from lacrimal glands, accessory lacrimal glands, conjunctiva, and meibomian glands. Compositional changes to tears occur in the normal state and during ocular surface disease, such as dry eye conditions. We have investigated compositional changes to tears after topical application of ophthalmic solutions, with regard to tear-specific proteins (secretory immunoglobulin A, lactoferrin, lipocalin-1, and lysozyme) and ocular surface mucin in normal and dry eye conditions using high-performance liquid chromatography. After application of saline solution (0.9% sodium chloride) in normal subjects, transient but significant decreases in all tear components were observed. The recovery of protein concentrations took up to 30 minutes and lasted longer when the saline solution was applied more frequently. When applying ophthalmic solutions, a balance between washout and dilutional effects should be considered in addition to the therapeutic effect. Investigation of the effect of diquafosol solution (3%) in normal subjects revealed a significant increase in sialic acid concentration, a marker of ocular mucin, at 5 minutes after application, whereas a significant decrease was observed with saline. This result indicates the accelerated secretion of mucin from ocular tissues induced by diquafosol. A clinical study to determine the efficacy of diquafosol in patients with dry eye revealed improvements in tear breakup time, keratoconjunctival staining scores, and Schirmer test score, accompanied by an increase in sialic acid concentration in tears. Investigating normal and dry eye conditions through tear analysis may clarify the pathophysiology of dry eye conditions and support the efficacy of treatments.

Clinical study to assess the efficacy of Keshanjana and Netra Parisheka in the management of Shushkakshipaka (dry eye syndrome).

PubMed

Vardhan, Prabhakar; Dhiman, Kartar Singh

2014-01-01

Dry eye syndrome (DES) is a common ophthalmic problem predominantly affecting middle-aged and elderly people. It is a disease of deficient or deranged tears and ocular surface disorder producing symptoms of discomfort, visual disturbance, and tears film instability. Shushkakshipaka, an etymologically and clinically similar entity to DES, is defined in Ayurveda as the disease affecting all parts of the eye characterized by Paka (inflammation) due to Shuskatva (dryness) caused by altered coherence of Ashru (tears) with ocular surface or due to lack of Ashru. To compare the effect of Keshanjana and Netra Parisheka in Shushkakshipaka with artificial tear drops (carboxy methyl cellulose [CMC]). To search a safe, potent and cost-effective Ayurvedic treatment for DES, a randomized comparative clinical trial was conducted on 32 patients. Patients were divided in two groups 15 in group I and 17 in group II. Group I treated with artificial tear drop four times a day for topical use and group II treated with combination therapy of Keshanjana applied topically once a day and Netra Prisheka was done thrice a day. The effect of Ayurvedic management was found to be equivalent to the standard therapy, although the trial drugs provided more relief in foreign body sensation, burning sensation, dryness, pain, photophobia, itching, crusting, stuck eyelids, tear meniscus, conjunctival congestion, Schirmer I test, and tear film break-up time (TUBT). The standard therapy provided more relief than trial drugs in mucous discharges, transiently blurred vision, redness, and the presence of mucin debris in tear film. Keshanjana and Netra Parisheka can be used as a potent, safe and cost-effective treatment to ameliorate the symptoms of DES.

Stalking perpetrators and psychological maltreatment of partners: anger-jealousy, attachment insecurity, need for control, and break-up context.

PubMed

Davis, K E; Ace, A; Andra, M

2000-01-01

Two studies of the correlates of self-reported courtship persistence, stalking-like behaviors following a relationship break-up, and psychological maltreatment of partners were conducted in samples of male (N = 46 and 93) and female (N = 123 and 110) college students. Approximately 40% (38.5% and 44.6%) engaged in at least one stalking behavior following a break-up. A total of 10.7% (study 1) and 7.6% (study 2) engaged in 6 or more stalking behaviors. Stalking was significantly related to psychological maltreatment of the partner (PMP) prior to the break-up. Being the recipient of the breakup was associated with feelings of anger, jealousy and obsessiveness and with higher levels of courtship persistence, and stalking. A replicated path model showed that anxious attachment and need for control were related to PMP and that need for control had a direct contribution to stalking. For anxious attachment, its connection to stalking was indirect, mediated by the degree of anger-jealousy over the break-up.

Collisionless kinetic theory of oblique tearing instabilities

NASA Astrophysics Data System (ADS)

Baalrud, S. D.; Bhattacharjee, A.; Daughton, W.

2018-02-01

The linear dispersion relation for collisionless kinetic tearing instabilities is calculated for the Harris equilibrium. In contrast to the conventional 2D geometry, which considers only modes at the center of the current sheet, modes can span the current sheet in 3D. Modes at each resonant surface have a unique angle with respect to the guide field direction. Both kinetic simulations and numerical eigenmode solutions of the linearized Vlasov-Maxwell equations have recently revealed that standard analytic theories vastly overestimate the growth rate of oblique modes. We find that this stabilization is associated with the density-gradient-driven diamagnetic drift. The analytic theories miss this drift stabilization because the inner tearing layer broadens at oblique angles sufficiently far that the assumption of scale separation between the inner and outer regions of boundary-layer theory breaks down. The dispersion relation obtained by numerically solving a single second order differential equation is found to approximately capture the drift stabilization predicted by solutions of the full integro-differential eigenvalue problem. A simple analytic estimate for the stability criterion is provided.

On the lipid composition of human meibum and tears: comparative analysis of nonpolar lipids.

PubMed

Butovich, Igor A

2008-09-01

To qualitatively compare the nonpolar lipids present in meibomian gland (MG) secretions (samples T1) with aqueous tears (AT) collected from the lower tear menisci of healthy, non-dry eye volunteers using either glass microcapillaries (samples T2) or Schirmer test strips (samples T3). Samples T1 to T3 were analyzed with the use of high-pressure liquid chromatography/positive ion mode atmospheric pressure chemical ionization mass spectrometry. Where possible, the unknown lipids were compared with known standards. Samples T1 had the simplest lipid composition among all the tested specimens. Samples T2 and T3 were similar to each other but were noticeably different from samples T1. In addition to all the compounds detected in samples T1, lower molecular weight wax esters and other compounds were found in samples T2 and T3. No appreciable amounts of fatty acid amides (e.g., oleamide), ceramides, or monoacyl glycerols were routinely detected. The occasionally observed minor signals of oleamide (m/z 282) in samples T3 were attributed to the contamination of the samples with common plasticizers routinely found in plastic ware extractives and organic solvents. The MG is a prominent source of lipids for the tear film. However, it would have been a mistake to exclude from consideration other likely sources of lipids such as conjunctiva, cornea, and tears produced by the lacrimal glands. These data showed that lipids in AT are more complex than MG secretions, which necessitates more cautious interpretation of the functions of the latter in the tear film.

Dry eye syndrome among computer users

NASA Astrophysics Data System (ADS)

Gajta, Aurora; Turkoanje, Daniela; Malaescu, Iosif; Marin, Catalin-Nicolae; Koos, Marie-Jeanne; Jelicic, Biljana; Milutinovic, Vuk

2015-12-01

Dry eye syndrome is characterized by eye irritation due to changes of the tear film. Symptoms include itching, foreign body sensations, mucous discharge and transitory vision blurring. Less occurring symptoms include photophobia and eye tiredness. Aim of the work was to determine the quality of the tear film and ocular dryness potential risk in persons who spend more than 8 hours using computers and possible correlations between severity of symptoms (dry eyes symptoms anamnesis) and clinical signs assessed by: Schirmer test I, TBUT (Tears break-up time), TFT (Tear ferning test). The results show that subjects using computer have significantly shorter TBUT (less than 5 s for 56 % of subjects and less than 10 s for 37 % of subjects), TFT type II/III in 50 % of subjects and type III 31% of subjects was found when compared to computer non users (TFT type I and II was present in 85,71% of subjects). Visual display terminal use, more than 8 hours daily, has been identified as a significant risk factor for dry eye. It's been advised to all persons who spend substantial time using computers to use artificial tears drops in order to minimize the symptoms of dry eyes syndrome and prevents serious complications.

Retinal tear: an unusual complication of ocular toxoplasmosis.

PubMed

Celebi, Ali Riza Cenk; Kilavuzoglu, Ayse Ebru; Altiparmak, Ugur Emrah; Cosar, Cemile Banu; Ozkiris, Abdullah

2015-01-01

It is aimed to report on a 16-year-old patient with acquired ocular toxoplasmosis complicated by a retinal tear. Retrospective medical chart review. A 16-year-old Caucasian female presented with vision loss in her right eye. In addition to a white active lesion between the fovea and the optic nerve head, marked vitreous opacification was noted. She was diagnosed with ocular toxoplasmosis. The patient was treated with oral azithromycin, clindamycin, and trimethoprimsulfamethoxazole. One month later, retinochoroiditis resolved and vitreous cleared. Three months after onset, patient presented with floaters in the right eye and a retinal tear was located at the temporal region of the retina. Prophylactic argon laser treatment that encircled the retinal tear was performed. No other abnormalities were noted during 6 months of follow-up. Retinal tear associated with ocular toxoplasmosis is rare; however, a retinal tear can occur due to vitreoretinal traction following post-inflammatory structural alteration of the vitreous. Retinal tears may be seen during the healing phase, when the inflammation turns into tightening of vitreous substance. Careful retinal examination in cases of ocular toxoplasmosis is warranted, especially in patients with severe vitreous inflammation.

Biomechanical consequences of a tear of the posterior root of the medial meniscus. Surgical technique.

PubMed

Harner, Christopher D; Mauro, Craig S; Lesniak, Bryson P; Romanowski, James R

2009-10-01

Tears of the posterior root of the medial meniscus are becoming increasingly recognized. They can cause rapidly progressive arthritis, yet their biomechanical effects are not understood. The goal of this study was to determine the effects of posterior root tears of the medial meniscus and their repairs on tibiofemoral joint contact pressure and kinematics. Nine fresh-frozen cadaver knees were used. An axial load of 1000 N was applied with a custom testing jig at each of four knee-flexion angles: 0 degrees , 30 degrees , 60 degrees , and 90 degrees . The knees were otherwise unconstrained. Four conditions were tested: (1) intact, (2) a posterior root tear of the medial meniscus, (3) a repaired posterior root tear, and (4) a total medial meniscectomy. Fuji pressure-sensitive film was used to record the contact pressure and area for each testing condition. Kinematic data were obtained by using a robotic arm to record the position of the knees for each loading condition. Three-dimensional knee kinematics were analyzed with custom programs with use of previously described transformations. The measured variables were axial rotation, varus angulation, lateral translation, and anterior translation. In the medial compartment, a posterior root tear of the medial meniscus caused a 25% increase in peak contact pressure compared with that found in the intact condition (p < 0.001). Repair restored the peak contact pressure to normal. No difference was detected between the peak contact pressure after the total medial meniscectomy and that associated with the root tear. The peak contact pressure in the lateral compartment after the total medial meniscectomy was up to 13% greater than that for all other conditions (p = 0.026). Significant increases in external rotation and lateral tibial translation, compared with the values in the intact knee, were observed in association with the posterior root tear (2.98 degrees and 0.84 mm, respectively) and the meniscectomy (4.45 degrees and 0

Property development for biaxial drawing of ethylene-tetrafluoroehtylene copolymer films and resultant fractural behavior analyzed by in situ X-ray measurements.

PubMed

Uehara, Hiroki; Ono, Yasunori; Kakiage, Masaki; Sakamura, Takumi; Masunaga, Hiroyasu; Yukawa, Yasumasa; Higuchi, Yoshiaki; Kamiya, Hiroki; Yamanobe, Takeshi

2015-03-19

The property development of the ethylene-tetrafluoroethylene copolymer (ETFE) membrane induced by simultaneous biaxial drawing was investigated. Commonly, tensile strength can be increased by drawing; conversely, tear resistance decreases. In this study, the balance between tensile strength and tear resistance for the resultant ETFE membrane was optimized achieved by a combination of lamination of low molecular weight (LMW) and high molecular weight (HMW) layers and subsequent biaxial drawing. The structural factor determining tear resistance of these biaxially drawn membranes was determined based on in situ small-angle X-ray scattering (SAXS) measurement during tensile deformation simulating tearing tests. Lozenge shaped scattering, which indicated inclined lamellae, was observed during such tensile deformation of the resultant membranes. Remarkably, this inclined lamellar structure was observed for the pure LMW membrane; however, it also appeared at the interface between LMW and HMW layers within biaxially drawn membranes. For the membrane exhibiting the highest tearing strength, the fraction of such inclined lamella increased up to the critical strain corresponding to the actual sample breaking. These results confirm that the inclined lamellar structure absorbed strain during membrane tearing.

Comparison of corneal biomechanics in Sjögren's syndrome and non-Sjögren's syndrome dry eyes by Scheimpflug based device.

PubMed

Long, Qin; Wang, Jing-Yi; Xu, Dong; Li, Ying

2017-01-01

To compare the corneal biomechanics of Sjögren's syndrome (SS) and non-SS dry eyes with Corneal Visualization Scheimpflug Technology (CorVis ST). Corneal biomechanics and tear film parameters, namely the Schirmer I test value, tear film break-up time (TBUT) and corneal staining score (CSS) were detected in 34 eyes of 34 dry eye patients with SS (SSDE group) and 34 dry eye subjects without SS (NSSDE group) using CorVis ST. The differences of the above parameters between the two groups were examined, and the relationship between corneal biomechanics and tear film parameters were observed. The differences in age, sex, intraocular pressure (IOP) and central corneal thickness (CCT) were not significant between the two groups ( P >0.05). The tear film parameters had significant differences between the SSDE group and NSSDE group (all P <0.05). Patients in the SSDE group had significantly lower A1-time and HC-time, but higher DA ( P =0.01, 0.02, and 0.02, respectively) compared with the NSSDE group. In the SSDE group, DA was negatively correlated with TBUT ( rho =-0.38, P =0.03); HC-time was negatively correlated with CSS ( rho =-0.43, P =0.02). In the NSSDE group, HC-time was again negatively correlated with CSS ( rho =-0.39, P =0.02). There are differences in corneal biomechanical properties between SSDE and NSSDE. The cornea of SSDE tends to show less "stiffness", as seen by a significantly shorter A1-time and HC-time, but larger DA, compared with the cornea of NSSDE. Biomechanical parameters can be influenced by different tear film parameters in both groups.

A comparison of basal and eye-flush tears for the analysis of cat tear proteins.

PubMed

Petznick, Andrea; Evans, Margaret D M; Madigan, Michele C; Markoulli, Maria; Garrett, Qian; Sweeney, Deborah F

2011-02-01

To identify a rapid and effective tear collection method providing sufficient tear volume and total protein content (TPC) for analysis of individual proteins in cats. Domestic adult short-haired cats (12-37 months; 2.7-6.6 kg) were used in the study. Basal tears without stimulation and eye-flush tears after instillation of saline (10 μl) were collected using microcapillary tubes from animal eyes either unwounded control or wounded with 9-mm central epithelial debridement giving four groups with n = 3. Tear comparisons were based on total time and rate for tear collection, TPC using micro bicinchoninic acid (BCA), tear immunoglobulin A (IgA), total matrix-metalloproteinase (MMP)-9 concentration using sandwich enzyme-linked immunosorbent assay (ELISA) and MMP-9 activity. Eye-flush tears were collected significantly faster than basal tears in wounded eyes with higher rates for tear collection in unwounded control and wounded eyes. TPC was significantly lower in eye-flush tears compared to basal tears. The relative proportion of tear IgA normalized to TPC (% IgA of TPC) was not significantly different between basal and eye-flush tears. In unwounded control eyes, MMP-9 was slightly higher in eye-flush than in basal tears; activity of MMP-9 in both tear types was similar. In wounded eyes, eye-flush tears showed highest MMP-9 levels and activity on Day 1, which subsequently decreased to Day 7. MMP-9 activity in basal tears from wounded eyes did not display changes in expression. Eye-flush tears can be collected rapidly providing sufficient tear volume and TPC. This study also indicates that eye-flush tears may be more suitable than basal tears for the analysis of MMPs following corneal wounding. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.

Superior labrum anterior to posterior tears and glenohumeral instability.

PubMed

Virk, Mandeep S; Arciero, Robert A

2013-01-01

Cadaver experiments and clinical studies suggest that the superior labrum-biceps complex plays a role in glenohumeral stability. Superior labrum anterior to posterior (SLAP) tears can be present in acute and recurrent glenohumeral dislocations and contribute to glenohumeral instability. Isolated SLAP tears can cause instability, especially in throwing athletes. Diagnosing a SLAP tear on the basis of the clinical examination alone is difficult because of nonspecific history and physical examination findings and the presence of coexisting intra-articular lesions. Magnetic resonance arthrography is the imaging study of choice for diagnosing SLAP tears; however, arthroscopy remains the gold standard for diagnosis. Arthroscopy is the preferred technique for the repair of a type II SLAP tear and its variant types (V through X) in acute glenohumeral dislocations and instability in younger populations. Clinical outcome studies report a low recurrence of glenohumeral instability after the arthroscopic repair of a SLAP tear in addition to a Bankart repair. Long-term follow-up studies and further advances in arthroscopic fixation techniques will allow a better understanding and improvement in outcomes in patients with SLAP tears associated with glenohumeral instability.

Even If They're Tearing up the Street Where You Were Born, Don't Throw Out the Baby with the Wash.

ERIC Educational Resources Information Center

Brown, James W.

This article comments on Gilbert A. Jarvis'"Teacher Education Goals: They're Tearing Up the Street Where I Was Born" in the December 1972 issue of "Foreign Language Annals." Remarks concerning teacher education, methods courses, teaching strategies, the audiolingual method of language instruction, and the Modern Language Association "Guidelines"…

Potential of FTIR spectroscopy for analysis of tears for diagnosis purposes.

PubMed

Travo, Adrian; Paya, Clément; Déléris, Gérard; Colin, Joseph; Mortemousque, Bruno; Forfar, Isabelle

2014-04-01

It has been widely reported that the tear film, which is crucially important as a protective barrier of the eye, undergoes biochemical changes as a result of a wide range of ocular pathology. This tends to suggest the possibility of early detection of ocular diseases on the basis of biochemical analysis of tears. However, studies of tears by conventional methods of biomolecular and biochemical analysis are often limited by methodological difficulties. Moreover, such analysis could not be applied in the clinic, where structural and morphological analyses by, mainly, slit-lamp biomicroscopy remains the recommended method. In this study, we assessed, for the first time, the potential of FTIR spectroscopy combined with advanced chemometric processing of spectral data for analysis of raw tears for diagnosis purposes. We first optimized sampling and spectral acquisition (tears collection method, tear sample volume, and preservation of the samples) for accurate spectral measurement. On the basis of the results, we focused our study on the possibility of discriminating tears from normal individuals from those of patients with different ocular pathologies, and showed that the most discriminating spectral range is that corresponding to variations of CH2 and CH3 of lipid aliphatic chains. We also report more subtle discrimination of tears from patients with keratoconus and those from patients with non-specific inflammatory ocular diseases, on the basis of variations in spectral ranges attributed notably to lipid and carbohydrate vibrations. Finally, we also succeeded in distinguishing tears from patients with early-stage and late-stage keratoconus on the basis of spectral features attributed to protein structure. Therefore, this study strongly suggests that FTIR spectral analysis of tears could be developed as a valuable and cost-saving tool for biochemical-based detection of ocular diseases, potentially before the appearance of the first morphological signs of diseases

Blocked Tear Duct

MedlinePlus

... of the nose (lacrimal sac). From there tears travel down a duct (the nasolacrimal duct) draining into your nose. Once in the nose, tears are reabsorbed. A blockage can occur at any point in the tear drainage system, from the puncta ...

Viscous bursting of suspended films

NASA Astrophysics Data System (ADS)

Debrégeas, G.; Martin, P.; Brochard-Wyart, F.

1995-11-01

Soap films break up by an inertial process. We present here the first observations on freely suspended films of long-chain polymers, where viscous effects are dominant and no surfactant is present. A hole is nucleated at time 0 and grows up to a radius R(t) at time t. A surprising feature is that the liquid from the hole is not collected into a rim (as it is in soap films): The liquid spreads out without any significant change of the film thickness. The radius R(t) grows exponentially with time, R~exp(t/τ) [while in soap films R(t) is linear]. The rise time τ~ηe/2γ where η is viscosity, e is thickness (in the micron range), and γ is surface tension. A simple model is developed to explain this growth law.

Ipsilateral Medial and Lateral Discoid Meniscus with Medial Meniscus Tear

PubMed Central

Shimozaki, Kengo; Nakase, Junsuke; Ohashi, Yoshinori; Numata, Hitoaki; Oshima, Takeshi; Takata, Yasushi; Tsuchiya, Hiroyuki

2016-01-01

Introduction: Discoid meniscus is a well-documented knee pathology, and there are many cases of medial or lateral discoid meniscus reported in the literature. However, ipsilateral concurrent medial and lateral discoid meniscus is very rare, and only a few cases have been reported. Herein, we report a case of concurrent medial and lateral discoid meniscus. Case Report: A 27-year-old Japanese man complained of pain on medial joint space in his right knee that was diagnosed as a complete medial and lateral discoid meniscus. In magnetic resonance imaging, although the lateral discoid meniscus had no tear, the medial discoid meniscus had a horizontal tear. Arthroscopic examination of his right knee similarly revealed that the medial discoid meniscus had a horizontal tear. In addition, the discoid medial meniscus also had an anomalous insertion to the anterior cruciate ligament, and there was also mild fibrillation of the medial tibial cartilage surface. We performed arthroscopic partial meniscectomy for the torn medial discoid meniscus but not for the asymptomatic lateral discoid meniscus. The latest follow-up at 18 months indicated satisfactory results. Conclusion: We report a rare case of ipsilateral medial and lateral discoid meniscus with medial meniscus tear. The medial discoid meniscus with tear was treated with partial meniscectomy, whereas the lateral discoid meniscus without tear was only followed up. PMID:28164045

Hard Break-Up of Two-Nucleons and QCD Dynamics of NN Interaction

NASA Astrophysics Data System (ADS)

Sargsian, Misak

2008-10-01

We discus recent developments in theory of high energy two-body break-up of few-nucleon systems. The characteristics of these reactions are such that the hard two-body quasielastic subprocess can be clearly separated from the accompanying soft subprocesses. We discuss in details the hard rescattering model (HRM) in which hard photodisintegration develops in two stages. At first, photon knocks-out an energetic quark which rescatters subsequently with a quark of the other nucleon. The latter provides a mechanism of sharing the initial high momentum of the photon between two outgoing nucleons. This final state hard rescattering can be expressed through the hard NN scattering amplitude. Within HRM we discuss hard break-up reactions involving D and 3He targets and demonstrate how these reactions are sensitive to the dynamics of hard pn and pp interaction. Another development of HRM is the prediction of new helicity selection mechanism for hard two-body reactions, which was apparently confirmed in the recent JLab experiment.

Early Changes in Ocular Surface and Tear Inflammatory Mediators after Small-Incision Lenticule Extraction and Femtosecond Laser-Assisted Laser In Situ Keratomileusis

PubMed Central

Gao, Shaohui; Li, Saiqun; Liu, Liangping; Wang, Yong; Ding, Hui; Li, Lili; Zhong, Xingwu

2014-01-01

Purpose To characterize the early ocular-surface changes or tear inflammatory-mediators levels following small-incision lenticule extraction (ReLEx smile) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK). Methods Forty-seven myopic subjects were recruited for this prospective study. Fifteen underwent ReLEx smile and thirty-two underwent FS-LASIK. Corneal fluorescein (FL) staining, tear break-up time (TBUT), Schirmer I test (SIT), ocular surface disease index (OSDI) and central corneal sensitivity were evaluated in all participants. Tears were collected and analyzed for interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), nerve growth factor (NGF) and intercellular adhesion molecule-1 (ICAM-1) levels using multiplex magnetic beads. All measurements were preformed preoperatively and 1 day, 1 week, 1 month and 3 months postoperatively. Results FL scores in ReLEx smile group were lower than those of FS-LASIK group 1 week postoperatively (P = 0.010). Compared to the FS-LASIK group, longer TBUT were observed in ReLEx smile group 1 month (P = 0.029) and 3 months (P = 0.045) postoperatively. No significant differences were found in tear secretion for the two groups (P>0.05). OSDI scores were higher in FS-LASIK group 1 month after surgery (P = 0.020). Higher central corneal sensitivity was observed in ReLEx smile group 1 week, 1 month and 3 months (P<0.05) postoperatively. Compared to FS-LASIK group, lower and faster recovery of IL-6 and NGF levels in tears was observed in ReLEx smile group postoperatively (P<0.05). Tears TNF-α and ICAM-1 concentrations were not significantly different between the two groups at any follow-up time (P>0.05). Moreover, IL-6 and NGF levels correlated with ocular surface changes after ReLEx smile or FS-LASIK. Conclusions In the early postoperative period, ReLEx smile results in milder ocular surface changes than FS-LASIK. Furthermore, the tear inflammatory mediators IL-6 and NGF may play a crucial role

Proteomic analysis of tears following acupuncture treatment for menopausal dry eye disease by two-dimensional nano-liquid chromatography coupled with tandem mass spectrometry.

PubMed

Liu, Qingyu; Liu, Junling; Ren, Chengda; Cai, Wenting; Wei, Qingquan; Song, Yi; Yu, Jing

2017-01-01

The purpose of this study was to investigate whether acupuncture is effective at treating dry eye disease among postmenopausal women and to identify the possible mechanisms. Twenty-eight postmenopausal women with dry eye disease were randomly divided into two groups: an acupuncture plus artificial tears (AC + AT) group and an artificial tears (AT) only group. After baseline examination of clinical parameters and tear sample collection, each patient received the designated modality of topical therapy for 2 months. Post-treatment documentation of clinical parameters was recorded, and tear samples were collected. Tear samples from the AC + AT group were subjected to two-dimensional nano-liquid chromatography coupled with tandem mass spectrometry (2D nano-LC-MS/MS). Western blot analysis was also performed on tear samples from both groups. After treatment, the Ocular Surface Disease Index scores, symptom assessment scores, scores of sign assessment, and tear break-up time were significantly improved in both groups ( P =0.000). Symptom assessment scores were significantly improved in the AC + AT group ( P =0.000) compared with the AT group. 2D nano-LC-MS/MS identified 2,411 proteins, among which 142 were downregulated and 169 were upregulated. After combined AC + AT treatment, the abundance of secreted proteins was increased, whereas that of cytoplasmic proteins decreased (Pearson's χ 2 test, P =0.000, P =0.000, respectively). Proteins involved in immunity and regulation were also more abundant (Pearson's χ 2 test, P =0.040, P =0.016, respectively), while components and proliferation-related proteins were downregulated (Pearson's χ 2 test, P =0.003, P =0.011, respectively). AC + AT treatment increased protein synthesis and secretion, and improved clinical symptoms. These results indicate that acupuncture may be a complimentary therapy for treating postmenopausal dry eye disease.

Proteases, proteolysis and inflammatory molecules in the tears of people with keratoconus.

PubMed

Balasubramanian, Sivaraman Arumugam; Mohan, Sujatha; Pye, David Cecil; Willcox, Mark Duncan Perry

2012-06-01

To investigate the expression of proteases, proteolytic activity and cytokines in the tear film of people with keratoconus. Basal tears from people with keratoconus, from individuals who had undergone corneal collagen cross-linking for the treatment of keratoconus, and from normal controls were collected using a capillary tube. Corneal curvature of each subject was mapped. The total protein in tears was estimated. Levels and activity of proteases in the tears were analysed using specific antibody arrays and activity assays. The total tear protein level was significantly reduced in keratoconus (4.1 ± 0.9 mg/ml) compared with normals (6.7 ± 1.4 mg/ml) (p < 0.0001) or subjects who had undergone corneal collagen cross-linking (5.7 ± 2.3 mg/ml) (p < 0.005). Significantly (p < 0.05) increased tear expression of matrix metalloproteinases (MMP) -1, -3, -7, -13, interleukins (IL) -4, -5, -6, -8 and tumour necrosis factor (TNF) -α, -β were evident in keratoconus. Tear IL-6 was the only cytokine significantly (p < 0.05) increased in tears of keratoconus subjects compared with the collagen cross-linked group. No significant difference in tear proteases were observed between the normal and the cross-linked groups, although the expression of TNF-α was significantly (p < 0.05) increased in the cross-linked group compared with the controls. Elevated gelatinolytic (87.5 ± 33.6 versus 45.8 ± 24.6 FIU, p < 0.0001) and collagenolytic (6.1 ± 3.2 versus 3.6 ± 2.0 FIU, p < 0.05) activities were observed in tears from keratoconus compared with normal subjects. The activity of tear gelatinases (69.6 ± 22.2 FIU) and collagenases (5.7 ± 3.3 FIU) in the collagen cross-linked group was not significantly different compared with either keratoconus or normals. Tears of people with keratoconus had 1.9 times higher levels of proteolytic activity and over expression of several MMPs and cytokines compared with tears from controls. Further investigations are required to study the possible

Radiographic progression of arthritic changes in shoulders with degenerative rotator cuff tears.

PubMed

Chalmers, Peter N; Salazar, Dane H; Steger-May, Karen; Chamberlain, Aaron M; Stobbs-Cucchi, Georgia; Yamaguchi, Ken; Keener, Jay D

2016-11-01

Very little longitudinal information has been available regarding the relationship of cuff tears and arthritis. The purpose of this study was to determine the midterm risk of and risk factors for rotator cuff tear arthropathy progression in a cohort of subjects with an asymptomatic rotator cuff tear. Baseline (visit 1), 5-year (visit 2), and most recent follow-up (visit 3) radiographs were reviewed in a cohort of 105 subjects enrolled for longitudinal surveillance of asymptomatic degenerative rotator cuff tears and 33 controls. The radiographs were assessed in a blinded, randomized fashion by 3 observers who graded glenohumeral arthritic changes using the Hamada scores, Samilson-Prieto (SPO) scores, and acromiohumeral interval (AHI). Osteoarthritis (SPO classification), cuff tear arthropathy (Hamada classification), and AHI progressed between visits 1 and 3 (median, 8 years; P < .001 in all cases). SPO progression was not significantly different for partial- vs. full-thickness vs. control baseline tear types (P = .19). Both full-thickness and partial-thickness tears had greater progression in Hamada scores than controls did in the first 5 years of follow-up (P = .02 and P = .03, respectively), but scores did not differ between partial- and full-thickness tears. Tears with and without enlargement did not differ in progression in SPO grade, Hamada grade, or AHI. Glenohumeral arthritic changes progress significantly but remain minimal within an 8-year period in early to moderate degenerative cuff disease. Whereas the presence of a rotator cuff tear influences progression in Hamada grade, the magnitude of radiographic progression is not influenced by tear severity or enlargement at midterm time points. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

On the Lipid Composition of Human Meibum and Tears: Comparative Analysis of Nonpolar Lipids

PubMed Central

Butovich, Igor A.

2009-01-01

PURPOSE To qualitatively compare the nonpolar lipids present in meibomian gland (MG) secretions (samples T1) with aqueous tears (AT) collected from the lower tear menisci of healthy, non-dry eye volunteers using either glass microcapillaries (samples T2) or Schirmer test strips (samples T3). METHODS Samples T1 to T3 were analyzed with the use of high-pressure liquid chromatography/positive ion mode atmospheric pressure chemical ionization mass spectrometry. Where possible, the unknown lipids were compared with known standards. RESULTS Samples T1 had the simplest lipid composition among all the tested specimens. Samples T2 and T3 were similar to each other but were noticeably different from samples T1. In addition to all the compounds detected in samples T1, lower molecular weight wax esters and other compounds were found in samples T2 and T3. No appreciable amounts of fatty acid amides (e.g., oleamide), ceramides, or monoacyl glycerols were routinely detected. The occasionally observed minor signals of oleamide (m/z 282) in samples T3 were attributed to the contamination of the samples with common plasticizers routinely found in plastic ware extractives and organic solvents. CONCLUSIONS The MG is a prominent source of lipids for the tear film. However, it would have been a mistake to exclude from consideration other likely sources of lipids such as conjunctiva, cornea, and tears produced by the lacrimal glands. These data showed that lipids in AT are more complex than MG secretions, which necessitates more cautious interpretation of the functions of the latter in the tear film. PMID:18487374

Automated Measurement of Tear Film Dynamics and Lipid Layer Thickness for Assessment of Non-Sjögren Dry Eye Syndrome With Meibomian Gland Dysfunction.

PubMed

Ji, Yong Woo; Lee, Jeihoon; Lee, Hun; Seo, Kyoung Yul; Kim, Eung Kweon; Kim, Tae-Im

2017-02-01

To investigate automated values from an advanced corneal topographer with a built-in real keratometer, color camera, and ocular surface interferometer for the evaluation of non-Sjögren dry eye syndrome (NSDES) with meibomian gland dysfunction (MGD). Sixty-four patients (64 eyes) diagnosed with NSDES with MGD were enrolled. All eyes were evaluated using the Ocular Surface Disease Index (OSDI), fluorescence staining score, tear film breakup time (TBUT), Schirmer test, and MGD grade. Noninvasive Keratograph average tear film breakup time (NIKBUTav), tear meniscus height (TMHk), meibomian gland (MG) dropout grade, and lipid layer thickness (LLT) using interferometry were measured. Among automated indexes, NIKBUTav (mean 7.68 ± 4.07 s) and the MG dropout grade (mean 1.0 ± 0.5) significantly correlated with the OSDI (mean 40.6 ± 22.9) (r = -0.337, P = 0.006; and r = 0.201, P = 0.023, respectively), as did all conventional indicators, except the Schirmer score (mean 9.1 ± 5.9 mm). TMHk (mean 0.21 ± 0.18 mm) had significant correlation with the Schirmer score, the staining score (mean 1.2 ± 0.7), TBUT (mean 3.8 ± 1.8 s), and NIKBUTav (r = 0.298, P = 0.007; r = -0.268, P = 0.016; r = 0.459, P < 0.001; and r = 0.439, P < 0.001, respectively), but not any MGD indicator, even the MG dropout grade. NIKBUTav showed significant correlations with all clinical parameters and other automated values, except the Schirmer score and LLT (mean 83.94 ± 20.82 nm) (all (Equation is included in full-text article.)≥ 0.25 and P < 0.01). The MG dropout grade highly correlated with all indexes except TMHk (all (Equation is included in full-text article.)≥ 0.25 and P < 0.05). LLT was significantly associated with TBUT, MGD grade (mean 2.0 ± 0.7), and MG dropout grade (r = 0.219, P = 0.047; r = -0.221, P = 0.039; and r = 0.433, P < 0.001, respectively), although it was not related to patient symptoms. Automated noninvasive measurements using an advanced corneal topographer and LLT

Surgery or conservative treatment for rotator cuff tear: a meta-analysis.

PubMed

Ryösä, Anssi; Laimi, Katri; Äärimaa, Ville; Lehtimäki, Kaisa; Kukkonen, Juha; Saltychev, Mikhail

2017-07-01

Comparative evidence on treating rotator cuff tear is inconclusive. The objective of this review was to evaluate the evidence on effectiveness of tendon repair in reducing pain and improving function of the shoulder when compared with conservative treatment of symptomatic rotator cuff tear. Search on CENTRAL, MEDLINE, EMBASE, CINAHL, Web of Science and Pedro databases. Randomised controlled trials (RCT) comparing surgery and conservative treatment of rotator cuff tear. Study selection and extraction based on the Cochrane Handbook for Systematic reviews of Interventions. Random effects meta-analysis. Three identified RCTs involved 252 participants (123 cases and 129 controls). The risk of bias was considered low for all three RCTs. For Constant score, statistically insignificant effect size was 5.6 (95% CI -0.41 to 11.62) points in 1-year follow up favouring surgery and below the level of minimal clinically important difference. The respective difference in pain reduction was -0.93 (95% CI -1.65 to -0.21) cm on a 0-10 pain visual analogue scale favouring surgery. The difference was statistically significant (p = 0.012) in 1-year follow up but below the level of minimal clinically important difference. There is limited evidence that surgery is not more effective in treating rotator cuff tear than conservative treatment alone. Thus, a conservative approach is advocated as the initial treatment modality. Implications for Rehabilitation There is limited evidence that surgery is not more effective in treating rotator cuff tear than conservative treatment alone. There was no clinically significant difference between surgery and active physiotherapy in 1-year follow-up in improving Constant score or reducing pain caused by rotator cuff tear. As physiotherapy is less proneness to complications and less expensive than surgery, a conservative approach is advocated as the initial treatment modality to rotator cuff tears.

Clinical study to assess the efficacy of Keshanjana and Netra Parisheka in the management of Shushkakshipaka (dry eye syndrome)

PubMed Central

Vardhan, Prabhakar; Dhiman, Kartar Singh

2014-01-01

Background: Dry eye syndrome (DES) is a common ophthalmic problem predominantly affecting middle-aged and elderly people. It is a disease of deficient or deranged tears and ocular surface disorder producing symptoms of discomfort, visual disturbance, and tears film instability. Shushkakshipaka, an etymologically and clinically similar entity to DES, is defined in Ayurveda as the disease affecting all parts of the eye characterized by Paka (inflammation) due to Shuskatva (dryness) caused by altered coherence of Ashru (tears) with ocular surface or due to lack of Ashru. Aim: To compare the effect of Keshanjana and Netra Parisheka in Shushkakshipaka with artificial tear drops (carboxy methyl cellulose [CMC]). Materials and Methods: To search a safe, potent and cost-effective Ayurvedic treatment for DES, a randomized comparative clinical trial was conducted on 32 patients. Patients were divided in two groups 15 in group I and 17 in group II. Group I treated with artificial tear drop four times a day for topical use and group II treated with combination therapy of Keshanjana applied topically once a day and Netra Prisheka was done thrice a day. Results: The effect of Ayurvedic management was found to be equivalent to the standard therapy, although the trial drugs provided more relief in foreign body sensation, burning sensation, dryness, pain, photophobia, itching, crusting, stuck eyelids, tear meniscus, conjunctival congestion, Schirmer I test, and tear film break-up time (TUBT). The standard therapy provided more relief than trial drugs in mucous discharges, transiently blurred vision, redness, and the presence of mucin debris in tear film. Conclusion: Keshanjana and Netra Parisheka can be used as a potent, safe and cost-effective treatment to ameliorate the symptoms of DES. PMID:26664237

Long-term results of treatment with diquafosol ophthalmic solution for aqueous-deficient dry eye.

PubMed

Koh, Shizuka; Ikeda, Chikako; Takai, Yoshihiro; Watanabe, Hitoshi; Maeda, Naoyuki; Nishida, Kohji

2013-09-01

To evaluate the preliminary long-term efficacy of diquafosol ophthalmic solution for aqueous-deficient dry eye. Fifteen patients with mild-to-moderate aqueous-deficient dry eye were enrolled. After a washout period, the patients were treated with 3 % diquafosol ophthalmic solution for 6 months. We assessed 12 subjective dry eye symptoms, corneal and conjunctival staining with fluorescein, tear film break-up time (BUT), lower tear meniscus height measured with anterior-segment optical coherence tomography, Schirmer's testing, and adverse reactions at baseline and 1, 3, and 6 months after the start of treatment. Treatment with diquafosol ophthalmic solution significantly improved dry eye symptoms, corneal staining, BUT, and tear meniscus height at 1 month and maintained the effectiveness for 6 months. Conjunctival staining significantly improved 3 and 6 months after treatment. No significant adverse reactions developed. Prolonged use of diquafosol ophthalmic solution for 6 months produced significant improvement both subjectively (dry eye symptom score) and objectively (ocular staining score and tear function tests) for aqueous-deficient dry eye.

Large Igneous Provinces, Mantle Plumes, and Continental Break-up: An Overview.

NASA Astrophysics Data System (ADS)

Peate, D. W.

2003-04-01

Although mantle plumes are widely implicated in models for the generation of large igneous provinces (LIPs) and the break-up of supercontinents such as Gondwana, the exact role of the mantle plume in these processes, and even the very existence of mantle plumes, is controversial and hotly debated. The large volumes of magma produced within a LIP (> 10^6 km^3) in a relative short time interval (< few Myrs) require elevated mantle temperatures such as is inferred for a plume, but it is not easy to determine whether the melting occurred as a result of the arrival of a plume head in the shallow mantle or in response to lithospheric extension. Numerous questions remain unresolved: e.g. Can all LIPs be explained by plume-like mantle upwellings, or are non-plume models such as edge-driven convection a plausible alternative?; Are plumes wet-spots rather than hot-spots?; Do they originate from the core-mantle boundary?; How important is the influence of the overlying lithosphere (limiting the upwelling and extent of melting, modifying the composition of deeper melts, and possibly acting as a source for melts)? In this presentation, I will summarise key observations from three young LIP's (< 135 Ma), each associated with continental break-up. These case studies will be: (i) North Atlantic LIP - Iceland plume, (ii) Parana-Etendeka LIP - Tristan plume, and (iii) Ethiopia-Yemen LIP - Afar plume. Aspects that will be considered include: the areal extent, volume and eruption rates of magmatism; temporal relationship of flood basalt volcanism to lithospheric extension and continental break-up; compositional similarities and differences between the flood basalts and more recent lavas from the associated plume; spatial and temporal compositional variations as a means of assessing the location and length-scales of heterogeneities in the upwelling mantle, seismic tomographic images of mantle thermal structure today; crustal structure of the rifted margins from wide-angle and

Collisionless kinetic theory of oblique tearing instabilities

DOE PAGES

Baalrud, S. D.; Bhattacharjee, A.; Daughton, W.

2018-02-15

The linear dispersion relation for collisionless kinetic tearing instabilities is calculated for the Harris equilibrium. In contrast to the conventional 2D geometry, which considers only modes at the center of the current sheet, modes can span the current sheet in 3D. Modes at each resonant surface have a unique angle with respect to the guide field direction. Both kinetic simulations and numerical eigenmode solutions of the linearized Vlasov-Maxwell equations have recently revealed that standard analytic theories vastly overestimate the growth rate of oblique modes. In this paper, we find that this stabilization is associated with the density-gradient-driven diamagnetic drift. Themore » analytic theories miss this drift stabilization because the inner tearing layer broadens at oblique angles sufficiently far that the assumption of scale separation between the inner and outer regions of boundary-layer theory breaks down. The dispersion relation obtained by numerically solving a single second order differential equation is found to approximately capture the drift stabilization predicted by solutions of the full integro-differential eigenvalue problem. Finally, a simple analytic estimate for the stability criterion is provided.« less

Collisionless kinetic theory of oblique tearing instabilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baalrud, S. D.; Bhattacharjee, A.; Daughton, W.

The linear dispersion relation for collisionless kinetic tearing instabilities is calculated for the Harris equilibrium. In contrast to the conventional 2D geometry, which considers only modes at the center of the current sheet, modes can span the current sheet in 3D. Modes at each resonant surface have a unique angle with respect to the guide field direction. Both kinetic simulations and numerical eigenmode solutions of the linearized Vlasov-Maxwell equations have recently revealed that standard analytic theories vastly overestimate the growth rate of oblique modes. In this paper, we find that this stabilization is associated with the density-gradient-driven diamagnetic drift. Themore » analytic theories miss this drift stabilization because the inner tearing layer broadens at oblique angles sufficiently far that the assumption of scale separation between the inner and outer regions of boundary-layer theory breaks down. The dispersion relation obtained by numerically solving a single second order differential equation is found to approximately capture the drift stabilization predicted by solutions of the full integro-differential eigenvalue problem. Finally, a simple analytic estimate for the stability criterion is provided.« less

Investigation of pepsin in tears of children with laryngopharyngeal reflux disease.

PubMed

Iannella, Giannicola; Di Nardo, Giovanni; Plateroti, Rocco; Rossi, Paolo; Plateroti, Andrea Maria; Mariani, Paola; Magliulo, Giuseppe

2015-12-01

Numerous investigations postulated that laryngopharyngeal reflux (LPR) is implicated in the pathogenesis of various upper airway inflammatory diseases as sinusitis or dacryostenosis. The presence of pepsin in tears might be confirmed the presuntive hypothesis of the arrival in the nasolacrimal ducts and precorneal tears film through the laryngopharyngeal reflux of either gastric acid or stomach secretions (pepsin) with inflammatory potentialities. The aim of this preliminary study was to identify the presence or absence of pepsin in the tears collected from children with a high suspicion of LPR who underwent 24-h pH (MII-pH) monitoring to confirm the disease. This study enrolled 20 patients suffering from symptoms of laryngopharyngeal reflux that underwent 24-h multichannel intraluminal impedance (MII)-pH monitoring to confirm the disease. The findings of the study group were compared with those of a control group of patients with negative pH monitoring. The quantitative analysis of human pepsin concentration in the tear samples was performed by ELISA method in both groups. Four children (20%) of the study group showed pepsin in the tears. All of the subjects belonging to the control group were negative for its presence. No difference differences in the total number of reflux episodes and the number of weakly basic reflux in the pepsin positive patients vs. pepsin negative children were present. 20% of the children with diagnosed LPR showed pepsin in the tears. Our specific investigation might provide information regarding sinusitis or dacryostenosis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Surface interactions on hydrogel contact lenses: scanning electron microscopy (SEM).

PubMed

Hart, D E

1987-12-01

SEM was used to visualize tear-film/hydrogel polymer surface interactions. Lenses were preserved by fixation including a quaternary ammonium complex to aid in mucin preservation. In less than 2 weeks of continuous wear the anterior surface was completely coated, yet the coating was absent from the posterior lens surface. Tear-film break-up over the deposited lens surface, combined with degradation and deformation at the polymer surface boundary, as well as entrapment of moieties within the polymer matrix, all occurred. These are the likely culprits which can contribute to adverse reactions as well as cause light scatter and diminished vision. Lenses removed directly from the eyes of patients suffering with different forms of conjunctivitis were obtained. Bacterial and viral conjunctivitis can induce a microbially contaminated as well as a heavily deformed and deposited lens. Viable and intact microbes were not typically observed in the mucoprotein layer of hydrogel contact lenses.

Radial tears associated with cleavage tears of the medial meniscus in athletes.

PubMed

Kidron, Amos; Thein, Rafael

2002-03-01

To evaluate the significance of a small radial tear in the root of the posterior horn of the medial meniscus in an otherwise normal-looking meniscus in individuals who play vigorous sports. Retrospective review. Arthroscopy was performed in 1,270 patients; 11 patients (0.86%) had a small radial tear in the root of the medial meniscus. Trimming of the tear revealed a large horizontal cleavage tear of the posterior horn and body of the meniscus. The average age of the affected patients was 29.6 years (range, 21 to 45 years), and all were active in sports. Magnetic resonance imaging was of dubious diagnostic value. Three patients had undergone previous arthroscopy at which time the small radial root tear had been noted but was not thought to warrant treatment. All 11 patients returned to their former levels of activity after adequate surgery. When a radial root tear in the medial meniscus is found in an athletic patient, the edges of the tear should be trimmed, the root of the medial meniscus examined, and any additional torn cartilage resected.

Symptomatic rotator cuff tears show higher radioisotope uptake on bone scintigraphy compared with asymptomatic tears.

PubMed

Koike, Yoichi; Sano, Hirotaka; Kita, Atushi; Itoi, Eiji

2013-09-01

Some patients with rotator cuff tears complain of pain, whereas others are asymptomatic. Previous studies have pointed out the presence of active bone metabolism in the painful shoulder, identified with increased radioisotope uptake during bone scintigraphy. Shoulders with symptomatic rotator cuff tears will demonstrate higher radioisotope uptake than shoulders with asymptomatic tears with bone scintigraphy, reflecting active bone metabolism in symptomatic tears. Cross-sectional study; Level of evidence, 3. The study consisted of 3 groups: patients with symptomatic tears (symptomatic group), patients with asymptomatic tears (asymptomatic group), and controls (no tear group). The symptomatic group consisted of 28 shoulders from 28 patients with symptomatic rotator cuff tears (pain score ≤4 on the University of California, Los Angeles [UCLA] shoulder evaluation form) who underwent bone scintigraphy followed by rotator cuff repair. Of 70 volunteers who had previously undergone bone scintigraphy for diseases unrelated to their shoulder, 34 were selected for the asymptomatic group (pain score ≥8 on the UCLA shoulder form), and 32 were selected for the no tear group. The mean radioisotope uptake in the symptomatic group was significantly higher than that in the asymptomatic group (P = .02) and the no tear group (P = .02). Ten of 28 shoulders (36%) in the symptomatic group showed increased radioisotope uptake exceeding 2 standard deviations from the mean of the no tear group. This percentage was significantly higher when compared with the asymptomatic group (0%) (P < .01). Shoulders with a symptomatic rotator cuff tear showed higher radioisotope uptake on bone scintigraphy than those with an asymptomatic tear. The radioisotope uptake in shoulders with an asymptomatic tear was comparable with that in shoulders without a tear. Positive radioisotope uptake may be associated with pain in a subgroup of patients with rotator cuff tears.

Treatment Strategy for Irreparable Rotator Cuff Tears

PubMed Central

Oh, Joo Han; Rhee, Sung Min

2018-01-01

Recently, patients with shoulder pain have increased rapidly. Of all shoulder disorders, rotator cuff tears (RCTs) are most prevalent in the middle-aged and older adults, which is the primary reason for shoulder surgery in the population. Some authors have reported that up to 30% of total RCTs can be classified as irreparable due to the massive tear size and severe muscle atrophy. In this review article, we provide an overview of treatment methods for irreparable massive RCTs and discuss proper surgical strategies for RCTs that require operative management. PMID:29854334

Biomechanical consequences of a tear of the posterior root of the medial meniscus. Similar to total meniscectomy.

PubMed

Allaire, Robert; Muriuki, Muturi; Gilbertson, Lars; Harner, Christopher D

2008-09-01

Tears of the posterior root of the medial meniscus are becoming increasingly recognized. They can cause rapidly progressive arthritis, yet their biomechanical effects are not understood. The goal of this study was to determine the effects of posterior root tears of the medial meniscus and their repairs on tibiofemoral joint contact pressure and kinematics. Nine fresh-frozen cadaver knees were used. An axial load of 1000 N was applied with a custom testing jig at each of four knee-flexion angles: 0 degrees, 30 degrees, 60 degrees, and 90 degrees. The knees were otherwise unconstrained. Four conditions were tested: (1) intact, (2) a posterior root tear of the medial meniscus, (3) a repaired posterior root tear, and (4) a total medial meniscectomy. Fuji pressure-sensitive film was used to record the contact pressure and area for each testing condition. Kinematic data were obtained by using a robotic arm to record the position of the knees for each loading condition. Three-dimensional knee kinematics were analyzed with custom programs with use of previously described transformations. The measured variables were axial rotation, varus angulation, lateral translation, and anterior translation. In the medial compartment, a posterior root tear of the medial meniscus caused a 25% increase in peak contact pressure compared with that found in the intact condition (p < 0.001). Repair restored the peak contact pressure to normal. No difference was detected between the peak contact pressure after the total medial meniscectomy and that associated with the root tear. The peak contact pressure in the lateral compartment after the total medial meniscectomy was up to 13% greater than that for all other conditions (p = 0.026). Significant increases in external rotation and lateral tibial translation, compared with the values in the intact knee, were observed in association with the posterior root tear (2.98 degrees and 0.84 mm, respectively) and the meniscectomy (4.45 degrees and 0

Compatibility of phospholipid liposomal spray with silicone hydrogel contact lens wear.

PubMed

Wang, Michael T M; Ganesalingam, Kalaivarny; Loh, Chee Seang; Alberquerque, Trisha; Al-Kanani, Suhaila; Misra, Stuti L; Craig, Jennifer P

2017-02-01

To assess the effects of two weeks of regular phospholipid liposomal spray application on lipid layer grade, tear film stability, subjective comfort, visual acuity, and lipid deposition in silicone hydrogel contact lens wearers. Thirty-one existing contact lens wearers were enrolled and fitted with two week planned replacement silicone hydrogel contact lenses (Acuvue ® Oasys ® ) in a prospective, randomized, paired-eye, investigator-masked trial. A phospholipid liposomal spray (Tears Again ® ) was applied to one eye (randomized) four times daily for two weeks. LogMAR high contrast visual acuity (VA), low contrast glare acuity (LCGA), non-invasive tear film break-up time (NIBUT), and lipid layer grade (LLG) were measured at baseline and day 14, in both treated and control eyes. Subjective comfort relative to baseline, and spectrofluorophotometric assessment of contact lens surface lipid deposition were also assessed on day 14. All measurements did not differ at baseline between treated and control eyes. Lipid layer thickness and tear film stability were increased on day 14 in treated eyes (all p<0.05), but not in control eyes (all p>0.05). A greater proportion of participants reported improved comfort in the treated eye relative to the control eye (p=0.002). There were no significant differences in visual acuity or in contact lens surface lipid deposition, between treated and control eyes, on day 14 (all p>0.05). The phospholipid liposomal spray increased tear film stability, lipid layer thickness and subjective comfort in silicone hydrogel contact lens wearers, without adversely affecting visual acuity or contact lens surface lipid deposition. Copyright © 2016 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

High resolution microscopy of the lipid layer of the tear film.

PubMed

King-Smith, P Ewen; Nichols, Jason J; Braun, Richard J; Nichols, Kelly K

2011-10-01

Tear film evaporation is controlled by the lipid layer and is an important factor in dry eye conditions. Because the barrier to evaporation depends on the structure of the lipid layer, a high resolution microscope has been constructed to study the lipid layer in dry and in normal eyes. The microscope incorporates the following features. First, a long working distance microscope objective is used with a high numerical aperture and resolution. Second, because such a high resolution objective has limited depth of focus, 2000 images are recorded with a video camera over a 20-sec period, with the expectation that some images will be in focus. Third, illumination is from a stroboscopic light source having a brief flash duration, to avoid blurring from movement of the lipid layer. Fourth, the image is in focus when the edge of the image is sharp - this feature is used to select images in good focus. Fifth, an aid is included to help align the cornea at normal incidence to the axis of the objective so that the whole lipid image can be in focus. High resolution microscopy has the potential to elucidate several characteristics of the normal and abnormal lipid layer, including different objects and backgrounds, changes in the blink cycle, stability and fluidity, dewetting, gel-like properties and possible relation to lipid domains. It is expected that high resolution microscopy of the lipid layer will provide information about the mechanisms of dry eye disorders. Illustrative results are presented, derived from over 10,000 images from 375 subjects.

Mechanical and Tear Properties of Fabric/Film Laminates

NASA Technical Reports Server (NTRS)

Said, Magdi A.

1998-01-01

Films reinforced with woven fabrics are being considered for the development of a material suitable for long duration scientific balloons under a program managed by the National Aeronautics and Space Administration (NASA). Recently developed woven fabrics provide a relatively high strength to weight ratio compared to standard homogenous films. Woven fabrics also have better crack propagation resistance and rip stop capabilities when compared to homogenous lightweight, high strength polymeric films such as polyester and nylon. If joining is required, such as in the case of scientific balloons, woven fabrics have the advantage over polymeric thin films to utilize traditional textile methods as well as other techniques including hot sealing, adhesion, and ultrasonic means. Woven fabrics, however, lack the barrier properties required for helium filled scientific balloons, therefore lamination with homogenous films is required to provide the gas barrier capabilities required in these applications.

Effect of controlled adverse chamber environment exposure on tear functions in silicon hydrogel and hydrogel soft contact lens wearers.

PubMed

Kojima, Takashi; Matsumoto, Yukihiro; Ibrahim, Osama M A; Wakamatsu, Tais Hitomi; Uchino, Miki; Fukagawa, Kazumi; Ogawa, Junko; Dogru, Murat; Negishi, Kazuno; Tsubota, Kazuo

2011-11-11

To prospectively evaluate the effect of controlled adverse chamber environment (CACE) exposure on tear function, including tear osmolarity, in subjects wearing narafilcon A versus those wearing etafilcon A soft contact lens (SCL). Thirty-one healthy subjects with no history of contact lens wear (13 women, 18 men; average age, 30.5 ± 6.5 years) were randomly divided into age- and sex-matched groups (15 subjects wearing narafilcon A SCL; 16 subjects wearing etafilcon A SCL) and entered a CACE for 20 minutes. All subjects underwent tear osmolarity, tear evaporation rate, strip meniscometry, tear film breakup time, fluorescein vital staining, and functional visual acuity measurement before and after exposure to the controlled adverse chamber. The mean blink rate increased with significant deteriorations in the mean symptom VAS scores, mean tear osmolarity, tear evaporation rate, strip meniscometry score, and tear stability with CACE exposure along with a decrease in visual maintenance ratio in functional visual acuity testing in etafilcon A wearers. The mean symptom VAS scores, mean tear evaporation rate, tear stability, blink rates, and visual maintenance ratios did not change significantly in narafilcon A wearers after CACE exposure. This study suggested marked tear instability, higher tear osmolarity, and increased tear evaporation with marked dry eye and visual symptomatology in nonadapted hydrogel SCL wearers, suggesting that silicone hydrogel SCLs may be suitable for persons who live and work in cool, low-humidity, and windy environments, as tested in this study.

Acetabular labral tears in patients with sports injury.

PubMed

Kang, Chan; Hwang, Deuk-Soo; Cha, Soo-Min

2009-12-01

We wanted to investigate acetabular labral tears and their correlation with femoroacetabular impingement in patients with sports injury. Among 111 patients who were diagnosed with the acetabular labral tears after arthroscopic treatment from January 2004 to December 2007, we selected 41 patients with sports injury. There were 12 cases of Taekwondo injury, 5 of golf injury, 4 of soccer injury, 3 of gymnastics injury, 2 of Hapkido injury, 2 of aerobics injury, 2 of rock-climbing injury, 2 of fitness training injury and 9 of other sports injuries. We checked the subtypes of acetabular labral tears and the accompanying femoroacetabular impingement. For the cases with accompanying femoroacetabular impingement, we investigated the subtypes according to the types of sports, gender and age. At last follow-up, we checked the Harris Hip Score (HHS), the Hip Outcome Score (HOS) sports scale and the percentage of patients who returned to their sports activity. The average age of symptomatic onset was 26 years (range, 12 to 65 years). The ratio of males to females was 29 : 12. An average duration of the hip pain was 17 months (range, 1 to 60 months). The degenerative type of acetabular labral tears was the most prevalent with 32 cases (78%), and there were 9 cases (22%) of the partial tear type. Thirty cases (73%) were accompanied by femoroacetabular impingement. The average age of the 23 cases (56%) of the cam-type was 23 years (range, 12 to 48 years), and it was more likely to occur in men (87%) and for people practicing martial arts such as Taekwondo or Hapkido. An average age of the 5 cases (12%) of the pincer-type was 26 (range, 16 to 43 years), it usually occurred in women (60%) and for non-martial arts such as golf and gymnastics. There were 2 cases of the mixed type (cam + pincer-type). At 27 months follow-up, the HHS was 61 to 92 points, the HOS sports scale increased 43 to 75%, and the rate of returning to sports was 71%. In spite of the early expression of symptoms

Does duration of symptoms affect clinical outcome after hip arthroscopy for labral tears? Analysis of prospectively collected outcomes with minimum 2-year follow-up

PubMed Central

Ni, Jake; Hohn, Eric A; Domb, Benjamin G

2017-01-01

Abstract Limited research exists on the possible association between duration of symptoms and clinical outcomes following hip arthroscopy for labral tears. The purpose of this study was to evaluate whether duration of symptoms affected clinical and patient-reported outcome (PRO) scores following hip arthroscopy for labral tears. From 2008 to 2011, data were collected prospectively on all patients undergoing primary hip arthroscopy for labral tears. Workers’ compensation cases, dysplasia cases and patients with previous ipsilateral hip surgeries were excluded. A total of 738 patients were identified with a minimum of 2-year follow-up, and clinical and PRO data were available for 680 patients. Uni- and multivariate analyses were performed to determine the relationship between duration of symptoms along with other variables and PROs. Overall, patients experienced significant improvements in all clinical and PRO scores. Results of univariate analysis revealed that all PROs were negatively associated with increasing Log10 months of symptoms as were pain and satisfaction scores. During multivariate analyses, increasing Log10 months of symptoms, age, body mass index and trauma were all negatively associated with PROs (P  < 0.05). Our study demonstrates that clinical and PRO scores were negatively associated with increasing duration of symptoms prior to hip arthroscopy for treatment of labral tears. Although this implies that delay in treatment may adversely affect outcome, conservative treatment remains the gold standard first line of treatment. Surgeons should incorporate this information into their treatment algorithm to maximize patient outcomes following treatment for labral tears. Level of evidence: Level IV, prospective case series. PMID:29250339

A Southern Hemisphere origin for campanulid angiosperms, with traces of the break-up of Gondwana

PubMed Central

2013-01-01

Background New powerful biogeographic methods have focused attention on long-standing hypotheses regarding the influence of the break-up of Gondwana on the biogeography of Southern Hemisphere plant groups. Studies to date have often concluded that these groups are too young to have been influenced by these ancient continental movements. Here we examine a much larger and older angiosperm clade, the Campanulidae, and infer its biogeographic history by combining Bayesian divergence time information with a likelihood-based biogeographic model focused on the Gondwanan landmasses. Results Our analyses imply that campanulids likely originated in the middle Albian (~105 Ma), and that a substantial portion of the early evolutionary history of campanulids took place in the Southern Hemisphere, despite their greater species richness in the Northern Hemisphere today. We also discovered several disjunctions that show biogeographic and temporal correspondence with the break-up of Gondwana. Conclusions While it is possible to discern traces of the break-up of Gondwana in clades that are old enough, it will generally be difficult to be confident in continental movement as the prime cause of geographic disjunctions. This follows from the need for the geographic disjunction, the inferred biogeographic scenario, and the dating of the lineage splitting events to be consistent with the causal hypothesis. PMID:23565668

[Rotator cuff tear athropathy prevalence].

PubMed

Guerra-Soriano, F; Encalada-Díaz, M I; Ruiz-Suárez, M; Valero-González, F S

2017-01-01

Glenohumeral arthritis secondary to massive rotator cuff tear presents with a superior displacement and femoralization of the humeral head with coracoacromial arch acetabularization. The purpose of this study was to establish prevalence of rotator cuff tear artropathy (CTA) at our institution. Four hundred electronic records were reviewed from which we identified 136 patients with rotator cuff tears. A second group was composed with patients with massive cuff tears that were analized and staged by the Seebauer cuff tear arthropathy classification. Thirty four patients with massive rotator cuff tears were identified, 8 male and 26 female (age 60.1 ± 10.26 years). Massive rotator cuff tear prevalence was 25%. CTA prevalence found in the rotator cuff group was 19 and 76% in the massive cuff tears group. Patients were staged according to the classification with 32% in stage 1a, 11% 1b, 32% 2a and 0% 2b. CTA prevalence in patients with rotator cuff tears and massive cuff tears is higher than the one reported in American population. We consider that a revision of the Seebauer classification to be appropriate to determine its reliability.

Prospective, randomized, controlled comparison of SYSTANE UD eye drops versus VISINE INTENSIV 1% EDO eye drops for the treatment of moderate dry eye.

PubMed

Jacobi, Christina; Kruse, Friedrich E; Cursiefen, Claus

2012-12-01

The aim of this prospective, randomized, clinical, single-center study was to compare the safety and efficacy of 2 ocular surface lubricant eye drops: preservative-free hydroxypropyl (HP)-Guar (SYSTANE UD(®)) eye drops versus preservative-free Tamarindus indica seed polysaccharide (TSP) 1% (VISINE INTENSIV 1% EDO(®)) eye drops. Fifty-six eyes of 28 patients with moderate keratoconjunctivitis sicca (DEWS severity level 2) were enrolled in the trial. Patients were randomized for 2 treatment groups (SYSTANE UD eye drops vs. VISINE INTENSIV 1% EDO eye drops). The eye drops in both groups were applied 5 times per day for 3 months. Statistical analyses were performed using Statistica™ software (Mann-Whitney U-test and Wilcoxon test). P-Values<0.05 were considered significant. After 3 months of treatment the patients of both groups had subjective benefit in the relief of symptoms of dry eye disease evaluated by the Ocular Surface Disease Index (OSDI) questionnaire score. Patients treated with HP-Guar and TSP showed improvements in tear film stability measured by tear break-up time (TBUT), which are statistically significant in the HP-Guar group (P=0.02). The results of this clinical trial show improvements of symptoms and signs in patients with moderate dry eye after the consistent use of preservative-free HP-Guar and TSP lubricant eye drops. Both artificial tear formulations produce amelioration in tear film stability improving eye conditions and patient quality of life. HP-Guar seems to be slightly more effective in improving ocular surface protection by decreasing tear film evaporation.

Efficacy of a crosslinked hyaluronic acid-based hydrogel as a tear film supplement: a masked controlled study.

PubMed

Williams, David L; Mann, Brenda K

2014-01-01

Keratoconjunctivitis sicca (KCS), or dry eye, is a significant medical problem in both humans and dogs. Treating KCS often requires the daily application of more than one type of eye drop in order to both stimulate tear prodcution and provide a tear supplement to increase hydration and lubrication. A previous study demonstrated the potential for a crosslinked hyaluronic acid-based hydrogel (xCMHA-S) to reduce the clinical signs associated with KCS in dogs while using a reduced dosing regimen of only twice-daily administration. The present study extended those results by comparing the use of the xCMHA-S to a standard HA-containing tear supplement in a masked, randomized clinical study in dogs with a clinical diagnosis of KCS. The xCMHA-S was found to significantly improve ocular surface health (conjunctival hyperaemia, ocular irritation, and ocular discharge) to a greater degree than the alternative tear supplement (P = 0.0003). Further, owners reported the xCMHA-S treatment as being more highly effective than the alternative tear supplement (P = 0.0024). These results further demonstrate the efficacy of the xCMHA-S in reducing the clinical signs associated with KCS, thereby improving patient health and owner happiness.

Persistence of increased Eotaxin-1 (CCL11) level in tears of patients wearing contact lenses: a long-term follow-up study.

PubMed

Tran, H V; Eperon, S; Guex-Crosier, Y

2011-04-01

Eotaxin-1 (CCL11) is a potent eosinophil chemotactic and activating peptide that may be implicated in the pathogenesis of chronic allergic eye disease and has been associated with the wearing of contact lenses (CL) in patients with contact lens papillary conjunctivitis (CLPC). The purpose of this study was to study eotaxin-1 expression in the tears of long-term CL wearers. Tears were collected with glass capillaries from 15 patients (2 male, 13 female) with various degree of CLPC at 2-year intervals. CLPC severity was graded from 0 to 4 with reference to standard slit-lamp photographs of the superior tarsal conjunctiva. The eotaxin-1 level in the tears was measured by an ELISA, using mouse anti-human eotaxin monoclonal antibodies. The mean age was 32.5 ± 13.3 years (range: 17 - 69 years). The mean interval between the tear collections was 30 ± 4.8 months. The mean concentration of eotaxin was 2150 ± 477 pg/mL and 2486 ± 810 pg/mL for the first and second series, respectively. The difference was not statistically significant (paired Wilcoxon/Kruskal-Wallis, p = 0.803). The mean score of papilla grade was 1.26 ± 0.18 for the first sample and 1.40 ± 0.19 two years later. There was no significant difference of grading between the two time periods (paired Wilcoxon/Kruskal-Wallis, p = 0.751). the eotaxin-1 level remains up-regulated over a long time period in patients wearing CL, most of them with chronic CLPC. Eotaxin may play a role in the pathogenesis of contact lens intolerance. © Georg Thieme Verlag KG Stuttgart · New York.

Human tears contain a chemosignal.

PubMed

Gelstein, Shani; Yeshurun, Yaara; Rozenkrantz, Liron; Shushan, Sagit; Frumin, Idan; Roth, Yehudah; Sobel, Noam

2011-01-14

Emotional tearing is a poorly understood behavior that is considered uniquely human. In mice, tears serve as a chemosignal. We therefore hypothesized that human tears may similarly serve a chemosignaling function. We found that merely sniffing negative-emotion-related odorless tears obtained from women donors induced reductions in sexual appeal attributed by men to pictures of women's faces. Moreover, after sniffing such tears, men experienced reduced self-rated sexual arousal, reduced physiological measures of arousal, and reduced levels of testosterone. Finally, functional magnetic resonance imaging revealed that sniffing women's tears selectively reduced activity in brain substrates of sexual arousal in men.

Subscapularis tendon tears

PubMed Central

Lenart, Brett A.; Ticker, Jonathan B.

2017-01-01

Tears of the subscapularis tendon have been under-recognised until recently. Therefore, a high index of suspicion is essential for diagnosis. A directed physical examination, including the lift-off, belly-press and increased passive external rotation can help identify tears of the subscapularis. All planes on MR imaging should be carefully evaluated to identify tears of the subscapularis, retraction, atrophy and biceps pathology. Due to the tendency of the tendon to retract medially, acute and traumatic full-thickness tears should be repaired. Chronic tears without significant degeneration should be considered for repair if no contraindication exists. Arthroscopic repair can be performed using a 30-degree arthroscope and a laterally-based single row repair; one anchor for full thickness tears ⩽ 50% of tendon length and two anchors for those ⩾ 50% of tendon length. Biceps pathology, which is invariably present, should be addressed by tenotomy or tenodesis. Timing of post-operative rehabilitation is dictated by the size of the repair and the security of the repair construct. The stages of rehabilitation typically involve a period of immobilisation followed by range of movement exercises, with a delay in active internal rotation (IR) and strengthening in IR. Cite this article: EFORT Open Rev 2017;2:484–495. DOI: 10.1302/2058-5241.2.170015 PMID:29387471

Changes in the ocular and nasal signs and symptoms of aircrews in relation to the ban on smoking on intercontinental flights.

PubMed

Wieslander, G; Lindgren, T; Norbäck, D; Venge, P

2000-12-01

This study determined the influence of exposure to environmental tobacco smoke (ETS) in aircraft on measured and perceived cabin air quality (CAQ), symptoms, tear-film stability, nasal patency, and biomarkers in nasal lavage fluid. Commercial aircrews underwent a standardized examination, including acoustic rhinometry, nasal lavage, and measurement of tear-film break-up time. Eosinophilic cationic protein, myeloperoxidase, lysozyme, and albumin were analyzed in the nasal lavage fluid. Inflight investigations [participation rate 98% (N=39)] were performed on board 4 flights, 2 in each direction between Scandinavia and Japan. Scandinavian crew on 6 flights from Scandinavia to Japan participated in postflight measurements after landing [participation rate 85% (N=41)]. Half the flights permitted smoking on board, and the other half, 0.5 months later, did not. Hygienic measurements showed low relative air humidity on board (2-10%) and a carbon dioxide concentration of <1000 ppm during 99.6% of the cruising time. The smoking ban caused a drastic reduction of respirable particles, from a mean of 66 (SD 56) microg/m3 to 3 (SD 0.8) microg/m3. The perceived CAQ was improved, and there were fewer symptoms, particularly ocular symptoms, headache and tiredness. Tear-film stability increased, and nasal patency was altered. Despite a high air exchange rate and spatial separation between smokers and nonsmokers, smoking in commercial aircraft may cause significant air pollution, as indicated by a large increase in respirable particles. This ETS exposure is associated with an increase in ocular and general symptoms, decreased tear-film stability, and alterations of nasal patency.

Dry eye findings worsen with anticholinergic therapy in patients with urge incontinence.

PubMed

Ozen Tunay, Zuhal; Ozdemir, Ozdemir; Ergintürk Acar, Damla; Cavkaytar, Sabri; Ersoy, Ebru

2016-06-01

To evaluate the effects of oral anticholinergic (OAC) drugs on tear secretion in women with overactive bladder over a 3-month follow-up period. In this prospective study, 108 women with a diagnosis of overactive bladder were evaluated. All patients were examined ophthalmologically at baseline (day 0), and after 1 month (day 30) and 3 months (day 90) of OAC treatment. Tear film break-up time (BUT) and Schirmer 1 test results were recorded. The subjective complaints of the patients including dry mouth, and burning, dryness and foreign body sensation in the eyes, were also recorded. The chi-squared test or the paired sample t test as appropriate, was used for statistical analysis. The mean age of the patients was 51.8 ± 9.2 years (30 - 69 years). The most frequent subjective complaints were dry mouth and dry eyes and both complaints were significant on both day 30 and day 90. Both tear film BUT and Schirmer 1 test results were significantly lower on day 30 and day 90. Dry eye measurement values worsened with prolongation of OAC treatment (p = 0.037 and p = 0.012 for BUT, and p = 0.046 and p = 0.035 for Schirmer 1 test, on day 30 and day 90, respectively). OAC treatment in women with overactive bladder significantly and progressively affects tear secretion.

Posterior root tear of the medial and lateral meniscus.

PubMed

Petersen, Wolf; Forkel, Philipp; Feucht, Matthias J; Zantop, Thore; Imhoff, Andreas B; Brucker, Peter U

2014-02-01

An avulsion of the tibial insertion of the meniscus or a radial tear close to the meniscal insertion is defined as a root tear. In clinical practice, the incidence of these lesions is often underestimated. However, several biomechanical studies have shown that the effect of a root tear is comparable to a total meniscectomy. Clinical studies documented progredient arthritic changes following root tears, thereby supporting basic science studies. The clinical diagnosis is limited by unspecific symptoms. In addition to the diagnostic arthroscopy, MRI is considered to be the gold standard of diagnosis of a meniscal root tear. Three different direct MRI signs for the diagnosis of a meniscus root tear have been described: Radial linear defect in the axial plane, vertical linear defect (truncation sign) in the coronal plane, and the so-called ghost meniscus sign in the sagittal plane. Meniscal extrusion is also considered to be an indirect sign of a root tear, but is less common in lateral root tears. During arthroscopy, the function of the meniscus root must be assessed by probing. However, visualization of the meniscal insertions is challenging. Refixation of the meniscal root can be performed using a transtibial pull-out suture, suture anchors, or side-to-side repair. Several short-term studies reported good clinical results after medial or lateral root repair. Nevertheless, MRI and second-look arthroscopy revealed high rates of incomplete or absent healing, especially for medial root tears. To date, most studies are case series with short-term follow-up and level IV evidence. Outerbridge grade 3 or 4 chondral lesions and varus malalignment of >5° were found to predict an inferior clinical outcome after medial meniscus root repair. Further research is needed to evaluate long-term results and to define evident criteria for meniscal root repair.

Is the arthroscopic modified tension band suture technique suitable for all full-thickness rotator cuff tears?

PubMed

Bae, Kyu Hwan; Kim, Jeong Woo; Kim, Tae Kyun; Kweon, Seok Hyun; Kang, Hong Je; Kim, Jong Yun; Joo, Min Su; Kim, Dong Moon

2016-09-01

We aimed to identify the clinical and structural outcomes after arthroscopic repair of full-thickness rotator cuff tears of all sizes with a modified tension band suture technique. Among 63 patients who underwent arthroscopic rotator cuff repair for a full-thickness rotator cuff tear with the modified tension band suture technique at a single hospital between July 2011 and March 2013, 47 were enrolled in this study. The mean follow-up period was 29 months. Visual analog scale scores, range of motion, American Shoulder and Elbow Surgeons scores, Constant scores, and Shoulder Strength Index were measured preoperatively and at the final follow-up. For radiologic evaluation, we conducted magnetic resonance imaging 6 months postoperatively and ultrasonography at the final follow-up. We allocated the small and medium tears to group A and the large and massive tears to group B and then compared clinical outcomes and repair integrity. Postoperative clinical outcomes at the final follow-up showed significant improvements compared with those seen during preoperative evaluations (P < .001). However, group B showed worse clinical results than group A. Evaluation with magnetic resonance imaging performed 6 months postoperatively and ultrasonography taken at the final follow-up revealed that group B showed a significantly higher retear rate than did group A (69% vs. 6%, respectively; P < .001). Arthroscopic repair with the modified tension band suture technique for rotator cuff tears was a more suitable method for small to medium tears than for large to massive tears. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Posterior root tear of the medial meniscus in multiple knee ligament injuries.

PubMed

Kim, Young Jae; Kim, Jin Goo; Chang, Seok Hwan; Shim, Jae Chan; Kim, Sang Bum; Lee, Mi Young

2010-10-01

The purposes of the present study were to examine the frequency and characteristics of root tears of the medial meniscus associated with ligament injuries of the knee and to evaluate the effectiveness of pull-out repair for restoring meniscus function. We retrospectively analyzed the 9 patients (10 knees) with posterior root tears of the medial meniscus and ligament injuries of the knee treated between August 2004 and February 2007. All the patients were male, with average age of 29.8 years, and the mean follow-up period was 29.7 months. The pull-out suture technique was used to repair the root tears. Clinical outcomes were evaluated using the Lysholm, IKDC, and Tegner scores, as well as the McMurray and Apley tests. The mean follow-up period was 41.1 months (range, 30 to 63 months). The incidence of root tears of the medial meniscus with ligament injuries was 2.74% (10 cases in 365 ligament surgeries). All clinical results showed significant improvement. At the final follow-up, McMurray test showed one positive and nine negative cases, and the Apley test revealed two positive and eight negative cases. There were no positive findings in anterior drawer test, posterior drawer test, valgus and varus stress test, and posterolateral instability test. Healing of the root tear was confirmed by arthroscopy in five patients and by MR in four patients. Root tears of the medial meniscus may occur in multiple knee ligament injuries. It is important not to miss them. Our results indicate that pull-out repair provides satisfactory results and evidence of healing. Copyright 2009 Elsevier B.V. All rights reserved.

Sebum/Meibum Surface Film Interactions and Phase Transitional Differences.

PubMed

Mudgil, Poonam; Borchman, Douglas; Gerlach, Dylan; Yappert, Marta C

2016-05-01

Sebum may contribute to the composition of the tear film lipid layer naturally or as a contaminant artifact from collection. The aims of this study were to determine: if sebum changes the rheology of meibum surface films; if the resonance near 5.2 ppm in the 1H-NMR spectra of sebum is due to squalene (SQ); and if sebum or SQ, a major component of sebum, interacts with human meibum. Human meibum was collected from the lid margin with a platinum spatula. Human sebum was collected using lipid absorbent tape. Langmuir trough technology was used to measure the rheology of surface films. Infrared spectroscopy was used to measure lipid conformation and phase transitions. We used 1H-NMR to measure composition and confirm the primary structure of SQ. The NMR resonance near 5.2 ppm in the spectra of human sebum was from SQ which composed 28 mole percent of sebum. Both sebum and SQ lowered the lipid order of meibum. Sebum expanded meibum films at lower concentrations and condensed meibum films at higher concentrations. Sebum caused meibum to be more stable at higher pressures (greater maximum surface pressure). Physiological levels of sebum would be expected to expand or fluidize meibum making it spread better and be more surface active (qualities beneficial for tear film stability). Sebum would also be expected to stabilize the tear film lipid layer, which may allow it to withstand the high shear pressure of a blink.

Dry Eye Syndrome in Non-Exophthalmic Graves' Disease.

PubMed

Bruscolini, A; Abbouda, A; Locuratolo, N; Restivo, L; Trimboli, P; Romanelli, F

2015-01-01

The present study aims to assess qualitative and quantitative characteristics of tear film and corneal related impairment and to evaluate the quality of life in a cohort of non-exophthalmic Graves' disease (GD) patients. The series comprised 50 eyes from 25 newly diagnosed GD patients with no proptosis. As control group, 56 eyes of 28 thyroid disease-free subjects were enrolled. The results of Schirmer I and II, break-up time, and Oxford scheme showed a significant difference between GD and controls. By ocular surface disease index (OSDI) questionnaire, eleven (44%) GD patients had normal ocular surface, while two (8%) had mild, four (16%) had moderate, and eight (32%) had severe dry eye. The mean score of the OSDI in the GD group was significantly (p < 0.001) higher with respect to the control group. This study shows that the tear film and cornea are damaged in newly non-exophthalmic GD subjects.

Theory of vibratory mobilization and break-up of non-wetting fluids entrapped in pore constrictions

NASA Astrophysics Data System (ADS)

Beresnev, I.; Li, W.; Vigil, D.

2006-12-01

Quantitative dynamics of a non-wetting (e. g., NAPL) ganglion entrapped in a pore constriction and subjected to vibrations can be approximated by the equation of motion of an oscillator moving under the effect of the external pressure gradient, inertial oscillatory force, and restoring capillary force. The solution of the equation provides the conditions under which the droplet experiences forced oscillations without being mobilized or is liberated upon the acceleration of the wall exceeding an "unplugging" threshold. This solution provides a quantitative tool for the estimation of the parameters of vibratory fields needed to liberate entrapped non-wetting fluids. For typical pore sizes encountered in reservoirs and aquifers, wall accelerations must exceed at least several m/sec2 and even higher levels to mobilize the droplets of NAPL; however, in the populations of ganglia entrapped in natural porous environments, many may reside very near their mobilization thresholds and may be mobilized by extremely low accelerations as well. For given acceleration, lower seismic frequencies are more efficient. The ganglia may also break up into smaller pieces when passing through pore constrictions. The snap-off is governed by the geometry only; for constrictions with sinusoidal profile (spatial wavelength of L and maximum and minimum radii of rmax and rmin, the break-up occurs if L > 2π(rmin rmax)1/2. Computational fluid dynamics shows the details of the break-up process.

Validation of a new classification system for skin tears.

PubMed

LeBlanc, Kimberly; Baranoski, Sharon; Holloway, Samantha; Langemo, Diane

2013-06-01

The aim of this study was to validate and establish reliability of the International Skin Tear classification system. A consensus panel of 12 internationally recognized key opinion leaders convened in 2011 to establish consensus statements on the prevention, prediction, assessment, and treatment of skin tears. Subsequently, a new skin tear classification system was proposed. The system was then tested for interrater and intrarater reliability between the experts before being tested more widely on a sample of 327 individuals from the United States, Canada, and Europe. The results of the study indicated a substantial level of agreement for the expert panel (Fleiss κ = 0.619; 2-month follow-up = 0.653). Intrarater reliability was high (Cohen κ = 0.877). Interrater reliability was moderate (Fleiss κ = 0.555) for healthcare professionals (n = 303) and fair for non-health professionals (Fleiss κ = 0.338; n = 24). This international study established the reliability and validity of a new classification system for skin tears.

A GEOCLIM Simulation Of Climatic And Biogeochemical Consequences Of Pangea Break Up

NASA Astrophysics Data System (ADS)

Donnadieu, Y.; Godderis, Y.; Pierrehumbert, R.; Dromart, G.; Jacob, R.

2006-12-01

Large fluctuations in continental configuration occur all along the Mesozoic times. While it has long been recognized that paleogeography may potentially influence atmospheric CO2 via the continental silicate weathering feedback, no numerical simulation have been done given the lack of a spatially resolved climate- carbon model. GEOCLIM, a coupled numerical model of the climate and global biogeochemical cycles, is used to investigate the consequences of the Pangea break up. The climate module of the GEOCLIM model is the FOAM atmospheric general circulation model, allowing the calculation of the consumption of atmospheric CO2 through continental silicate weathering with a spatial resolution of 7.5°long 4.5°lat. Seven time slices have been simulated. We show that the break up of the Pangea supercontinent triggers an increase in continental runoff, resulting in enhanced atmospheric CO2 consumption through silicate weathering. As a result, atmospheric CO2 falls from values above 3000 ppmv during the Triassic, down to rather low levels during the Cretaceous (around 400 ppmv), resulting in a decrease in continental temperatures from about 20°C to 10°C. Silicate weathering feedback and paleogeography both act to force the Earth system toward a dry and hot world reaching its optimum over the last 260 Ma during the Middle-Late Triassic. In the super continent case, given the relative aridity that cannot be climatically overwhelmed, the model generates high CO2 values to produce very warm continental temperatures compensating for the lack of continental humidity. Conversely, in the fragmented case, the runoff becomes the most important contributor to the silicate weathering rate, hence, producing a CO2 drawdown and a fall in continental temperatures. Finally, an other unexpected outcome is the pronounced fluctuations in carbonate accumulation simulated by the model in response to the Pangea break up. These fluctuations are driven by changes in continental carbonate

Analysis of the possible cause of break up of PSLV-C3/PS4 stage

NASA Astrophysics Data System (ADS)

Bandyopadhyay, P.; Sharma, R.; Adimurthy, V.

On 19t h December 2001 the orbiting spent PS4 stage of PSLV -C3 had undergone a break up. Following this event, the Two Line Element (TLE) sets of more than 300 debris pieces from the upper stage are available in public domain by January 2002. These TLE sets are the major input used in this study. Here the velocity components imparted on the fragments are evaluated by a new approach, which is less sensitive to the errors in the TLE sets. In Ref-1, the normal, radial and tangential components of fragment velocity additions are estimated from the differences in semi-major axis, eccentricity and inclination with respect to those of parent object. Unfortunately, when the parent orbit has small eccentricity or the break up occurs near either apogee or perigee, as it is likely in the case of PSLV-C3/PS4, the computation of radial component of velocity increment becomes close to a singular point and hence prone to errors because of imperfect orbital element data. In Ref-2, velocity increments are estimated from semi-major axis, eccentricity, inclination, and right ascension of ascending node and true anomaly of fragments as well as parent at the time of break up. It is very difficult to obtain true anomaly of fragments at the time of break up by propagating the element sets of debris pieces backward in time owing to uncertainties in orbital elements and drag parameters. Moreover, whenever the apogee of fragment orbit, computed from the TLE sets, becomes less than the perigee of parent orbit, this method does not yield any solution for radial component of velocity increment. The authors have estimated three components of velocity addition, utilizing relations involving the differences in semi-major axis, eccentricity and inclination and argument of perigee (Ref- 3) in a particular combination and sequence, which avoids the singularity in the computation. With this approach, the characteristics of velocity additions are similar in all the three directions and velocity

History of satellite break-ups in space

NASA Technical Reports Server (NTRS)

Gabbard, J.

1985-01-01

By 28 June 1961 the 1st Aerospace Control Squadron had cataloged 115 Earth orbiting satellites from data supplied by a rather diverse collection of radar and optical sensors. On 29 June 1961, the Able Star rocket of the 1961 Omicron launch exploded causing a quantum jump in the number of Earth orbiting objects. Since that time there have been 69 Earth orbiting satellites break up in space whose debris remained in orbit long enough for orbital elements to be developed. A list of the 69 breakups is provided. The debris from some of the lower altitude breakups has all decayed. Among the 69 breakups, 44 have cataloged debris remaining in orbit. As of 1 July 1982, the size of the cataloged orbiting population was exactly 4700. Forty-nine percent of these objects are fragments of the forty-four breakups. For each breakup the various orbits of its debris represent a family of orbits that are related in characteristics due to their common impulse launch. A few examples are shown of how the families are oriented in space.

Tear dynamics in healthy and dry eyes.

PubMed

Cerretani, Colin F; Radke, C J

2014-06-01

Dry-eye disease, an increasingly prevalent ocular-surface disorder, significantly alters tear physiology. Understanding the basic physics of tear dynamics in healthy and dry eyes benefits both diagnosis and treatment of dry eye. We present a physiological-based model to describe tear dynamics during blinking. Tears are compartmentalized over the ocular surface; the blink cycle is divided into three repeating phases. Conservation laws quantify the tear volume and tear osmolarity of each compartment during each blink phase. Lacrimal-supply and tear-evaporation rates are varied to reveal the dependence of tear dynamics on dry-eye conditions, specifically tear osmolarity, tear volume, tear-turnover rate (TTR), and osmotic water flow. Predicted periodic-steady tear-meniscus osmolarity is 309 and 321 mOsM in normal and dry eyes, respectively. Tear osmolarity, volume, and TTR all match available clinical measurements. Osmotic water flow through the cornea and conjunctiva contribute 10 and 50% to the total tear supply in healthy and dry-eye conditions, respectively. TTR in aqueous-deficient dry eye (ADDE) is only half that in evaporative dry eye (EDE). The compartmental periodic-steady tear-dynamics model accurately predicts tear behavior in normal and dry eyes. Inclusion of osmotic water flow is crucial to match measured tear osmolarity. Tear-dynamics predictions corroborate the use of TTR as a clinical discriminator between ADDE and EDE. The proposed model is readily extended to predict the dynamics of aqueous solutes such as drugs or fluorescent tags.

Characteristics of radial tears in the posterior horn of the medial meniscus compared to horizontal tears.

PubMed

Choi, Chul-Jun; Choi, Yun-Jin; Song, In-Bum; Choi, Chong-Hyuk

2011-06-01

The clinical and radiologic features of radial tears of the medial meniscus posterior horn were compared with those of horizontal tears. From January 2007 to December 2008, 387 consecutive cases of medial meniscal tears were treated arthroscopically. Among these, 91 were radial tears in the medial meniscus posterior horn, and 95 were horizontal tears in the posterior segment of the medial meniscus. The patients' data (age, gender, duration of symptom, body mass index, and injury history), radiographic findings (Kellgren and Lawrence score, posterior tibial slope, and femorotibial angle), and chondral lesions were recorded. The patient factors of age, gender, and body mass index were related to radial tears of the medial meniscus posterior horn. Radial tears were significantly correlated with Kellgren and Lawrence score, varus alignment, posterior tibial slope, and severity of the chondral lesion. Radial tears of the medial meniscus posterior horn are a unique clinical entity that are associated with older age, females and obesity, and are strongly associated with an increased incidence and severity of cartilage degeneration compared to horizontal tears.

Laser-tissue soldering with biodegradable polymer films in vitro: film surface morphology and hydration effects.

PubMed

Sorg, B S; Welch, A J

2001-01-01

Previous research introduced the concept of using biodegradable polymer film reinforcement of a liquid albumin solder for improvement of the tensile strength of repaired incisions in vitro. In this study, the effect of creating small pores in the PLGA films on the weld breaking strength is studied. Additionally, the effect of hydration on the strength of the reinforced welds is investigated. A 50%(w/v) bovine serum albumin solder with 0.5 mg/mL Indocyanine Green dye was used to repair an incision in bovine aorta. The solder was coagulated with an 806-nm CW diode laser. A poly(DL-lactic-co-glycolic acid) (PLGA) film was used to reinforce the solder (the controls had solder but no reinforcement). Breaking strengths were measured acutely and after hydration in saline for 1 and 2 days. The data were analyzed by ANOVA (P < 0.05) and multiple comparisons of means were performed using the Newman-Keuls test. The creation of pores in the PLGA films qualitatively improved the film flexibility without having an apparent adverse effect on the breaking strength, while the actual technique of applying the film and solder had more of an effect. The acute maximum average breaking strengths of some of the film reinforced specimens (114.7 g-134.4 g) were significantly higher (P < 0.05) than the acute maximum average breaking strength of the unreinforced control specimens (68.3 g). Film reinforced specimens were shown to have a statistically significantly higher breaking strength than unreinforced controls after 1- and 2-day hydration. Reinforcement of liquid albumin solders in laser-assisted incision repair appears to have advantages over conventional methods that do not reinforce the cohesive strength of the solder in terms of acute breaking strength and after immersion in moist environments for short periods of time. Using a film with the solder applied to one surface only may be advantageous over other techniques.

Single particles accelerate final stages of capillary break-up

NASA Astrophysics Data System (ADS)

Lindner, Anke; Fiscina, Jorge Eduardo; Wagner, Christian

2015-06-01

Droplet formation of suspensions is present in many industrial and technological processes such as coating and food engineering. Whilst the finite-time singularity of the minimum neck diameter in capillary break-up of simple liquids can be described by well-known self-similarity solutions, the pinching of non-Brownian suspension depends in a complex way on the particle dynamics in the thinning thread. Here we focus on the very dilute regime where the filament contains only isolated beads to identify the physical mechanisms leading to the pronounced acceleration of the filament thinning observed. This accelerated regime is characterized by an asymmetric shape of the filament with an enhanced curvature that depends on the size and the spatial distribution of the particles within the capillary thread.

Tear analysis in contact lens wearers.

PubMed Central

Farris, R L

1985-01-01

Tear analysis in contact lens wearers was compared with tear analysis in aphakics without contact lens wear and normal phakic patients. Subjects were divided into five groups: group 1, aphakic without contact lens; group 2, phakic with daily-wear hard contact lens; group 3, phakic with daily-wear soft contact lens; group 4, phakic with extended-wear soft contact lens; and group 5, aphakic with extended-wear soft contact lens. The experimental groups were compared with age- and sex-matched control groups for statistical analysis of tear variables by means of the Student's t-test. The variables measured were tear osmolarity, tear albumin, and lysozyme and lactoferrin concentrations in basal and reflex tears. Highly significant elevations of tear osmolarity were found in aphakic subjects without contact lenses. Less significant differences in tear osmolarity were found in phakic subjects with hard daily-wear lenses or with extended-wear soft lenses. Tear albumin, lysozyme, and lactoferrin in basal and reflex tears were not significantly different in the different groups of contact lens wearers or in the group of aphakic subjects without contact lenses compared with their control groups. Individual variations in tear albumin, lysozyme, and lactoferrin appeared to be responsible for the inability to demonstrate significant differences in tear composition in association with the wearing of different types of contact lenses. Older and aphakic patients demonstrated a tendency to have increased concentrations of proteins in the tears compared with younger, phakic contact lens wearers and normal controls without contact lenses. PMID:3914131

Arthroscopic-Assisted Latissimus Dorsi Tendon Transfer for Massive, Irreparable Rotator Cuff Tears: Technique and Short-Term Follow-Up of Patients With Pseudoparalysis.

PubMed

Kanatlı, Ulunay; Özer, Mustafa; Ataoğlu, Muhammet Baybars; Öztürk, Burak Yağmur; Gül, Orkun; Çetinkaya, Mehmet; Ayanoğlu, Tacettin

2017-05-01

To describe a modified technique for arthroscopic-assisted transfer of the latissimus dorsi tendon in a selected group of patients with irreparable rotator cuff tears and pseudoparalysis and to evaluate its short-term results. Fifteen patients with irreparable rotator cuff tears and pseudoparalysis treated by arthroscopic-assisted latissimus dorsi tendon transfer were included. The mean patient age was 61.53 ± 6.24 years (range, 52-71 years). Patients were assessed with physical examination, University of California Los Angeles (UCLA) Score and Constant-Murley score, as well as visual analog scale score at a mean follow-up of 26.4 ± 2.58 months (range, 24-31 months). At final follow-up, mean UCLA score increased to 27.47 ± 6.31 compared with the preoperative UCLA score of 6.53 ± 2.1 (P < .001). Constant-Murley score was 21 ± 7.41 and 59.73 ± 13.62 (P < .001), visual analog scale pain score was 7.47 ± 1.06 and 2.47 ± 0.91 (P < .001), active forward flexion was 58° ± 21.11° and 130° ± 30.05° (P < .001), active abduction was 51° ± 21.64° and 129.67° ± 25.45° (P < .001), and active external rotation was 13.33° ± 21.68° and 32° ± 18.03° (P < .001) preoperatively and postoperatively, respectively. Mean acromiohumeral distance was 3.13 ± 1.40 mm preoperatively, whereas it was 5.67 ± 1.67 mm postoperatively (P < .001). No significant complications requiring a revision surgery was observed during the final follow-up. The modified technique of arthroscopic-assisted transfer of the latissimus dorsi tendon is a feasible, minimally invasive option for the surgical treatment of irreparable rotator cuff tears in a subset of patients with pseudoparalysis. Level IV, therapeutic case series. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Energy expenditure and heart rate response to breaking up sedentary time with three different physical activity interventions.

PubMed

Carter, S E; Jones, M; Gladwell, V F

2015-05-01

Prolonged sedentary behaviour is associated with increased cardiovascular disease risk and decreased energy expenditure (EE). Workplace interventions breaking up sedentary time have increased EE but the cardiovascular responses are unknown. The practicalities of these interventions, such as required costs and workplace adaptations, are questioned. Calisthenics exercises overcome such limitations, but have not been assessed. The aim of this study was to assess the EE and heart rate (HR) response when breaking up sedentary time with a short bout of standing, walking or calisthenics. Twenty healthy participants (15 male) completed four 30 min conditions: a) 30 min sitting, or breaking up this period with two minutes of b) standing, c) treadmill walking (4 km·h(-1)) or d) a set of calisthenics exercises (including squats and lunges). HR and EE (indirect calorimetry) were assessed throughout. During the activity break, calisthenics caused the highest HR (90 ± 12 bpm) compared to all other conditions (Sit: 70 ± 12 bpm; Stand:72 ± 13 bpm; Walk:84 ± 10 bpm; p < 0.001) and EE was the highest with calisthenics (13 ± 5 kcal) compared to all conditions except walking (Sit:3 ± 1 kcal; Stand:5 ± 1 kcal; p < 0.001). The recovery following calisthenics had highest total EE (27 ± 7 kcal) compared to walking (23 ± 6 kcal) and standing (22 ± 6 kcal) and also the longest elevation of HR (p < 0.001). Calisthenics led to a greater total EE and HR response compared to standing or walking interventions. Calisthenics may be a time efficient method to break up sedentary time without individuals leaving their work environment. Hence calisthenics could be utilised to disrupt workplace sedentary time and improve cardiovascular health and assist in weight management. Copyright © 2015 Elsevier B.V. All rights reserved.

Anomalous Lower Crustal and Surface Features as a Result of Plume-induced Continental Break-up: Inferences from Numerical Models

NASA Astrophysics Data System (ADS)

Beniest, A.; Koptev, A.; Leroy, S. D.

2016-12-01

Anomalous features along the South American and African rifted margins at depth and at the surface have been recognised with gravity and magnetic modelling. They include high velocity/high density bodies at lower crustal level and topography variations that are usually interpreted as aborted rifts. We present fully-coupled lithosphere-scale numerical models that permit us to explain both features in a relatively simple framework of an interaction between rheologically stratified continental lithosphere and an active mantle plume. We used 2D and 3D numerical models to investigate the impact of thermo-rheological structure of the continental lithosphere and initial plume position on continental rifting and breakup processes. Based on the results of our 2D experiments, three main types of continental break-up are revealed: A) mantle plume-induced break-up, directly located above the centre of the mantle anomaly, B) mantle plume-induced break-up, 50 to 250 km displaced from the initial plume location and C) self-induced break-up due to convection and/or slab-subduction/delamination, considerably shifted (300 to 800 km) from the initial plume position. With our 3D, laterally homogenous initial setup, we show that a complex system, with the axis of continental break-up 100's of km's shifted from the original plume location, can arise spontaneously from simple and perfectly symmetric preliminary settings. Our modelling demonstrates that fragments of a laterally migrating plume head become glued to the base of the lithosphere and remain at both sides of the newly-formed oceanic basin after continental break-up. Underplated plume material soldered into lower parts of lithosphere can be interpreted as the high-velocity/high density magmatic bodies at lower crustal levels. In the very early stages of rifting, first impingement of the vertically upwelled mantle plume to the lithospheric base leads to surface topographic variations. Given the shifted position of the final

Classification of ulnar triangular fibrocartilage complex tears. A treatment algorithm for Palmer type IB tears.

PubMed

Atzei, A; Luchetti, R; Garagnani, L

2017-05-01

The classical definition of 'Palmer Type IB' triangular fibrocartilage complex tear, includes a spectrum of clinical conditions. This review highlights the clinical and arthroscopic criteria that enable us to categorize five classes on a treatment-oriented classification system of triangular fibrocartilage complex peripheral tears. Class 1 lesions represent isolated tears of the distal triangular fibrocartilage complex without distal radio-ulnar joint instability and are amenable to arthroscopic suture. Class 2 tears include rupture of both the distal triangular fibrocartilage complex and proximal attachments of the triangular fibrocartilage complex to the fovea. Class 3 tears constitute isolated ruptures of the proximal attachment of the triangular fibrocartilage complex to the fovea; they are not visible at radio-carpal arthroscopy. Both Class 2 and Class 3 tears are diagnosed with a positive hook test and are typically associated with distal radio-ulnar joint instability. If required, treatment is through reattachment of the distal radio-ulnar ligament insertions to the fovea. Class 4 lesions are irreparable tears due to the size of the defect or to poor tissue quality and, if required, treatment is through distal radio-ulnar ligament reconstruction with tendon graft. Class 5 tears are associated with distal radio-ulnar joint arthritis and can only be treated with salvage procedures. This subdivision of type IB triangular fibrocartilage complex tear provides more insights in the pathomechanics and treatment strategies. II.

Partial articular-sided rotator cuff tears: in situ repair versus tear completion prior to repair.

PubMed

Sethi, Paul M; Rajaram, Arun; Obopilwe, Elifho; Mazzocca, Augustus D

2013-06-01

Uncertainty exists over the ideal surgical treatment method for partial articular-sided rotator cuff tears, with options ranging from debridement to in situ repair to tear completion prior to repair. The purpose of this study was to determine whether in situ repair was a viable biomechanical treatment option compared with tear completion prior to repair of partial articular-sided rotator cuff tears. Fourteen fresh-frozen cadaveric shoulders were dissected. Partial articular-sided tears were created and repaired using in situ repair or tear completion prior to the repair. Strain and displacement were measured at 45°, 60°, and 90° of glenohumeral abduction. Testing was performed with a load of 100 N applied for 30 cycles. Data from the biomechanical testing displayed 4 conditions that showed improved characteristics of in situ repair over completion and repair: bursal-sided strain anteriorly at 45°, bursal-sided strain anteriorly at 90°, bursal-sided displacement anteriorly at 45°, and bursal-sided displacement anteriorly at 90°. The data indicate that in situ repair is a viable biomechanical treatment option compared with tear completion prior to repair of partial articular-sided rotator cuff tears. When clinically appropriate, the in situ repair may offer some biomechanical advantages, with lower strain and displacement observed on the bursal side compared with tear completion prior to repair. Copyright 2013, SLACK Incorporated.

Effect of Autologous Serum Eye Drops in Patients with Sjögren Syndrome-related Dry Eye: Clinical and In Vivo Confocal Microscopy Evaluation of the Ocular Surface.

PubMed

Semeraro, Francesco; Forbice, Eliana; Nascimbeni, Giuseppe; Taglietti, Marco; Romano, Vito; Guerra, Germano; Costagliola, Ciro

To evaluate in vivo changes after therapy using autologous serum (AS) eye drops in Sjögren's syndrome (SS)-related dry eyes by confocal microscopy. In this study, 24 patients with SS-related dry eyes [12 in AS eye drop therapy and 12 in artificial tear (AT) therapy] and 24 healthy volunteers were recruited. Ocular Surface Disease Index (OSDI), central corneal thickness, tear film, break-up time, corneal and conjunctival staining, Schirmer's test and corneal confocal microscopy were investigated. Tear production, tear stability, corneal staining, inflammation, and central corneal thickness, Langherans cells, activated keratocytes, intermediate epithelial cell density, nerve tortuosity, number of sub-basal nerve branches, and number of bead-like formations differed between patients and controls (p<0.0001). The AT and AS groups differed in the OSDI, number of branches, and number of beadings (p<0.0001). AS eye drops improve symptoms and confocal microscopy findings in SS-related dry eyes. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Tear-Duct Obstruction and Surgery

MedlinePlus

... Staying Safe Videos for Educators Search English Español Tear-Duct Obstruction and Surgery KidsHealth / For Parents / Tear- ... year old with little or no treatment. About Tear Ducts Our eyes are continually exposed to dust, ...

Sebum/Meibum Surface Film Interactions and Phase Transitional Differences

PubMed Central

Mudgil, Poonam; Borchman, Douglas; Gerlach, Dylan; Yappert, Marta C.

2016-01-01

Purpose Sebum may contribute to the composition of the tear film lipid layer naturally or as a contaminant artifact from collection. The aims of this study were to determine: if sebum changes the rheology of meibum surface films; if the resonance near 5.2 ppm in the 1H-NMR spectra of sebum is due to squalene (SQ); and if sebum or SQ, a major component of sebum, interacts with human meibum. Methods Human meibum was collected from the lid margin with a platinum spatula. Human sebum was collected using lipid absorbent tape. Langmuir trough technology was used to measure the rheology of surface films. Infrared spectroscopy was used to measure lipid conformation and phase transitions. We used 1H-NMR to measure composition and confirm the primary structure of SQ. Results The NMR resonance near 5.2 ppm in the spectra of human sebum was from SQ which composed 28 mole percent of sebum. Both sebum and SQ lowered the lipid order of meibum. Sebum expanded meibum films at lower concentrations and condensed meibum films at higher concentrations. Sebum caused meibum to be more stable at higher pressures (greater maximum surface pressure). Conclusions Physiological levels of sebum would be expected to expand or fluidize meibum making it spread better and be more surface active (qualities beneficial for tear film stability). Sebum would also be expected to stabilize the tear film lipid layer, which may allow it to withstand the high shear pressure of a blink. PMID:27145473

The adhesion of Pseudomonas aeruginosa to high molecular weight human tear film species corresponds to glycoproteins reactive with Sambucus nigra lectin.

PubMed

Aristoteli, Lina Panayiota; Willcox, Mark D P

2006-11-01

Pseudomonas aeruginosa is a pathogen gaining prevalence in contact lens-related corneal ulcers. Tear outflow protects the ocular surface, where high molecular weight tear glycoproteins bind bacteria for removal from the eye. The purpose of the present study was to identify glycoproteins in human tears involved in the adhesion of ocular P. aeruginosa isolates. Basal human tears were applied to a bacterial adhesion assay involving electrophoretic separation of tear components, transfer to nitrocellulose and incubation with biotin-labelled bacteria. Glycoproteins were further characterised using lectin profiling. The results showed large-dimension agarose gels were imperative for the detection of at least four glycoproteins with a migration >200 kDa, including species not previously identified. P. aeruginosa 6294 preferentially bound to a well-defined glycoprotein near the origin of the gel that, unlike other glycoproteins >200 kDa, reacted with Sambucus nigra lectin (sialic acid alpha2-6) but not WGA lectin (N-acetylglucosamine, sialic acid alpha2-3). Adhesion did not involve free biotin label or hydrophobic interactions. Also, the pre-incubation of separated tear glycoproteins with S. nigra lectin increased subsequent adhesion of 6294 to this tear glycoprotein. The less virulent Paer1 strain showed diffuse adhesion in the S. nigra-reactive region at the gel origin. In conclusion, an overlay adhesion assay was developed that identified slow-migrating sialylated glycoprotein species in human tears preferentially bound by P. aeruginosa ocular strains, and S. nigra lectin seemed to enhance the interaction. The study provides a basis for direct investigation of bacterial adhesion to glycoproteins with an apparent migration >200 kDa in tear fluid.

The effects of hormone replacement therapy on dry eye syndromes evaluated by Schirmer test depend on patient age.

PubMed

Feng, Yanhong; Feng, Gang; Peng, Shuli; Li, Hui

2016-04-01

This study was performed to explore the effects of hormone replacement therapy (HRT) on aqueous tear production and tear quality in dry eye syndrome (DES) patients of different ages. Eighty-eight women with DES at least one year after spontaneous menopause were randomly divided into the HRT group that were treated with orally estrogen and medroxyprogesterone acetate or a control group that did not receive any treatment. The aqueous tear production and tear quality were measured by Schirmer test and tear film break up time (TBUT) before and after one month of treatment. The subjects were subdivided according to age; the HRT group was divided into groups A (age range: 44-49 years) and B (age range: 50-57 years), and the controls were divided into groups C (age range: 46-49 years) and D (age range: 50-55 years). The changes in results of Schirmer test and TBUT before and after treatment were compared within each group and were correlated with the age of the participants. After one-month follow-up, HRT use improved the Schirmer test but the effect was significant only for participants less than 50 years old. The improvement in Schirmer test result was negatively correlated with the age of the participants. The TBUT did not change significantly within each group after HRT use. HRT use may improve aqueous tear production but not the quality of tears in DES, and the effect on tear production is dependent on age. Copyright © 2015 Elsevier Ltd. All rights reserved.

Rotator cuff tears in children and adolescents: experience at a large pediatric hospital.

PubMed

Zbojniewicz, Andrew M; Maeder, Matthew E; Emery, Kathleen H; Salisbury, Shelia R

2014-06-01

rotator cuff tears and physeal patency (P > 0.05). Most patients were athletes (76%). Five tears were confirmed at surgery. Poor clinical follow-up limited evaluation of patient outcomes. Rotator cuff tears can be identified during MRI examination of symptomatic child and adolescent shoulders and often consist of tear patterns associated with repetitive microtrauma in overhead athletic activities or with single traumatic events. Rotator cuff tears are seen throughout the range of skeletal maturity, often coexist with labral tears and typically are found in athletes.