Understanding Macular Degeneration

If you had asked me this question 15 years ago I would have answered differently, but today the answer is much clearer. Before I give you my opinion, you should have a better understanding of macular degeneration. It is caused by the breakdown of the metabolism that nourishes the most sensitive group of visual cells found in the retina, an area called the “macula”. The macula is located where rays of light entering the eye come together in a point on the retina. That small area has an overall width of 6 millimeters, about the size of the head of a pencil eraser. In the center of that area is the “fovea”. The very center of the fovea is known as the fovea centralis , an area about the size of the head of a pin. The fovea centralis contains about 50,000 visual cells called cones. Each cone is connected to a ganglion cell and each ganglion cell has a long “tail” called an axon. Each axon ends up as part of the optic nerve.

Importance of Genglion Cells

The importance of these 50,000 ganglion cells can’t be overemphasized because it is these cells, as a group, that give detail to what you see. If these retinal cells are destroyed all you would see would be in the shape of a donut where there would be no detail where the donut hole is (straight ahead) but the rest of the donut (your peripheral vision) would be intact. This is the way most people with severe macular degeneration see the world- a blurred out center but normal side vision.

What about the rest of the retina?

How does that play a part in vision? It turns out that the images produced by the macula as a whole are represented in the brain by 80% of the visual cortex, the part of the brain that allows you to see. Thus, the rest of the retina just plays a supporting role in locating objects but not identifying objects. This is how we use our peripheral vision.

3 Things that Destroy the Macula

Now that you have an idea of how the macula helps us to see, what can destroy that ability? Those central foveal cells are very sensitive to things that poison our bodies:

  1. THE SUNS RADIATION- constant exposure to the sun over long periods cause a breakdown in metabolism that causes disruption of the macula because that’s where sunlight is focused! The sun “cooks” the macula and destroys most of those foveal cells. The cure is good sunglasses and a hat. Don’t think that just because it’s cloudy that you don’t need that protection.
  2. SMOKING- You may not know that cigarette smoke produces carbon MONOXIDE (CO), the same gas given off by cars that kill and other combustion equipment such as grills. When you take the smoke into your lungs the CO binds with blood and greatly reduces oxygen availability. When that happens in such a highly metabolic tissue such as the retina, the tissue becomes sick and dies. If you stop smoking you may manage the situation but damage done is permanent.
  3. HEREDITY- You can’t pick your family, however if you know that there is macular degeneration in your family, you can take preventive measures. First wear sunglasses outside with a hat. Second, don’t smoke and three, take macular vitamins. There is solid evidence that macular vitamins support macular health. In addition eating green, leafy vegetables such as spinach and kayle really help.

So I hope that gives you something to think about. No one wants macular degeneration and if we can prevent it through proactive activities, why not?

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