“Effect of cyclic biomechanical stress on fluid flow through conventional drainage tissue”
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Abstract: Glaucoma is the leading cause of irreversible blindness worldwide. The most common type of glaucoma, primary open angle glaucoma, is frequently associated with an increased outflow resistance to aqueous humor through the conventional pathway, resulting in elevated intraocular pressure.
Intraocular pressure is generated as a result of the balance of aqueous humor production and aqueous humor outflow. In humans, approximately 90% of the aqueous humor exits the eye via the conventional outflow pathway. The conventional outflow pathway consists of several tissues, including trabecular meshwork and Schlemm’s Canal, that actively respond to their microenvironment by regulating fluid flow. In vivo, the conventional pathway is exposed to mechanical stresses due to fluctuations in intraocular pressure that occur in association with each heartbeat, averaging 2.7 mmHg. Using the anterior segment perfusion model, we are able to simulate magnitude and frequency of in vivo intraocular pulsations. Understanding the effect of cyclic biomechanical stress in outflow facility allows us to gain a better understanding of the tissues involved in regulation of intraocular pressure.FSI simulations were conducted in a model of a vulnerable plaque- a pathology that prompts strokes and fatal heart attacks (sudden cardiac death), and in abdominal aortic aneurysms (AAA) reconstructed from patients CT images, in order to predict plaque vulnerability and AAA risk of rupture. For the vulnerable plaque the analysis indicates regions where a combination of elevated strains in the vessel wall and shear stresses induced by the flow, combined with the fibrous cap thickness, enhance the plaque vulnerability and may lead to rapid thrombus formation. The role of calcification in the plaque was examined, indicating that it significantly increases the plaque vulnerability. For the AAA, the role of intraluminal (ILT) thrombus in the AAA was examined and used to predict potential rupture locations, using hyperelastic and orthotropic material models. |
