Written by Greg Arnold, DC, CSCS. In this study of 332 subjects with glaucoma, those who supplemented with bilberry for 2 years had a significant 31.25 % improvement in vision compared to an 18% improvement in the gingko biloba group and a 6.5% improvement in the control group.

gingko biloba - botanicalsGlaucoma is a group of diseases that damage the eye’s optic nerve and can result in vision loss and blindness.  Glaucoma occurs when fluid in the eye is not properly drained, causing pressure in the eye to rise and damage the main nerve in the eye called the optic nerve. But glaucoma can also occur in the eye without an increase in eye pressure. This is called “normal tension glaucoma” (1).

While the exact cause of normal tension glaucoma isn’t known, some contributing factors are thought to be increased cell damage by free radicals (2) as well as inflammation (3). Now a new study (4) suggests that two supplements — gingko biloba or antioxidants from a plant called bilberry — may help with normal tension glaucoma.

The study involved 332 subjects (209 men, 123 women) aged 39 to 65 with normal tension glaucoma.  They were given either 120 milligrams (one 60-mg capsule twice daily) of antioxidants in bilberry anthocyanins (132 subjects), 160 milligrams (one 80-mg capsule twice daily) of gingko biloba (103 subjects) or placebo (97 subjects) for 2 years.  Eye exams were given at the beginning and end of the study on each subject.

After 2 years, those in the bilberry group showed the greatest improvement in vision through an exam called “Best Corrected Visual Acuity”, in which a positive value indicates worsening vision (5). While the bilberry group saw a 31.25% improvement in their vision (0.16 to 0.11 logMAR), the gingko group saw a 16.7% decline in vision (0.06 to 0.07 logMAR) and the control group saw a 85.7% decline in their vision (0.07 to 0.13 logMAR) (p = 0.08).

In another measure of visual acuity called The Humphrey Visual Field Test (6), a negative number indicates a worsening of vision. Those in the bilberry group saw a 17.1% improvement in their vision (-6.44 to -5.34) compared to a 18% improvement in the gingko group (- 5.25 to -4.31) and a 6.5% improvement in the control group (-5.41 to -5.06) (p = 0.001).

When suggesting how bilberry and gingko elicited these healthful effects on the eye, the researchers pointed to the anti-inflammatory (7, 8) and antioxidant (9, 10) properties of gingko and bilberry, as well as their ability to improve blood circulation (11).

For the researchers, “These results suggest that anthocyanins and gingko biloba may be helpful in improving visual function in some individuals with normal tension glaucoma” and that “These results can help clinicians manage patients with normal tension glaucoma.”

Source: Shim, Seong Hee, et al. “Ginkgo biloba extract and bilberry anthocyanins improve visual function in patients with normal tension glaucoma.” Journal of medicinal food 15.9 (2012): 818-823.

© 2010 Elsevier Ltd. All rights reserved.

Posted November 2, 2015.

Greg Arnold is a Chiropractic Physician practicing in Hauppauge, NY.  You can contact Dr. Arnold directly by emailing him at PitchingDoc@msn.com or visiting his web site at www.PitchingDoc.com.

References:

  1. “Facts About Glaucoma” posted on the National Eye Institute Website
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  3. Yan X, Tezel G, Wax MB, Edward DP: Matrix metalloproteinases and tumor necrosis factor alpha in glaucomatous optic nerve head. Arch Ophthalmol 2000;118:666–673
  4. Shim SH.  Ginkgo biloba extract and bilberry anthocyanins improve visual function in patients with normal tension glaucoma. J Med Food 2012 Sep;15(9):818-23. doi: 10.1089/jmf.2012.2241. Epub 2012 Aug 7
  5. Holladay JT: Proper method for calculating average visual acuity. J Refract Surg 1997;13:388–391
  6. Smith SD, Katz J, Quigley HA: Analysis of progressive change in automated visual fields in glaucoma. Invest Ophthalmol Vis Sci 1996;37:1419–1428
  7. Tsoyi K, Park HB, Kim YM, et al.: Anthocyanins from black soybean seed coats inhibit UVB-induced inflammatory cyclooxygenase-2 gene expression and PGE2 production through regulation of the nuclear factor-kappaB and phosphatidylinositol 3-kinase/Akt pathway. J Agric Food Chem 2008;56:8969–8974
  8. Salvayre R, Braquet P, Perruchot T, Douste-Blazy L: Flavonoids and Bioflavonoids 1981. Elsevier Press, Amsterdam-Oxford-New York, 1982, pp. 437–442
  9. Eckert A, Keil U, Scherping I, Hauptmann S, Mu¨ ller W: Stabilization of mitochondrial membrane potential and improvement of neuronal energy metabolism by Ginkgo biloba extract EGb 761. Ann NY Acad Sci 2005;1056:474–485
  10. Hirooka K, Tokuda M, Miyamoto O, et al.: The Ginkgo biloba extract (EGb 761) provides a neuroprotective effect on retinal ganglion cells in a rat model of chronic glaucoma. Curr Eye Res 2004;28:153–157.
  11. Colantuoni A, Bertuglia S, Magistretti MJ, Donato L: Effects of Vaccinium myrtillus anthocyanosides on arterial vasomotion. Arzneimittelforschung 1991;41:905–909.