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Glaucoma
Pigment Dispersing Syndrome
Another cause of glaucoma is considered to be the pigment dispersing syndrome (PDS) or pigmentary glaucoma. In PDS, the concavity (curving inward) of the mid-peripheral iris allows iridozonular contact, causing a shedding of the pigmented iris. Released pigment is then carried to the trabecular meshwork where it can reside benignly, not affecting the IOP, or it can malignantly elevate the IOP, as in pigmentary glaucoma. Flattening of the concave iris by mitotic therapy and laser iridotomy appears the key to current and future management. Studies confirm that PDS is inherited as an autosomal dominant trait, observed most frequently in young, myopic (nearsighted) men (Campbell et al. 1995). An autosomal dominant trait is one in which the inheritance of a dominant gene on an autosome, not a sex chromosome, causes the characteristic to be expressed.
Note: Primary juvenile glaucoma is a rare form of glaucoma that typically affects individuals from 3-20 years of age, and it, too, is an autosomal dominant trait (Wiggs et al. 1995).
In some individuals, exercise causes pigment release and an increase in IOP, contributing to the complexities of PDS management. A study conducted at the Institute of Ophthalmology in Italy determined that exercise-induced pigment release temporarily obstructs the aqueous outflow channels, causing IOP increase in some patients with PDS. Pre-exercise treatment with dapiprazole, an alpha-adrenergic blocking agent, was useful in reducing IOP spikes and increasing outflow facilities after intensive exercise (Mastropasqua et al. 1995; Mastropasqua et al. 1996).
Scientists are one step closer to locating the gene responsible for PDS. The New England Medical Center in 1997 stated that the telomeric end of the long arm of chromosome 7 appears incriminated in PDS. Locating a gene responsible for this condition is the first step toward the isolation of the gene itself. Characterization of the responsible gene will potentially lead to new methods of diagnosis and treatment. PDS is one type of glaucoma, accounting for 12-15% of all cases of blindness each year.
TREATMENT OPTIONS
Current Drug Therapy
Betaxolol, a beta-blocker presently used to reduce IOP, has calcium channel-blocking functions. Experimental studies show that betaxolol is an efficient neuroprotective agent against retinal ischemia in animals when injected directly into the eye or intraperitoneally. Betaxolol exerts its primary neuronal actions on retinal ganglion cells. Unfortunately, betaxolol has an aggressive list of side effects.
Interviews with hospital pharmacists revealed two prescription drugs being filled with more regularity than others for the treatment of glaucoma. Timoptic eye drops, a beta-adrenergic blocking agent, represents an older, but still popular, approach to treating glaucoma. Xalatan, a prostaglandin analogue, generically known as latanoprost, is a newer method of treatment. Its mechanism of efficacy deals with replicating the activity of prostaglandins, hormone-like unsaturated fatty acids that act in minuscule amounts on local target organs. Latanoprost reduces IOP by increasing the outflow of aqueous humor.
Research conducted at the University of Nebraska Medical Center involved 272 patients taking latanoprost for one year (Camras et al. 1996). Of those enrolled in the study, about 70 individuals withdrew before the end of the study. Withdrawals were caused in 1% by inadequate control of IOP; 5% because of increased iris pigmentation; 3% because of other ocular problems; and 17% because of unrelated medical and nonmedical reasons. The final consensus was that latanoprost safely and effectively reduces IOP for one year, evidencing its usefulness in POAG. However, latanoprost usage can cause a darkening of the pigment in the iris, which might aesthetically disappoint a unilateral glaucoma patient.
Supplements That May Lessen Neurotoxicity and Glaucoma Progression
Experimental studies have identified a variety of naturopathic substances that may prove useful in preventing the death of retinal neurons, particularly ganglion cells, induced by ischemia. It may be possible to protect cells against glutamate toxicity by taking methylcobalamin supplements, the biologically active form of B12 (Akaike et al. 1993; Kikuchi et al. 1997). Methylcobalamin is immediately active upon absorption, although cyanocobalamin must be converted to either methylcobalamin or adenosylcobalamin by the body, removing the cyanide molecule and adding either a methyl or adenosyl group.
Note: The amount of cyanide produced in the conversion process is extremely small.
Acetyl-L-carnitine is said to possess efficacy by attenuating age-related neural deficits. Acetyl-L carnitine has produced stunning results in protecting neurons in a wide range of disease processes.
The antioxidant activities of lacrimal fluid and blood plasma were studied in glaucoma, as compared to normal eyes (Makashova et al. 1999). The findings indicate that the progress of glaucoma is paralleled by a gradual decrease in the lacrimal fluid antioxidant levels. A broad-spectrum antioxidant is a recommendation frequently made by various national and international researchers with regard to glaucoma treatment. The antioxidant complex should provide 200-400 IU of vitamin E daily.
Alpha lipoic acid (ALA), both water- and fat-soluble, is a vitamin-like antioxidant, sometimes referred to as the "universal antioxidant." Dr. Lester Packer, a scientist who heads the Membrane Bioenergetics Group at the University of California, regards lipoic acid as a "free agent," meaning that it can substitute for the other antioxidants when they are in short supply. Primary evidence indicates that 150 mg of alpha lipoic acid, taken daily for 1 month, improves visual function and ocular hypertension in glaucoma patients (Filina et al. 1995).
Thiamine (vitamin B1) has been used to improve visual acuity (van Noort et al. 1987). This may be of particular advantage to glaucoma patients, for thiamine-deficient states are frequently associated with glaucoma (Asregadoo 1979).
Can Diet Make a Difference?
The watchful selection of foodstuffs appears to be another modality that impacts the control level of glaucoma. The value of vitamin C has been documented with regard to both lowering IOP and maintaining the reliability of ocular collagen (Pfister 1980; Pasquali et al. 1997; Head 2001). For this reason, glaucoma patients should acquaint themselves with foods rich in this essential vitamin and use them freely in meal planning.
Fresh fruits and vegetables are reliable sources of vitamin C. Select from kiwi, bell peppers, broccoli, cabbage, citrus fruits, Brussels sprouts, kale, parsley, strawberries, tomatoes, and cantaloupe to contribute to an adequate vitamin C intake. Remember to emphasize dark-colored berries (raspberries, blackberries, blueberries), grapes, raisins, and plums, which are sources of anthocyanoside antioxidants having a special affinity for the eye.
Try to plan a diet around whole, unprocessed foods, including whole grains, legumes, nuts, and seeds.
The omega-3 fatty acids have shown benefit in lowering IOP (Kulkarni et al. 1989). One tbsp of flaxseed oil (a source of alpha-linolenic acid) daily provides a good supply of omega-3 fatty acids. Because flaxseed oil is highly polyunsaturated, it should not be heated.
Evidence is mounting pertaining to excitatory neurotoxins encountered in our food supply. The most frequently encountered food excitotoxin is glutamate, which is commercially added to many foods despite evidence that it can freely penetrate certain brain regions and rapidly destroy neurons by hyperactivating glutamate receptors (Olney 1994). Avoidance of glutamate may be of particular advantage to individuals with glaucoma.
The herb oregano, from the mint family, may have a worthwhile place in the diet of a glaucoma patient. James A. Duke, Ph.D. (1997) suggests that of the 60 mints he investigated, all high in antioxidant value, oregano had the highest concentration of antioxidants. He suggests using 1-2 tsp of dried oregano per cup of boiling water. The therapeutic strength of this drink can be amplified with the addition of peppermint and rosemary.
Identify and eliminate the consumption of allergenic substances in ingested food materials. Allergies are individualized and impossible to distinguish universally, but milk, onion, eggs, and chocolate are among the most common in patients.
Drink at least 48 oz of clean water daily. This amount should be metered throughout the day, with at least 1-hour intervals, consuming only a few ounces at one time. Individuals who enjoy juice in their diets or support the healing benefits associated with juice may wish to combine bilberry, cranberry, and huckleberry, all of which are high in anthocyanosides. Avoid stimulating beverages, such as coffee and tea, which cause vasoconstriction and elevated blood pressure.
Topical Eye Drops
Research shows that orally taken antioxidants will effectively raise blood plasma levels of the nutrients, but the intake does not always correlate directly in eye tissues. In one study, oral antioxidant therapy normalized blood antioxidant levels in advanced glaucoma patients but did not help lacrimal antioxidant activity. Although further research needs to be conducted, this may indicate that topically applied antioxidant eye drops may be the preferred treatment in glaucoma patients (Makashova et al. 1999).
Lifestyle Changes
Glaucoma is considered to be a stress disease. Avoid emotional upsets and upheavals, for external pressure increases internal ocular pressure (Kaluza et al. 1996; Flammer et al. 1999). Try to develop a composed, peaceful lifestyle. Climates with great temperature variances are thought to be detrimental. More stable climates and temperatures appear to be better tolerated by the glaucoma patient. Don't smoke, for tobacco constricts blood vessels, reducing the blood supply to the eye. Avoid prolonged eye stresses such as long movies, excessive TV viewing, or excessive reading.
Discuss with your ophthalmologist your physical and sexual activity. Normally, after treatment, regular exercise and activities are resumed. Restraint should be observed to avoid fatigue. Sexual relations are usually permitted, when eye pressure is under control.
SUMMARY
Current glaucoma research appears to focus on providing neuroprotection to retinal ganglion cells (Osborne et al. 1999a; 1999b). This approach may benefit those displaying normal tension but still experiencing progressive visual-field loss. Recommendations to reduce IOP are also included. Glaucoma represents a serious eye condition, requiring monitored supervision by a qualified ophthalmologist. Best results might be obtained by working with a complementary physician who employs the best of orthodox and alternative wisdom.
Some of the following suggestions replicate the same mechanism and should be structured to individual needs:
- Vitamin B12, methylcobalamin, is the choice of many wishing to delay the death of neurons observed in the aging process. Sublingual methylcobalamin supplementation is considered therapeutic for central and peripheral neurological damage, at dosages of 5 mg dispensed throughout the day so that the total intake amounts to 40 mg a day. Do not eat the tablet as one would candy. Let the B12 dissolve slowly under the tongue. This form of vitamin B12 is an alternative to weekly B12 shots and may be quite useful in the prevention of neurotoxicity.
- Aminoguanidine (300 mg daily) has shown neuroprotective benefits. Aminoguanidine reduces nitric oxide, protecting against oxygen deprivation and decreasing the death of the retinal ganglion cells. Limited clinical experience involving aminoguanidine suggests it should not be used in doses greater than 300 mg a day.
- Alpha-lipoic acid has attained favorable attention in the treatment of glaucoma. It appears to improve ocular hypertension and visual function. Current glaucoma research considers a daily dose of 150 mg adequate for glaucoma treatment.
Note: Much larger dosages are used in diabetes and AIDS (300-600 mg daily) without significant side effects. (This information is included to illustrate the safety parameters of alpha lipoic acid.) Possible side effects include skin rash and hypoglycemia. Lipoic acid can worsen a B1 deficiency. Chronic usage of lipoic acid can interfere with biotin utilization, so make sure you are taking plenty of biotin and vitamin B1 when taking over 100 mg a day of alpha lipoic acid.
- Topically applied eye drops may be a more effective delivery system for antioxidant protection. Brite Eyes II contains nutrients that protect against free radicals. The formula also contains the antiglycating agent N-acetyl-L-carnosine, which helps prevent the formation of nonfunctioning protein crosslinks. A daily dose of 1-2 drops in each eye is suggested for general eye health.
- The Life Extension Mix, 9 tablets or 14 capsules daily, or 1 tbsp. of powder daily provides a storehouse of nutrients, including magnesium, zinc, chromium, selenium, vitamin A, thiamine, vitamin C, bioflavonoids, grape-seed-skin extract, vitamin E, and bilberry, which could benefit ocular health. Some individuals may wish to emphasize additional amounts of the most beneficial of these herbs and nutrients, regarding glaucoma management.
- Use vitamin C crystals or a powdered form of vitamin C, buffered with magnesium. (This type is added to a liquid and is considered highly absorbable.) The buffered form of vitamin C is easier on the stomach when large amounts of ascorbate are ingested. The magnesium will tend to act as a calcium channel-blocker and temper a sympathetic nervous response. The vitamin C may assist in lowering IOP and establishing healthy collagen. Some individuals will realize benefit from as little as 2 grams of vitamin C daily; others will need as much as 35 grams daily. Some practitioners use 500 mg of vitamin C per kilogram (2.2 lbs) of body weight, a dose that must be reached gradually. Vitamin C should be spaced throughout the day, allowing a continuous supply of ascorbate.
- Grape-seed-skin extract, rich in proanthocyanidins, increases the effectiveness of vitamin C. Together they support healthy collagen and defend against free radicals. A therapeutic dose of proanthocyanidins is considered to be 150-300 mg daily. Usually this dose can be reduced after a month's saturation.
- Select bilberry by evaluating its anthocyanosides content. (This is calculated by the percentage of anthocyanidin present, typically 25%.) The dosage for bilberry, the "eye herb," is 100 mg, 2 times daily (or as directed by your health-care professional).
- Acetyl-L-carnitine is an important adjuvant in neuropharmacology. A dosage of 3000 mg daily may be used. With most supplements, including acetyl-L-carnitine, gradual introduction of the supplement is advisable, allowing the body to adjust to the actions of the substance.
- Individuals with healthy liver function may use 25,000-50,000 IU daily of vitamin A. (Some research indicates the emulsified form of vitamin A is less stressful on the liver.) Vitamin A from all supplemental sources should be calculated into the daily total, being watchful of the cumulative amounts. Although toxicity is not usually associated with low doses, people should acquaint themselves with the symptoms of vitamin A toxicity (see Appendix A). Pregnant women should use vitamin A only after careful consultation with their physician. The benefits of vitamin A include decreased dry, itchy, inflamed eyeballs and an increase in visual purple, a substance needed for night vision.
- Select Coleus forskohlii standardized to contain 18% forskolin. Use 50 mg (9 mg of forskolin 2-3 times per day) to assist in lowering IOP.
Do not use C. forskohlii if prostate cancer is apparent. During C. forskohlii usage, monitor blood pressure, being alert for hypotension.
- Hydergine's mechanism of efficacy appears similar to C. forskohlii. Hydergine reduces hypoxia and free-radical damage. A dosage of 3-20 mg daily is considered appropriate.
- Attempts to reduce stress are valuable to the glaucoma patient. External stress begets internal stress, both of which equate to physical disruption. Unpleasant interactions with others, temperature extremes, and fatigue are not desirable for anyone, especially individuals with glaucoma.
The preceding pages have delineated many pharmaceutical drugs that have been efficacious in glaucoma control. Nutritional pharmacology offers choices, as well. It appears important to have a relationship with a physician who employs the best from all disciplines. Side effects and quality of life should impact the selection of an ongoing protocol. When contemplating the number of therapeutic agents available to a glaucoma patient, obviously the individual has many options.
FOR MORE INFORMATION
Contact the Glaucoma Research Foundation, (800) 826-6693.
PRODUCT AVAILABILITY
Methylcobalamin, Life Extension Mix, ascorbic acid (vitamin C) powder, grape-seed-skin extract, bilberry, forskolin, liquid emulsified vitamin A, acetyl-L-carnitine, and alpha- lipoic acid may be obtained by calling (800) 544-4440 or ordering online. Aminoguanidine and Hydergine can be purchased offshore. Contact the Life Extension Foundation at (800) 226-2370 for further information. |