The same text includes a description of retinal detachment, as "the eyes turn dull and develop specks:"

Retinal detachment is caused by depletion in the kidney. Even though the eyes belong to the orifices [that is, the eyes are the orifices associated with the liver], they are tied to the kidneys as their ruler. When the kidney is depleted, the eyesight will become dim. Greed, licentiousness, overindulgence in pleasures, and an unrestrained passion for wine and women weaken and exhaust the kidney. Or, when a person's original qi and essence are incomplete, or when essential spirits have become insufficient, all this causes the pupil and the spirit water to lose their clarity and the eyes to be without strength. As a result, the eyes develop specks and the patient is unable to watch anything for an extended time. To regulate this condition, one must employ Bushen Guijing Wan (pills to nourish the kidney and return the essence). They cause the yin water to be sufficient again, and to return everywhere.

Bushen Guijing Wan (Pills to nourish the kidney and return the essence)

The instructions are to grind the herbs to powder, combine with honey, and form pills, or boil the powder in water to make a decoction. The total amount of herbs to be consumed for each dose is unclear. This formula includes several herbs for nourishing the eyes and dispelling wind-heat.

According to this text, the fluid in the vitreous cavity is viewed as an integral part of the kidney water, or yin essence. When the kidney's yin essence is depleted, not only does the eye fluid become drier, but the wood of the liver/gallbladder system dries out. This causes a turbid essence to go upward from the gallbladder, and a weak fire to arise from the liver and kidneys, which combines with invading wind and distorts the fluid contents of the eye. The gallbladder channel starts at the corner of the eye (tongziliao; GB-1, a point indicated for redness and pain of the eyes, failing of vision, and excess tearing). The remedy is to lower the fire, clear it, and then replenish the fluids.

Just as modern medicine recognizes the vitreous fluid as an original fluid of the developing eye, the Chinese doctrine views it as part of the "original water" associated with the kidney, but located in the upper body (referred to as heavenly original water; tian yizhi shui). It degrades by the weakening of the kidney and the invasion of pathogenic influences, such as internal heat from the liver/gallbladder and external wind-heat.

A formula devised after the Yinhai Jingwei was written, Qi Ju Dihuang Wan (Lycium, Chrysanthemum, and Rehmannia Formula), is an example of an eye nourishing prescription used to treat this basic condition. Similarly, the eye-brightening formula, Mingmu Dihuang Wan (Eye-brightening Rehmannia Formula) is aimed at alleviating the dry deficiency of kidney and liver. Yet another formula, Yiqi Congming Tang, is designed to clear the deficiency heat and dispel wind-heat, while benefiting the kidney water indirectly, by nourishing the spleen. It is indicated for deteriorating vision with aging.

In the English-Chinese Encyclopedia of Practical Traditional Chinese Medicine (2), there is a short section on diseases of the vitreous. The clinical manifestations are said to range from mild cases with black shadows floating up and down like flying flies (but no other change in vision) to severe cases, where the eyes seem to be covered by a membrane. There are three categories of causation listed:

• Accumulation and steaming up of damp-heat and attack of turbid qi. This corresponds to the disorder of the gallbladder described above. A recommended formula is modified Sanren Tang (Three Seed Decoction), which clears damp-heat.
  
• Stagnation of liver qi, resulting in blood stasis and extravasation of blood. This corresponds to the leakage of blood into the vitreous cavity, perhaps as a result of retinitis. A recommended formula is modified Jiawei Xiaoyao San (Bupleurum and Peony Formula).
  
• Deficiency of kidney and liver, resulting in flaring up of deficiency fire. This corresponds to the weakness of the kidney water, and associated heat that causes drying of the vitreous. The recommended formula is a modified Zhibai Dihuang Tang (Anemarrhena, Phellodendron, and Rehmannia Formula).
  

SUMMARY
Floaters are rarely caused by release of materials into the eye, and are not a sign of blood deficiency, as is often relayed to Western acupuncturists. Rather, they are a result of natural processes that may be exacerbated or accelerated by overexposure to sunlight, poor circulation in the retina, and lack of hydration, along with deficiency of yin essence and associated flaring of deficiency heat or accumulation of damp-heat. Although there is no proof that the formulas described in the Chinese texts can eliminate floaters and prevent retinal detachment, the use of the herbs and formulas described here is consistent with the basic tenets of the Chinese medical system. In general, one wishes to clear deficiency heat, gently dry damp-heat, and nourish the fluids, particularly the kidney yin, to assure the moistness of the vitreous.

REFERENCES
Kovacs J and Unschuld PU, Essential Subtleties on the Silver Sea, 1998 University of California Press, Berkeley, CA.
Xu Xiangcai (chief editor), The English-Chinese Encyclopedia of Practical Traditional Chinese Medicine, vol. 17: Ophthalmology, 1994 Higher Education Press, Beijing.
December 2002

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