NCT02376114

Ginkgo Biloba and Ocular Blood Flow in Primary Open-angle Glaucoma

The Effect of Ginkgo Biloba on Ocular Blood Flow in Primary Open-Angle Glaucoma Patients: A Double-Blind Randomized Crossover Trial

• Status: Completed
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 19 (actual)
• Sponsor: Maisonneuve-Rosemont Hospital · Academic / Other
• Sex: All
• Age: 40 Years – 80 Years
• Healthy volunteers: Not accepted

Summary

Glaucoma is one of the leading causes of blindness. Ginkgo biloba may be part of an effective treatment strategy for glaucoma because it has been shown to improve blood flow, it has antioxidant properties, it can relax smooth muscle, and it can protect neurons from damage. The goal of our study was to determine whether Ginkgo biloba would result in increased ocular blood flow which may protect against glaucoma damage.

Detailed description

Glaucoma is one of the leading causes of blindness. Glaucoma progression sometimes occurs despite apparent control of intraocular pressure. Therefore, there may be other factors involved in glaucoma progression in some patients. Evidence is mounting that glaucoma patients are more likely to have abnormal ocular blood flow and vasospasm compared to those without glaucoma. Also, a study showed that those with progressive glaucoma had decreased blood flow compared to those with stable glaucoma or healthy controls. Endothelin-1, a potent vasoconstrictor, may be involved in these blood flow abnormalities. If the dysregulation of blood flow is causally related to the progression of glaucoma, then therapies aimed at improving the regulation of blood flow may help to prevent this progression. Ginkgo may be part of an effective treatment strategy for glaucoma because it has been shown to improve peripheral and cerebral blood flow. Other properties of Ginkgo that may aid in the treatment of glaucoma include antioxidant properties, inhibition of platelet activating factor, relaxation of smooth muscle, and neuroprotective properties. Ginkgo may be particularly useful in relaxing vasospasm. Two controlled trials have examined the effect of Ginkgo on ocular blood flow in healthy subjects. One randomized crossover trial found that 2 days of Ginkgo increased the end diastolic velocity in the ophthalmic artery compared to placebo. However, another trial found that 1 dose of Ginkgo had no significant effects on ocular blood flow parameters. In people with normal tension glaucoma, Park et al found that 4 weeks of Ginkgo increased peripapillary retinal blood flow. Two randomized controlled trials have examined the impact of Ginkgo biloba on visual field in people with normal tension glaucoma with conflicting results. Clearly, there is a need for more research on this topic. The goal of our study was to determine whether Ginkgo biloba would result in increased ocular blood flow, reduced vasospasm, and reduced endothelin-1 levels.

Conditions

• Glaucoma, Open-Angle

Interventions

Type	Name	Description
DRUG	Ginkgo biloba	The Ginkgo biloba extract that was used contained 24% ginkgo flavone glycosides and 6% terpene lactones (Vitamin Research Products, Carson City, Nevada). Patients took 60 mg of Ginkgo or a placebo twice daily by mouth for two weeks. The placebo consisted of 40 mg of corn starch. Ginkgo and the placebo were encapsulated to ensure identical appearance.
DRUG	Placebo to Ginkgo biloba

Timeline

• Start date: 2011-08-01
• Primary completion: 2014-02-01
• Completion: 2014-02-01
• First posted: 2015-03-03
• Last updated: 2015-03-03

Locations

1 site across 1 country: Canada