Age Related Macular Degeneration (AMD)

amd1The macula is the most sensitive part of the retina and is located at the back of the eye. The macula contains light-sensitive cells which provide clear, sharp central vision. Age-related macular degeneration (AMD) occurs when the arteries that nourish the retina harden. Deprived of nutrients, the retinal tissues begin to weaken and die, causing vision loss. Patients may experience anything from a blurry, gray or distorted area to a blind spot in the center of vision. Age-related macular degeneration is the leading cause of vision loss in the United States. Macular degeneration doesn’t cause total blindness because it doesn’t affect the peripheral vision.

Causes of Age-Related Macular Degeneration

  • The formation of deposits, known as drusen, under the retina
  • Abnormal blood vessel growth

Types of Age-Related Macular Degeneration

There are two types of macular degeneration: dry, or non-neovascular/atrophic and wet, or neovascular/exudative.

amd2Dry Macular Degeneration – dry AMD is much more common than wet AMD. The dry form is a more gradual process and has three stages: early, intermediate and advanced. Symptoms include thinning of the retina, loss of retinal pigment and the formation of small, round particles inside the retina called drusen. Vision loss with dry AMD is slower and often less severe than with wet AMD. About 90 percent of patients with AMD have the dry form.


amd2Wet Macular Degeneration
– is an advanced form of AMD. The wet form is a rapid process and is characterized by the leakage of blood and fluid, or the growth of blood vessels under the macula to compensate for the blocked arteries. The leakage distorts vision and when the blood dries, scar tissue forms on the retina. This creates a dark spot in the patient’s vision. Patients who develop the wet form have had the intermediate stage of the dry form of AMD. About 10 percent of patients with AMD have the wet form.

Risk Factors for Age-Related Macular Degeneration

Age-related macular degeneration typically occurs in people age 50 and older. Possible risk factors include:

    amd3

  • Genetics
  • Age
  • Diet
  • Smoking
  • Exposure to sunlight
  • High blood pressure
  • Elevated cholesterol levels
  • Poor dietary habits

Symptoms of Age-Related Macular Degeneration

Symptoms of macular degeneration may include:

  • A gradual loss of ability to see objects clearly
  • A gradual loss of color vision
  • Distorted or blurry vision
  • Dimmed vision
  • Drusen under the retina
  • A dark or empty area appearing in the center of vision
  • Wavy lines in the vision

Diagnosis of Age-Related Macular Degeneration

After performing a medical examination of the eyes, the physician will perform some of the following diagnostic tests:

  • Visual acuity test
  • Dilated eye examination
  • Fluorescein angiogram
  • Test for central vision loss

Treatment of Age-Related Macular Degeneration

There is no cure for AMD. Recent developments in ophthalmology allow doctors to treat many patients with early-stage AMD with the help of lasers and medication. With regular eye exams macular degeneration can be detected early, allowing for proper treatment and preventing permanent vision loss. Some of the treatment methods used to slow the progression of AMD include:

  • Injections of vascular endothelial growth factor
  • Laser therapy
  • Laser surgery