Macular Degeneration - AMD
Even though the macula makes up only a small part of the retina, it is much more sensitive to detail than the rest of the retina, called the peripheral retina. The macula is what allows you to thread a needle, read small print, and read street signs. The peripheral retina gives you side (or peripheral) vision.
If someone is standing off to one side of your vision, your peripheral retina helps you know that person is there by allowing you to see their general shape. It is your macula that allows you to recognize the details of the person’s face. Many older people develop macular degeneration as part of the body’s natural aging process.
There are different kinds of macular problems, but the most common is age-related macular degeneration. The retina is made up of many layers that work together to help you see clearly. AMD develops when a layer under the retina called the retinal pigment epithelium (RPE) is affected by deposits of tiny yellow or white pieces of fatty protein called drusen, or by other age-related changes.
With AMD, you may have blurriness, dark areas or distortion in your central vision, and perhaps permanent loss of your central vision. It usually does not affect your side, or peripheral vision. For example, with advanced AMD, you could see the outline of a clock, yet may not be able to see the hands of the clock to tell what time it is.
Most people who have AMD have the dry form. This condition is caused by aging and thinning of the tissues of the macula.
If you have been diagnosed with dry AMD, you should use a chart called an Amsler grid every day to monitor your vision, as dry AMD can change into the more damaging wet form.
- Cover one eye.
- Look directly at the center dot with the uncovered eye and keep your eye focused on it.
- While looking directly at the center dot, note whether all lines of the grid are straight or if any areas are distorted, blurry or dark.
- Repeat this procedure with the other eye.
- If any area of the grid looks wavy, blurred or dark, or you detect any changes while looking at the grid, contact your ophthalmologist immediately.
Wet, or exudative, AMD (also called neovascular AMD)
The wet form of macular degeneration occurs in about 10 percent of all macular degeneration cases, but it can cause more damage to your central or detail vision than the dry form.
The longer these abnormal vessels leak or grow, the more risk you have of losing more of your detailed vision. Also, if abnormal blood vessel growth happens in one eye, there is a risk that it will occur in the other eye. The earlier that wet AMD is diagnosed, the better chance you have of preserving some or much of your central vision. That is why it is so important that you and your ophthalmologist monitor your vision in each eye carefully.