Now comes the science stuff. Your eye has an area that takes care of the background and an area that takes care of seeing the stuff that you really want to look at. The part that does the seeing of what you really want to look at is called the macula. It is part of the retina which is the inside back layer of the eyeball. The retina converts light and images into electrical signals that are sent to the brain—light into sight.
The macula is made up of the photoreceptors, rods and cones, and the retinal pigmentation epithelials, RPEs for short. There are other parts of the eye, but this is Age-Related Macular Degeneration for Dummies.
I am not a physician nor a scientist. There is quite a lot of information on the Internet if you’d like more details.
According to what I have read, the photoreceptors have the important job of turning ‘light into sight’. However, they are somewhat prima donnas and not very capable of taking care of themselves. I refer to them as the Masters. The RPEs are the Servants. Their job is to do everything for the Masters that the Masters cannot do for themselves. The Servants (RPEs) go to the store (the blood vessels in the choroid) and bring home nutrients for their Masters (the photoreceptors). They cook up a concoction of pigments and feed their Masters. They also clean up after their Masters.
The photoreceptors are the Masters, the RPEs are the Servants who feed and clean up after the Masters.
The trouble comes when the Servants/RPEs are not doing their job anymore. One of the first signs of AMD is the presence of something called drusen. My reading very nicely indicated that these are fatty, metabolic byproducts of the photoreceptors’ job of turning light into sight. Basically, it seems to me that they are piles of poop. These piles of eye-poop suggest that the RPEs are not functioning as they should.
When the RPE Servants don’t clean up the eye-poop, it piles up & creates all kinds of problems!
As the eye-poop builds up, the environment becomes more toxic to the Masters, the photoreceptors. The Servants, the RPEs, also are not doing an extremely efficient job of feeding their Masters. As a result, both the RPEs and photoreceptors start to die. This causes the vision loss.
The Masters and the Servants die. That’s what causes vision loss in dry MD.
Written in February 2016. Updated September 2018.