Retina Institute of Indiana, P.C.

Age Related Macular Degeneration

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What is age related macular degeneration?
Age-related macular degeneration (AMD) is a deterioration or breakdown of the eye's macula. The macula is a small area in the retina — the light-sensitive tissue lining the back of the eye. The macula is the part of the retina that is responsible for your central vision, allowing you to see fine details clearly.

The macula makes up only a small part of the retina, yet 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.

There are two types of macular degeneration:

Dry, or atrophic, macular degeneration (also called non-neovascular macular degeneration) with drusen

Most people who have macular degeneration have the dry form. This condition is caused by aging and thinning of the tissues of the macula. Macular degeneration usually begins when tiny yellow or white pieces of fatty protein called drusen form under the retina. Eventually, the macula may become thinner and stop working properly. With dry macular degeneration, vision loss is usually gradual.

Wet macular degeneration

This occurs when abnormal blood vessels begin to grow underneath the retina. This blood vessel growth is called choroidal neovascularization (CNV), because these vessels grow from the layer under the retina called the choroid. These new blood vessels may leak fluid or blood, blurring or distorting central vision. Vision loss from this form of macular degeneration may be faster and more noticeable than that from dry macular degeneration.

Who is at risk for age related macular degeneration?
The following is a list of risk factors:

* Age - The number one risk factor is age. One third of adults over the age of 75 are affected by age-related macular degeneration.
* Smoking - Smoking increases an individual’s chances of developing age-related macular degeneration by two to five-fold. The retina has a high rate of oxygen consumption. Anything that affects the rate of oxygen delivery to the retina has the potential to negatively impact vision. Smoking causes oxidative damage, which is thought to contribute to the development and progression of this disease.
* Family history of macular degeneration - An individual is more likely to be affected by age-related macular degeneration if someone in his or her immediate family has been affected.
* Gender - Females are more likely to be affected by age-related macular degeneration than males. This may be due to the fact that females live longer than males, and thus have more time to develop the disease.
* Race - Caucasians are more likely to be affected by age-related macular degeneration than other races. This may be due to differences in genetic background or pigmentation.
* Prolonged sun exposure – Ultra-violet (UV) light damages retinal tissue directly, and can also lead to the accumulation of products that are harmful to the retina.
* A high fat diet, and/or one that is low in nutrients and antioxidants - Individuals with diets high in fat, cholesterol and sugar, and low in antioxidants are more likely to be affected by age-related macular degeneration.
* Obesity - Overweight individuals are more likely to be affected by age-related macular degeneration. An individual with a body mass index (BMI is a measure of body fat) of greater than 30 is 2.5 times more likely to be affected by age-related macular degeneration.
* High blood pressure - Individuals with high blood pressure are more likely to be affected by age-related macular degeneration. High blood pressure, like smoking, leads to a constriction, or narrowing, of the blood vessels that nourish the retina, negatively affecting its health.
* Eye color - Individuals with light-colored eyes are more likely to be affected by dry age-related macular degeneration. This may be due to the fact that light-pigmented eyes offer less protection from damaging UV light.
* Inactivity - Individuals who do not follow a regular exercise routine are more likely to be affected by age-related macular degeneration. In dry age-related macular degeneration, the retina does not receive adequate oxygen, leading to the death of cells in the macula. It is known that exercise improves cardiovascular health, and might prevent an individual from developing this disease.
* The presence of macular degeneration in one eye - If an individual has macular degeneration in one eye, he or she is more likely to develop it in the other eye.

What are the symptoms of age related macular degenaration?

Dry macular degeneration signs and symptoms
* Blurry distance and/or reading vision

* Need for increasingly bright light to see up close
* Colors appear less vivid or bright
* Hazy vision
*Difficulty seeing when going from bright light to low light
* Trouble or inability to recognize people's faces
* Blank or blurry spot in your central vision

Dry macular degeneration can affect one or both eyes. You may not notice vision changes if only one eye is affected, as your unaffected eye will compensate for vision loss in the other eye.

Wet macular degeneration signs and symptoms
* Distorted vision — straight lines will appear bent, crooked or irregular
* Dark gray spots or blank spots in your vision
* Loss of central vision
* Size of objects may appear different for each eye
* Colors lose their brightness; colors do not look the same for each eye

How is macular degeneration treated?

With or without treatment, macular degeneration alone almost never causes total blindness. People with more advanced cases of macular degeneration continue to have useful vision using their side, or peripheral vision. In many cases, macular degeneration's impact on your vision can be minimal.