TREATMENT OF GLAUCOMA WITH CHINESE HERBS

by Subhuti Dharmananda, Ph.D., Director, Institute for Traditional Medicine, Portland, Oregon

Glaucoma is a common eye disorder, often associated with aging. It mostly occurs in persons over age 35, with increasing incidence among the elderly: about 2% of persons over age 40, and about 10% of persons over age 70 have chronic glaucoma. This disorder is usually caused by a gradual blockage of the outflow of aqueous humor, the fluid in the front compartment of the eye. If the pressure gets high enough, due to progression of the disease without adequate treatment, the small internal blood vessels and the optic nerve fibers become compressed, eventually causing irreversible damage, with loss of vision or complete blindness. In fact, about 15% of blindness in adults is due to glaucoma. New drug therapies, such as Xalatan, offer hope for keeping glaucoma under control.

The simple type of chronic glaucoma is known as "open-angle" glaucoma (the reference is to the iridocorneal angle measured during an eye examination). It usually affects both eyes, has a genetic component (runs in families; the predisposing genetic background may yield an early age of onset), and is more common among diabetics. There is also an acute type of glaucoma, which can become chronic, known as "closed angle" or "angle-closure" glaucoma; this type can rapidly lead to vision loss and there may be obvious symptoms, such as severe eye pain. This is considered an emergency condition, treated by drugs (internal and topical), and sometimes by surgery. It most often occurs in one eye (though the other eye may later become affected). The simple open-angle glaucoma is the main focus of discussion in this article.

Glaucoma was not a subject of discussion in traditional Chinese medicine before the introduction to China of tonometry (during this century). In the absence of pressure testing, conducted by tonometry devices, chronic open-angle glaucoma is essentially asymptomatic (the person may experience headaches, but these are not necessarily attributed to the eyes), and one simply experiences deteriorating vision, which can have numerous other causes. Along with the introduction of the diagnostic tool for glaucoma came the Western understanding of the disease nature, that is, a fluid-pressure in the eye. This Western description was then translated by Chinese doctors into a traditional Chinese description.

CHINESE VIEW

Fluid build-up is a well-known phenomena in the literature of traditional Chinese medicine. Following the most general principles of yin and yang, fluids, which are inherently of yin nature, tend to be downward draining (just as one sees the downward motion of water in the environment). Therefore, in the absence of other contributing factors, one expects to observe symptoms of fluid accumulation or fluid drainage primarily in the lower part of the body: frequent urination, watery diarrhea, leukorrhea, or swelling of the legs and feet. Other types of disorders, aside from simply having too much fluid, are usually necessary to cause localization of the fluids elsewhere.

Thus, for example, fluid accumulation in the skin, muscles, and joints is usually thought to be the result of the influence of "wind," one of the six classically-recognized environmental pathogenic influences: wind causes blockage of circulation, which can yield fluid accumulation at the sites of blockage. Skin swellings, muscle aching, and joint inflammation are often described as a combination of wind and dampness factors resulting in localized fluid accumulation. The wind and dampness may further be influenced by another environmental pathogenic influence, cold or heat, to yield wind-damp-cold (producing a "bi" syndrome, which corresponds to many cases of muscular or articular rheumatism) or wind-damp-heat (producing red swellings, such as wheals, eczema, or arthritic syndrome with red, swollen joints).

In the case of an eye disorder that develops gradually and involves fluid-pressure within the eye (an internal site, as opposed, for example, to corneal inflammation, a superficial site), yet another explanation is called for. First, the underlying cause is expected to be internal in nature, rather than environmental (environmental influences more often produce rapid development of disease, and the disease often manifests first in the superficial tissues and later in the internal tissues); internal disorders are often influenced by genetics and aging. Since the fluid is accumulated in the upper body, it is understood that the fluid must be forced upward by something. In the general scheme of yin and yang, it is the yang influences that flow upward. These influences have the nature of fire rather than water. As observed in nature, the flames of fire (and the heated air that accompanies it) travel upward.

The combining of internal yin and yang influences to yield a specific fluid disorder occurs in two basic patterns. On the one hand, the yin influence (water) can be dominant and the yang influence (fire) can be secondary. In that case, it is said that the water carries the heat downward (it overcomes the tendency of the heat to rise), and one may experience symptoms of "damp-heat" in the lower part of the body. This kind of syndrome could include, for example, genito-urinary sores and/or infections characterized by colored or thick discharge or burning pain. Sores or other red swellings and irritations on the legs and feet would be a second example. On the other hand, the yang influence can be dominant and the yin influence secondary, in which case the fire carries the water upward (it overcomes the tendency of water to drain downward). The latter is the situation with glaucoma. This is also a common explanation for thyroid swellings, which are thought to represent masses of phlegm (congealed fluid) accumulated at the base of the neck (1).

The traditional Chinese description for glaucoma that arises from this line of thought is that a fire syndrome is generated internally which carries fluids upwards, congesting in the eyes. The origin of the fire syndrome may vary from person to person, and the most likely scenario depends upon the age of onset, as well as factors that are revealed by traditional diagnostic indicators (such as pulse and tongue). For those who experience glaucoma at a relatively early age (say before age 55), the most likely cause of the fire syndrome is a chronic stagnation syndrome.

The Chinese explain the relation of fire to stagnation by this type of analogy: if you form a large pile of wet leaves and let them sit for a while undisturbed, the center of the pile will become quite hot; in fact, under the right conditions (if the outer leaves dry out), the pile of leaves could burst into flames. This phenomena is often observed today in piles of garbage, especially piles of discarded tires. The heat is generated by the accumulation and stagnation: individual leaves, or piles that are quickly dispersed do not become hot.

The common stagnation syndromes are liver qi stagnation, fluid accumulation, and blood stasis. If any of these persist for an extended period of time, one can experience a secondary fire syndrome. Since blood stasis often generates pain or other obvious symptoms, it is not usually deemed a cause of chronic open-angle glaucoma, which can arise without obvious signs of blood-stasis (note, however, that damage to the microvessels in the eyes occurs after the eye pressure is elevated). Liver qi stagnation and "phlegm-fluid" accumulation are quite common in persons with glaucoma, and are considered the most likely causes.

To treat glaucoma (formed by the above-mentioned mechanisms) with traditional methods, one would use a combination of herbs to drain the accumulated fluid from the eyes with additional herbs to decrease the internal fire that drives the fluids upward to cause pressure. Further, one would attempt to reduce the underlying accumulation and stagnation, so that the fire does not continually arise.

If glaucoma develops at a later age, the most likely cause is expected to be the consequence of declining yin essences, a natural part of the aging process, which, as a result of genetic factors or diseases, may become a serious problem for some individuals. The deficiency of yin results in dominance of yang forces, which will drive fluids upward. These yin essences, stored in the kidney and nourishing the liver, can be replenished by tonic herbs and foods.

SPECIFIC TREATMENT STRATEGIES

Herbs used in the treatment of glaucoma in China that are consistent with the principles described here are listed in the accompanying tables. The formulas that incorporate them are discussed in this section; some formulas include herbs, not listed in the tables, which may not have general application to glaucoma.

The primary formula for draining excess fluids is the Hoelen Five Herb Formula (Wu Ling San). It is comprised of four water-draining herbs-hoelen, alisma, polyporus, and atractylodes-plus cinnamon twig, which opens the circulatory channels and helps return upward and outward flowing substances to the interior. In recent years, many Chinese physicians have adjusted this formula by adding a large dose of plantago seed, which also has a fluid-draining action. It is appropriate to treating glaucoma because plantago is said to clear away heat, promote diuresis, and improve visual acuity (2).

The primary formula for removing heat associated with liver qi stagnation is the modified Bupleurum and Tang-kuei Formula (Xiao Yao San), known as Bupleurum and Peony Formula (Jia Wei Xiao Yao San). Xiao Yao San is a widely used ancient formula that addresses disorders of liver qi stagnation, especially when fluid accumulation and heat is involved (it contains hoelen and atractylodes for draining dampness). The Bupleurum and Peony Formula is mainly applied when the heat (or fire) syndrome is especially strong, by incorporating the fire-purging herbs gardenia and moutan; gardenia also drains fluids.

In cases where fluid accumulation (usually in the form of thickened fluid: phlegm) causes fire, a traditional prescription (3) that is commonly relied upon is modified Antelope Horn Powder (Ling Yang Jiao San). The formula is based on the fire-purging action of antelope horn, a substance which is supposed to be especially beneficial for eye disorders associated with liver fire, and the channel-opening (that is, obstruction-removing) and drying action of tu-huo and siler. It is usually indicated for conditions in which phlegm is "rushing upward." If there is a more gradual syndrome of upward movement of phlegm, it is common to rely on Pinellia and Arisaema Combination (Dao Tan Tang), made from the traditional Citrus and Pinellia Combination (Er Chen Tang) by adding arisaema and chih-shih (chih-shih has a downward-draining action). These latter formulas do not purge fire, but can be modified to do so by adding antelope horn, or other herbs that accomplish the same, such as uncaria.

In the event that deficiency of yin essences results in dominance of yang, one often relies on Rehmannia Six Formula (Liu Wei Di Huang Tang) as a prescription for nourishing the yin, or the modified version, Lycium, Chrysanthemum, and Rehmannia Formula (Qi Ju Di Huang Tang), which adds the two herbs in the formula name; they help treat eye disorders that are due to liver yin deficiency and liver fire. These formulas include hoelen and alisma for draining fluids, and moutan for clearing heat in the blood.

The principles of glaucoma treatment are summarized, along with suggested formulas, in the recent compendium English-Chinese Encyclopedia of Practical Traditional Chinese Medicine (4), in which Volume 17 is devoted to ophthalmology. As to cause of open-angle glaucoma, it says:

Emotional depression of a person may cause stagnation of liver qi that will turn into fire. When the fire goes upward to attack the eyes, the disease occurs. Or, if a person suffers from retention of dampness due to hypofunction of the spleen, phlegm will originate from the retention and form phlegm stagnation which will further convert into fire. When the fire moves upward to attack the eye, the disease is caused. Besides, deficiency of the liver and kidney, a condition called consumption of primordial yin, will result in asthenic fire, and attack of the eye by the fire will lead to the disease.

Three sample formulas are given in the encyclopedia. For the case of liver qi stagnation as underlying cause, the following modification of Jia Wei Xiao Yao San is recommended: 9 grams each of bupleurum, moutan, gardenia, hoelen, atractylodes, angelica, chrysanthemum, and prunella, plus 12 grams each of tang-kuei, peony, and uncaria; this is taken in decoction, with 3 grams of antelope horn powder added into the strained decoction at the end of cooking. Prunella, uncaria, antelope horn, and chrysanthemum drain upward rising fire derived from the disturbed liver. These herbs also treat hypertension due to liver-fire.

For the fluid-accumulation type of disorder, a modification of Ling Yang Jiao San and Dao Tan Tang is recommended: 9 grams each of pinellia, arisaema, bamboo, and licorice, 12 grams each of plantago seed, red peony, hoelen, ophiopogon, vitex, cassia seed, and chrysanthemum, plus 3 grams of antelope horn. Vitex, cassia seed, and chrysanthemum are commonly used to "direct" the action of an herb formula to the eyes. Pinellia, arisaema, bamboo, plantago seed, and hoelen resolve phlegm and drain fluid.

For the yin-deficiency type of disorder, the encyclopedia recommends the following modification of Qi Ju Di Huang Tang: 9 grams each of alisma, plantago seed, and gastrodia, plus 12 grams each of hoelen, codonopsis, peony, rehmannia, chrysanthemum, and lycium fruit.

EFFECTIVENESS OF INTERNAL REMEDIES

As to how well such formulas work, we must rely on the small number of published studies for an indication. The published studies usually involve a combination of patients young and old and with both open and closed type glaucoma, as well as acute and chronic cases of the latter. Two studies that involved a large proportion of the simple chronic glaucoma (open-angle type) will provide an indication of what can be expected.

In one study (5) involving 55 patients, Hoelen Five Herb Formula was utilized. The herbs were extracted, made into tablets, and taken 8 tablets at a time, twice daily (equivalent to using 9 grams each of hoelen and polyporus, 6 grams each of atractylodes and cinnamon twig, and 12 grams alisma each day). This formula was used for chronic glaucoma, with either open-angle or closed-angle type. Only the herbs were utilized during the trial period. It was reported that as a result of the treatment, 63.6% of all the affected eyes showed a significant decline in pressure after just one month. No adverse effects of treatment were reported. For purposes of comparison, a physician described (6) an individual case of acute glaucoma successfully treated by Chinese herbs. He used essentially the same formula, but a much higher dose was used and rhubarb was added (rhubarb is used to rapidly drain heat and dampness and is intended to function by causing a laxative action). The formula, in decoction form, contained 30 grams alisma, 30 grams plantago seed, 25 grams polyporus, 25 grams hoelen, 15 grams atractylodes, 10 grams cinnamon twig, and 15 grams rhubarb.

In the other large study (7), the specially-designed formula Xie Gan Jie Yu Tang was utilized. It contained platycodon, leonurus fruit, plantago seed, prunella, phragmites, lepidium, siler, scute, cyperus, and licorice. Lepidium is a drastic purger of fluid accumulation; leonurus fruit is thought to nourish the eyes (it contains vitamin A and essential fatty acids). The exact amounts of each were not specified, but routine dosages were used (this usually means 9-12 grams for most of the herbs, with less for lepidium and licorice, more for plantago seed). There were 29 patients, most having the open-angle type of glaucoma. Of 25 eyes affected by the open-glaucoma type, 17 (68%) attained normal pressure by the treatment, and 5 more could remain normal only if 1% pilocarpine drops (a standard Western medical therapy) were continued.

As these studies indicate, using herbal formulas internally can result in about 2/3 of affected eyes having an improvement in the pressure without use of drug therapies.

TOPICAL TREATMENTS

It should be pointed out that much of the treatment of glaucoma is done by eye drops rather than, or in addition to, systemic treatment, both in Western medicine and in Chinese medicine. In China, the main herb-derived eye drops for glaucoma are pueraria flavonoids (called puerarin), areca seed extract, or, perhaps most commonly, the alkaloids from erycibe (Erycibe obtusifolia; dinggongteng aka baogongteng). These eye drops appear to work as well or better than the Western eye drops, such as pilocarpine, which is usually used as a comparative standard (8), but they are not available to Western practitioners.

REFERENCES

1. Dharmananda S, Treatment of thyroid disorders with Chinese herbs, 1995 START Group Manuscripts, Portland, OR.
2. Ou Ming (chief editor), Chinese-English Manual of Commonly Used Herbs in Traditional Chinese Medicine, 1989 Joint Publishing Company, Hong Kong.
3. Huang Bingshan and Wang Yuxin, Thousand Formulas and Thousand Herbs of Traditional Chinese Medicine, 1993 Heilongjiang Education Press, Harbin.
4. Lu Shengnian and Cai Huasong (chief editors), English-Chinese Encyclopedia of Practical Traditional Chinese Medicine, Volume 17: Ophthalmology, 1989 Higher Education Press, Beijing.
5. Guangdong Medical Journal Editorial Department, Clinical observation of curative effects of Wu Ling San for treatment of glaucoma, Guandong Medical Journal 1982; 3(2): 40.
6. Zhang Xiangxu, Personal experience of clinical application of Wu Ling San, Zhejiang Journal of Traditional Chinese Medicine 1983; 516-517.
7. Shi Shouli, Glaucoma treated by modified Xie Gan Jie Yu Tang, New Journal of Traditional Chinese Medicine 1986; 18(10): 29.
8. Zhang Mingsheng et al., Comparison between baogongteng A and pilocarpine eyedrops in the treatment of primary glaucoma, Shanghai Medical Journal 1981; 4(12): 24-27.

TABLES OF HERBS USED IN TREATMENT OF GLAUCOMA

The following are some of the herbs commonly used to treat glaucoma in China. They are subdivided by their principal actions, namely draining dampness/resolving phlegm, clearing heat (purging fire), and nourishing the kidney and liver. In some cases, the herbs have overlapping properties; they are grouped by traditional categories. The descriptions in the actions sections retain the wording in reference 2, which is the principal source of the information in this table.

Herbs to Drain Dampness

Herbs for Clearing Heat and Purging Fire

Herbs for Nourishing Yin

January 1997