Clinical Trial Details
— Status: Not yet recruiting
Administrative data
| NCT number |
NCT04846179 |
| Other study ID # |
1026588 |
| Secondary ID |
|
| Status |
Not yet recruiting |
| Phase |
Phase 4
|
| First received |
|
| Last updated |
|
| Start date |
May 2021 |
| Est. completion date |
September 2022 |
Study information
| Verified date |
April 2021 |
| Source |
Nova Scotia Health Authority |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Glaucoma is defined as progressive neuropathy of the optic nerve. It is an important cause of
irreversible blindness worldwide. Lowering the intraocular pressure is the only proven
treatment for this neurodegenerative disease. However, there is ongoing research looking at
another modifiable risk factor that affects the development and progression of this disease.
Ginkgo biloba (Ginkgoacease) is a tree species that has been used in traditional medicine for
several hundred years to treat various diseases include improving vascular perfusion. We
propose a study examining the effect of Ginkgo biloba extract supplementation on ocular
perfusion using optical coherence tomography angiography.
Description:
Glaucoma is defined as progressive neuropathy of the optic nerve. It is an important cause of
irreversible blindness worldwide. Lowering the intraocular pressure is the only proven
treatment for this neurodegenerative disease. However, there is ongoing research looking at
another modifiable risk factor that affects the development and progression of this disease.
There is growing evidence that vascular dysfunction plays a role in the pathogenesis of
glaucoma. Low ocular perfusion pressure (OPP), which is expressed as the difference between
mean arterial pressure and intraocular pressure (IOP), has been hypothesized to lead to
glaucomatous optic neuropathy via ischemic damage to the optic nerve. The Barbados Eye Study
showed that reduced OPP at baseline was associated with a three-fold increased risk of
glaucoma development. Evidence has also shown that optic nerve hypoperfusion may contribute
to the progression of glaucoma.
Ginkgo biloba (Ginkgoacease) is a tree species that has been used in traditional medicine for
several hundred years to treat various diseases. There have been recent studies that have
examined its medicinal properties in treating age-related cognitive disease and neuronal
degeneration resulting from ischaemic events. Studies examining systemic vascular ischemic
diseases have shown a beneficial effect of ginkgo Biloba extract (GBE) on systemic arterial
occlusive diseases. There is also preliminary research examining the effect GBE has on optic
nerve head perfusion in patients with glaucoma. There is a study that examined the effects of
antioxidants including GBE on ocular blood flow in patients with glaucoma using doppler
ultrasound. When compared with patients receiving placebo, patients after antioxidant therapy
containing GBE were shown to have increased peak systolic and/or end-diastolic blood
velocities in all retrobulbar blood vessels, reduced vascular resistance in the central
retinal and nasal short posterior ciliary arteries, increased superior and inferior temporal
retinal capillary mean blood flow, an increased ratio of active to nonactive retinal
capillaries. In the area of optic nerve head perfusion studies, fluorescein angiography has
also been used in investigating alteration in blood flow in glaucomatous versus normal eyes.
However, utility in clinical practice is limited by the qualitative nature of the test and
the risk for adverse events. While color Doppler ultrasound is greatly limited in terms of
resolution and can be openly used to examine large vessels of the eye. New development in
ocular imaging has shown that OCTA can provide reproducible and quantifiable information
about the microvasculature of the optic nerve and peripapillary retina in patients with
glaucoma and can do so in a rapid and non-invasive manner avoiding some of the limitations on
doppler ultrasound and fluorescein angiography.
GBE Egb761 is a standardized GBE that's used in most published research on the effect of
ginkgo Biloba. It is a standardized GBE used in evidence-based medicine and clinical
investigations ensuring clinical standardization and a safe manufacturing process. It has
much of the toxic ginkgolic acid removed leaving behind the active components of flavonoid
glycosides and terpene lactones. In general, GBE is well tolerated with a low side effect
profile. Several systematic reviews on research using GBE (daily dose of up to 600 mg) report
no statistical difference in side effects with GBE compared with placebo. There have been
some concerns regarding the bleeding risk while on ginkgo supplementation. However,
randomized placebo-controlled studies in healthy volunteers have not shown any changes in
bleeding time, coagulation parameters, or platelet function. Multiple studies have reported
minimal adverse effects (AEs) of GBE within a specific prescribed dosage range. Overall, GBE
continues to be a well-tolerated supplement with a low side effect profile. Systematic
reviews of the Cochrane databases, PubMed/MEDLINE, EMBASE, and Google Scholar, report no
statistically significant difference in AEs between 80 and 600 mg of GBE and placebo.
