Age-Related Macular Degeneration (AMD)

Age-related macular degeneration (AMD) is a retinal disease that affects the small central area of the retina known as the macula.  With AMD your vision maybe less, sharp, seem distorted or blurry, which can make it difficult to do everyday tasks, like reading, driving and even seeing or recognizing a friends face. Early signs of AMD may have no symptoms at all and the exact cause of AMD is not known, however it develops as the eye ages.  It’s the leading cause of vision loss in older Americans. 

The two basic forms of Age-Related Macular Degeneration are wet and dry: 
 

  • Dry AMD – This is the most common form of AMD, which develops and worsens slowly over time.

Wet AMD – This is less common form of AMD. It’s not fully understood, however a minority of people with macular degeneration develop this more serious form of the disease. Unfortunately, this form can progress much faster, and cause central, irreversible, vision loss in one or both eyes.   In wet macular degeneration, new blood vessels grow (neovascularization) underneath the retina in response to a decreased supply of nutrients and slow transport of wastes. Unfortunately, new blood vessels do not improve the health of the retina. Instead, they often leak blood or fluid into the retina.  Eventually, these areas of neovascularization and leakage can lead to the death of the overlying photoreceptors and scarring of the macula. Scarring is the final stage of macular degeneration, and it frequently results in a significant central/detail vision loss.  Peripheral or side vision is rarely affected by macular degeneration. While macular degeneration is the leading cause of legal blindness, it rarely leads to total blindness.

For the majority of people with macular degeneration who have the early [dry] form of the condition, their symptom maybe minimal vision loss.  For those with the more severe Wet AMD, the first sign of fluid under the retina is a distortion of straight lines or distorted images.  These changes can be subtle. 

 

As the condition worsens, blind spots may appear.  As the surface of the retina becomes uneven, due to the neovascularization and leaking, objects in your vision may appear wavy, blurred and/or distorted. If caught early enough, this stage may be treatable before it causes too much damage. 

If ignored or left untreated, these areas can lead to death of the overlying photoreceptors and scaring of the macula.  This scarring is the final stage of macular degeneration and it's frequently associated with the significant central vision loss in that eye.  Legal blindness means the vision is 20/200 or worse in the better eye even with corrective lenses, or that the peripheral visual field is restricted sufficiently causing tunnel vision.

Unfortunately, AMD cannot be prevented.  The primary risk factor for AMD is age.  The older you get, the greater your risk.  Also,

if you have a family history of AMD, you are at greater risk, as are women and people who are Caucasian or European decent. 

Other risk factors include:

  • Cigarette smoking

  • Obesity

  • Hypertension (High blood pressure)

  • Excessive sun exposure

  • Diets deficient in fruits and vegetables