Glaucoma is a condition of poor circulation within the eye. All types of glaucoma can cause damage to the optic nerve, resulting in tunnel vision or loss of sight. Glaucoma is the leading cause of blindness among African-Americans and the second most common cause of blindness in the United States as a whole. Risk factors other than African-American descent include diabetes, high blood pressure, migraine, nearsightedness, and the use of cholesterol-lowering medications and steroids.
The progress of glaucoma is insidious. There are usually no symptoms or only vague symptoms during the early stages of the disease. The only hint something is wrong may be difficulty parking a car into a parallel slot or missing words in reading, or difficulty adjusting to dim light. Once the optic nerve has begun to atrophy, peripheral vision is loss first. The tunnel of good vision grows smaller and smaller until blindness finally results.
The most common form of glaucoma is the so-called open-angle form of the disease. The lens is nourished by a watery fluid known as the aqueous humor rather than by the bloodstream. This nourishing fluid is produced by the ciliary bodies at the edges of the lens. It has to flow around a 180º bend to reach the canal of Schlemm, a porous vein that transports essential nutrients and oxygen into the cornea. If this angle is closed, circulation to the cornea is cut off and intense pain and rapid destruction of the optic nerve results. If circulation is merely impeded as the angle remains open, the consequences are lesser pain and slow destruction of the optic nerve.
Changes in the structure of the collagen of the eye precede circulation problems. A filtration barrier keeps large particles from entering the aqueous humor. This barrier is composed of glycosaminoglycans (GAGs). In eyes affected by glaucoma, chondroitin sulfate builds up and hyaluronic acid is depleted in the filtration barrier. This imbalance makes the filtration barrier inelastic and impermeable to fluids, with the result that the cornea ceases to be well hydrated and pressure builds up behind the barrier.
Russian scientists have found that ineffective antioxidant defense systems also contribute to the progress of glaucoma. Patients with advanced glaucoma were especially likely to have low levels of glutathione in both the aqueous humor and the bloodstream. Patients with advanced glaucoma had on average twice the levels of oxidation of essential fatty acids in the vitreous humor inside the eye. While glaucoma is usually associated with elevated intraocular pressure (IOP), although it is not the same as elevated IOP. Normal IOP ranges from 7 to 22 mg/Hg.
Approximately 90 percent of people with IOPs greater than 22 mm/Hg never develop glaucoma, while some people with normal IOPs (especially migraine sufferers) nonetheless develop optic nerve injury. People with elevated IOP who avoid the damage to the optic nerve do so because they maintain good circulation despite elevated pressure.
Bioflavonoids are helpful in a wide range of eye problems, including poor night vision, nearsightedness, and retinopathy. A small-scale study in Italy found that the bioflavonoids found in bilberry increase circulation in the retina in glaucoma patients, even after a single dose (equivalent to 800 milligrams of standardized bilberry extract). The bioflavonoid rutin has been used to lower IOPs when patients are unresponsive to medication alone.
Three B’s for Glaucoma: What are the foods that are richest in rutin? For glaucoma emphasize the “three B’s,” blackberries, blueberries, and buckwheat.