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Macular Degeneration

 

Macular Degeneration Introduction

Macular degeneration is an age related disease. It is also known as senile macular degeneration, or age related macular degeneration. It is the atrophy, or loss of function, of the macula portion of the retina. [1] The macula is the area of the retina is a highly pigmented area, responsible for fine vision, and allows us to focus daily images. Macular degeneration is believed to be the result of damage caused from sunlight, oxidative stress, or poor blood flow to the retina. [2]

There are two forms of macular degeneration. The dry form, atrophic macular degeneration, which involves a disruption in the pigmented cells in the macula resulting in decreased function, and the wet form, or exudative macular degeneration. In exudative macular degeneration there is a formation of a neovascular network, and retinal hemorrhages and exudates; both eventually result in permanent scaring. In addition, both forms are bilateral. [3]

Macular degeneration affects men and women equally. It is world-wide disease that is more common in whites than blacks. There are no predisposing risk factors. I t may be hereditary. Smoking is associated with an increase prevalence of macular degeneration. [4]

Macular Degeneration Symptoms

Individuals will complain of a sudden or gradual loss of vision. There is no pain associated with macular degeneration. Most often. the central vision is affected and peripheral vision remains intact. Visual distortion is common and can be tested using a special grid chart. On exam of the retina, pigment disruption or retinal hemorrhages can be observed. [5]

Macular Degeneration Statistics

  • An estimated 1 in 3 Americans are affected by macular degeneration.
  • Currently, over 15 million Americans have been diagnosed with the condition.
  • 1.8 million people over the age of 40 have advanced macular degeneration, which results in blindness.
  • 7.3 million people are living with the intermediate stage of the disease. 90% of macular degeneration is the dry form, 10% the wet form.
  • The wet form of macular degeneration accounts for 90% of all cases of legal blindness in the United States. [6]
  • Over 150,000 Americans are legally blinded from macular degeneration, and some 20,000 new cases are diagnosed each year. [7]

Macular Degeneration Treatment

There are no medicinal treatments for macular degeneration. If an individual is diagnosed with the wet form, laser photocoagulation is recommended as soon as possible to prevent the onset of blindness. This procedure is only effective when performed in the early stage, by the advanced stage, the damage is irreversible. The dry form does not have any treatment options. For individuals who have lost their central vision, low vision devices are available to assist their peripheral vision. [8]

Alternative treatment is focused on preventing the wet form and limiting the damage caused as a result of the dry form. The underlying theory is to prevent oxidative damage from free radicals and to improve circulation to the retina.

Supplements helpful for Macular Degeneration

Zinc

Zinc is an essential mineral for metabolism of the retina. It is often deficient in elderly patients. Low intake of zinc is associated with an increased risk for age related macular degeneration. [9] In the large Age Related Eye Disease Study (AREDS) zinc use was associated with a decreased rate of mortality in patients with macular degeneration. It was also found to be an integral aspect of treatment with antioxidants to prevent advanced stage macular degeneration. [10]

Copper

Copper is a necessary addition to the treatment regimen for macular degeneration, to offset the adverse reactions associated with high doses of zinc. Supplementation with high doses of zinc can cause reflex copper deficiency, which can result in anemia. Copper must be supplemented to avoid this side effect. [11]

Vitamin E

Vitamin E is an antioxidant. It is present in large amounts in the retina. Vitamin E is the most abundant fat-soluble antioxidant in the retina. Studies have shown Vitamin E to be protective against the development of macular degeneration. [12] One study found that supplementation with Vitamin E reduced the risk of macular degeneration by as much as 13%. [13] Vitamin E was also a piece of the antioxidant formulation used in the AREDS study that found its supplementation prevented advanced stages of macular degeneration. [14]

Vitamin C

Vitamin C is a potent antioxidant. It is present in high amounts in the retina, and functions along side Vitamin E in preventing free radical damage to the eyes. Vitamin C is a protective nutrient, and is used by the retina for preventing damage caused by sunlight. Vitamin C was included in the antioxidant formula in the large AREDS study. It was shown to prevent the development of advanced macular degeneration.

Beta-carotene

Beta-carotene is essential for proper function of the retina. It is present in high amounts in the pigmented cells of both the retina and macula. Beta-carotene was found to be effective at preventing the advanced stage of macular degeneration in the AREDS study. {15]

Lutein

Lutein is a carotenoid. It is present in high amounts in the pigmented cells of the macula. Lutein is protective against the damage caused by sunlight. Medium to high intake of lutein is associated with a decreased risk of developing macular degeneration. [16]

Ginkgo biloba

Ginkgo is a botanical antioxidant that has been shown to improve blood flow to the eyes. It is also considered anti-atherogenic. Ginkgo has been proven in studies to improve visual acuity in patients with macular degeneration. [17] This improvement is thought to be due to its potent antioxidant effects.

References

[1] Beers M and Berkow R. Macular degeneration. The Merck Manual 17th Ed. 1999: 731.

[2] Pizzorno J, Murray M, Joiner-Bey H. Macular degeneration. The Clinicians Handbook of Natural Medicine. Churchill Livingstone New York; 2002: 306-309.

[3] Beers M and Berkow R. Macular degeneration. The Merck Manual 17th Ed. 1999: 731.

[4] Beers M and Berkow R. Macular degeneration. The Merck Manual 17th Ed. 1999: 731.

[5] Beers M and Berkow R. Macular degeneration. The Merck Manual 17th Ed. 1999 : 731.

[6] http://www.pdrhealth.com/drug_info/nmdrugprofiles/herbaldrugs/101840.shtml The Macular Degeneration Foundation. November 2004.

[7] Pizzorno J, Murray M, Joiner-Bey H. Macular degeneration. The Clinicians Handbook of Natural Medicine. Churchill Livingstone New York; 2002: 306-309.

[8] Beers M and Berkow R. Macular degeneration. The Merck Manual 17th Ed. 1999 : 731.

[9] Mares-Perlman JA et al. Association of zinc and anti-oxidant nutrients with age related maculopathy. Ophthamol. 1996; 114: 991-997.

[10] AREDS Research Group. Association of mortality with ocular disorders and an intervention of high dose antioxidants and zinc in age related eye disease study.

[11] http://www.pdrhealth.com/drug_info/nmdrugprofiles/herbaldrugs/101840.shtml National Eye Institute. Macular degeneration. November 2004

[12] West S et al. Are antioxidants or supplements protective for age related macular degeneration? Arch Ophthamol. 1994; 112: 222-227.

[13] Christen WG. Antioxidant vitamins and age related eye disease. Proc Ass Am Phys. 1999; 3: 16-21.

[14] AREDS Research Group. Association of mortality with ocular disorders and an intervention of high dose antioxidants and zinc in age related eye disease study.

[15] AREDS Research Group. Association of mortality with ocular disorders and an intervention of high dose antioxidants and zinc in age related eye disease study.

[16] Seldon JM et al. Dietary carotenoids, Vitamin A, Vitamin C, Vitamin E and advanced age related macular degeneration. JAMA. 1994; 272: 1413-1420.

[17] Head K. Natural therapies for ocular disorders, part one: diseases of the retina. Altern Med Rev. 1999 Oct; 4(5): 342-359.