The 124 study subjects comprised 36 patients diagnosed with obstructive MGD at the University of Tokyo and Itoh Clinic and 88 normal volunteers (72 men and 52 women; mean±SD aged 38.1±14.4 years, range 20–80). The characteristics of the subjects are shown in table 1 . The diagnosis of MGD was based on the presence of ocular symptoms, lid margin abnormalities (irregular lid margin, vascular engorgement, plugged meibomian gland orifices and antero- or postero- replacement of the mucocutaneous junction) and poor meibum expression even with hard digital pressure. The subjects included 80 eyelids of 42 subjects without meibomian gland loss on visual inspection of images (meiboscore=0), 104 eyelids of 57 patients with meibomian gland area loss of less than one-third of the total area (meiboscore=1), 26 eyelids of 11 patients with meibomian gland area loss between one-third and two-thirds of the total area (meiboscore=2) and 23 eyelids of 14 patients with meibomian gland area loss of more than two-thirds of the total area (meiboscore=3). Exclusion criteria included ocular allergies, contact lens wear, continuous eyedrop use, history of eye surgery and systemic or ocular diseases that might interfere with tear film production or function. Patients whose eyes exhibited excessive meibomian lipid secretion were also excluded. Images that were not sufficiently clear for automatic analysis were excluded. The exclusion criteria for the images included out of focus images and images that included something other than the eyelids and their surrounding tissues.
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Meibum
Meibum
Meibum is the lipid-rich secretion produced by the meibomian glands, located within the eyelids.
This complex mixture of lipids, proteins, and other substances plays a crucial role in maintaining the stability and integrity of the tear film, which is essential for healthy eyes and vision.
Understanding the composition, function, and regulation of meibum is a vital area of research for ophthalmologists and vision scientists, as disruptions in meibum production or quality can contribute to conditions like dry eye disease.
PubCompare.ai's AI-powered platform can help researchers optimize their meibum studies by easily identifying the most effective protocols, pre-prints, and patents, as well as the most promising products and procedures to advance this important field of ophthalmic reasearch.
This complex mixture of lipids, proteins, and other substances plays a crucial role in maintaining the stability and integrity of the tear film, which is essential for healthy eyes and vision.
Understanding the composition, function, and regulation of meibum is a vital area of research for ophthalmologists and vision scientists, as disruptions in meibum production or quality can contribute to conditions like dry eye disease.
PubCompare.ai's AI-powered platform can help researchers optimize their meibum studies by easily identifying the most effective protocols, pre-prints, and patents, as well as the most promising products and procedures to advance this important field of ophthalmic reasearch.
Most cited protocols related to «Meibum»
Blood Vessel
Congenital Abnormality
Contact Lenses
Diagnosis
Eye
Eyelids
Fingers
Hyperemia
Hypersensitivity
Meibomian Glands
Meibum
Normal Volunteers
Ophthalmic Solution
Ophthalmologic Surgical Procedures
Patients
Pressure
secretion
Tears
Tissues
Vision
Woman
1-Propanol
Acetic Acid
Capillaries
High-Performance Liquid Chromatographies
Ions
Lipids
Meibum
n-hexane
Nitrogen
Solvents
Vaporizers
The transcriptomic datasets were processed using Expression and Transcriptome Analysis Consoles (v.4.0.1.36; both from Affymetrix) and SigmaStat (v.3.5, from Systat Software, Inc., San Jose, CA, USA). The default (and currently the industry standard) filter criteria: (1) (+2) < LFC < (−2), and (2) ANOVA p-value (condition pair) ≤0.05, were used to analyze the data. A tighter LFC of >(+1.2) and <(−1.2), as proposed in [34 (link)], was also tested, but deemed impractical because of an unrealistically high number of samples needed to satisfy statistical criteria (see Discussion).
The RP-UPLC/MS data were analyzed using MassLynx (v.4.1), MSe Data Viewer (v.1.4), and Progenesis QI software packages (from Waters). ASupplemental Table S1 lists major lipids of human meibum relevant to this study, and their corresponding m/z values. SigmaStat and SigmaPlot software packages from Systat Software, Inc. were used to conduct statistical evaluation of the data.
The transcriptomic and lipidomic data for two genders were compared gender-wide using Student’s t-test for the two groups. Tests with p-values ≤ 0.05 were considered statistically significant. Principal component analyses were performed using Transcriptome Analysis Console, Progenesis QI, and EZInfo (v.3.0.3.0 from Umetrics AB, Umeå, Sweden).
The RP-UPLC/MS data were analyzed using MassLynx (v.4.1), MSe Data Viewer (v.1.4), and Progenesis QI software packages (from Waters). A
The transcriptomic and lipidomic data for two genders were compared gender-wide using Student’s t-test for the two groups. Tests with p-values ≤ 0.05 were considered statistically significant. Principal component analyses were performed using Transcriptome Analysis Console, Progenesis QI, and EZInfo (v.3.0.3.0 from Umetrics AB, Umeå, Sweden).
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Gene Expression Profiling
Homo sapiens
Lipids
Meibum
neuro-oncological ventral antigen 2, human
Student
Biological Assay
Lipids
Meibum
Mucins
Phosphoric Acids
Proteins
sulfuric acid
vanillin
Clinical assessments were performed sequentially as follows: symptom questionnaires, tear meniscus height (TMH), tear break-up time (TBUT), corneal fluorescein staining (CFS), lid margin abnormality, MG expressibility, and meibography. All of the subjects completed the Ocular Surface Disease Index (OSDI) questionnaire, and they were asked whether they had any of the 14 MGD-related ocular symptoms.10 (link)
The Keratograph 5M (K5M; Oculus, Wetzlar, Germany) was used to measure TMH and to perform the meibography scans. TMH was measured 5 seconds after blinking, and we measured the central TMH of the lower eyelid. TBUT was measured and CFS was performed after the instillation of fluorescein. TBUT was measured three times, and the mean value was recorded. CFS was graded using the Baylor grading scheme from 0 to 4.11 (link) Lid margin abnormalities were scored from 0 through 4 according to the following four parameters: anterior or posterior displacement of the mucocutaneous junction, vascular engorgement, plugged meibomian gland orifices, and irregularity of the lid margin. We assessed the meibum quality and quantity of the 15 glands on each lower eyelid. The MG expressibility score ranged from 0 to 45.12 (link),13 (link)
Images of both the upper and lower MGs were captured by the K5M. To assess the degree of MG atrophy, we used the method described by Arita et al.14 (link) to calculate the meiboscore: 0, no atrophy; 1, atrophy of <1/3 of the total lid area; 2, atrophy of 1/3 to 2/3 of the total lid area; and 3, atrophy of >2/3 of the total lid area. The meiboscore results ranged from 0 to 6.
Parameters including MG density and MG tortuosity were calculated from the meibography images. We further analyzed the images using VIA 3 software (http://www.robots.ox.ac.uk/∼vgg/software/via/ ).15 First, we created a grid over the whole tarsus of the eyelid and then marked out the boundaries of each MG point by point. These points were then transformed into pixel coordinates for further analysis. MG density was defined as the ratio of the sum of the area of MGs to the total area of the tarsus:
This study defined MG tortuosity as the ratio of the imaginary straight length between the two nodes and the actual length of each MG. A similar method was used previously to measure the vessel tortuosity of the retina.16 (link) MG tortuosity was calculated as follows:
The MG perimeter was the pixels at the edge of the MG. As the width of each MG was small, we used half of the MG perimeter to represent the actual length of the MG. Also, because the outlines of MGs are irregular and some MGs are tilted, the minimum external rectangle was used as the outline of the MG, and its height was calculated as the imaginary straight length (Fig. 1 G). To start MG tortuosity at 0, the ratio minus 1 was recorded.
The Keratograph 5M (K5M; Oculus, Wetzlar, Germany) was used to measure TMH and to perform the meibography scans. TMH was measured 5 seconds after blinking, and we measured the central TMH of the lower eyelid. TBUT was measured and CFS was performed after the instillation of fluorescein. TBUT was measured three times, and the mean value was recorded. CFS was graded using the Baylor grading scheme from 0 to 4.11 (link) Lid margin abnormalities were scored from 0 through 4 according to the following four parameters: anterior or posterior displacement of the mucocutaneous junction, vascular engorgement, plugged meibomian gland orifices, and irregularity of the lid margin. We assessed the meibum quality and quantity of the 15 glands on each lower eyelid. The MG expressibility score ranged from 0 to 45.12 (link),13 (link)
Images of both the upper and lower MGs were captured by the K5M. To assess the degree of MG atrophy, we used the method described by Arita et al.14 (link) to calculate the meiboscore: 0, no atrophy; 1, atrophy of <1/3 of the total lid area; 2, atrophy of 1/3 to 2/3 of the total lid area; and 3, atrophy of >2/3 of the total lid area. The meiboscore results ranged from 0 to 6.
Parameters including MG density and MG tortuosity were calculated from the meibography images. We further analyzed the images using VIA 3 software (
This study defined MG tortuosity as the ratio of the imaginary straight length between the two nodes and the actual length of each MG. A similar method was used previously to measure the vessel tortuosity of the retina.16 (link) MG tortuosity was calculated as follows:
The MG perimeter was the pixels at the edge of the MG. As the width of each MG was small, we used half of the MG perimeter to represent the actual length of the MG. Also, because the outlines of MGs are irregular and some MGs are tilted, the minimum external rectangle was used as the outline of the MG, and its height was calculated as the imaginary straight length (
Ankle
Atrophy
Blood Vessel
Congenital Abnormality
Cornea
Eye
Eyelids
Hyperemia
Meibomian Glands
Meibum
Meniscus
Neoplasm Metastasis
Perimetry
Radionuclide Imaging
Retinal Vessels
Tears
Most recents protocols related to «Meibum»
Conjunctival hyperemia was assessed using the Cornea and Contact Lens Research Unit (CCLRU) grading scale, which was scored from 0 to 4 (0—absent, 1—very slight, 2—slight, 3—moderate and 4—severe) [41 (link)].
LIPCOF was assessed in the lower lateral quadrant of the bulbar conjunctiva, parallel to the lower lid margin, without fluorescein, and graded on a scale from 0 to 3 (0—no conjunctival folds, 1—one permanent and clear parallel fold, 2—two permanent and clear parallel folds and 3—more than two permanent and clear parallel folds) [42 (link)].
TBUT was measured using standardized fluorescein strips (Biotech, Minneapolis, MN, USA, Fluorescein Sodium Ophthalmic Strip USP). Three consecutive TBUT measurements were performed first on the left eye and then on the right eye [5 (link)].
Fluorescein corneal staining was assessed using National Eye Institute/Industry Workshop (NEI) scale [38 (link)]. According to that scale, the cornea was divided into five zones: central, upper, lower, nasal and temporal; the staining intensity was graded from 0 (absent) to 3 (severe) in each zone based on the amount, size and confluence of the punctate keratitis. The maximum score is 15.
Meibomian gland assessment was performed after MGX on the lower eyelid of both eyes after other dry eye tests to obtain them unaffected by MGX. Korb’s description of the digital expression of Meibomian glands was used [43 ]. Meibum quantity (MG expressibility) was assessed according to the scale: 3—most MG ducts secrete a clear meibum under-expression; 2—about half of the excretory MG ducts secrete meibum, the secretion is scarce; 1—a few ducts secrete meibum, barely visible secretion; 0—there is no visible MG secretion after the expression. Meibum quality was assessed according to the scale: 4—clear; 3—cloudy; 2—cloudy with debris (granular); 1—toothpaste-like.
LIPCOF was assessed in the lower lateral quadrant of the bulbar conjunctiva, parallel to the lower lid margin, without fluorescein, and graded on a scale from 0 to 3 (0—no conjunctival folds, 1—one permanent and clear parallel fold, 2—two permanent and clear parallel folds and 3—more than two permanent and clear parallel folds) [42 (link)].
TBUT was measured using standardized fluorescein strips (Biotech, Minneapolis, MN, USA, Fluorescein Sodium Ophthalmic Strip USP). Three consecutive TBUT measurements were performed first on the left eye and then on the right eye [5 (link)].
Fluorescein corneal staining was assessed using National Eye Institute/Industry Workshop (NEI) scale [38 (link)]. According to that scale, the cornea was divided into five zones: central, upper, lower, nasal and temporal; the staining intensity was graded from 0 (absent) to 3 (severe) in each zone based on the amount, size and confluence of the punctate keratitis. The maximum score is 15.
Meibomian gland assessment was performed after MGX on the lower eyelid of both eyes after other dry eye tests to obtain them unaffected by MGX. Korb’s description of the digital expression of Meibomian glands was used [43 ]. Meibum quantity (MG expressibility) was assessed according to the scale: 3—most MG ducts secrete a clear meibum under-expression; 2—about half of the excretory MG ducts secrete meibum, the secretion is scarce; 1—a few ducts secrete meibum, barely visible secretion; 0—there is no visible MG secretion after the expression. Meibum quality was assessed according to the scale: 4—clear; 3—cloudy; 2—cloudy with debris (granular); 1—toothpaste-like.
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Conjunctiva
Conjunctiva, Bulbar
Contact Lenses
Cornea
Dry Eye
Eye
Eyelids
Fingers
Fluorescein
Hyperemia
Keratitis
Meibomian Glands
Meibum
Nose
secretion
Sodium Fluorescein
Toothpaste
All individuals underwent a tear film assessment, including the measurement of (1) matrix metallopeptidase 9 (MMP-9) (Inflammadry, Quidel, San Diego, CA, USA), qualitatively graded on a scale of 0–3 based on the intensity of the pink stripe (1, none; 2, faint pink; 3, fuchsia); (2) assessment of upper and lower eyelid laxity determined by the snap back test (scale 0–2); (3) anterior blepharitis graded on a scale of 0–3 (0, none; 1, mild; 2, moderate; 3, severe); (4) eyelid vascularity graded on a scale of 0–3 (0, none; 1, mild engorgement; 2, moderate engorgement; 3, severe engorgement); (5) inferior meibomian gland plugging graded on a scale 0–3 (0, none; 1, less than 1/3 lid involvement; 2, between 1/3 and 2/3 lid involvement; 3, greater than 2/3 lid involvement); (6) lower eyelid Meibomian gland [1 (link)] dropout graded via the Meiboscale, 0–4; (7) papillary changes graded on a scale of 0–2 (0, none; 1, mild; 2, severe); (8) conjunctivochalasis graded as absent or present in each area of the lower eyelid (temporal, central, and nasal) based on the obliteration of the tear film by conjunctivae in the region of interest, scale 0–3; (9) tear stability measured via tear breakup time (TBUT) (5 µL fluorescein placed, three measurements taken in each eye and averaged), lower times indicate more tear instability; (10) corneal epithelial cell disruption measured via corneal staining (National Eye Institute (NEI) scale, five areas of cornea assessed (score 0–4 in each, and total 15)), higher levels indicate more disruption; (11) anesthetized Schirmer’s, mm wetting at 5 min, lower levels indicate decreased tear production; and (12) meibum quality assessed on a scale of 0 to 4 (0, clear; 1, cloudy; 2, granular; 3, toothpaste; 4, no meibum extracted).
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Blepharitis
Blood Vessel
Conjunctiva
Cornea
Epithelial Cells
Eyelids
Fluorescein
Hyperemia
Matrix Metalloproteinases
Meibomian Glands
Meibum
Nose
Syncope
Tears
Toothpaste
All measurements were obtained between 9 and 11 a.m. to eliminate the effect of diurnal variation. The ambient conditions of the examination room were kept relatively constant, with temperatures ranging from 22–28 °C and a relative humidity of 40–50%. The following examinations were performed sequentially: ocular surface disease index questionnaire, Keratograph 5 M examination, tear break-up time, corneal fluorescein staining, eyelid margins, meibomian gland orifices, meibomian gland secretion expressibility, meibum quality, and Schirmer I test.
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Circadian Rhythms
Cornea
Eye
Eyelids
Humidity
Meibomian Glands
Meibum
Physical Examination
secretion
Tears
Meibomian gland expression was examined using slit-lamp biomicroscopy. meibomian gland secretion expressibility was evaluated by applying digital pressure over 5 meibomian glands at the center of the upper eyelid [23 (link)]. The number of meibomian glands from which meibum could be expressed was scored from 0 to 3: 0, all 5 meibomian glands; 1, 3–4 meibomian glands; 2, 1–2 meibomian glands; and 3, 0 meibomian glands. Meibum quality [24 (link)] of the eight central meibomian glands in the upper and lower eyelid was assessed and scored on a scale of 0 to 3: 0, clear; 1, cloudy; 2, cloudy with debris; and 3, inspissated.
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Eyelids
Fingers
Meibomian Glands
Meibum
Pressure
secretion
Slit Lamp Examination
MGs secrete meibum, which contains components of the lipid layer of the tear film. The quality of meibum was assessed for the upper and lower eyelids according to the grading schemes: 0, clear (normal); 1, cloudy; 2, cloudy with particles; and 3, inspissated (like toothpaste). A score was recorded only the highest grade encountered from any of central eight glands, and the score range was 0 to 3 [14 (link)].
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Eyelids
Lipids
Meibum
Tears
Toothpaste
Top products related to «Meibum»
Sourced in Germany, United States
The Keratograph 5M is a medical device designed for corneal topography and anterior segment analysis. It utilizes advanced imaging technology to capture comprehensive data about the surface of the eye. The Keratograph 5M provides detailed information about the curvature and shape of the cornea, which is essential for various ophthalmic applications and procedures.
Sourced in United States
InflammaDry is a rapid in-vitro diagnostic test that detects the presence of matrix metalloproteinase-9 (MMP-9), an inflammatory marker, in human tear fluid. The test is designed to provide a qualitative result indicating the presence or absence of MMP-9 in the sample.
Sourced in Japan, China, United States
Oxybuprocaine hydrochloride eye drops is a topical anesthetic solution used to numb the surface of the eye. It contains the active ingredient oxybuprocaine hydrochloride, which works by blocking the transmission of pain signals from the eye to the brain.
Sourced in United States
The LipiView interferometer is a diagnostic device used to measure the thickness of the tear film on the eye. It utilizes interferometry, a technique that analyzes the interference patterns created by the reflection of light from the tear film. The LipiView provides objective data about the tear film, which can be used by eye care professionals to assess and manage various ocular surface conditions.
Sourced in United States, Japan, United Kingdom, Germany, Belgium, Australia, Spain, Switzerland
SPSS Statistics version 22 is a statistical software application developed by IBM. It is designed to analyze and manipulate data, providing users with tools for data management, statistical analysis, and reporting. The software supports a wide range of data types and offers a variety of statistical procedures, enabling users to explore relationships, test hypotheses, and generate insights from their data.
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The LockSpray unit is a component of a mass spectrometry system designed to facilitate sample introduction and ionization. Its core function is to deliver a consistent and stable spray of the sample into the mass spectrometer for analysis.
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The Acquity UPLC BEH C18 column is a reversed-phase liquid chromatography column designed for ultra-high-performance liquid chromatography (UPLC) applications. The column features a sub-2 μm bridged ethylene hybrid (BEH) particle technology that provides efficient and high-resolution separations.
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SPSS 24.0 is a statistical software package developed by IBM. It provides data management, analysis, and reporting capabilities. The software is designed to handle a wide range of data types and is commonly used for social science research, market research, and business analytics.
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The TriVersa NanoMate is a robotic nanoelectrospray system designed for automated sample introduction and ionization in mass spectrometry applications. The device features a multi-channel pipetting robot and integrated nanoelectrospray chips to enable precise, high-throughput sample handling and ionization.
Sourced in Sweden
Progenesis QI is a software solution for comprehensive label-free quantitative proteomics analysis. It provides advanced data processing, statistical analysis, and visualization tools to enable robust and reliable protein quantification from mass spectrometry data.
More about "Meibum"
Meibum is a complex, lipid-rich secretion produced by the meibomian glands, which are located within the eyelids.
This vital substance plays a crucial role in maintaining the stability and integrity of the tear film, which is essential for healthy eyes and optimal vision.
Understanding the composition, function, and regulation of meibum is a key area of research for ophthalmologists and vision scientists, as disruptions in meibum production or quality can contribute to conditions like dry eye disease.
Researchers studying meibum can utilize advanced tools and techniques to optimize their investigations.
The Keratograph 5M, for example, is a non-invasive imaging device that can provide detailed information about the tear film and meibomian gland function.
The InflammaDry test, on the other hand, can help detect elevated levels of the inflammatory marker MMP-9, which may be associated with meibomian gland dysfunction.
In terms of pharmaceutical interventions, Oxybuprocaine hydrochloride eye drops can be used to anesthetize the eye, facilitating the collection of meibum samples for analysis.
The LipiView interferometer is another valuable tool that can measure the thickness and quality of the lipid layer within the tear film, providing insights into meibum composition and function.
When analyzing meibum samples, researchers may utilize statistical software like SPSS Statistics version 22 or SPSS 24.0 to perform advanced data analysis.
The LockSpray unit can be used in conjunction with an Acquity UPLC BEH C18 column to separate and identify the various lipid components of meibum using liquid chromatography-mass spectrometry (LC-MS) techniques.
Furthermore, the TriVersa NanoMate, a robotic nanoelectrospray system, can enable high-throughput analysis of meibum samples, while Progenesis QI software can facilitate the identification and quantification of meibum lipids and other biomolecules.
By leveraging these cutting-edge tools and techniques, researchers can optimize their meibum studies, leading to a better understanding of this vital secretion and the development of improved treatments for conditions related to meibomian gland dysfunction and tear film instability.
This vital substance plays a crucial role in maintaining the stability and integrity of the tear film, which is essential for healthy eyes and optimal vision.
Understanding the composition, function, and regulation of meibum is a key area of research for ophthalmologists and vision scientists, as disruptions in meibum production or quality can contribute to conditions like dry eye disease.
Researchers studying meibum can utilize advanced tools and techniques to optimize their investigations.
The Keratograph 5M, for example, is a non-invasive imaging device that can provide detailed information about the tear film and meibomian gland function.
The InflammaDry test, on the other hand, can help detect elevated levels of the inflammatory marker MMP-9, which may be associated with meibomian gland dysfunction.
In terms of pharmaceutical interventions, Oxybuprocaine hydrochloride eye drops can be used to anesthetize the eye, facilitating the collection of meibum samples for analysis.
The LipiView interferometer is another valuable tool that can measure the thickness and quality of the lipid layer within the tear film, providing insights into meibum composition and function.
When analyzing meibum samples, researchers may utilize statistical software like SPSS Statistics version 22 or SPSS 24.0 to perform advanced data analysis.
The LockSpray unit can be used in conjunction with an Acquity UPLC BEH C18 column to separate and identify the various lipid components of meibum using liquid chromatography-mass spectrometry (LC-MS) techniques.
Furthermore, the TriVersa NanoMate, a robotic nanoelectrospray system, can enable high-throughput analysis of meibum samples, while Progenesis QI software can facilitate the identification and quantification of meibum lipids and other biomolecules.
By leveraging these cutting-edge tools and techniques, researchers can optimize their meibum studies, leading to a better understanding of this vital secretion and the development of improved treatments for conditions related to meibomian gland dysfunction and tear film instability.