Clinical Trial Details
— Status: Active, not recruiting
Administrative data
| NCT number |
NCT03108443 |
| Other study ID # |
1022071 |
| Secondary ID |
|
| Status |
Active, not recruiting |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
April 1, 2018 |
| Est. completion date |
May 2025 |
Study information
| Verified date |
August 2023 |
| Source |
Nova Scotia Health Authority |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
Current methods of detecting glaucoma and monitoring its progression over time involve visual
assessment of the optic nerve, thickness measurements of nerve tissue in the eye (using
optical coherence tomography, OCT) as well as functional tests which measure peripheral, or
side, vision. The objective of this study is to determine if a new technique of measuring
blood flow in the eye, using OCT, can be used to better detect and/or monitor changes in
glaucoma patients and suspects than these methods.
Description:
Changes in the superficial optic nerve head (ONH) surface and loss of retinal nerve fibre
layer (RNFL) thickness detected with clinical imaging are predictive of future visual field
loss. Imaging of the deep ONH, the likely origin of glaucomatous damage, represents the next
logical next step, but has eluded clinicians because of the lack of capable technology.
New advances in optical coherence tomography (OCT) imaging now offer an exciting opportunity
to close the gap between the histomorphometric knowledge on deep ONH changes gained with
research in experimental monkey glaucoma and imaging in clinical glaucoma.
There is compelling evidence that gross ONH and retinal hemodynamic changes are functional
indicators of glaucoma progression. Accurate tracking of blood flow in the ONH is a logical
step, but has evaded researchers for several reasons including the highly reflective ONH
tissue which variably inhibits signal penetration making the complex nature of retinal and
posterior ciliary contributions to ONH flow difficult to segregate. Even though glaucoma
damage originates in the ONH, retinal ganglion cell (RGC) axons may show the earliest
functional alterations as they have high metabolic demand and vulnerability to damage.
Therefore, tracking blood flow in the RNFL, which is highly segmental and resolvable, could
be a better and more sensitive approach compared to that in the ONH. The macula contains
almost 50% of the entire RGC population; likewise, monitoring blood flow in the macular inner
vascular plexus corresponding to the ganglion cell layer (GCL) is likely to be highly
informative for glaucoma progression. OCT based angiography (OCTA), which maps vessel density
in different retinal vascular beds with unparalleled axial resolution, will finally allow us
to quantify highly localized parameters related to blood flow and identify patients with
higher progression risk. Current data analysis of progression detection based on
inter-subject or population-based variability models are inefficient, leading to
false-positive and false-negative results. Innovative data analysis techniques that build
accurate models of intra-subject variability will add cumulative value to the novel imaging
markers for progression.
