Why does macular degeneration occur

The macula is the part of the retina responsible for clear vision in your direct line of sight. Dry macular degeneration may first develop in one or both eyes and then affect both eyes.

Over time, your vision may worsen and affect your ability to do things, such as read, drive and recognize faces. But this doesn't mean you'll lose all of your sight. Vision loss is typically central and people retain their peripheral vision. Some people have only mild central vision loss, while in others it can be more severe.

Dry macular degeneration can affect one or both eyes. If only one eye is affected, you may not notice any changes in your vision because your good eye may compensate for the weak eye. And the condition doesn't affect side peripheral vision, so it rarely causes total blindness. Dry macular degeneration is one of two types of age-related macular degeneration.

It can progress to wet neovascular macular degeneration, which is characterized by blood vessels that grow under the retina and leak.

The dry type is more common, but it usually progresses slowly over years. The wet type is more likely to cause a relatively sudden change in vision resulting in serious vision loss. These changes may be the first indication of macular degeneration, particularly if you're over age Located at the back of your eye in the center of your retina, a healthy macula allows for normal central vision acuity.

The macula is made up of densely packed light-sensitive cells called cones and rods. Cones are responsible for color vision, and rods enable you to see shades of gray. No one knows exactly what causes dry macular degeneration. Early symptom detection and diagnosis is important. Treatment may involve special eye medications, medical procedures as well as lifestyle remedies. Macular degeneration is the leading cause of vision loss in people aged over 50 years.

General information The macula is the central region of the retina, which is the light-sensitive inner layer of tissue at the back of the eye. The retina processes visual images, with the macula being responsible for central i. As the eye ages the macula deteriorates and the central sharp vision that is used for seeing detail is gradually lost. This means tasks such as reading, driving and recognising faces become more difficult. Although it can lead to legal blindness, macular degeneration does not result in total blindness.

Macular degeneration differs from glaucoma , which is characterised by gradual loss of peripheral side-ways vision , and cataracts , in which the normally clear lens of the eye becomes cloudy. Macular degeneration is also known as age-related macular degeneration or AMD because it is associated with getting older and mainly affects people later in life. Inherited forms of the disease can, however, affect young people.

Causes The exact cause of macular degeneration is not known. Dry macular degeneration has three stages, which may occur in one or both eyes: Early stage — small yellow deposits called drusen accumulate beneath the retina and may be detected during an eye examination. Vision is not usually affected and there are no symptoms.

Intermediate stage — one or more large drusen are present. There may be a blurred spot in the centre of the visual field. More light may be required to read or do detailed work. Advanced stage — several large drusen and breakdown of the macula tissue is present. The symptoms of age-related macular degeneration may look like other eye conditions. Speak with an eye care professional for diagnosis.

In addition to a complete medical history and eye exam, your eye doctor may do the following tests to diagnose age-related macular degeneration:. Visual acuity test. This common eye chart test measures vision ability at various distances.

Pupil dilation. Fluorescein angiography. Used to detect wet age-related macular degeneration, this diagnostic test involves a special dye injected into a vein in the arm. Pictures are then taken as the dye passes through the blood vessels in the retina, helping the doctor evaluate if the blood vessels are leaking and whether or not the leaking can be treated. Amsler grid. Used to detect wet age-related macular degeneration, this test uses a checkerboardlike grid to determine if the straight lines in the pattern appear wavy or missing to the patient.

Both indications may signal the possibility of age-related macular degeneration. If you notice any areas of the grid that appear darker, wavy, blank or blurry, contact your ophthalmologist right away. Specific treatment for age-related macular degeneration will be determined by your doctor based on:. Currently, there is no treatment for dry age-related macular degeneration, though vision rehabilitation programs and low-vision devices can be used to build visual skills, develop new ways to perform daily living activities and adjust to living with age-related macular degeneration.

VEGF stands for vascular endothelial growth factor. Anti-VEGF agents are used to combat the disease process and reduce the damaging effects of these leaky abnormal blood vessels. Your donations are critical to support ongoing research into the causes and treatment of macular degeneration. Click to learn how your generosity can contribute to treatment breakthroughs in macular degeneration.

Macular Degeneration Macular Degeneration is the leading cause of vision loss, affecting more than 10 million Americans — more than cataracts and glaucoma combined. At present, Macular Degeneration is considered an incurable eye disease. Illustrations of the anatomy of a normal human eye and loss of central vision: Anatomy of a Normal Human Eye Animation of loss of central vision One can compare the human eye to a camera.

Early AMD — Most people do not experience vision loss in the early stage of AMD, which is why regular eye exams are important, particularly if you have more than one risk factor see below. Early AMD is diagnosed by the presence of medium-sized drusen yellow deposits beneath the retina. Intermediate AMD — At this stage, there may be some vision loss, but there still may not be noticeable symptoms.

Late AMD — At this stage, vision loss has become noticeable.