Interferometric Studies of the Fluid Dynamics of the Tear Film

泪膜流体动力学的干涉研究

• 批准号: 8318777
• 负责人: PETER E KING-SMITH
• 金额: $ 28.99万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8318777
• 关键词: Air; Air Conditioning; Area; Blinking; Characteristics; Clinical; Controlled Environment; Cornea; Disease; Dry Eye Syndromes; Film; Fluorescein; Fluorescence; Goals; Goggles; Health; Humidity; Image; Laboratories; Lipids; Liquid substance; Measurement; Measures; Meniscus structure of joint; Methods; Osmolar Concentration; Patients; Pattern; Phospholipids; Positioning Attribute; Process; Relative (related person); Reporting; Research; Resolution; Role; Sampling; Speed; Spottings; Staining method; Stains; Stress; Surface; Syndrome; System; Temperature; Testing; Thick; Time; Video Recording; Vision Disorders; aqueous; evaporation; eye dryness; falls; fluorescence imaging; meibomian gland; meibomian gland dysfunction; ocular surface; programs; research study; water diffusion

DESCRIPTION (provided by applicant): The long term goal of this research program is to analyze the tear dynamics and characteristics which are involved in tear film thinning between blinks, and the consequent ocular surface damage in meibomian gland dysfunction (MGD) and other dry eye conditions. Our laboratory has developed a unique method for measuring tear film thickness and tear thinning rate between blinks. Tear thinning could be caused either by evaporation or by divergent "tangential flow" of tears along the corneal surface. Evaporative thinning would cause an increase in local osmolarity, leading to ocular surface damage from hyperosmolar stress. Divergent tangential flow could cause ocular surface damage by generating breakup (dry spots) without increase in osmolarity. In this study, the relative contributions of evaporation and divergent tangential flow will be studied to evaluate the role of hyperosmolarity and dry spot formation in ocular surface damage. Because preliminary studies indicate that evaporation is generally more important than divergent tangential flow, external factors controlling evaporation rate will also be investigated. A "controlled environment goggle" will be constructed to control humidity and air flow rate over the cornea. Both evaporation rate and tear thinning rate will be measured in conditions of low and high humidity, and of low and high air flow speed. The phenomenon of fluorescence "quenching" (reduction of fluorescent efficiency at high concentrations of fluorescein) will also be used to study the effects of evaporation. If tear film thinning is due to evaporation rather than tangential flow, the amount of fluorescein per unit area should remain constant and there should be little change in fluorescence for low concentrations of fluorescein; for high concentrations, however, quenching will cause a marked fall in fluorescence as the tear film thins and concentration increases. Using these principles, fluorescence measurements will be used to study how evaporation contributes to tear thinning rate and to fluorescein breakup times. Evaporation is limited by diffusion of water through the lipid layer of the tear film. To study the relation between tear thinning rate and lipid thickness, they will be measured simultaneously, using a lipid thickness method unique to our laboratory. Additionally, high resolution images of the lipid layer will be obtained to give information about the spatial variability of the lipid layer, and its contribution to tear film thinning. The relation of fluorescent (breakup) images to simultaneous lipid interference images will also be studied. An effective lipid barrier to evaporation is thought to require enough phospholipid to form a good interface between polar lipids and the aqueous layer, so meibomian lipid samples will be collected to analyze phospholipid concentration. In these studies, patients with MGD will be compared to normals in terms of tear thinning rate, lipid thickness and its spatial variability, and phospholipid concentration. An ultimate aim of these studies is therefore to help characterize tear film and external factors which cause ocular surface damage in MGD. PUBLIC HEALTH RELEVANCE: Dry Eye Syndrome is a common visual disorder which is poorly understood. This project will investigate the role of both evaporation and tear flow along the corneal surface in causing the ocular surface damage in this syndrome. Additionally, the characteristics of the lipid layer which may be deficient in Dry Eye will be investigated.

描述（由申请人提供）：该研究项目的长期目标是分析眨眼之间泪膜变薄所涉及的泪液动力学和特征，以及睑板腺功能障碍（MGD）和其他干眼症中随之而来的眼表损伤。我们的实验室开发了一种独特的方法来测量眨眼之间的泪膜厚度和泪液变薄率。泪液变薄可能是由于蒸发或泪液沿着角膜表​​面发散的“切向流”引起的。蒸发变薄会导致局部渗透压增加，导致高渗应激导致眼表损伤。发散的切向流可能会在不增加渗透压的情况下产生破裂（干斑），从而导致眼表损伤。在本研究中，将研究蒸发和发散切向流的相对贡献，以评估高渗透压和干斑形成在眼表损伤中的作用。由于初步研究表明蒸发通常比发散切向流更重要，因此还将研究控制蒸发速率的外部因素。将建造一个“受控环境护目镜”来控制角膜上的湿度和空气流速。蒸发率和泪液稀化率都将在低湿度和高湿度、低空气流速和高空气流速的条件下测量。荧光“猝灭”现象（高浓度荧光素下荧光效率降低）也将用于研究蒸发的影响。如果泪膜变薄是由于蒸发而不是切向流，则单位面积的荧光素量应保持恒定，并且对于低浓度的荧光素，荧光应几乎没有变化；然而，对于高浓度，随着泪膜变薄和浓度增加，猝灭将导致荧光显着下降。利用这些原理，荧光测量将用于研究蒸发如何影响泪液稀释率和荧光素破裂时间。水通过泪膜脂质层的扩散限制了蒸发。为了研究泪液稀释率和脂质厚度之间的关系，将使用我们实验室独有的脂质厚度方法同时测量它们。此外，还将获得脂质层的高分辨率图像，以提供有关脂质层的空间变异性及其对泪膜变薄的贡献的信息。还将研究荧光（分解）图像与同时脂质干扰图像的关系。有效的脂质蒸发屏障被认为需要足够的磷脂以在极性脂质和水层之间形成良好的界面，因此将收集睑板脂质样品来分析磷脂浓度。在这些研究中，MGD 患者与正常人在泪液变薄率、脂质厚度及其空间变异性以及磷脂浓度方面进行比较。因此，这些研究的最终目的是帮助表征 MGD 中导致眼表损伤的泪膜和外部因素。公众健康相关性：干眼综合症是一种常见的视觉障碍，但人们对其知之甚少。该项目将研究沿着角膜表​​面的蒸发和泪液流动在导致该综合征的眼表损伤中的作用。此外，还将研究干眼症中可能缺乏的脂质层的特征。

项目成果

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

计算眼形域上的泪膜和渗透压动态。

• DOI: 10.1093/imammb/dqv013
• 发表时间: 2016
• 期刊: Mathematical medicine and biology : a journal of the IMA
• 作者: Li,Longfei;Braun,RichardJ;Driscoll,TobinA;Henshaw,WilliamD;Banks,JeffreyW;King-Smith,PEwen
• 通讯作者: King-Smith,PEwen

Mathematical modelling of glob-driven tear film breakup.

球驱动泪膜破裂的数学模型。

• DOI: 10.1093/imammb/dqx021
• 发表时间: 2019
• 期刊: Mathematical medicine and biology : a journal of the IMA
• 作者: Zhong,L;Ketelaar,CF;Braun,RJ;Begley,CG;King-Smith,PE
• 通讯作者: King-Smith,PE

Analysis of Comparison of Human Meibomian Lipid Films and Mixtures with Cholesteryl Esters In Vitro Films using High Resolution Color Microscopy.

使用高分辨率彩色显微镜分析体外人睑板腺脂质膜和胆固醇酯混合物的比较。

• DOI: 10.1167/iovs.12-10022
• 发表时间: 2012
• 期刊: Investigative ophthalmology & visual science
• 影响因子: 4.4
• 作者: Millar,ThomasJ;King-Smith,PEwen
• 通讯作者: King-Smith,PEwen

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

• DOI: 10.1016/j.preteyeres.2014.11.001
• 发表时间: 2015-03
• 期刊: PROGRESS IN RETINAL AND EYE RESEARCH
• 影响因子: 17.8
• 作者: Braun, R. J.;King-Smith, P. E.;Begley, C. G.;Li, Longfei;Gewecke, N. R.
• 通讯作者: Gewecke, N. R.

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

眼形域上具有蒸发、润湿和时间依赖性通量边界条件的泪膜动力学。

• DOI: 10.1063/1.4871714
• 发表时间: 2014
• 期刊: Physics of fluids (Woodbury, N.Y. : 1994)
• 作者: Li,Longfei;Braun,RJ;Maki,KL;Henshaw,WD;King-Smith,PE
• 通讯作者: King-Smith,PE