Macular Degeneration

Age-related macular degeneration, often referred to as AMD, is a degenerative eye condition. The condition gradually causes vision loss in the center of a person’s field of view. A person with AMD will notice deterioration in their central sight, including blurring and a loss of color tone. There is no cure for age-related macular degeneration, but there are treatments to help slow its progression.

What Causes Macular Degeneration?

The macula is located at the centre of the retina, and provides the sharpest image in a person’s field of view. A healthy macula is essential for optimal vision, as light is focused towards it by the lens. The macula is especially important for tasks such as reading and writing.

There are two common types of age-related macular degeneration – dry and wet. Dry age-related degeneration is caused by a breakdown in the tissue that covers the retina. This tissue is used by the retina to remove waste products into the blood stream. Without it, waste products start to accumulate in the retina, which damages the light sensitive cells of the macula. This results in blurred vision.

Wet macular degeneration is caused by new blood vessels growing behind the macula. These new blood vessels, which are designed to remove waste from the retina, grow in the wrong location, and can often leak blood. This causes damage to the macula, resulting in blind spots and other visual problems.

What Are The Symptoms?

Initially, macular degeneration doesn’t cause any noticeable symptoms. For this reason it’s often not diagnosed until the condition has progressed.  Symptoms include:

  • Distortion of straight lines. This is often the first noticeable symptom.
  • Center of vision distortion.
  • Dark or blank areas in the center of vision.
  • Decrease in color vibrancy.

Macular degeneration is a painless condition, as the retina (including the macular) doesn’t contain pain receptors. If you notice any problems with your vision, you should seek immediate medical attention. If your ophthalmologist isn’t available, go directly to a hospital. The earlier age-related macular degeneration is treated, the greater chance of preventing further damage to vision.

The condition can sometimes be diagnosed before it causes symptoms during an eye exam, which is why regular checkups are important. Once the condition has been identified, an ophthalmologist may use retinal imaging to check how much damage has been caused.

Who Is Most At Risk?

There is still some uncertainty about the true cause of both types of macular degeneration. Factors which may increase the risk include:

  • Gender. Women tend to develop macular degeneration more often than men, although the reason for this isn’t clear.
  • Genetics. Macular degeneration often runs in families.
  • Ethnicity. White people have higher rates of macular degeneration compared to black. Chinese people also appear to have a higher risk of suffering from macular degeneration.
  • Smoking. Smokers are at least twice as likely to develop macular degeneration, although the risk may actually be even higher.
  • Alcohol. Alcohol in large quantities on a daily basis can increase the risk.

People over 50 are most at risk of developing age-related macular degeneration, so it’s important to have regular checkups. If you’re diagnosed with the condition, you should check your vision on a daily basis, and notify your ophthalmologist of any changes.

What Treatments Are Available?

There is currently no cure for age-related macular degeneration, although it’s sometimes possible to prevent vision from getting worse. These include:

  • Laser Therapy. Wet macular degeneration, which is caused by growth of unwanted blood vessels, can sometimes be treated with laser therapy. A high powered beam of light is directed onto the blood vessels, causing them to be destroyed. A treatment called photodynamic laser therapy, which uses a drug that damages blood vessels and is activated by a laser, is also sometimes used.
  • Anti-angiogenic drugs. These drugs are injected into the eye and stop new blood vessels from forming. They also prevent existing vessels from leaking blood, which is one of the most common causes of wet macular degeneration.
  • Vitamin Supplements. There is some evidence to suggest that certain vitamins, including C, E, zinc, copper and beta-carotene, can slow vision loss in people who have dry macular degeneration.

If vision has already been damaged, low vision aids may be used. These are special glasses that magnify nearby objects, reducing the effect of damage to the macular.

There are a number of potential treatments for age-related macular degeneration currently being trialed. Surgery to remove blood vessels, for example, may be effective but isn’t widely used yet.

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