What is macular degeneration?
Macular degeneration is a lesion or decomposition of the macula. The macula is a small area of the retina located at the back of the eye, allowing you to see fine details clearly and perform activities such as reading or driving a vehicle. When the macula does not work properly, its central vision may be affected by the formation of blurred images, with dark or deformed areas. Macular degeneration affects your ability to see near and far objects. It can make some activities such as threading a needle or reading difficult or impossible.
Although macular degeneration reduces vision in the central part of the retina, it does not affect the lateral or peripheral vision of the eye. For example, you can see the outline of the clock, but you cannot tell what time it is.
Macular degeneration alone does not lead to total blindness. Even in the most advanced cases, people continue having some useful vision and can often take care of themselves. In many cases, the impact of macular degeneration on vision may be minimal.
What is the cause of macular degeneration?
Many elderly 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 AMD.
The precise cause by which it is developed is unknown. No treatment has been effective on a constant basis. Macular degeneration is the leading cause of severe vision loss in people over the age of 65. The two types of AMD are:
- Dry (atrophic).
- Wet (exudative).
Dry Macular Degeneration (atrophic)
Most people face dry macular degeneration which is age related and occurs when the cells in the macula slowly get thinner, gradually blurring central vision as less of the macula functions.
Wet Macular Degeneration (exudative)
Wet macular degeneration (approximately 10% of all the cases) occurs when abnormal blood vessels behind the retina start to grow under the macula. These new blood vessels tend to be very fragile, and often leak blood and fluid. The blood and fluid raise the macula from its normal place at the back of the eye. Damage to the macula occurs rapidly.
With wet macular degeneration, loss of central vision can occur quickly. Wet macular degeneration is a more advanced form of the disease, and is more severe than dry macular degeneration.
Which are the symptoms of macular degeneration?
Macular degeneration can cause diverse symptoms on different people. This condition may be almost imperceptible in the beginning. Sometimes only one eye loses vision, while the other continues seeing well for many years.
But when it affects both eyes, the loss of central vision can be perceived more quickly. The following are several ways in which vision loss is detected:
- Words written on a page appear blurry.
- A dark or empty area appears in the center of vision.
- Straight lines appear deformed.
How is AMD diagnosed?
Many people do not perceive the macular condition until blurred vision becomes obvious. Your ophthalmologist (eye doctor) can detect AMD in its early stages during an eye exam that includes the following:
- A simple vision test in which you look at a graph that looks like grid paper (Amsler grid).
- Observing the macula with an ophthalmoscope.
- By practicing an OCT Retinal Scanner, which gives us images of anatomical cuts of the macula.
- Special photographs of the eye are sometimes taken with fluorescein called angiograms, in order to find abnormal blood vessels behind the retina. Fluorescein is injected into an arm vein and the eye is then photographed as the color passes through the blood vessels in the back of the eye.
The deposits that are concentrated below the retina, called "drusen", are a common cause of AMD. These deposits do not cause vision loss alone, but their increase in numbers may be an indication of the risk of developing advanced AMD. People at risk of developing advanced AMD have a significant amount of "drusen", prominent dry AMD or abnormal blood vessels behind the macula in one eye (wet AMD).
How is AMD treated?
Although the precise causes of AMD are not fully understood, the use of antioxidant vitamins and zinc can reduce the impact of AMD in some people.
An extensive scientific study has determined that people at risk for developing advanced stages of AMD can reduce that risk by 25% through a treatment that combines vitamin C, vitamin E, beta carotene and zinc.
These nutritional supplements appear to provide no benefit among people without AMD, or in the early stages of AMD development.
It is very important to remember that vitamin supplements are not a cure for AMD, nor will they restore vision that has already been lost due to illness. However, specific amounts of these supplements play an important role in helping to maintain vision among people who have a high risk of developing advanced AMD. You should talk to your ophthalmologist to determine if you are at risk of developing advanced AMD, and to find out if vitamin supplements are advisable.
Laser Surgery and Photodynamic Therapy:
Certain types of "wet" AMD can be treated by laser surgery, a brief outpatient basis procedure. Laser surgery and another form of treatment called photodynamic therapy uses a focused beam of light to slow or stop fluid from the blood vessels that damage the macula. These procedures may help preserve vision more, but they are not cures that can bring back normal vision.
Intravitreal antiangiogenic injections:
It is considered to be the state-of-the-art treatment by excellence.
Despite advances in medical treatment, many people with AMD still experience some loss of vision.
In order to help you adjust to lower vision levels, your ophthalmologist may prescribe ophthalmic devices, transfer you to a specialist or a center aimed at patients with reduced vision. There is also a wide range of support services and rehabilitation programs that help people with AMD to keep an acceptable standard of living.
Because the peripheral vision is not usually affected, the patient's vision is still very useful. People often continue carrying out many of their favorite activities by using optical devices such as magnifying glasses, closed-circuit television, large-print reading materials, and computerized voice devices.