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Updated: May 27, 2025

Evaluation of Capillary and Other Vessel Contribution to Macular Perfusion Density Measured with Optical Coherence Tomography Angiography
Published on: February 18, 2022
Effect of ginkgo biloba extract on macula and peripapillary perfusion examined using optical coherence tomography
Kevin Hodgson1, Mathew M Palakkamanil2, Angela Zhang3
1Dalhousie University, Faculty of Medicine, Halifax, NS, Canada.
Objective:
To evaluate the effect of ginkgo biloba extract (GBE) on optical coherence tomography angiography (OCT-A) macula and peripapillary perfusion parameters among patients with treated early-to-moderate primary open-angle glaucoma.
Design:
Clinical trial.
Participants:
Seventeen patients with early-to-moderate (≥10 dB MD) primary open-angle glaucoma were matched to 17 control patients based on age, sex, and glaucoma status. A total sample size of 34 was determined for effect size 0.5, alpha 0.05, power 0.81, and critical t = 2.03. Normality was confirmed using the Kolmogorov-Smirnov and Shapiro-Wilk tests.
Methods:
The intervention was 120 mg oral GBE twice daily for 4 months. OCT-A scans (15° × 15°) of the macula and peripapillary retina were acquired, two-dimensional projection slab images of the superficial vascular complex were exported, and image analysis was performed. Student's t test was used to compare perfusion density between groups, and between baseline and follow-up for each group. The main outcomes were perfusion density of the superficial vascular complex of the macula and the peripapillary region.
Results:
Comparison between baseline and 4 months' supplementation with GBE revealed no significant change in perfusion density in the macular area, 0.32 (0.04) versus 0.30 (0.04); p = 0.17, and was significantly lower in the peripapillary area, 0.44 (0.05) versus 0.42 (0.04); p = 0.02. No differences were observed in the control group.
Conclusion:
Four-month supplementation with GBE did not result in clinically significant improvement in macula or peripapillary perfusion density in patients with treated early-to-moderate primary open-angle glaucoma. Larger studies are needed to confirm an absence of neuroprotective effects of GBE.

