AMD

[HysteryDiagnosis]

Complete article at:


http://www.lef.org/LEFCMS/aspx/PrintVersionMagic.aspx?CmsID=115172

Emerging Options: Hormone Therapy

Research has shown that the hormone dehydroepiandrosterone, or DHEA, is abnormally low in patients with AMD (Bucolo 2005). DHEA also has been shown to protect the eyes against oxidative damage (Tamer 2007). Because the macula requires hormones to function, an emerging theory hypothesizes that low blood sex hormone levels cause the retinal macula to accumulate cholesterol in an attempt to produce its own hormones (Dzugan 2002). The accumulation of cholesterol in macula may lead to the production of pathologic drusen and subsequent macular degeneration. Inverse association of female hormone with neovascular AMD was observed with current and former use of hormone replacement therapy use among Caucasian and Latino women (Edwards 2010). Restoring optimal hormone balance with bioidentical hormones may be an effective new treatment for both men and women. Clinical studies are in process to test this hypothesis and possible hormonal treatment options.

Melatonin is a hormone and strong antioxidant that scavenges free radicals. Several studies have shown that many areas of the eye have melatonin receptors (Rastmanesh 2011, Lundmark 2006). Clinical study has shown that treatment with 3 mg of melatonin at bedtime in those with AMD prevented further vision loss (Yi 2005). In the study, 100 patients with dry or wet AMD received the nighttime dose. After six months, visual acuity had not diminished and the majority of patients had reduced pathologic macular changes upon examination.
Macular Pigments: Lutein, Zeaxanthin, and Meso-zeaxanthin.

The relation between the density of macular pigment and the onset of AMD is well established. The macular pigment is composed principally of three carotenoids: lutein, zeaxanthin, and meso-zeaxanthin. They represent roughly 36, 18, and 18% of the total carotenoid content of the retina. They are found within the macula and surrounding tissues, including blood vessels and capillaries which nourish the retina (Rapp 2000).

Lutein, zeaxanthin and meso-zeaxanthin ensure proper functioning of the macula by filtering out harmful ultraviolet light and by acting as antioxidants (Beatty 2000, Kaya 2010). During the aging process, there is a decrease in levels of lutein and zeaxanthin; low levels of macular pigments are linked to AMD (Johnson 2010). An autopsy study on donated eyes found that levels of all three carotenoids (lutein, zeaxanthin, and meso-zeaxanthin) were reduced in those with macular degeneration compared to control subjects. The most significant finding, however, was the sharp decrease in meso-zeaxanthin in the macula of macular degeneration subjects (Bone 2000). This postmortem study helped confirm other studies indicating the importance of all three carotenoids in maintaining the structural integrity of the macula (Krinsky 2003). These carotenoids protect the macula and the photoreceptor cells beneath via their antioxidant properties and light-filtering capabilities (Landrum 2001).

[laconicsax]

1. "These statements have not been evaluated by the Food and Drug Administration....

These products are not intended to diagnose, treat, cure or prevent any disease."

[HysteryDiagnosis]

2. Tough crap isn't it. n/t

[laconicsax]

3. I just thought it relevant to note the standard snake-oil disclaimer on the linked website. n/t

[Name removed]

5. Deleted message

Sub-thread removed by moderator. Click here to review the message board rules.

[HysteryDiagnosis]

4. let's see if you can tell me who evaluated these statements.... or is it too much for you?

http://www.ncbi.nlm.nih.gov/pubmed/20590393

Curr Med Res Opin. 2010 Aug;26(8):2011-23.
Dietary supplementation: effects on visual performance and occurrence of AMD and cataracts.
Barker FM 2nd.
Source

Pennsylvania College of Optometry at Salus University, Elkins Park, PA 19027, USA. [e-mail]
Abstract
OBJECTIVE:

To evaluate results of studies that have provided information regarding the effects of dietary supplementation on visual performance, development and progression of age-related macular degeneration (AMD), and risk for cataracts.
RESEARCH DESIGN AND METHODS:

Studies with information about the effects of dietary supplementation were identified via PubMed searches that combined (in separate searches) the terms 'supplement' OR 'supplementation' OR 'diet' AND 'cataract' or 'macular degeneration' or 'visual' OR 'vision'. Additional references concerned with biologic effects of specific agents, measurement of visual function, and the etiology and epidemiology of cataracts and AMD were identified on the basis of PubMed conventional literature searches.
RESULTS:

Studies of the effects of dietary supplementation, primarily with preparations including lutein and zeaxanthin, have demonstrated improvements in contrast sensitivity and visual performance under glare conditions that, in some studies, have been correlated with effects of treatment on macular pigment optical density. Results from both observational and prospective interventional studies generally support the conclusion that dietary supplements including these xanthophylls significantly decrease the occurrence of AMD and the development of nuclear lens opacities. However, there is variability in results regarding effects of dietary supplementation that may be related to limitations of long-term observational or interventional studies and which cannot be easily controlled or which may also be related in some studies to other important, yet unrecorded, diet- and lifestyle-related factors that are capable of influencing the risks for AMD and/or cataracts.
CONCLUSIONS:

The multiple benefits of dietary supplementation support the development and use of these preparations to promote optimal visual function and decrease risk for AMD and cataracts. Increasing understanding of the optimal approach to supplementation will depend upon results from interventional studies that also carefully evaluate and analyze well-established factors for these two conditions.

PMID:
20590393

[laconicsax]

6. False equivalency.

A study showing a benefit to dietary supplementation =/= a supplement supplier advertising their products.