Phase-Contrast Micro-Computed Tomography Measurements of the Intraocular Pressure-Induced Deformation of the Porcine Lamina Cribrosa

Coudrillier, Baptiste; Geraldes, Diogo M.; Vo, Nghia T.; Atwood, Robert C.; Reinhard, Christina; Campbell, Ian C.; Raji, Yazdan; Albon, Julie; Abel, Richard; Ethier, C. Ross

doi:10.1109/tmi.2015.2504440

Cited by 49 publications

(63 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From the shape functions of the highest resolution mesh we computed at each pixel an in-plane deformation matrix, and from this matrix, in turn, the first (maximum) and second (minimum) principal strains 9 . These were further slightly smoothed to remove very large deformations caused by outlier high-aspect ratio elements 12 .…”

Section: Methodsmentioning

confidence: 99%

Mapping in-vivo optic nerve head strains caused by intraocular and intracranial pressures

et al. 2017

View full text Add to dashboard Cite

Although it is well documented that abnormal levels of either intraocular (IOP) or intracranial pressure (ICP) can lead to potentially blinding conditions, such as glaucoma and papilledema, little is known about how the pressures actually affect the eye. Even less is known about potential interplay between their effects, namely how the level of one pressure might alter the effects of the other. Our goal was to measure in-vivo the pressure-induced stretch and compression of the lamina cribrosa due to acute changes of IOP and ICP. The lamina cribrosa is a structure within the optic nerve head, in the back of the eye. It is important because it is in the lamina cribrosa that the pressure-induced deformations are believed to initiate damage to neural tissues leading to blindness. An eye of a rhesus macaque monkey was imaged in-vivo with optical coherence tomography while IOP and ICP were controlled through cannulas in the anterior chamber and lateral ventricle, respectively. The image volumes were analyzed with a newly developed digital image correlation technique. The effects of both pressures were highly localized, nonlinear and non-monotonic, with strong interactions. Pressure variations from the baseline normal levels caused substantial stretch and compression of the neural tissues in the posterior pole, sometimes exceeding 20%. Chronic exposure to such high levels of biomechanical insult would likely lead to neural tissue damage and loss of vision. Our results demonstrate the power of digital image correlation technique based on non-invasive imaging technologies to help understand how pressures induce biomechanical insults and lead to vision problems.

show abstract

Section: Methodsmentioning

confidence: 99%

Mapping in-vivo optic nerve head strains caused by intraocular and intracranial pressures

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Pig, cat and dog eyes have a well-developed LC (Coudrillier et al, 2016a; Coudrillier et al, 2016b; Fatehee et al, 2011; Grozdanic et al, 2010; Radius and Bade, 1982a, b), but their ONH vascular anatomy is considerably different to that of the human (De Schaepdrijver et al, 1989; May, 2008). Glaucoma commonly caused by anterior segment dysgenesis and high IOP is a frequent condition seen in cats and dogs (McLellan and Miller, 2011; Pizzirani, 2015).…”

Section: Animal Models Of Glaucomamentioning

confidence: 99%

Biomechanical aspects of axonal damage in glaucoma: A brief review

Tamm

Ethier

Dowling

et al. 2017

Experimental Eye Research

Self Cite

100

View full text Add to dashboard Cite

The biomechanical environment within the optic nerve head (ONH) is complex and is likely directly involved in the loss of retinal ganglion cells (RGCs) in glaucoma. Unfortunately, our understanding of this process is poor. Here we describe factors that influence ONH biomechanics, including ONH connective tissue microarchitecture and anatomy; intraocular pressure (IOP); and cerebrospinal fluid pressure (CSFp). We note that connective tissue factors can vary significantly from one individual to the next, as well as regionally within an eye, and that the understanding of ONH biomechanics is hindered by anatomical differences between small-animal models of glaucoma (rats and mice) and humans. Other challenges of using animal models of glaucoma to study the role of biomechanics include the complexity of assessing the degree of glaucomatous progression; and inadequate tools for monitoring and consistently elevating IOP in animal models. We conclude with a consideration of important open research questions/challenges in this area, including: (i) Creating a systems biology description of the ONH; (ii) addressing the role of astrocyte connective tissue remodeling and reactivity in glaucoma; (iii) providing a better characterization of ONH astrocytes and non-astrocytic constituent cells; (iv) better understanding the role of ONH astrocyte phagocytosis, proliferation and death; (v) collecting gene expression and phenotype data on a larger, more coordinated scale; and (vi) developing an implantable IOP sensor.

show abstract

“…Other applications followed in the field of biomechanics (e.g., see Refs. [194,11,106,241,17,193,44,40,43,109]). At the beginning of the current decade, DVC was clearly identified as one technique very suited to biomechanical applications [239].…”

Section: Introductionmentioning

confidence: 99%

Digital Volume Correlation: Review of Progress and Challenges

et al. 2018

View full text Add to dashboard Cite

3D imaging has become popular for analyzing material microstructures. When time lapse series of 3D pictures are acquired during a single experiment, it is possible to measure displacement fields via digital volume correlation (DVC), thereby leading to 4D results. Such ForewordThe present paper aims at reviewing the major developments in Digital Volume Correlation (DVC) over the past ten years. It follows the first review on DVC that was published in 2008 by its pioneer [11]. In the latter, the interested reader will find all the general principles associated with what is now called local DVC. They will not be recalled hereafter. In such approaches the region of interest is subdivided into small subvolumes that are independently registered. In addition to its wider use with local approaches, DVC has been extended to global approaches in which the displacement field is defined in a dense way over the region of interest. Kinematic bases using finite element discretizations have been selected. To further add mechanical content, elastic regularization has been introduced. Last, integrated approaches use kinematic fields that are constructed from finite element simulations with chosen constitutive equations. The material parameters (and/or boundary conditions) then become the quantities of interest.These various implementations assume different degrees of integration of mechanical knowledge about the analyzed experiment. First and foremost, DVC can be considered as a stand-alone technique, which has seen its field of applications grow over the last ten years. In this case the measured displacement fields and post-processed strain fields are reported. With the introduction of finite element based DVC, the measured displacement field is continuous. It is also a standalone technique. However, given the fact that it shares common kinematic bases with numerical simulations, it can be easily combined with the latter. One route is to require local satisfaction of equilibrium via mechanical regularization. Another route is to fully merge DVC analyses and numerical simulations via integrated approaches. Different examples will illustrate how these various integration steps can be tailored and what are the current challenges associated with various approaches.

show abstract

Phase-Contrast Micro-Computed Tomography Measurements of the Intraocular Pressure-Induced Deformation of the Porcine Lamina Cribrosa

Cited by 49 publications

References 48 publications

Mapping in-vivo optic nerve head strains caused by intraocular and intracranial pressures

Mapping in-vivo optic nerve head strains caused by intraocular and intracranial pressures

Biomechanical aspects of axonal damage in glaucoma: A brief review

Digital Volume Correlation: Review of Progress and Challenges

Contact Info

Product

Resources

About