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The Impact of Ocular Pressures, Material Properties and Geometry on Optic Nerve Head DeformationAlteration in intracranial pressure (ICP) has been associated with various diseases that cause visual impairment, including glaucoma, idiopathic intracranial hypertension and Visual Impairment and Intracranial Pressure (VIIP) syndrome. However, how changes in ICP lead to vision loss is unclear, although it is hypothesized to involve deformations of the tissues in the optic nerve head (ONH). Recently, understanding the effect of ICP alterations on ocular tissues has become a major concern for NASA, where 42 of astronauts that partake in long duration space missions suffer from VIIP syndrome. Astronauts with VIIP syndrome suffer from visual impairment and changes in ocular anatomy that persist after returning to earth (1). It is hypothesized that the cephalad fluid shift that occurs upon entering microgravity increases ICP, which leads to an altered biomechanical environment in the posterior globe and optic nerve sheath, and subsequently VIIP syndrome. Our goal was to develop a finite element (FE) model to simulate the acute effects of elevated ICP on the posterior eye. Here, we simulated how inter-individual differences affect the deformation of ONH tissues. Further, we examined how several different geometries influenced deformations when exposed to elevated ICP.
Document ID
20170001725
Acquisition Source
Glenn Research Center
Document Type
Presentation
Authors
Feola, Andrew J.
(Georgia Inst. of Tech. Atlanta, GA, United States)
Myers, Jerry G.
(NASA Glenn Research Center Cleveland, OH United States)
Raykin, Julia
(Georgia Inst. of Tech. Atlanta, GA, United States)
Nelson, Emily S.
(Georgia Inst. of Tech. Atlanta, GA, United States)
Samuels, Brian C.
(Alabama Univ. Birmingham, AL, United States)
Ethier C. Ross
(Georgia Inst. of Tech. Atlanta, GA, United States)
Date Acquired
February 22, 2017
Publication Date
June 21, 2017
Subject Category
Numerical Analysis
Aerospace Medicine
Report/Patent Number
GRC-E-DAA-TN33356
Meeting Information
Meeting: Summer Biomechanics, Bioengineering and Biotransport Conference (SB3C 2017)
Location: Tucson, AZ
Country: United States
Start Date: June 21, 2017
End Date: June 24, 2017
Sponsors: Virginia Institute of Technology, University of Utah
Funding Number(s)
WBS: WBS 516724.01.02.10
Distribution Limits
Public
Copyright
Public Use Permitted.
Keywords
mathematical models
intraocular pressure
eye (anatomy)
fluid shift (biological)
microgravity
intracranial pressure
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