What is an herb?
Gingko Biloba Leaf Extract (GBE)
Docosohexaenoic Acid (DHA)
Lutein and Zeaxanthin
Quality of the Herbs
During the past decade, several studies have examined whether changes in diet and herbal supplementation can help prevent or reverse the effects of cataracts, age-related macular degeneration and other ocular diseases. My patients are aware of these studies, and they ask me to recommend specific types of herbs that may offer them a line of defense.
What's more, confidence in the herbal industry continues to grow, and consumer use of the supplements has increased four-fold since 1994. A 1998 Celestial Seasonings/Harris survey of 500 U.S. households indicates that 51 percent of consumers are willing to use herbs to treat their health problems and nearly 20 percent take them to prevent health problems. Furthermore, nearly 80 percent of consumers think herbal products are safe, and the industry did nearly $4 billion in total annual sales in 1998. (1)
What is an Herb?
An herb is a food product that is not considered nutritionally active. It is something that you do not take for carbohydrate or fat intake. It is not something that we'd normally eat to maintain our normal health. It is a spice or some other type of plant that has no nutritive value itself. Many of the herbs that are in use today have been in use for over 4500 years for the same problems. All of the herbs described here may be found at local health food stores and pharmacies.
Gingko Biloba Leaf Extract (GBE)
This herbal supplement acts as an antioxidant for the macula, and it's my primary choice of defense for patients with optic nerve disease of various causes. More than 400 studies have been published on the results of GBE, and I offer it to patients regularly. I have seen interesting positive results in patients with ischemic optic neuropathy and other vascular disorders that affect the optic nerve. I also use it in some of my glaucoma patients.
GBE has been used in Europe for the treatment of Alzheimer's disease (2) and multiple infarct dementia.(3) It's use for these conditions has recently been substantiated in the United States peer-reviewed literature,(4) and GBE has also been shown to increase intracranial circulation by regulating tone and elasticity of blood vessels.(5, 6) It's because of these effects that GBE is commonly used in Europe for the treatment of memory loss, hearing loss and dementia, which are usually vascular in origin.
Other studies have shown that the terpene lactone fraction of GBE inhibits platelet activating factor,(7) thus decreasing platelet "stickiness" and increasing circulation amplifying the effects of aspirin. What's more, the ginkgolide fraction has been shown to protect nerves during times of ischemic damage, and there is some evidence that it may stimulate nerve regeneration.(8) It is this aspect of the GBE that attracted me to use it in treating ischemic optic neuropathies, arterial and vein occlusions, and more recently, advanced glaucoma.
The results of GBE, like any herbal supplement, are not immediate. The supplement's effects can be much slower than drugs. I had one 55-year-old patient with bilateral optic atrophy from bilateral ischemic optic neuropathy who noticed the first positive effects of the herb 13 months after her first dose. She presented with 20/200 BCVA in both eyes, and her vision was so poor that the Humphrey visual field test results were black. I placed her on the GBE and some vitamins, and after one year there was no progress. At that point, I told her that she did not have to keep taking the GBE. She insisted on trying for a few more months.
She came back one month later (at 13 months) and insisted she be checked. To my surprise, she was 20/50 in one eye and 20/60 in the other, and we could get about a 5-10 degree visual field. We kept the GBE going, and by 18 months she was 20/40 and 20/50. She also developed a 20-degree visual field in the superior half of each eye and about a 10-degree visual field in the lower half. She still clearly has an altitudinal-type defect, but she has improved vision and has regained her peripheral vision to the point that she no longer has to rely on her husband to lead her. That was about two years ago (four years after I first saw her), and she is ecstatic.
A word of caution: Excessive bleeding may result from taking GBE and aspirin together. I never give it to any patients who are on anticoagulants such as Coumadin or Warfarin. I have given it to patients who take baby aspirin, but with cautions to report any increased bruising or bleeding.
For GBE to have a therapeutic effect, it should be in a concentrated form of 37:1 up to 67:1. Most GBEs are 50:1 concentrates that have a minimum standardized concentration of 24 percent ginkgolides and 6 percent terpene lactones. This information should be clearly marked on the bottle's label.
I typically recommend that patients take 120 mg of GBE twice a day in either tablets or capsules for the first six months then go to maintenance dose of 60 mg twice a day. For most patients, the maintenance dose is plenty.
Docosohexaenoic Acid (DHA)
In patients who have optic nerve damage and whom I place on GBE, I also recommend taking omega-3 fish oils that have an adequate amount of DHA (at least two to four grams a day). This essential fatty acid is found at the very end of the omega-3 cascade and is the major component of the plasma membranes of the neurons and the photoreceptors. (9) Considering that GBE has apparent nerve regenerative properties as previously cited, the nerves may need these fatty acids in order to rebuild the cell membranes. I also recommend DHA to my patients with retinitis pigmentosa, since studies have found that these patients have deficiencies in red blood cell membrane DHA,(10,11) and they may not have the enzymes necessary to make DHA from the omega-6 fatty acids found in the normal diet.(12) DHA is also found in algae, kelp and seaweed. In addition, the Texas Retina Associates are currently performing an ongoing study of its protective benefits. I typically recommend that patients take 240 mg of DHA twice a day.
Bilberry is believed to support blood vessel elasticity and permeability, according to several European studies, and it should be helpful in preventing bleeding and leakage in macular degeneration and diabetic retinopathy. It's also good for capillary fragility and leakage in patients who have small blood vessels that have a tendency to leak. Bilberry is very good at strengthening the junctions in the capillaries.(13, 14) I recommend that patients take 240-480 mg of bilberry extract (25 percent anthocyanosides) two to three times a day.
There are two sources of this herb. One is from grape seeds, and the other is from pine bark. Both sources are good antioxidants but the grape seed pycnongenol, according to European studies, seems to be better at preventing female uterine disorders whereas the pine bark extract seems to be more specific to the eye and retina. The pine bark variety also produces other antioxidant bioflavinoids. I normally prescribe the herb in 50-mg amounts twice a day to prevent macular degeneration and retinal problems such as retinitis pigmentosa.
Lutein and Zeaxanthin
Studies have shown that the photonutrient lutein, which is a pigment found in green leafy vegetables such as spinach, kale and collard greens, is protective against the progression of age-related macular degeneration.(15) That's because lutein is specifically deposited in the eye. Small amounts of zeaxanthin, which appears to rebuild the pigment epithelial layer, are also located in fruits and vegetables where lutein is found. I tell patients to take 5-10 mg twice a day.
Quality of the Herbs
One of the problems with the herbal industry is that it's currently unregulated and there are more than 400 manufacturers. You never really know what's in the bottles (concentration and quality). However, in the near future, there will likely be some sort of FDA intervention to regulate the industry's clinical study standards.
Typically, buying a product from one of the better known companies, such as Pharmanex (its the only company in the PDR), Twin Labs, Allergy Research Group or Nature's Way, ensures quality, and you will pretty much be getting what's advertised on the bottle.
A number of companies offer eye formula multiherbals that are specifically designed for eyes. These are combinations of lutein, ginkgo, zinc, vitamin E and other antioxidants. Most of the eye formulas on the market now are designed for macular degeneration, and most are effective for this. But I tend to do things on a case-by-case basis, because patients' needs vary. I tend to go with the individual herbs.
There is no danger in prescribing all of the herbs at once, as some of my patients typically do. The only herb that may possibly react with the sun is St. John's Wart for depression. There have been a number of cases of photosensitivity related with that herb.
This is a growing field and over the next few years we will see more integration of herbal medication into the American pharmacopoeia. Herbal medicine is not a cure-all and not a substitute for traditional Western medicine, but it is a good adjunct. Most of these herbs have been taken for hundreds of years with no serious adverse affects. Our patients want it, and it is our code of ethics to provide them with all the information and medicine they can get against eye disease.
1. Brevoort, Peggy. The Booming U.S. Botanical Market: A New Overview. HerbalGram 1998;44;33-45
2. Hofferberth B. The efficacy of Egb 761 in patients with senile dementia of the Alzheimer type: a double-blind, placebo-controlled study on different levels of investigation. Hum Psychopharcol 1994; 9:215-222.
3. Mancini M, Agozzino B, Bompani R. Clinical and therapeutic effects of ginkgo biloba extract (GBE) versus placebo in the treatment of psychoorganic senile dementia of arteriosclerotic origin. Gaz Med Ital 1993; 152;69-80.
4. LeBars PL, Katz MM, Berman N, et al. A placebo-controlled, double-blind, randomized trial of an extract of ginkgo biloba for dementia. JAMA 1997; 278:1327-1332.
5. Clostre F. From the body to the cellular membranes: the different levels of pharmacological action of ginkgo biloba extract. In Funfgeld EW, ed. Rokan (Ginkgo biloba): Recent Results in Pharmacology and Clinic. Springer-Verlag, Berlin, 1988, pp.180-198.
6. Jung F, Mrowietz C, et al. Effect of Ginkgo biloba on fluidity of blood and peripheral microcirculation in volunteers. Arzneim-Forsch Drug Res 1990; 40:589-593.
7. Lamant V, Mauco G, et al. Inhibition of the metabolism of platelet activating factor (PAF-acether) by three specific antagonists from Ginkgo biloba. Biochem Pharmacol 1987; 36:2749-2752.
8. Krieglstein J. Neuroprotective properties of Ginkgo biloba-constituents. Z Phytother 1994; 15:92-96.
9. Martinez M. Polyunsaturated fatty acids in the developing human brain, erythrocytes and plasma in peroxisomal disease; therapeutic implications. J Inher Metab Dis 1995; 18(Supp 1):61-75.
10. Schaefer EJ, Robins SJ, Patton GM, et al. Red blood cell phosphotidylethanolamine fatty acid content in various forms of retinitis pigmentosa. J Lipid Res 1995;36:1427-1433.
11. Hoffman DR, Birch DG. Docosahexanoic acid in red blood cells of patients with X-linked retinitis pigmentosa. Inv Ophth Vis Sci 1995; 36:1009-1018.
12. Hoffman DR, Uauy R, Birch DG. Metabolism of omega-3 fatty acids in patients with autosomal dominant retinitis pigmentosa. Exp Eye Res 1995; 60:279-289.
13. Lietti A and Forni G: Studies on Vaccinium myrtillus and anthocyanosides. I. Vasoprotective and anti-inflammatory activity. Arzneim-Forsch Drug Res. 26:829-832, 1976
14. Mian E. Curri SB, et al. Anthocyanosides and the walls of microvessels: Further aspects of the mechanism of the protective effect in syndromes due to abnormal capillary fragility. Minerva Med 68:3565-3581, 1977.
15. Seddon JM, Ajani UA, Sperduto RD, et al. Dietary carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration. JAMA 1994; 272:1413-1420.
*Dr. Reader [Information taken from an article by August L. Reader, III MD, FACS. in Review of Ophthalmology, September 1999 and used by permission. Dr. Reader is board certified in ophthalmology and is an Associate Clinical Professor at the University of Southern California (USC). Dr. Reader has received an Honor Award from the American Academy of Ophthalmology in 1996 and has been involved with vitamin and herbal supplementation for more than 20 years. He practices neuro-ophthalmology and refractive surgery in San Francisco.]