DNA TESTING

Controversies in use of AREDS Vitamins in Age Related Macular Generation (AMD)
 

There have been several articles in the press recently about the possibility of harm in 13% of individuals using AREDS vitamins for AMD. This has understandably raised questions and concerns for our patients. We hope the following information is helpful in addressing them. But if not, please don’t hesitate to contact us.

 

What are the AREDS studies?

The AREDS studies are large-scale studies conducted by the National Institute of Health in Washington. 

 

  • AREDS 1 showed a combination of high dose antioxidants and high dose zinc reduced the rate of adverse outcomes from AMD.
    The 5-year risk of severe visual loss was reduced by 20%.  An AREDS vitamin was created based on these findings.
     

  • AREDS 2 showed the active ingredients in reducing the risk of visual loss were antioxidants, zinc, 
    lutein and zeathanthine.  AREDS 2 vitamins were created based on the new findings.

 

Which factors are important in development of AMD

  1. Genetics – several genes have been identified

  2. Lifestyle  –  smoking , body mass index (BMI) and diet 

  3. Age, Caucasian ethnicity, hypertension 

 

What is the relationship between genetic data and use of AREDS vitamins?

Eye care providers routinely prescribe AREDS 2 vitamins to appropriate patients in order to diminish risk 

of progression to severe AMD and risk of severe visual loss.  These vitamins were thought to do no 

harm; however that may not be the case for one particular genetic group.

 

In a 2015 study published in the journal of the American Academy of Ophthalmology, the genetic data 

from nearly 1000 Caucasian patients in the original AREDS study was divided into four groups based on 

four gene variants known to be associated with AMD.   When the effects of AREDS treatment was then 

analyzed for each of the groups, the study concluded:

 

  • Only the antioxidant component of the AREDS vitamins was helpful in reducing risk of AMD progression in the first group.

  • Zinc doubled the risk of AMD progression throughout the seven-year study in the second group. 

  • Both antioxidants and zinc diminished risk of progression in the third group. 

  • AREDS vitamins had no effect on progression in the fourth group.

 

The NIH reanalyzed their data and maintained that AREDS 2 vitamins benefitted all genetic groups albeit 

to varying degrees. Both the NIH and companies testing for genetic data have been accused of having a 

vested interest in their interpretations of the data. Essentially, this has become a battle of statisticians. 

 

So whose statistics do we believe? 

There are no geneticists or statisticians in our office, but as physicians, we are guided by an imperative 

to do no harm.   We put that into action by staying on top of research and using that information to 

guide decisions and inform our patients about the risks and benefits of various tests and treatments.   

 

Based on that, we have decided to work with Arctic Dx and offer the genetic testing that is now available to help identify patients in the genetic group that will potentially be harmed by zinc supplementation, and guide our choices in vitamin and supplement treatment of AMD. 

 

What are the tests offered?

Vita Risk:  In patients who will benefit from ocular vitamins and supplements, this test will 

direct your doctor to prescribe the appropriate combination.

 

Macula Risk: This test is for patients with early or intermediate AMD. In conjunction with data on age, smoking, BMI, and education level, this test is said to be 90% accurate in estimating whether an individual has a low, medium or high risk of 

AMD progression risk within 10 years. If you have a high probability of 

progression, you should be examined more frequently. 

 

How are these tests done?

The tests are done in our office by swabbing the inside of your cheek to obtain a sample of DNA. 

 

Will genetic testing affect my insurability? 

Most patients with AMD are in an age group where they have already purchased any insurance they 

require. Nevertheless, it is important for everyone considering genetic testing of any type to be aware of 

privacy issues. There are no laws in Canada that specifically address the use of genetic 

test results by insurance companies; however, that may change shortly.  Legislators have proposed laws 

that will prohibit organizations from requiring an individual to disclose existing results of a genetic test 

as a condition of providing goods or services.   There is a moratorium in place whereby insurance 

companies are not asking for genetic test results while the bill works its way through the Canadian 

Senate.  

 

How does this information apply to the VitaRisk Test?

Individuals who opt for this test are already known to have AMD, so it should not impact your insurability. The purpose of the test is to optimize your choice of vitamin.

 

How does this information apply to the Macula Risk Test?

Your insurance company will already be aware of weight and smoking history.  Still, if this test finds that 

you have a high risk of progression, it is not impossible that this may affect your future insurability. 

 

What do these tests cost?

Vita Risk testing fee: $300.00

Vita Risk + Macula Risk testing fee: $400.00

 

Summary
Though not without controversy, genetics is a continually evolving field with tremendous 

potential benefits for improved medical care.  Eye care specialists are now able to use genetic 

data to better guide our choices in vitamin and supplement treatment of AMD.   

Based on our research and imperative to “do no harm”,  we have concluded there is sufficient 

merit to genetic testing in patients with AMD and have therefore decided to make two tests 

available to our patients:  1) Vita Risk testing to help separate out patients who may be harmed 

by AREDS 2 vitamins from those who are helped by these vitamins and 2) Macula Risk to help 

separate out those patients who may require more frequent follow up.  

 

You may find the following links helpful:

Arctic Dx  -   http://www.macularisk.com

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Suite 810

Toronto ON

M4S 1Y2

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Tel: (416)482-3311

Fax: (416)482-0831

 

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