Name: trabecular meshwork response to pressure elevation in the living human eye
Uploaded: 2015-06-20T14:00:00.000+00:00
Duration: 9 min 3 s
Description: Watch this Scientific Journal Video about Trabecular Meshwork Response to Pressure Elevation in the Living Human Eye at JoVE.com

Supported in part by National Institute of Health contracts R01-EY13178, and P30-EY08098 (Bethesda, MD), the Eye and Ear Foundation (Pittsburgh, PA), and unrestricted grants from Research to Prevent Blindness (New York, NY).

伦理声明:批准从医学匹兹堡大学的大学机构审查委员会获得的对象招募开始之前。参与研究之前提供所有受试者签署知情同意书。 1.数据采集<ol><li>压力上升<ol><li>取基线测量（眼压和OCT测量）灌输一滴0.5％丙美卡因的入眼睛。等待3分钟的疗效。 </li><li>轻轻施加压力的时间巩膜与ophthalmodynamometer，将30g在第1组，和5，然后用10克队列2。然后取所需的（眼压及OCT）测量如下<ol><li>眼压测量<ol><li>测量基线眼压。如第1.1节所述升高的压力。 </li><li>在第1组灌输一滴0.5％丙美卡因的，允许3分钟为疗效，并应用将30克的压力来巩膜。当压力被应用，测量眼压使用眼压计厂家专业如下cturer的说明。 </li><li>在第2组，灌输一滴0.5％丙美卡因的，允许3分钟为疗效，并使用ophthalmodynamometer申请将5g巩膜压力。期间使用眼压计根据制造商的说明压力上升测量眼压。 <ol><li>等待5克测定后5分钟。 </li><li>应用将10克巩膜压力ophthalmodynamometer，并使用以下制造商的说明在眼压计中压力上升测量眼压。记录在研究记录中的IOP和条件（ 即基准或10克）。 </li></ol></li></ol></li><li>华侨城扫描<ol><li>座位在OCT扫描仪的主题。输入病人的人口统计数据为新的科目，或者从先前扫描的科目华侨城数据库回忆人口统计数据。 </li><li>选择的前部部分512×128的扫描协议。居中眼在视频图像的窗口。降低扫描器之间的距离和眼睛直到角膜断层图像显示在扫描窗口</li><li>利用口头指令通过引导病人注视在鼻方向定位颞缘到扫描窗口的中心</li><li>获得基线扫描，并查看质量扫描。如果可以接受，保存，如果不能接受，重复此步骤。 <ol><li>接受扫描如果没有闪烁，并且角度被可视化在整个体积而不漂流断图像的边缘或翻转顶部。 </li></ol></li><li>灌输一滴0.5％丙美卡因的，允许3分钟的疗效，并重复步骤1.3.2至1.3.5。 </li><li>为1组，应用将30克巩膜压力ophthalmodynamometer，并获得扫描的同时施加压力的状态。卸下压力和审查质量的扫描。如果可以接受，保存，如果不能接受，重复此步骤。 </li><li>对于队列2，加5克巩膜压力ophthalmodynamomETER，并且获得在扫描的同时施加压力的状态。卸下压力和审查质量的扫描。如果可以接受，保存，如果不能接受，重复此步骤。 </li><li>等待5分钟，让眼睛从5克压力扰动中恢复过来。 </li><li>为第2组，应用将10克巩膜压力ophthalmodynamometer，并获得扫描的同时施加压力的状态。卸下压力和审查质量的扫描。如果可以接受，保存，如果不能接受，重复此步骤。 </li><li>记录扫描时间，条件在研究记录（ 即，基线或10克）和位置。 </li></ol></li></ol></li></ol></li></ol> 2.数据处理<ol><li>插头的高容量的USB存储设备插入十月从华侨城记录菜单中选择" 导出 "。指定一个文件位置为USB驱动器上的导出文件。取消选择".ZIP"选项。输入SC患者姓名答要出口，并选择扫描出口。启动出口。 </li><li>当导出完成后，卸载USB驱动器，并从华侨城删除。请将包含导出图像到图像处理工作站的高容量USB驱动器。 </li><li>在这种情况下的ImageJ推出的图像处理程序。 </li><li>导入原始图像数据;选择" 文件- &gt;导入- &gt;原始 "从文件菜单中。选择与结尾的"_cube_raw.img"被从USB驱动器处理的文件。 </li><li>保存使用新名称导入的文件，使原来的图象数据被保存不变（http://www.ori.dhhs.gov/education/products/RIandImages）。 </li><li>进入导入参数如下，图片类型:8位，宽度:512，高度:1,024偏移:0;图片数:128。 </li><li>从插件菜单中选择"&gt; StackReg插件- - &gt;研究egistration"。然后选择" 刚体"选项。然后选择" 文件- &gt;另存为- &gt; TIFF"保存对齐堆栈。 </li><li>选择" 过程- &gt;过滤器- &gt; 3D平均 "从过程菜单。输入参数X = 1，Y = 1和Z = 1作为过滤器选项。重复此步骤两次。 </li><li>选择" 文件- &gt;另存为- &gt; TIFF"，保存平均堆栈。旋转鼠标滚轮移动到活动的堆栈帧1。 </li><li>选择" 过程- &gt;增强局部对比度（CLAHE）"，从处理菜单。使用参数块大小:31，直方图箱:256，最大坡度:5，面膜:没有，勾选"快速"选项。使用右箭头键前进到下一帧。 </li><li>移动到活动堆栈帧2和重复流程 - &gt;增强局部对比度（CLAHE）。重复，直到所有的帧有对比增强。 </li><li>选择" 文件- &gt;另存为- &gt; TIFF";保存对比增强栈。然后选择" 图像- &gt;调整- &gt;大小 "从图像菜单。取消选择" 约束纵横比 "选项，然后输入宽:2048，高:1024值。 </li><li>选择" 图像- &gt;变换- &gt;垂直翻转 "从图像菜单。然后选择" 分析- &gt;设置比例 "，从分析菜单。以像素为单位输入距离:2048，已知的距离:4000，而像素长宽比:1，然后单击确定。选择" 文件- &gt;另存为- &gt; TIFF"，保存校准1:1宽高比堆栈。 </li><li>慢慢转动鼠标滚轮来直观地检查扫描，以确定一个鲜明的船只穿越作为一个点的扫描范围内引用。记录在分析电子表格中的图像数目和参考帧号。 </li><li>按左方向键15次赴第一次测量框架。选择"写意SelectionsR21;从工具栏。 </li><li>鼠标放置在SC的中心，按向上箭头。重复此步骤，直到SC充满屏幕。 </li><li>手动段SC由盘旋的边界用鼠标。按住控制（Ctrl）键，然后按D当前图像帧。按住Ctrl键，然后按M.转录SC截面积和测量帧数的测量分析电子表格。取消选择的轮廓区域。按右箭头键3次。直到SC已经在10帧为单位重复此步骤。 </li><li>按左方向键30次返回到第一测量框架。 </li><li>从工具栏中选择直线段工具。 </li><li>借鉴SC上最前到最靠后的位置的直线。按住Ctrl键，然后按D仅当前帧。按住Ctrl键，然后按M.抄表SC长度和帧数来分析电子表格。取消选择的轮廓区域。按下右箭头键3次。直到SC长度已在相同的10帧作为对SC截面积被测量重复此步骤。 </li><li>插入公式SC-IOWD = SC-CSA /轴向长度到电子表格分析除以面积测量的长度测量计算平均SC内壁至外壁的距离（SC-IOWD）。 </li><li>按左方向键30次返回到第一测量框架。 </li><li>从工具栏中选择直线段工具。 </li><li>从画一条直线最前的​​SC到小梁网和前室的边界。确保线垂直于边界。按住Ctrl键，然后按D，然后M. </li><li>绘制从SC的最靠后的位置和TM的边界和前房的线。确保垂直于边界线。按住控制并按下D，则M. </li><li>绘制从SC的中心和TM的边界和前房的线。确保林Ë垂直边界。按住Ctrl键，然后按D仅当前帧。 </li><li>录制三个TM厚度测量和帧号到分析电子表格。要做到这一点按右箭头键3次。直到TM厚度已经在相同的10帧作为对SC截面积被测量重复此步骤。 </li></ol>

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舒曼博士收到版权费知识产权由美国麻省理工学院和马萨诸塞州眼耳医院蔡司公司许可

本技术利用非侵入性的观察软组织的机械响应量化的SC崩溃。利用人类尸体的眼睛今后的工作中，需要解剖后校准组织变形实际组织硬度。但是，这样的研究将遭受先前流出模型的相同的限制;具体地，该活肌到组织张力的贡献将不存在。在哺乳动物活眼模型进一步校准可以让影像和TM的刚度直接测量校准。 有几个限制的技术。它尚待证实在其他平台华侨城。该文献表明，相同的结构可被可视化在其他的OCT设备，然而灵敏度与急性眼压升高在这些设备相关的尚未被证明在人眼的变化。本装置采用了方便，因为没有额外的光学是所需的眼前段扫描。最大的挑战这项工作是扫描识别范围内的SC。这是不可能的一个片内肯定识别SC。体积的询问需要首先找到的含有组织SC的区域。其身份，然后通过观察收集渠道窦口，和互连SC的各个环节中出现一片切片证实。根据我们的经验，SC将呈现为可合并成单一的大开口附近的一个收藏家通道口，或折叠到完全关闭的捏段内缘0〜4开口之间。 这种突破技术的最大意义在于，有没有其他的选择TM刚度原位的评估。以旧换新的形态和刚度与相关设施的流出14,15，强调需要测量的流出途径的生物力学特性。在未来，这样的测量可以提供深入了解当前在青光眼的管理不可用。

青光眼是全球第二大不可逆转的失明1的原因。升高的眼内压（IOP）是用于青光眼2-7的存在和发展的主要致病危险因素。 &#160;眼压是由房水8的形成和流出之间的平衡调节。最大流出阻力的位置是juxtacanicular组织和Schlemm管（SC）的内壁，SC和小梁网（TM）9-11之间的接口。而TM刚度可以在IOP升高的脸向预防SC崩溃，奥弗等人 12最近证明在青光眼基因表达被改变，从而提高SC内皮变硬，妨碍形成气孔，导致高眼压中青光眼13。 TM形态和刚度与相关设施的流出14,15，强调牛逼他需要测量其生物力学特性。 以旧换新的原子力显微镜测量表明高架刚度眼青光眼患者（81千帕）捐赠的眼睛捐助者无青光眼（4.0千帕）16相比，但这些测量是在解剖离体组织进行。后TM被锚定到经由纵肌细胞中插入到外lamellated和cribiform TM 17的前肌腱睫状肌。睫状肌（CM）的活动可能会增加TM绷紧，酷似TM升高17的刚度。观察改建耐诱导的平滑肌扰动SC崩溃的能力已经显示出在动物模型18。我们已经证明了能够非侵入性图像的主房水外流系统在活的人的眼睛的远端并包括SC使用谱域光学相干断层扫描（OCT）&lt;SUP&gt; 19-21。使用这种技术，我们已经证明，量化TM和SC急性IOP升高22的形态反应的能力。 本文所描述的方法的总体目标是量化活流出道急性IOP升高的在生物体组织中原位形态响应。这种技术具有检查在生理条件下对TM，其中既包括收缩纤维活性的T M和CM以TM刚度内贡献相比，在解剖组织制成公布的测量的优点。背后采用这种技术来观察机械TM响应的理由是，它为我们提供了其他原因无法分析上市公司以旧换新，我们现在知道被直接链接到水流出阻力，眼压第13条的力学性能。辨别收缩组织对整体刚度，小的银的贡献受试者室温进行了检查，并没有与抑制平滑肌的活动由托的管理。

<table><tbody><tr><td>Spectral Domain OCT</td><td>Zeiss</td><td>Cirrus</td><td></td></tr><tr><td>Imaging Workstation</td><td>Apple</td><td>iMac</td><td></td></tr><tr><td>Ophthalmodynamometer</td><td>Baillairt Matalene Ophthalmodynamometer, Surgical instruments CO., Inc. New York, NY</td><td></td><td></td></tr><tr><td>Image Processing Program</td><td>rsb.info.nih.gov/ij</td><td>ImageJ, FIJI</td><td></td></tr></tbody></table>

trabecular meshwork response to pressure elevation in the living human eye

小梁网（TM）的机械特性都与流出阻力和眼内压（IOP）调节。这种技术背后的基本原理是直接观察以旧换新急性眼压升高的机械反应。在扫描之前，眼压测量在基线和在IOP升高。角膜缘是在基线和在高眼压扫描谱域光学相干断层扫描（ophthalmodynamometer（ODM）施加于30挤压力g）。扫描处理，以提高使用ImageJ房水外流通路的可视化。血管地标被用于识别在基线和高眼压扫描体积相对应的位置。 Schlemm管（SC）的截面积（SC-CSA）和由前向沿其长轴后路SC长度手动在SC的1毫米段内10个位置测量。平均数内到外壁上的距离（短轴长度）计算为SC的由划分区域其长轴长度。为了检查邻近组织的效果的IOP升高的贡献，重复测量不具有和具有平滑肌松弛与托滴注。 TM迁移进入SC由TM刚度抵抗，但由它附着到相邻的平滑肌睫状体内的支持增强。这种技术是在第一测量生理条件下，人眼内的活的人类TM响应于压力上升的原位 。

利用这些数据采集和图像分析技术，对流出道形态学参数眼压小和大的变化，如SC截面积的影响，获得（ 图1）。我们可以看到，水平高的眼压增加产生的SC的可观察到的塌陷，因为由大的减少的截面面积表示。眼睛看来是能够容纳小增加眼压，就证明了缺乏变化的SC-CSA的（ 图1）。这些结果表明，该技术能够定量流出道的锐角眼压挑战的形态反应。技术或技术没有其他家庭既提供有关流出道生物力学的视觉和定量信息。 整个研究过程中，观察到在TM厚度没有显著变化。响应于一个23毫米汞柱眼压升高，SC内到外壁距离减少了5.03微米。 W¯¯ithout和抑制平滑肌的活动，一个6毫米汞柱增加眼压造成SC内外壁的距离由0.18微米和2.34微米的下降分别。此外，基线的SC-CSA从4597±2503微米2下降到3588±1198微米2（平均值±标准差）与平滑肌的活性抑制。一起，与来自睫状肌其中插入到外lamellated和cribiform TM 17前肌腱的插入，这意味着一个控制系统，以保持涉及平滑肌SC通畅。进一步的研究是值得。 <img alt="图1" src="/files/ftp_upload/52611/52611fig1.jpg" /> 图1. Schlemm管区域与在活的眼睛的眼内压。Schlemm管（SC）提供从受试者的两个队列横截面积。在我误差线目前1标准误差ntraocular压（IOP）上的X轴和SC面积上的Y轴。

Watch this Scientific Journal Video about Trabecular Meshwork Response to Pressure Elevation in the Living Human Eye at JoVE.com

Trabecular Meshwork Response to Pressure Elevation in the Living Human Eye

小梁网（TM）迁移进入施累姆氏管的空间可以由急性压力上升来诱导由ophthalmodynamometer，并通过谱域光学相干断层扫描观察。该方法的目标是要量化活流出道急性压力升高的在生物体组织的原位的形态反应。

小梁响应压升高在活的人类眼睛

The mechanical characteristics of the trabecular meshwork (TM) are linked to outflow resistance and intraocular pressure (IOP) regulation. The rationale ...

trabecular-meshwork-response-to-pressure-elevation-living-human

Nanyang Technological University

Research

JoVE Journal

Medicine

9.9K 次观看.  University of Pittsburgh School of Medicine. 小梁网（TM）迁移进入施累姆氏管的空间可以由急性压力上升来诱导由ophthalmodynamometer，并通过谱域光学相干断层扫描观察。该方法的目标是要量化活流出道急性压力升高的在生物体组织的原位的形态反应。 

视频: Trabecular Meshwork Response to Pressure Elevation in the Living Human Eye

Experimental Glaucoma Induced by Ocular Injection of Magnetic Microspheres

Progress in understanding the pathophysiology, and providing novel treatments for glaucoma is dependent on good animal models of the disease. We present here a protocol for elevating intraocular pressure (IOP) in the rat, by injecting magnetic microspheres into the anterior chamber of the eye. The use of magnetic particles allows the user to manipulate the beads into the iridocorneal angle, thus providing a very effective blockade of fluid outflow from the trabecular meshwork. This leads to long-lasting IOP rises, and eventually neuronal death in the ganglion cell layer (GCL) as well as optic nerve pathology, as seen in patients with the disease. This method is simple to perform, as it does not require machinery, specialist surgical skills, or many hours of practice to perfect. Furthermore, the pressure elevations are very robust, and reinjection of the magnetic microspheres is not usually required unlike in some other models using plastic beads. Additionally, we believe this method is suitable for adaptation for the mouse eye.

We present a method for inducing elevated intraocular pressure (IOP), by injecting magnetic microspheres into the rat eye, to model glaucoma. This leads to strong pressure rises, and extensive neuronal death. This protocol is easy to perform, does not require repeat injections, and produces stable long-lasting IOP rises.

实验诱发青光眼通过磁性微球注射眼

Progress in understanding the pathophysiology, and providing novel treatments for glaucoma is dependent on good animal models of the disease. We present ...

科研

医学

A Magnetic Microbead Occlusion Model to Induce Ocular Hypertension-Dependent Glaucoma in Mice

The use of rodent models of glaucoma has been essential to understand the molecular mechanisms that underlie the pathophysiology of this multifactorial neurodegenerative disease. With the advent of numerous transgenic mouse lines, there is increasing interest in inducible murine models of ocular hypertension. Here, we present an occlusion model of glaucoma based on the injection of magnetic microbeads into the anterior chamber of the eye using a modified microneedle with a facetted bevel. The magnetic microbeads are attracted to the iridocorneal angle using a handheld magnet to block the drainage of aqueous humour from the anterior chamber. This disruption in aqueous dynamics results in a steady elevation of intraocular pressure, which subsequently leads to the loss of retinal ganglion cells, as observed in human glaucoma patients. The microbead occlusion model presented in this manuscript is simple compared to other inducible models of glaucoma and also highly effective and reproducible. Importantly, the modifications presented here minimize common issues that often arise in occlusion models. First, the use of a bevelled glass microneedle prevents backflow of microbeads and ensures that minimal damage occurs to the cornea during the injection, thus reducing injury-related effects. Second, the use of magnetic microbeads ensures the ability to attract most beads to the iridocorneal angle, effectively reducing the number of beads floating in the anterior chamber avoiding contact with other structures (e.g., iris, lens). Lastly, the use of a handheld magnet allows flexibility when handling the small mouse eye to efficiently direct the magnetic microbeads and ensure that there is little reflux of the microbeads from the eye when the microneedle is withdrawn. In summary, the microbead occlusion mouse model presented here is a powerful investigative tool to study neurodegenerative changes that occur during the onset and progression of glaucoma.

Here, we present a protocol to induce ocular hypertension in the murine eye that results in the loss of retinal ganglion cells as observed in glaucoma. Magnetic microbeads are injected into the anterior chamber and attracted to the iridocorneal angle using a magnet to block the outflow of aqueous humour.

A磁条微珠缺血模型，以诱导小鼠高眼压，青光眼相关

The use of rodent models of glaucoma has been essential to understand the molecular mechanisms that underlie the pathophysiology of this multifactorial ...

Glaucoma-inducing Procedure in an In Vivo Rat Model and Whole-mount Retina Preparation

Glaucoma is a disease of the central nervous system affecting retinal ganglion cells (RGCs). RGC axons making up the optic nerve carry visual input to the brain for visual perception. Damage to RGCs and their axons leads to vision loss and/or blindness. Although the specific cause of glaucoma is unknown, the primary risk factor for the disease is an elevated intraocular pressure. Glaucoma-inducing procedures in animal models are a valuable tool to researchers studying the mechanism of RGC death. Such information can lead to the development of effective neuroprotective treatments that could aid in the prevention of vision loss. The protocol in this paper describes a method of inducing glaucoma - like conditions in an in vivo rat model where 50 &#181;l of 2 M hypertonic saline is injected into the episcleral venous plexus. Blanching of the vessels indicates successful injection. This procedure causes loss of RGCs to simulate glaucoma. One month following injection, animals are sacrificed and eyes are removed. Next, the cornea, lens, and vitreous are removed to make an eyecup. The retina is then peeled from the back of the eye and pinned onto sylgard dishes using cactus needles. At this point, neurons in the retina can be stained for analysis. Results from this lab show that approximately 25% of RGCs are lost within one month of the procedure when compared to internal controls. This procedure allows for quantitative analysis of retinal ganglion cell death in an in vivo rat glaucoma model.

Glaucoma-inducing Procedure in an In Vivo Rat Model and Whole-mount Retina Preparation

Glaucoma is characterized by damage to retinal ganglion cells. Inducing glaucoma in animal models can provide insight into the study of this disease. Here, we outline a procedure that induces loss of RGCs in an in vivo rat model and demonstrates the preparation of whole-mount retinas for analysis.

青光眼诱导在程序<em&gt;在体内</em&gt;大鼠模型和全安装视网膜准备

Glaucoma is a disease of the central nervous system affecting retinal ganglion cells (RGCs). RGC axons making up the optic nerve carry visual input to the ...

A Model of Glaucoma Induced by Circumlimbal Suture in Rats and Mice

The circumlimbal suture is a technique for inducing experimental glaucoma in rodents by chronically elevating intraocular pressure (IOP), a well-known risk factor for glaucoma. This protocol demonstrates a step-by-step guide on this technique in Long Evans rats and C57BL/6 mice. Under general anesthesia, a "purse-string" suture is applied on the conjunctiva, around the equator and behind the limbus of the eye. The fellow eye serves as an untreated control. Over the duration of our study, which was a period of 8 weeks for rats and 12 weeks for mice, IOP remained elevated, as measured regularly by rebound tonometry in conscious animals without topical anesthesia. In both species, the sutured eyes showed electroretinogram features consistent with preferential inner retinal dysfunction. Optical coherence tomography showed selective thinning of the retinal nerve fiber layer. Histology of the rat retina in cross-section found reduced cell density in the ganglion cell layer, but no change in other cellular layers. Staining of flat-mounted mouse retinae with a ganglion cell specific marker (RBPMS) confirmed ganglion cell loss. The circumlimbal suture is a simple, minimally invasive and cost-effective way to induce ocular hypertension that leads to ganglion cell injury in both rats and mice.

Chronic ocular hypertension is induced by applying a circumlimbal suture in rats and mice, leading to functional and structural deterioration of the retinal ganglion cells consistent with glaucoma.

Circumlimbal 缝合法诱导大鼠和小鼠青光眼模型的建立

The circumlimbal suture is a technique for inducing experimental glaucoma in rodents by chronically elevating intraocular pressure (IOP), a well-known ...

Translaminar Autonomous System Model for the Modulation of Intraocular and Intracranial Pressure in Human Donor Posterior Segments

There is a current unmet need for a new preclinical human model that can target disease etiology ex vivo using intracranial pressure (ICP) and intraocular pressure (IOP) which&#160;can identify various pathogenic paradigms related to the glaucoma pathogenesis. Ex vivo human anterior segment perfusion organ culture models have previously been successfully utilized and applied as effective technologies for the discovery of glaucoma pathogenesis and testing of therapeutics. Preclinical drug screening and research performed on ex vivo human organ systems can be more translatable to clinical research. This article describes in detail the generation and operation of a novel ex vivo human translaminar pressure model called the translaminar autonomous system (TAS). The TAS model can independently regulate ICP and IOP using human donor posterior segments. The model allows for studying pathogenesis in a preclinical manner. It can reduce the use of living animals in ophthalmic research. In contrast to in vitro experimental models, optic nerve head (ONH) tissue structure, complexity, and integrity can also be maintained within the ex vivo TAS model.

We describe and detail the use of the translaminar autonomous system. This system utilizes the human posterior segment to independently regulate the pressure inside the segment (intraocular) and surrounding the optic nerve (intracranial) to generate a translaminar pressure gradient that mimics features of glaucomatous optic neuropathy.

用于调节人类供体后段眼内压和颅内压的跨层自主系统模型

There is a current unmet need for a new preclinical human model that can target disease etiology ex vivo using intracranial pressure (ICP) and intraocular ...

神经科学

自动压缩猪晶状体的生物力学表征

Automated Compression Testing of the Ocular Lens

The biomechanical properties of the ocular lens are essential to its function as a variable power optical element. These properties change dramatically with age in the human lens, resulting in a loss of near vision called presbyopia. However, the mechanisms of these changes remain unknown. Lens compression offers a relatively simple method for assessing the lens' biomechanical stiffness in a qualitative sense and, when coupled with appropriate analytical techniques, can help quantify biomechanical properties. A variety of lens compression tests have been performed to date, including both manual and automated, but these methods inconsistently apply key aspects of biomechanical testing such as preconditioning, loading rates, and time between measurements. This paper describes a fully automated lens compression test wherein a motorized stage is synchronized with a camera to capture the force, displacement, and shape of the lens throughout a preprogrammed loading protocol. A characteristic elastic modulus may then be calculated from these data. While demonstrated here using porcine lenses, the approach is appropriate for the compression of lenses of any species.

作者聚焦：增进对与年龄相关的晶状体僵硬变化的理解 

We present an automated method for characterizing the effective elastic modulus of an ocular lens using a compression test.

人工晶状体的自动压缩测试

The biomechanical properties of the ocular lens are essential to its function as a variable power optical element. These properties change dramatically ...

生物工程

Full-Circle Cauterization of Limbal Vascular Plexus for Surgically Induced Glaucoma in Rodents

Glaucoma, the second leading cause of blindness worldwide, is a heterogeneous group of ocular disorders characterized by structural damage to the optic nerve and retinal ganglion cell (RGC) degeneration, resulting in visual dysfunction by interrupting the transmission of visual information from the eye to the brain. Elevated intraocular pressure is the most important risk factor; thus, several models of ocular hypertension have been developed in rodents by either genetic or experimental approaches to investigate the causes and effects of the disease. Among those, some limitations have been reported such as surgical invasiveness, inadequate functional assessment, requirement of extensive training, and highly variable extension of retinal damage. The present work characterizes a simple, low-cost, and efficient method to induce ocular hypertension in rodents, based on low-temperature, full-circle cauterization of the limbal vascular plexus, a major component of aqueous humor drainage. The new model provides a technically easy, noninvasive, and reproducible subacute ocular hypertension, associated with progressive RGC and optic nerve degeneration, and a unique post-operative clinical recovery rate that allows in vivo functional studies by both electrophysiological and behavioral methods.

The goal of this protocol is to characterize a novel model of glaucomatous neurodegeneration based on 360&#176; thermic cauterization of limbal vascular plexus, inducing subacute ocular hypertension.

角膜缘血管丛全圆烧灼治疗啮齿动物手术诱发的青光眼

Glaucoma, the second leading cause of blindness worldwide, is a heterogeneous group of ocular disorders characterized by structural damage to the optic ...

Laser Capture Microdissection of Highly Pure Trabecular Meshwork from Mouse Eyes for Gene Expression Analysis

Laser capture microdissection (LCM) has allowed gene expression analysis of single cells and enriched cell populations in tissue sections. LCM is a great tool for the study of the molecular mechanisms underlying cell differentiation and the development and progression of various diseases, including glaucoma. Glaucoma, which comprises a family of progressive optic neuropathies, is the most common cause of irreversible blindness worldwide. Structural changes and damage within the trabecular meshwork (TM) can result in increased intraocular pressure (IOP), which is a major risk factor for developing glaucoma. However, the precise molecular mechanisms involved are still poorly understood. The ability to perform gene expression analysis will be crucial in obtaining further insights into the function of these cells and its role in the regulation of IOP and glaucoma development. To achieve this, a reproducible method for isolating highly enriched TM from frozen sections of mouse eyes and a method for downstream gene expression analysis, such as RT-qPCR and RNA-Seq is needed. The method described herein is developed to isolate highly pure TM from mouse eyes for downstream digital PCR and microarray analysis. In addition, this technique can be easily adapted for the isolation of other highly enriched ocular cells and cell compartments that have been difficult to isolate from mouse eyes. The combination of LCM and RNA analysis can contribute to a more comprehensive understanding of the cellular events underlying glaucoma.

Here, we describe a protocol for a reproducible laser capture microdissection (LCM) for isolating trabecular meshwork (TM) for downstream RNA analysis. The ability to analyze changes in gene expression in the TM will help in understanding the underlying molecular mechanisms of TM-related ocular diseases.

从小鼠眼中激光捕捉高纯大梁网的基因表达分析

Laser capture microdissection (LCM) has allowed gene expression analysis of single cells and enriched cell populations in tissue sections. LCM is a great ...

小梁响应压升高在活的人类眼睛

摘要

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此视频中的章节

实验诱发青光眼通过磁性微球注射眼

A磁条微珠缺血模型，以诱导小鼠高眼压，青光眼相关

青光眼诱导在程序

Circumlimbal 缝合法诱导大鼠和小鼠青光眼模型的建立

用于调节人类供体后段眼内压和颅内压的跨层自主系统模型

人工晶状体的自动压缩测试

人工晶状体的自动压缩测试

人工晶状体的自动压缩测试

角膜缘血管丛全圆烧灼治疗啮齿动物手术诱发的青光眼

从小鼠眼中激光捕捉高纯大梁网的基因表达分析