scholarly journals Effects of Lipid Saturation on the Surface Properties of Human Meibum Films

2018 ◽  
Vol 19 (8) ◽  
pp. 2209 ◽  
Author(s):  
Yana Nencheva ◽  
Aparna Ramasubramanian ◽  
Petar Eftimov ◽  
Norihiko Yokoi ◽  
Douglas Borchman ◽  
...  
Keyword(s):  
Surface Properties ◽  
Acyl Chain ◽  
Tear Film ◽  
Meibomian Gland ◽  
Film Structure ◽  
Strong Impact ◽  
Heterogeneous Structure ◽  
Brewster Angle Microscopy ◽  
Chain Order ◽  
Compression Isotherms

Elevated levels of acyl chain saturation of meibomian lipids are associated with vastly different effects: from enhanced tear film (TF) stability in infants to shortened TF breakup time in meibomian gland disease patients. Thus it is important to study the effect of saturation on the surface properties of human meibum (MGS). Therefore, MGS films (1, 2, 3, 4, 5, 10, 25, 50, 67, and 100% saturation) were spread at the air/water interface of a Langmuir surface balance. The layers’ capability to reorganize during dynamic area changes was accessed via the surface pressure (π)-area (A) compression isotherms and step/relaxation dilatational rheology studies. Film structure was monitored with Brewster angle microscopy. The raise in the % (at ≥10%) of saturation resulted in the formation of stiffer, thicker, and more elastic films at π ≥ 12 mN/m with the effects being proportional to the saturation level. At the same time, at low (≤10 mN/m) π the raise in saturation resulted in altered spreading and heterogeneous structure of MGS layers. The strong impact of saturation on MGS surface properties correlates with our recent spectroscopy study, which demonstrated that saturation induced increase of MGS acyl chain order, phase transition temperature, and cooperativity.

scholarly journals Lipid Saturation and the Rheology of Human Tear Lipids

2019 ◽  
Vol 20 (14) ◽  
pp. 3431 ◽  
Author(s):  
Georgi As. Georgiev ◽  
Douglas Borchman ◽  
Petar Eftimov ◽  
Norihiko Yokoi
Keyword(s):  
Phase Transition ◽  
Surface Properties ◽  
Acyl Chain ◽  
Tear Film ◽  
Meibomian Gland ◽  
Lipid Phase ◽  
Strong Impact ◽  
Brewster Angle Microscopy ◽  
Lipid Phase Transitions ◽  
Pressure Area

Elevated levels of acyl chain saturation of meibomian lipids are associated with enhanced tear film (TF) stability in infants to shortened TF breakup time with meibomian gland dysfunction. Thus, the effect of saturation on the surface properties of human TF lipids (TFLs) using a Langmuir surface balance and Brewster angle microscopy was studied. Lipid phase transitions were measured using infrared spectroscopy. The raise in the % of saturation resulted in thicker, and more elastic films at π = 12 mN/m, with the effects being proportional to the saturation level. At the same time, at lower (≤10 mN/m) π, the raise in saturation resulted in an altered spreading and modified structure of TFL layers. The strong impact of saturation on TFL surface properties correlated with a saturation induced increase of the TFL acyl chain order, phase transition temperature, and lipid–lipid interactions. The native TFL order and πmax were significantly greater, compared with native meibum collected from the same individual. Aggregation of lipids on the tear surface due to saturation was not as significant as it was for meibum. Although the surface pressure/area isotherms for TFL were similar for meibum, differences in rheology and phase transition parameters warrant the study of both.

Human meibum and tear film derived cholesteryl and wax esters in meibomian gland dysfunction and tear film structure

2021 ◽  
Author(s):  
Safal Khanal ◽  
Yuqiang Bai ◽  
William Ngo ◽  
Kelly K. Nichols ◽  
Landon Wilson ◽  
...  
Keyword(s):  
Tear Film ◽  
Meibomian Gland ◽  
Film Structure ◽  
Wax Esters ◽  
Meibomian Gland Dysfunction

Eyelid Tattooing Induces Meibomian Gland Loss and Tear Film Instability

Cornea ◽  
2015 ◽  
Vol 34 (7) ◽  
pp. 750-755 ◽  
Author(s):  
Young Bok Lee ◽  
Jin Joo Kim ◽  
Joon Young Hyon ◽  
Won Ryang Wee ◽  
Young Joo Shin
Keyword(s):  
Tear Film ◽  
Meibomian Gland ◽  
Film Instability

scholarly journals Image-based quantitative analysis of tear film lipid layer thickness for meibomian gland evaluation

2017 ◽  
Vol 16 (1) ◽  
Author(s):  
Hyeonha Hwang ◽  
Hee-Jae Jeon ◽  
Kin Choong Yow ◽  
Ho Sik Hwang ◽  
EuiHeon Chung
Keyword(s):  
Quantitative Analysis ◽  
Layer Thickness ◽  
Tear Film ◽  
Meibomian Gland ◽  
Lipid Layer

scholarly journals Effects of a New Eyelid Shampoo on Lid Hygiene and Eyelash Length in Patients with Meibomian Gland Dysfunction: A Comparative Open Study

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Asuka Kobayashi ◽  
Takeshi Ide ◽  
Teruki Fukumoto ◽  
Emiko Miki ◽  
Kazuo Tsubota ◽  
...  
Keyword(s):  
Dry Eye ◽  
Tear Film ◽  
Meibomian Gland ◽  
Meibomian Gland Dysfunction ◽  
Controlled Study ◽  
Subjective Symptoms ◽  
Eyelid Margin ◽  
Before And After ◽  
And Function ◽  
Lid Hygiene

Purpose. Meibomian gland dysfunction (MGD) can lead to abnormalities in the composition and function of tear film, resulting in dry eye. Eyelid hygiene is a key to management of MGD. We tested a novel eyelid shampoo (Eye Shampoo Long, ESL) for its ability to maintain lid hygiene. This shampoo is nonirritating and can potentially lengthen eyelashes. This study was aimed to evaluate the efficacy of ESL in the treatment of MGD and its effects on eyelash length. Methods. Ten patients with MGD and 10 healthy subjects without MGD applied ESL twice daily for 8 weeks. Patients were examined for lid margin and dry eye before and after the trial. Subjective symptoms were evaluated. Eyelash length was measured at baseline and at the end of the trial. Results. In the MGD group, significant improvements were observed in subjective symptoms obstruction of the meibomian orifice, secretion of meibum, eyelashes contamination, eyelid margin foam, and SPK. Eyelash length became significantly longer. Conclusions. Maintaining eyelid hygiene using ESL improved the eyelid margins and symptoms of dry eye in MGD patients and increased eyelash length. These findings are promising and warrant confirmation in a larger randomized controlled study.

Structure of Escherichia coli membranes. Fatty acyl chain order parameters of inner and outer membranes and derived liposomes

Biochemistry ◽  
1980 ◽  
Vol 19 (8) ◽  
pp. 1638-1643 ◽  
Author(s):  
Hans Ulrich Gally ◽  
Gerd Pluschke ◽  
Peter Overath ◽  
Joachim Seelig
Keyword(s):  
Escherichia Coli ◽  
Acyl Chain ◽  
Fatty Acyl ◽  
Order Parameters ◽  
Fatty Acyl Chain ◽  
Outer Membranes ◽  
Chain Order

A Fresh Look at Tear Film Structure and Dynamics

2015 ◽  
Vol 93 ◽  
pp. n/a-n/a
Author(s):  
A.J. Bron ◽  
N. Yokoi ◽  
G. Georgiev
Keyword(s):  
Tear Film ◽  
Film Structure ◽  
Structure And Dynamics

scholarly journals Diagnostic Test Efficacy of Meibomian Gland Morphology and Function

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jiaxin Xiao ◽  
Muhammed Yasin Adil ◽  
Jonatan Olafsson ◽  
Xiangjun Chen ◽  
Øygunn A. Utheim ◽  
...  
Keyword(s):  
Dry Eye ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Tear Film ◽  
Cross Sectional Study ◽  
Meibomian Gland ◽  
Clinical Parameters ◽  
Cross Sectional ◽  
And Function ◽  
Breakup Time

AbstractMeibomian gland dysfunction (MGD) is the leading cause of dry eye and proposed treatments are based on disease severity. Our purpose was to establish reliable morphologic measurements of meibomian glands for evaluating MGD severity. This retrospective, cross-sectional study included 100 MGD patients and 20 controls. The patients were classified into dry eye severity level (DESL) 1–4 based on symptoms and clinical parameters including tear-film breakup time, ocular staining and Schirmer I. The gland loss, length, thickness, density and distortion were analyzed. We compared the morphology between patients and controls; examined their correlations to meibum expressibility, quality, and DESL. Relative to controls, the gland thickness, density and distortion were elevated in patients (p < 0.001 for all tests). The area under the receiver operating characteristic curve was 0.98 (95% confidence interval [CI], 0.96–1.0) for gland loss, and 0.96 (CI 0.91–1.0) for gland distortion, with a cutoff value of six distorted glands yielding a sensitivity of 93% and specificity of 97% for MGD diagnosis. The gland distortion was negatively correlated to the meibum expressibility (r = −0.53; p < 0.001) and DESL (r = −0.22, p = 0.018). In conclusion, evaluation of meibomian gland loss and distortion are valuable complementary clinical parameters to assess MGD status.

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