Age Related Macular Degeneration (ARMD)

Age related macular degeneration (ARMD) is the term used to describe the breakdown of the macula, the central part of the retina on the back inside wall of the eye.

When light enters the eye, it is focused onto the retina. This delicate light-sensing membrane captures images, like the film of a camera, and sends them to the brain where vision is interpreted. The entire retina is important for good vision, but the central portion, known as the macula, is much more sensitive than the peripheral areas. The macula contains the greatest concentration of cones, the light receptors that make detailed vision and colour vision possible. If the macula deteriorates, the affected eye will be unable to perceive detail, such as print on a page, or to see the world in vivid colour. Progressive macular degeneration often results in a complete loss of central vision, but it does not lead to total blindness since the peripheral (side) vision is unaffected.

Types and Causes

Macular degeneration is the leading cause of central vision loss in North America. There is more than one type of macular degeneration, but the results are similar for people affected with the disease.

• The Dry Form: The dry form is the most common type of macular degeneration. In theses cases, the delicate tissues of the macula become thin and stop working well.
  
  
• The Wet Form: The wet form of macular degeneration is not nearly as common as the dry form, but it is potentially more damaging. It is caused by the growth of abnormal blood vessels behind the macula. These abnormal blood vessels leak and form scar tissue. Sometimes, the dry form of macular degeneration can turn into the wet form.

Common Symptoms and Diagnosis

Since macular degeneration develops differently in each case, the symptoms also vary. Some of the common symptoms include:

• A loss of ability to see objects clearly
• Distorted vision—objects appear to be the wrong size or shape—straight lines appear crooked
• A loss of clear colour vision
• A dark or empty area appears in the centre of the vision

People who think they may have a macular problem need to see an ophthalmologist for a thorough retinal examination.

Dry Macular Degeneration

Unfortunately, there is no treatment for the most common dry form of macular degeneration. Once the delicate retina begins to break down, little can be done to stop the progression and there is no way to regenerate the tissue after it has deteriorated.

Wet Macular Degeneration

If it is not controlled, the wet form of macular degeneration usually reduces central vision significantly. However, if diagnosed early, the disease may be controlled by laser treatments. Lasers create a bright beam of light which seals leaking blood vessels. Although laser surgery cannot restore vision which has already been damaged, it can sometimes prevent or delay further loss of sight.

Preventative Measures

Although there is no cure for macular degeneration, people can try to reduce their chance of developing this problem by altering their lifestyle. Research into this area indicates that the following measures may help:

• Eating a balanced diet which is rich in leafy green vegetables such as spinach.
• Wearing sunglasses which block ultraviolet light.
• Following a regular exercise program.
• Eating foods low in fat and cholesterol.
• Quitting smoking.