Magnetic Resonance Imaging of Glaucoma

  • Duong, Timothy Q (PI)

Project: Research project

Project Details

Description

Glaucoma, a leading cause of irreversible blindness in the world, is characterized by
progressive degeneration of the retinal ganglion cells (RGCs), the retinal nerve fiber layer, and
the optic nerve. Glaucoma is often associated with elevated intraocular pressure (IOP), and
because the increased IOP exerts a compressing force on the blood vessels in the eye, it has
long been hypothesized that the RGC damage is caused by mild, but chronic, reduction of basal
blood flow and/or blood-flow dysregulation. For many patients, by the time glaucoma is detected
in examinations or patients notice vision loss, more than half of the RGCs have already
degenerated. The eventual outcome is often blindness. Thus, non-invasive imaging
technologies capable of detecting depth-resolved blood flow, oxygenation, and stimulus-evoked
hemodynamic changes to evaluate blood flow reduction and dysregulation in the retina and the
optic nerve head could enable objective early detection, longitudinal disease staging, and
monitoring of therapeutic interventions. Although optically based imaging techniques provide high spatial resolution, they are
depth limited which precludes quantitative resolution of retinal, choroidal, and optic nerve blood
flow. Our laboratory pioneered the application of multimodal MRI to image high-resolution
lamina-specific anatomy, blood flow, oxygenation, and function of the retina without depth
limitation. Here we propose: i) to develop a multimodal MRI approach to markedly improve
contrast and spatial resolution (35x35x300 ¿m) without MRI susceptibility artifact by using a 3D
balanced Steady State Free Precession (bSSFP) data acquisition scheme, and ii) to apply this
approach in an established genetic (DBA/2J) mouse glaucoma model to determine whether MRI
can detect glaucomatous changes in early stage and examine a plausible mechanism of
glaucoma pathogenesis. We hypothesize that: 1) MRI can provide high resolution, depth-resolved, laminar-
specific anatomical, blood flow, and functional images free of susceptibility artifacts; and 2) the
pathogenesis of glaucoma is mediated by reduced blood flow and/or blood-flow dysregulation in
the early stage, resulting in eventual loss of RGCs by ischemic hypoxia, and, if this is the cause,
hyperoxia treatment should halt glaucomatous damage.
StatusFinished
Effective start/end date9/1/138/31/17

Funding

  • National Institutes of Health: $299,000.00
  • National Institutes of Health: $293,020.00
  • National Institutes of Health: $293,020.00

ASJC

  • Medicine(all)

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