Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of vision loss for people over the age of 50 in the Western world, affecting approximately 25-30 million people.

AMD is a degenerative condition of the macula. As a result, the central vision deteriorates. Macular degeneration varies widely in severity. In the worst cases, it causes a complete loss of central vision, making reading or driving impossible. For others, it may only cause slight distortion. Fortunately, macular degeneration does not cause total blindness since it does not affect the peripheral vision.

What is the difference between wet and dry macular degeneration?

AMD is classified as either wet (neovascular) or dry (non-neovascular). About 10% of patients who suffer from macular degeneration have wet AMD. This type occurs when new vessels form underneath the retina. However, the new vessels are very delicate and break easily, causing bleeding and damage to surrounding tissue.

What causes macular degeneration?

Macular degeneration may be caused by variety of factors. Genetics, age, nutrition, smoking, and sunlight exposure may all play a role.

Signs and Symptoms

  1. Loss of central vision. This may be gradual for those with the dry type. Patients with the wet type may experience a sudden decrease of the central vision.
  2. Difficulty reading or performing tasks that require the ability to see detail.
  3. Distorted vision (Straight lines such as a doorway or the edge of a window may appear wavy or bent).

Treatment

There is no proven medical therapy for dry macular degeneration. In selected cases of wet macular degeneration, laser photocoagulation is effective for sealing leaking or bleeding vessels. Unfortunately, laser photocoagulation usually does not restore lost vision, but it may prevent further loss.

Recently, photodynamic therapy has proven to be effective in stopping abnormal blood vessel growth in some patients with wet AMD. This new type of laser treatment is far less damaging than laser photocoagulation and is the treatment of choice in many cases. Early diagnosis is critical for successful treatment of wet macular degeneration.

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