What is Macular Degeneration?
Key Symptoms
What Causes Macular Degeneration?
Conventional Treatments
Medications
Tests and Procedures
Treatment and Prevention
How Supplements Can Help
Self-Care Remedies
Alternative Therapies
When to Call a Doctor
References
Evidence Based Rating Scale

What is Macular Degeneration?

Macular degeneration is the most common cause of vision loss in people over age 55. (1) In fact, it is also referred to as age-related macular degeneration, or AMD. The macula is the central and most light-sensitive portion of the retina, which is located at the back of the eye. It controls the central field of vision and the ability to distinguish color and fine detail.

When macular degeneration occurs, objects in a person's central viewing area—things being looked at directly—may appear blurred, gray, or simply blank, even though peripheral vision remains normal. As the condition progresses, it threatens the ability to read, drive, watch television, or recognize people easily.

There are two forms of macular degeneration: "dry" and "wet," both of which are painless and usually affect one eye at a time. The dry form occurs when the light-sensitive cells in the macula slowly break down causing tiny bits of debris to accumulate beneath the macula as it becomes thinner over time. Dry macular degeneration, which accounts for about 90% of cases, progresses slowly enough that, initially, most patients do not have serious loss of vision.

One of the most common early signs of dry AMD are tiny yellow protein and fat deposits under the retina known as drusen that may be seen with an ophthalmologic examination. (1-2) The amount of drusen determines which stage of dry AMD is present. Patients with early AMD have either several small drusen or a few medium-sized drusen. In intermediate dry AMD, patients have either many medium-sized drusen or one or more large drusen. They may also see a blurred spot in the center of their vision and require more light for reading and other tasks. When dry AMD reaches the advanced stage, patients may experience a breakdown of light-sensitive cells and supporting tissue in the central retinal area. This breakdown can cause a blurred spot in the center of vision which may grow larger and darker over time, taking away more central vision. Patients may experience difficulty reading or recognizing faces unless they are very close. (2)

In wet macular degeneration, abnormal blood vessels behind the retina begin to grow under the macula. The vessels often leak blood and fluid, which raises the macula from its normal place at the back of the eye. Unlike dry AMD, wet AMD does not have stages and can advance rapidly resulting in permanent damage to central vision. Patients with dry macular degeneration may sometimes suddenly develop wet AMD. However, all patients with wet AMD had the dry form first. It is worth noting that both the wet form and the advanced dry form are considered advanced AMD. (2)

Key Symptoms

• A hazy, gray, or blank spot obstructing the center of your vision with peripheral vision that is not affected
  
  
• Colors that are altered or faded
  
  
• Slightly blurred vision (most common symptom of dry AMD)
  
  
• Straight lines appearing wavy (early symptom of wet AMD)

Patients who have dry AMD in only one eye may not notice any changes in overall vision; they can still drive, read, and see fine details primarily using the other eye. Anyone who experiences the above symptoms should consult an eye care professional. 

What Causes Macular Degeneration? 

Drusen are present in dry AMD, but they are not the sole cause of vision loss. Scientists are unclear about the connection between AMD and drusen but they know that increases in the size and number of drusen increase the risk of developing either form of AMD. Advancing age is the greatest risk factor for AMD. One study showed that those over 60 have a two percent risk of developing AMD, but the risk increases to 30 percent for those over age 75. (2)

Risk factors for AMD include environmental and lifestyle factors such as high dietary levels of saturated fat, tobacco smoke, and years of exposure to the sun's ultraviolet rays. Medical conditions such as high blood pressure, diabetes, and heart disease can also contribute to macular degeneration by decreasing the supply of blood to the eye. 

Genetics are also a risk factor in developing AMD. In 2005, three independent research groups discovered a gene that appears to be linked to at least fifty percent of all AMD cases. (1) The gene known as Complement Factor H (CFH) regulates inflammation, which researchers believe may play a role in the development of AMD. (3) Having light-colored eyes also increases the risk of macular degeneration. (4)

Conventional Treatments

There is no cure for macular degeneration but it can be treated. Wet AMD can be treated with the following methods:

Laser surgery. This is only used on a small percentage of patients with wet AMD; it's more effective if the leaky blood vessels have developed away from the central part of the macula. Laser surgery is done in a doctor's office or eye clinic where a high-energy beam of light (laser) is aimed directly at the fragile blood vessels and destroys them in order to prevent further vision loss. However, the laser may also destroy surrounding healthy tissue and vision. The risk of developing new blood vessels after laser treatment is high and repeated treatments may be necessary. In some patients, vision loss may progress even after treatments.

Photodynamic therapy. A drug called verteporfin (Visudyne®) is injected into the arm where it travels through the body and eventually "sticks" to the surface of the leaky blood vessels in the eye. Next, the doctor shines a light into the eye for 90 seconds to activate the drug. Once activated, verteporfin destroys the blood vessels and slows the rate of vision loss. Since light activates the drug, patients must avoid exposing skin and eyes to direct sunlight and bright indoor light for five days following treatment. Photodynamic therapy takes about 20 minutes to complete, is painless, and can be performed in a doctor's office. It slows vision loss but does not restore vision. This treatment is often temporary and may have to be redone.

Injections. Drugs known as vascular endothelial growth factor (VEGF) inhibitors are thought to decrease the growth of new blood vessels in wet AMD. Most are injected directly into the eye (Ranibizumab, Bevacizumab, Pegaptanib); however Bevacizumab is currently also being studied for systemic use. Repeat injections every one to three months are typically needed; dosing schedules and costs vary considerably between these drugs. The patient's eye is anesthetized (numbed) before each injection, and then the patient is monitored by the doctor following the injection. In clinical trials, improved vision is achieved for a significant number of patients. (See below)

Glucocorticoid (triamcinolone) injections into the eye have also been shown to provide short-term vision improvement in uncontrolled studies; however they are also associated with glaucoma, cataract, and endophthalmitis.

For dry AMD, treatments can delay and possibly prevent the patient from reaching the intermediate stage. However, once dry AMD reaches the advanced stage, no treatment can prevent vision loss. The National Eye Institute sponsored a large study known as the Age-Related Eye Disease Study (AREDS). Results from this study indicate high levels of antioxidants and zinc significantly reduced the risk of advanced AMD and vision loss. (2)

Medications

In 2006, the FDA approved the drug Lucentis (ranibizumab injection) for the treatment of wet AMD. Results from a large two-year study showed monthly injections of Lucentis halted vision loss in more than 90 percent of patients with wet AMD and restored vision in 33 percent of the study participants. (5)

Tests and Procedures

If a patient is over age 60 and complains of recent changes in central vision, an eye care professional may test for AMD during a comprehensive eye exam. The doctor will begin with a visual acuity test using the eye chart to measure how well the patient sees at various distances. Next, the pupils will be dilated (enlarged) with drops in order to examine the retina and optic nerve for signs of any eye problems with a special magnifying lens. A tonometry test will be done with a special instrument to measure eye pressure. 

The doctor may ask the patient to look at an Amsler grid which has a pattern resembling a checkerboard with a dot in the middle of the board. The patient covers one eye at a time and stares at the dot. If some lines are missing or appear wavy, this could be an early sign of AMD.  If the doctor believes AMD may be present, a fluorescein angiogram may be ordered. In this test, a dye is injected into the arm and pictures are taken as the dye passes through the blood vessels in the retina. With this test, the doctor can identify any leaking blood vessels. (2)

Optical coherence tomography (OCT) is an imaging technique that produces cross sectional images of the retina. It provides high resolution anatomic images of the various components of the eye that can be used to identify retinal edema and/or subretinal fluid. OCT has made a significant impact in the diagnosis and management of wet AMD. (19)

Treatment and Prevention

Although regular ophthalmic checkups are essential for anyone at risk for macular degeneration, a program of preventive steps can lower the risks of developing this condition dramatically. While advancing age and genetic factors cannot be changed, lifestyle and environmental risk factors can be adjusted to reduce the risk of developing AMD.

Just a reminder: Anyone with a serious medical condition or who is taking medication should check with a doctor before beginning a supplement program.

How Supplements Can Help

The ARED study showed the most valuable protection against macular degeneration is supplied by a specific high-dose formulation of antioxidants and zinc. The specific daily amounts used in the study were 500mG vitamin C, 400 IU's vitamin E, 15mG of beta-carotene (equivalent to 25,000 IU's of vitamin A), 80mG of zinc as zinc oxide, and 2mG of copper as cupric oxide. Copper was included to prevent copper deficiency anemia, a condition associated with high zinc intakes. (2, 6)

The antioxidant properties of bilberry appear to boost oxygen and blood delivery to the eye. Animal studies suggest it may help prevent AMD; human studies are needed to confirm these results. (7)

A lubricant eye drop derived from the amino acid carnosine is being studied for use in AMD. Preliminary studies indicate a preventive effect for AMD; more studies are needed. (8)

Deficiency in the omega-3 fatty acid DHA is associated with AMD. Since DHA comprises 60 percent of the fatty acids in the retina, supplementation with DHA could potentially prevent occurrences of macular degeneration. However, studies are needed before DHA supplementation can be recommended as preventive therapy. (9)

Some studies indicate ginkgo biloba may benefit AMD because it increases blood flow to the fibers of the eyes. Additionally, gingko's antioxidant properties may benefit the eyes. (10)

Glutathione deficiency is associated with AMD. A 2000 review of risk factors for AMD found that supplementation may enhance the glutathione capacity of the cells that nourish retinal cells. (11-12)

Grapeseed extract improves blood flow in the vessels of the eyes and has antioxidant properties. Studies are needed to determine if it specifically benefits AMD. (13)

Finally, the general effectiveness of the body's antioxidants may get a boost from selenium (in doses of no more than 400 to 600 mcg daily). (14)

Self-Care Remedies

Protect eyes from ultraviolet light by wearing sunglasses and hats that shade the face. People with light-colored eyes need to be especially careful.

Avoid exposure to cigarette smoke, a possible cause of macular degeneration.

Reduce the amount of saturated fat in the diet; it is another powerful risk factor.

Spinach, collard greens, and other dark green vegetables may prevent macular degeneration because of their high levels of the carotenoids lutein and zeaxanthin.

Alternative Therapies

The effect of acupuncture on AMD compared to medication was observed in a small study of 84 patients with AMD. At the end of the study, the rate of improvement in the acupuncture group was 28 percent higher than in the medication (Vitamins A and C) group. However the article is in Chinese, and it is unclear how efficacy was determined. Further studies are warranted. (15)

Microcurrent stimulation is recommended by one alternative ophthalmologist who suggests that it increases circulation to the eye, stimulates function of retinal cells, and reduces scar tissue. A 2002 Lion's Club International newsletter describes golfer Sam Snead's experience with microcurrent therapies, which purportedly improved his vision enough that he could return to golf and pass his driver's license eye exam. However, no clinical trials have been reported. (16)

Homeopathy is based on the Principle of Similars: substances that could cause pathology when given in toxic doses, (in this case, cause injury to the retina or macula) are used in highly dilute form to stimulate a healing response in those who have symptoms similar to the toxicity. For example, three dilute homeopathic medicines that have been used to treat macular degeneration: Benzinum dinitricum, Iodoformium, and Carboneum sulphuratum, are toxic petrochemicals that can damage the retina and produce changes of macular degeneration. (17) During the 19^th and 20^th centuries when homeopathy was popular in the U.S., standard medical texts included Ophthalmic Diseases and Therapeutics (A.B. Norton M.D., 1872) and Homeopathic Therapeutics in Ophthalmology (J.L Moffat M.D., 1916). Indeed, Royal Copeland M.D., the New York Senator who sponsored the 1938 FDA legislation had formerly been a homeopathic ophthalmologist at the University of Michigan. (18) However, there are no modern studies on the use of homeopathy for macular degeneration. Use it for this indication only under consultation with a licensed professional homeopath.

When to Call a Doctor

• Any of the symptoms described above is a signal to see an ophthalmologist immediately. Early treatment can dramatically reduce eye damage and loss of vision.
  
  
• Individuals over age 50 should have yearly ophthalmic checkups to screen for macular degeneration and other eye disorders.

References

1. The Foundation Fighting Blindness. Available at http://www.blindness.org/index.php?option=com_content&view=article&id=45&Itemid=55. Accessed August 7, 2011.
2. National Eye Institute. Available at http://www.nei.nih.gov/health/maculardegen/armd_facts.asp.  Accessed August 7, 2011.
3. Telander DG. Inflammation and age-related macular degeneration (AMD). Semin Ophthalmol. 2011 May;26(3):192-7.
4. Kolár P. Epidemiology of the age-related macular degeneration. Cesk Slov Oftalmol. 2010 Jul;66(3):127-30.
5. Rosenfeld PJ, Brown DM, Heier JS, Boyer DS, Kaiser PK, Chung CY, Kim RY; MARINA Study Group. Ranibizumab for neovascular age-related macular degeneration. N Engl J Med. 2006 Oct 5;355(14):1419-31.
6. Age-Related Eye Disease Study Research Group. A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss: AREDS report no. 8. Arch Ophthalmol. 2001 Oct;119(10):1417-36.
7. Fursova AZh, Gesarevich OG, Gonchar AM, Trofimova NA, Kolosova NG. Dietary supplementation with bilberry extract prevents macular degeneration and cataracts in senesce-accelerated OXYS rats. Adv Gerontol. 2005;16:76-9.
8. Babizhayev MA, Micans P, Guiotto A, Kasus-Jacobi A. N-Acetylcarnosine lubricant eyedrops possess all-in-one universal antioxidant protective effects of L-Carnosine in aqueous and lipid membrane environments, aldehyde scavenging, and transglycation activities inherent to cataracts: a clinical study of the new vision-saving drug N-Acetylcarnosine Eyedrop Therapy in a database population of Over 50,500 patients. American Journal of Therapeutics. 16(6):517-533, November/December 2009.
9. Desmettre T, Lecerf JM, Souied EH. Nutrition and age-related macular degeneration. J Fr Ophtalmol. 2004 Nov;27(9 Pt 2):3S38-56.
10. Evans JR. Ginkgo biloba extract for age-related macular degeneration. Cochrane Database Syst Rev 2003;(2):CD001775.
11. Samiec PS, Drews-Botsch C, Flagg EW, et al. Glutathione in human plasma: decline is associated with aging, age-related macular degeneration, and diabetes. Free Radic Biol Med. 1998;24:699-704.
12. Cai J, Nelson KC, Wu M, et al. Oxidative damage and protection of the RPE. Prog Retin Eye Res. 2000 Mar;19(2):205-21.
13. Shi J, Yu J, Pohorly JE, Kakuda Y. Polyphenolics in grape seeds-biochemistry and functionality. J Med Food. 2003 Winter;6(4):291-9.
14. McDermott JH. Antioxidant nutrients: current dietary recommendations and research update. J Am Pharm Assoc (Wash). 2000 Nov-Dec;40(6):785-99.
15. Jiao NJ. Observation on therapeutic effect of age-related macular degeneration treated with acupuncture. Zhongguo Zhen Jiu. 2011 Jan;31(1):43-5.
16. Changes in Microcurrent Stimulation for the treatment of eye disease. Healing the Eye: Vision Therapy and Restoration, http://www.healingtheeye.com/microcurrent.html, accessed August 17, 2011.
17. Homeopathic approach to treating eye disease. Healing the Eye: Vision Therapy and Restoration, http://www.healingtheeye.com/homeopathy.html, accessed August 17, 2011.
18. Robbins N. Copeland's Cure: Homeopathy and the War Between Conventional and Alternative Medicine, Alfred A. Knopf, New York, 2005.
19. Arroyo JG. Age-related macular degeneration: Epidemiology, etiology, and diagnosis. UpToDate:Last literature review version 19.2: May 2011 | This topic last updated: June 6, 2011