Age-related macular degeneration (AMD) is a decrease or degeneration of the macula of the eye. The macula is a small part of the retina, which is responsible for central vision, which lets you see fine detail clearly.
The macula is only a small part of the retina, but it is way more sensitive to detail than the rest of the retina (called the peripheral retina). The macula is what lets us put a thread into a needle, read small fonts and road signs. The peripheral retina is responsible for peripheral vision.
Many elder adults develop macular degeneration as a natural part of aging of the organism. There are different types of macular problems, but the most common one is the age-related macular degeneration.
In macular degeneration, you can experience symptoms such as clouding, dark zones or anomalies in the central part of the vision, while permanent loss of central vision is also possible. The disease usually doesn’t affect peripheral vision.
In macular degeneration, deposits called drusen can be seen under the retina, and in some cases anomalous blood vessels can also be seen under the retina. With or without treatment, it is rare that macular degeneration causes complete blindness. In most cases, the effect of macular degeneration on eyesight can be minimal.
When macular degeneration causes loss of vision, it usually starts in one eye, even though it can affect the other eye later.
There are 2 types of macular degeneration:
Dry or atrophic macular degeneration with drusen.
Most people who suffer from macular degeneration have the dry form. This condition is caused by aging and thinning of the tissues of the macula. The macular degeneration usually starts when small white or yellow pieces of lipid proteins called drusen show up under the retina.
In dry macular degeneration, vision loss is usually slow and gradual. People who develop dry macular degeneration must carefully monitor their central vision. If they notice any changes in eyesight, they must immediately notify their ophthalmologist. The dry form can become more severe and cause the heavier form of macular degeneration – wet (exudative) macular degeneration. There is no definitive treatment for dry macular degeneration, but some people can have good results with vitamins and supplements.
Using the Amsler net to test for macular degeneration
If you have been diagnosed with dry macular degeneration, you must use a diagram called an Amsler net every day to monitor the condition of your eyesight.
To use the Amsler net, wear reading glasses and hold the diagram 12-15 inches from your face in good light.
Cover one eye. Then:
- Look directly in the central point with one uncovered eye and try to keep your focus on it
- While looking directly in the central point, note whether all dark lines on the net are straight or bent, blurred or dark.
- Repeat this with the other eye
- If any part of the net looks wave-like, blurred or dark, contact your ophthalmologist
- If you notice any changes while looking at the net, you must notify your ophthalmologist immediately.
Wet or exudative macular degeneration (also called neovascular macular degeneration)
About 10% of people who have macular degeneration have the wet form. It can cause more damage to central or peripheral vision than the dry type.
Wet macular degeneration occurs when anomalous blood vessels start growing under the retina. This growth of blood vessels is called choroidal neovascularization (CNV). From those new blood vessels, liquid or blood can leak, blurring central vision. Eyesight loss from this form of macular degeneration can be faster and more noticeable than those of dry macular degeneration.
The longer those abnormal vessels leak or grow, the higher the chance eyesight is lost. If abnormal vessels have developed in one eye, it is very likely that they will develop in the other eye as well.
Until now, there has been no treatment for the dry form of macular degeneration. Scientific studies have shown that antioxidants, vitamins and zinc can decrease the effects of macular degeneration in some people by slowing down progression to more advanced stages.
Treatment of wet macular degeneration
Treatment of the wet form of macular degeneration can include using anti-VEGF treatment, thermic treatment with a laser or photodynamic therapy (PDT). Treatment of wet macular degeneration usually decreases, but does not eliminate risk of eyesight loss.