AGE-RELATED MACULAR DEGENERATION (AMD)

The DRY FORM is present in about 90% of AMD cases and consists of a thinning of the macula and yellow pigmentation spots called drusen forming in a scattered random pattern. Progression of this condition is unpredictable, but may be affected by risk factors mentioned below. However some cases progress to;

The WET FORM accounts for the remaining 10% of AMD cases and consists of a proliferation of capillary type blood vessels beneath the macula which "leak" and distort the macula. This condition predictably progresses to complete loss of central vision. A medical specialist may try LASER treatment for this form in the early stages which zap the proliferating blood vessels, but such treatment is not a cure and there are reports that it may do more harm than good. Anyone considering laser treatment may want to consider a second opinion from a qualified medical specialist.

RISK FACTORS -

• AGING over 50, increasing with time.
• GENES ? Some studies have claimed a familial link. There is a specific condition called Stargart Disease which involves the Stargardt Disease Gene (STGD1 or ABCR) which is responsible for Stargardts. Yet Stargardt Disease which has an estimated incidence of 1:10,000 does not include all forms of AMD, leaving a population for which studies can establish no genetic link.
• SMOKING ! There is a 6.6 times greater risk of developing macular degeneration in smokers, even former smokers have a 3.2 greater risk. (source http://www.homeopathiceye.com/smd.htm)
• GENERAL HEALTH - There is a higher incidence of macular degeneration with hypertension, arteriosclerotic vascular disease and diabetes.
• CRONIC SUNLIGHT SUNLIGHT EXPOSURE - UV light damage to natural filtering pigments in the eye may lead to AMD, and it has been suggested that people with AMD should avoid direct sunlight, wearing dark glasses to slow AMD progression. Current research is aimed at further understanding of this concept. (http://fundedresearch.cos.com/cgi-bin/NIH/getRec?S06GM082050021)
• BLUE/GREEN EYES and light skin color relates to the EXPOSURE risk factor in that such factors have less melanin to act as a UV filter and anti-oxidant.
• NUTRITIONAL DEFICIENCIES -
  • ZINC ? This micro nutrient has been associated with slowing AMD in some studies, but other studies discount this. See zinc treatment below.
  • CAROTENOIDS -Beyond a doubt the two carotiniods LUTEIN and its chemical brother ZEAXANTHIN are found in the eye and there is little doubt that they can function as UV filters, protecting substructures in the eye from damaging UV light. Humans are not known to make either of these two caroteniods from other building blocks and are consequently wholly dependant on diet for them. Studies indicate a strong relationship between risk reduction for AMD and higher amounts of dietary LUTEIN.

  • Eating eight grams a day of olestra--about 16 chips--with meals for two weeks led to a 20 percent drop in lutein levels in the blood of volunteers, according to P&G's own study. (http://cspinet.org/olestra/pbg.html)

• LASER - This is Western Medicine's best attempt at treatment for the WET form of AMD. Not inexpensive, it is at best a postponement of questionable duration for the WET form, and at worst reports can be found that indicate it makes matters worse for some.
• Photodynamic therapy (PDT) is an un-established experimental procedure for WET AMD.
  With PDT a light-sensitive dye is injected into the bloodstream and is transported to the retina at the back of the eye. This chemical highlights the blood vessels that are growing abnormally. A low energy or cold laser beam is then shone onto the macula. This makes the chemical react and destroy the leaking blood vessels without damaging the healthy tissue around the affected area in the back of the eye, obviously preferable to the "hot" lazer method which inadvertently can damage normal tissue. More than one treatment is usually required, and even then the effect does not seem to be lasting. For information on the photodynamic therapy trial, call Ciba Vision Opthalmics, 800-757-1314
• Thalidomide has been suggested since it interferes with new blood vessel development. If the proliferation of capillary type blood vessels present in wet AMD could be stopped with a drug then the degenerative process may slow or stop depending on whether capillary proliferation is a primary cause of AMD rather than an effect of some other fundamental problem (as nutritional deficiencies suggest). Since laser treatments which attempt to stop capillary proliferation are at best temporary, any similar approach using drugs may be subject to the same fate. Yet the concept is not without merit since the proliferative process would be stopped at a more biologically persistant and fundamental level than the occasional blast from a laser. A number for trials at the Sheie Eye Institute (215-662-8142) is no longer valid.

  In the off-the-wall suggestion category where it can't hurt and might help is the consideration that inhibiting new blood vessel growth is a hot topic in current research to fight cancer by fighting a tumors need for new blood vessels. While the drugs that do this in the case on cancer studies are not available for AMD treatment*, what is available is the knowledge that oriental cultures that have a high dietary intake of soybean products such as tofu have a lower rate of some cancers, and the reason is attributed to natural agents in soy that inhibit new blood vessel growth. The final connection here is left to the reader.

  * There is now information available that this approach merits further consideration.
  See http://www.genaera.com/pressreleases/2003_oct7.html.

• NUTRITIONAL SUPPLEMENTATION -
  • ZINC may or may not be effective for slowing ADM progression and it would seem that no harm could result from using a zinc supplement in the hope that it may actually help. To a point this is not unreasonable but it is cautioned that excess zinc can be detrimental so never use the "if some is good, more is better" rational with zinc supplements. See NEW SCIENTIST Oct 18,'97 p48 for report on Zinc causing heartbeat abnormalities. See www.cc.nih.gov/ccc/supplements/zinc.html and http://www.atsdr.cdc.gov/tfacts60.html for advice that the upper limit for adults is 40mg per day and "Harmful health effects generally begin at levels from 10-15 times the RDA (in the 100 to 250 mg/day range)". Considering that zinc supplements are sold containing 100 mg per pill this is very relavent to anyone intending to use some of the eye health supplements sold that include zinc. Remember that any amounts of zinc taken as a supplement are in addition to what one gets as part of a normal diet, so careful attention to the possibility of overdosing should be given.
  • LUTEIN definitely falls into the "it doesn't do harm and could help" category, so much so that "could" actually means "probably". Since 1994 valid scientific studies have supported this and despite the fact that the medical treatment community chooses to ignore lutein dietary supplementation in favor of their more expensive high tech treatments, studies continue to support the value of this nutritional factor as a risk reducer and treatment adjunct.
• ARTIFICIAL IMPLANTED RETINA is a futuristic concept that the present may be catching up to. There are reports in the popular press of a well known blind recording artist hoping to regain some vision through this technology. Additionally the National Science Foundation has awarded research grants to researchers to "provide the fundamental knowledge needed to make an artificial, implanted, retina to enable the more than 10 million persons afflicted by retinal diseases such as retinal pigmentosa, and age-related macular degeneration, to regain the sense of sight." (http://www.nsf.gov/cgi-bin/showaward=9509758 )

DIAGNOSIS -Depending on individual risk factors, periodic visits to the eye doctor would help to identify early signs of AMD. The presumptive indication of AMD in either form can be determined by viewing a chart consisting of a cross pattern of straight lines. If any of the lines appear to be curved around the center of vision consultation with an eye doctor is recommended to determine pending AMD.

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