Types of AMD

Age-related macular degeneration, or AMD, is unfortunately a very common cause of vision loss. In those over 60 years old, AMD is the most common cause of non-reversible central vision loss.  It affects over 10 million Americans, with nearly all of these over 65 years old. It is characterized as degeneration of the fovea and macula, which is the center part of your retina and is responsible for your central vision and fine acuity.

AMD can be broken down into two forms: dry AMD, and wet AMD.   AMD always starts with the dry form, which is characterized by drusen.

As time goes on, these drusen typically increase in size and become more numerous. A less common version of dry AMD is called geographic atrophy, which is characterized by having large areas of dead and missing photoreceptors and other retinal cells. This is usually considered end stage dry AMD.

Wet AMD is when ”bad” blood vessels break through the retina’s barrier membrane and begin to grow under the retina. These blood vessels are called choroidal neovascularization. These blood vessels can cause bleeding and leakage (similar to blood plasma) to accumulate in and under the retina. Left untreated, this blood or leakage will turn into scar tissue, leaving a large visual blind spot. Currently there is no treatments or cure for scarring, so it is very important to catch any bleeding or leakage early.  

It’s important to note that the dry form is always present and progressive, even if you have the wet form as well.

Treatment = AREDS 2 Vitamins

 At this point, the only treatment for dry macular degeneration is a proven formula of vitamins.  This specific formula was studied in a large randomized controlled clinical trial called the Age-Related Eye Disease Study or AREDS.   There are two versions of these vitamins, the best and most recent being be AREDS 2 formulation:

500 milligrams (mg) of vitamin C
400 international units of vitamin E
10 mg lutein
2 mg zeaxanthin
25 mg zinc as zinc oxide
2 mg copper as cupric oxide

Interestingly, in the new and updated formula, beta-carotene was removed (due to concerns of lung cancer in smokers) and the dose of zinc was reduced.  Omega fatty acids were also tested and found to not be helpful for AMD.

The AREDS and AREDS 2 trial showed that taking the vitamins will reduce the likelihood of progression to advanced AMD (significant vision loss) by about 33% over 5 years, and more as time goes on.  

So, if your Ophthalmologist or Retina Specialists tells you to, Take Your Vitamins!

NEXT TIME:  Who should AREDS 2 vitamins?   Everyone with AMD?