Macular Problems in the Eye

The macula is the portion of the eye that is responsible for central vision--the vision that allows for reading, driving and other detail dependent tasks. It is a part of the retina and is located very near to the optic nerve on the back of the eye. It is prone to a variety of conditions that are degenerative and affect central vision.

Age-Related Macular Degeneration

• Age-related macular degeneration principally affects the elderly. The website AllAboutVision.com reports that 1.75 million American suffer from age-related macular degenerative conditions.

  There are two forms of age-related macular degeneration: dry macular degeneration and wet macular degeneration. Dry macular degeneration, also known as non-neovascular macular degeneration, is more common. It is characterized by the appearance of drusen (deposits in the macula) and slow loss of central vision. Wet macular degeneration, or neovascular macular degeneration, is characterized by the growth of unstable, new blood vessels that leak and rupture, which causes scarring in the retina. Wet macular degeneration quickly leads to vision loss.

Macular Dystrophies

• Degenerative macular conditions that affect the young are known as macular dystrophies. Macular dystrophies damage the macula, typically in both eyes. The dystrophy begins to inhibit clear central vision and ultimately results in legal blindness. The American Macular Degeneration Foundation reports that one child in 10,000 will develop a macular dystrophy between the ages of 6 and 25.

Symptoms

• The progression of symptoms tends to be the same across all the forms of macular degeneration, though the time frame varies. The first symptom is typically haziness in central vision. This can manifest as blurred vision or lines (on a grid, for example) that appear to be wavy or distorted. Central vision will worsen with the appearance of gray or black areas. The remaining vision also may experience the loss of color. The final stage is the complete or near-complete loss of all central vision.

Causes

• As of October 2009, the precise cause of macular degenerative conditions remained unknown. However, the condition appears to run in families. AllAboutVision.com reports that research conducted at Duke University and Columbia University have identified two genes--complement factors B and H--which are present in a large percentage of macular degeneration patients. Other risk factors include age, obesity, smoking and hypertension.

Treatment

• The progression of dry macular degeneration may be slowed by wearing UV blocking sunglasses and by taking nutritional supplements of lutein, zinc and vitamins A, B and C. Wet macular degeneration can be treated by limiting vessel growth with medications (ranibizumab and pegaptanib sodium injections). It also can be treated with Visudyne, a laser-activated medication that destroys abnormal vessels. As of October 2009, there was no cure for macular degeneration.