Effect of ginkgo biloba extract on macula and peripapillary perfusion examined using optical coherence tomography angiography.

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.