Short-term effects of Ginkgo biloba extract on peripapillary retinal blood flow in normal tension glaucoma.

Based on the vascular theory of glaucoma pathogenesis, we wanted to evaluate the effect of Ginkgo biloba extract (GBE) on peripapillary blood flow in patients with normal tension glaucoma (NTG). Thirty patients with NTG were randomly placed in the GBE-treated or control groups. The GBE-treated group received 80 mg GBE orally, twice a day for four weeks, and the control group received a placebo twice a day for four weeks. Complete ocular examinations including visual field, Heidelberg retina flowmeter, and systemic examinations were performed on the first study day and on the day treatment was completed. After GBE treatment, the mean blood flow, volume, and velocity increased at almost all points, and there was a statistically significant increase in blood flow at almost all points, in comparison to the placebo. Blood volume significantly increased only in the superior nasal and superior temporal neuroretinal rim areas. GBE also significantly increased blood velocity in areas of the inferior temporal neuroretinal rim and superior temporal peripapillary area. GBE administration appears to have desirable effect on ocular blood flow in NTG patients.