Influence of Ginkgo biloba on ocular blood flow.
OBJECTIVE
To investigate the effect of Ginkgo biloba extract (EGb761) on ocular blood flow.


METHODS
This randomized, double-masked, placebo-controlled, two-way crossover study included 15 healthy male volunteers. Measurements were taken with laser Doppler flowmetry, laser Doppler velocimetry, a retinal vessel analyser, laser interferometry and applanation tonometry, before and up to 3 hours after oral intake of 240 mg EGb761.


RESULTS
At baseline, no significant differences in ocular and systemic haemodynamic parameters were observed between the two study days. Ginkgo biloba significantly decreased retinal venous diameters (p < 0.05 versus baseline), but there was no significant difference between the two groups. Blood pressure, retinal arterial and venous diameters, choroidal blood flow, fundus pulsation amplitude, intraocular pressure and retinal blood flow remained unchanged in both groups and did not differ between groups. Optic nerve head blood flow significantly increased in response to Ginkgo biloba (p < 0.002 versus baseline), but this effect was not significant compared with that of placebo.


CONCLUSIONS
The results of this study indicate that a single administration of Ginkgo biloba does not influence ocular blood flow to a relevant degree. Whether the drug may influence ocular blood flow in patients with ocular vascular disease after longterm treatment remains to be investigated in a randomized, placebo-controlled clinical trial.
Wimpissinger
Barbara
B
Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
Berisha
Fatmire
F
Garhoefer
Gerhard
G
Polak
Kaija
K
Schmetterer
Leopold
L
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D002317:Cardiovascular Agents / Q000008:administration & dosage*; D002829:Choroid / Q000098:blood supply; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005123:Eye / Q000098:blood supply*; D020441:Ginkgo biloba; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007368:Interferometry; D007429:Intraocular Pressure / Q000187:drug effects; D017078:Laser-Doppler Flowmetry; D008297:Male; D009898:Optic Disk / Q000098:blood supply; D010936:Plant Extracts / Q000008:administration & dosage*; D012039:Regional Blood Flow / Q000187:drug effects; D012171:Retinal Vessels / Q000502:physiology; D014065:Tonometry, Ocular; D000096983:Ginkgo Extract
D002317:Cardiovascular Agents; D010936:Plant Extracts; C063170:Ginkgo biloba extract; D000096983:Ginkgo Extract