AMD usually occurs in people who are age 50 and older. As people get older, the risk increases. Other risk factors include the following:

• Smoking : Research shows that smoking increases the risk of AMD two-fold.
• Race : Caucasians are much more likely to get AMD than people of African descent.
• Family history : People with a family history of AMD are at higher risk.

Does lifestyle make a difference?

Some lifestyle choices, like smoking, are linked to AMD although it remains unknown if altering any of these would alter the impact of AMD on an individual.

Nevertheless, the following choices may have an impact on AMD and certainly promote healthy living, including the following:

• Avoiding smoking
• Exercising
• Maintaining normal blood pressure and cholesterol levels
• Eating a healthy diet rich in green, leafy vegetables and fish

How is AMD detected?

The early and intermediate stages of AMD usually start without symptoms. Only a comprehensive dilated eye exam can detect AMD. The eye exam may include the following:

• Visual acuity test : This eye chart measures how well you see at distances.
• Dilated eye exam : Your eye care professional places drops in your eyes to widen or dilate the pupils. This gives him or her a better view of the back of your eye. Using a special magnifying lens, he or she then looks at your retina and optic nerve for signs of AMD and other eye problems.
• Amsler grid : Your eye care professional also may ask you to look at an Amsler grid. Changes in your central vision may cause the lines in the grid to disappear or appear wavy, a sign of AMD.
• Fluorescein angiogram : In this test, fluorescein dye is injected into the arm and pictures are taken as the dye passes through the blood vessels. The test allows to identify leaking blood vessels and decide the best treatment.
• Ocular coherence tomography : In this retinal layer anatomy is seen and thickness is measured.

What are the forms of AMD that can cause vision loss?

There are two forms of AMD: dry and wet. Either form can advance and cause severe vision loss.

• The dry form is more common and has three stages-early, intermediate, and advanced. It happens when the light-sensitive cells in the macula slowly break down, gradually blurring central vision.
• The wet form is considered advanced AMD and can be more severe. It happens when new blood vessels under the macula leak blood and fluid. Damage to the macula can occur rapidly. All people who have the wet form had the dry form first.

Dry AMD is the most common form of AMD in its early or intermediate stages. It occurs in about 90 percent of the people with the condition.

Dry AMD happens when the light-sensitive cells in the macula slowly break down, gradually blurring central vision in the affected eye. As dry AMD progresses, you may see a blurred spot in the center of your vision. Your eye care professional may call this "geographic atrophy."

Over time, central vision in the affected eye can be slowly lost as less of the macula works.

What are the symptoms?

Dry AMD has few symptoms in the early stages. It is important to have your eyes examined regularly before the disease progresses.

In the later stages, blurred vision is the most common symptom of dry AMD. Objects also may not appear to be as bright as they used to be.

As a result, you may have trouble recognizing faces. You may need more light for reading and doing other tasks. Both eyes can have dry AMD or one eye can be affected first.

What are drusen?

Drusen are another early sign of dry AMD. They are yellow deposits under the retina. They can be small or large in size.Drusen alone do not usually cause vision loss. But people with large drusen are at risk of developing a more severe form of AMD, which results in severe vision loss.

Three stages of dry AMD

Dry AMD has three stages, all occurring in one or both eyes. These stages are defined in part by the size and number of drusen under the retina:

• Early AMD :Small drusen or a few medium-sized drusen. At this stage, you may not have any symptoms or vision loss.
• Intermediate AMD : Many medium-sized drusen or one or more large drusen. Many people will have no symptoms or may see a blurred spot in the center of their vision.
• Advanced dry AMD : In addition to drusen,a breakdown of light-sensitive cells supporting tissue in the macula. This breakdown can cause a blurred spot in the center of your vision, often called geographic atrophy.

What is wet AMD?

Wet AMD affects about 10 percent of all people with AMD. This type, however, is more severe than the early and intermediate stages of the dry form.

Wet AMD happens when abnormal blood vessels behind the retina start to grow under the macula known as choroidal neovascular membrane (CNVM). These new blood vessels can be fragile and leak blood and fluid. The blood and fluid cause the macula to swell and damage occurs rapidly. The damage may also cause scarring of the retina.

What are the symptoms?

• Blurred vision.
• Straight lines may appear wavy.
• May see a blind spot, which results in the loss of central vision.

What is wet AMD?

• Injections : One option to slow the progression of wet AMD is to inject drugs into your eye. With wet AMD, abnormally high levels of vascular endothelial growth factor (VEGF) are secreted in your eyes. This substance promotes the growth of new abnormal blood vessels. The anti-VEGF injection therapy blocks its effects. If you get this treatment, you may need multiple injections. Before each injection, your eye care professional will numb your eye and clean it with antiseptics. To prevent the risk of infection, a doctor may prescribe antibiotic drops.
• Photodynamic therapy : This technique involves laser treatment of select areas of the retina. First, a drug called verteporfin will be injected into a vein in your arm. The drug travels through the blood vessels in your body, including any new, abnormal blood vessels in your eye. A laser beam is aimed at new vessel to activate the drug in the blood vessels. Once activated, the drug destroys the new blood vessels and slows the rate of vision loss. This procedure takes about 20 minutes.
• Laser surgery : Eye care professionals sometimes treat certain cases of wet AMD with laser surgery, though this is less common than other treatments. This treatment is performed in a doctor’s office or eye clinic. It involves aiming an intense beam of light at the new blood vessels in your eyes to destroy them. However, laser treatment also may destroy some surrounding healthy tissue and cause more blurred vision.