PMID- 27088762
OWN - NLM
STAT- MEDLINE
DCOM- 20160823
LR  - 20160419
IS  - 1552-5783 (Electronic)
IS  - 0146-0404 (Linking)
VI  - 57
IP  - 4
DP  - 2016 Apr
TI  - Finite Element Modeling of Factors Influencing Optic Nerve Head Deformation Due 
      to Intracranial Pressure.
PG  - 1901-11
LID - 10.1167/iovs.15-17573 [doi]
AB  - PURPOSE: Visual impairment and intracranial pressure (VIIP) syndrome is a health 
      concern for long-duration spaceflight, and a proposed risk factor is elevation of 
      intracranial pressure (ICP). Our goal was to use finite element modeling to 
      simulate how elevated ICP and interindividual differences affect tissue 
      deformation within the optic nerve head (ONH). METHODS: We considered three ICP 
      conditions: the upright and supine position on earth and an elevated ICP assumed 
      to occur in chronic microgravity. Within each condition we used Latin hypercube 
      sampling to consider a range of pressures and ONH tissue mechanical properties, 
      determining the influence of each input on the following outcome measures: peak 
      strains in the prelaminar tissue, lamina cribrosa, and retrolaminar optic nerve. 
      Elevated strains can alter cell phenotype and induce tissue remodeling. RESULTS: 
      Elevating ICP increased the strains in the retrolaminar optic nerve. Variations 
      in IOP, ICP, and in optic nerve and lamina cribrosa stiffness had the strongest 
      influence on strains within the ONH. We predicted that 5% to 47% of individuals 
      in microgravity would experience peak strains in the retrolaminar optic nerve 
      larger than expected on earth. Having a soft optic nerve or pia mater and 
      elevated ICP were identified as risk factors for these "extreme" strains. 
      CONCLUSIONS: Intracranial pressure and mechanical properties of the ONH influence 
      the risk for experiencing extreme strains in the retrolaminar optic nerve. These 
      extreme strains may activate mechanosensitive cells that induce tissue remodeling 
      and are a risk factor for the development of VIIP. Future studies must also 
      consider variations in ONH anatomy.
FAU - Feola, Andrew J
AU  - Feola AJ
AD  - Department of Biomedical Engineering Georgia Institute of Technology/Emory 
      University, Atlanta, Georgia, United States.
FAU - Myers, Jerry G
AU  - Myers JG
AD  - NASA Glenn Research Center, Cleveland, Ohio, United States.
FAU - Raykin, Julia
AU  - Raykin J
AD  - Department of Biomedical Engineering Georgia Institute of Technology/Emory 
      University, Atlanta, Georgia, United States.
FAU - Mulugeta, Lealem
AU  - Mulugeta L
AD  - Universities Space Research Association, Houston, Texas, United States.
FAU - Nelson, Emily S
AU  - Nelson ES
AD  - NASA Glenn Research Center, Cleveland, Ohio, United States.
FAU - Samuels, Brian C
AU  - Samuels BC
AD  - Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, 
      Alabama, United States.
FAU - Ethier, C Ross
AU  - Ethier CR
AD  - Department of Biomedical Engineering Georgia Institute of Technology/Emory 
      University, Atlanta, Georgia, United States.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - Invest Ophthalmol Vis Sci
JT  - Investigative ophthalmology & visual science
JID - 7703701
SB  - IM
MH  - Disease Progression
MH  - *Finite Element Analysis
MH  - Glaucoma/complications/*pathology/physiopathology
MH  - Humans
MH  - Intracranial Hypertension/complications/*pathology/physiopathology
MH  - Intracranial Pressure/*physiology
MH  - Intraocular Pressure/physiology
MH  - Optic Disk/*pathology
MH  - Optic Nerve Diseases/etiology/*pathology/physiopathology
MH  - Reproducibility of Results
MH  - Syndrome
EDAT- 2016/04/19 06:00
MHDA- 2016/08/24 06:00
CRDT- 2016/04/19 06:00
PHST- 2016/04/19 06:00 [entrez]
PHST- 2016/04/19 06:00 [pubmed]
PHST- 2016/08/24 06:00 [medline]
AID - 2515514 [pii]
AID - 10.1167/iovs.15-17573 [doi]
PST - ppublish
SO  - Invest Ophthalmol Vis Sci. 2016 Apr;57(4):1901-11. doi: 10.1167/iovs.15-17573.