Macular degeneration

Macular Degeneration

What is the Macula?The macula is the part of the retina

responsible for straight-ahead central vision It is responsible for focusing central vision in

the eye, and it controls our ability to read, drive a car, recognize faces or colors, and see objects in fine detail.

Any disease that affects the macula will cause a change and impairment in the central vision.

Macula

Age-Related Macular DegenerationMacular degeneration is an age-associated

degenerative disorder of the macula, the part of the retina responsible for straight-ahead, central vision.

Age-Related Macular DegenerationAge-related macular degeneration (AMD) is

the leading cause of central vision loss in the Western world in people over the age of 55.

As some people age, the macula weakens and its cells begin to break down. This may result in the loss of central vision.

Age Related Macular Degeneration

Dry AMDDry AMD is the most common form of macular

degeneration, affecting 90 percent of people with the disease.

In the dry form, aging changes called "drusen" become deposited underneath the macula.

The changes that AMD patients develop as they age don't necessarily affect quality of life.

In fact the vast majority of patients with drusen have no visual changes.

Dry AMDHowever in some AMD patients, drusen can

cause the macula to thin, resulting in a gradual decrease in central vision.

This late stage of the dry type is called geographic atrophy.

If the drusen cause substantial weakening of important layers of the macula, they can set the stage for the "wet" form of AMD.

Wet AMDWet AMD develops when abnormal blood

vessels start to grow through important layers of the macula that have been weakened by the dry form of AMD.

This abnormal growth of blood vessels, called choroidal neovascularization (CNV), can cause bleeding, leakage of fluid, and scar tissue formation in highly sensitive parts of the macula.

Wet AMDWhen this happens, loss of central vision can

be rapid and severe.Although only one in 10 patients with AMD

will convert from the dry to the wet form, the wet form accounts for 90 percent of the vision loss associated with AMD.

Symptoms of AMDThe vast majority of patients with dry AMD will

not notice any change in their central vision. However, patients with advanced dry AMD may

notice a gradual decrease in their central vision over many months or years.

This decline in vision is often accompanied by blank spots that slowly develop in and around the central vision.

The most common symptom of wet AMD is the sudden onset of blurred or distorted central vision that may occur over several days or weeks

AMD TreatmentThe various treatment options for AMD

depend on the type and stage of AMD that is present.

At this time, the only treatment for dry AMD is high-dose antioxidant vitamin therapy.

AMD TreatmentTreatment options for the wet form of AMD

include:ObservationHot laser therapyCold laser therapy -- also knows as

photodynamic therapy or Visudyne™ therapyMacular translocation surgeryMacugenLucentisAvastin

Juvenile Macular DegenerationJuvenile macular degeneration is the term for

several inherited eye diseases -- including Stargardt's disease, Best disease, and juvenile retinoschisis -- that affect children and young adults.

These rare diseases cause central vision loss that may begin in childhood or young adulthood.

Stargardt’s DiseaseStargardt disease is the most common form

of juvenile macular degeneration. It's named after German ophthalmologist Karl Stargardt, who discovered it in 1901. Stargardt disease affects about one in 10,000 children in the U.S. Although the disease starts before age 20, a person may not notice vision loss until age 30 to 40.

Signs of Stargardt’s DiseaseThe condition can be diagnosed by yellow-

white spots that appear in and around the macula.

If the spots appear throughout the back of the eye, then it is called fundus flavimaulatus.

These deposits are an abnormal buildup of a fatty substance produced during normal cell activity.

Symptoms of Stargardt’s DiseaseSymptoms include difficulty reading and gray or black

spots in the central vision. Loss of vision occurs gradually at first and affects both eyes. Once vision reaches 20/40, the disease progresses more rapidly, eventually reaching 20/200, which is legal blindness. Some people lose vision to 10/200 very quickly over a few months. Most people will have vision loss ranging from 20/100 to 20/400 by age 30 to 40.

Stargardt disease does not cause a loss of peripheral, or side, vision. Most people don't lose night vision, but may have trouble adjusting between dark and light environments. Color vision is also affected in later stages of the disease.

Genetics of Stargardt’s Disease Researchers have identified a specific gene

that they believe causes Stargardt disease. If both parents carry one mutated gene and one normal gene, their children have a 25% chance of developing the disease. People who inherit only one mutated gene don't develop the disease. However, they can pass on the disease without knowing it.