Macular Degeneration

What Is Macular Degeneration?

Age-related macular degeneration (AMD) is an eye disease that destroys central vision by damaging the macula, a small area at the back of the eye. The macula provides color and the fine detail needed for central vision. AMD makes it increasingly difficult to read, drive and recognize faces.

There are two types of AMD wet and dry. Dry AMD is the most common form, and it develops slowly and does not usually cause severe vision loss. In dry AMD, cells and blood vessels beneath the macula break down and cause deposits in the back of the eye called drusen. This damages the macula and affects its ability to send signals to the brain. Central vision slowly becomes dimmer or more blurry over time.

Wet AMD is much less common but far more aggressive than dry AMD. Wet AMD can cause permanent damage to the macula over months or even weeks and often occurs where dry AMD already exists. Abnormal, fragile blood vessels grow in the back of the eye. These blood vessels leak, causing the macula to break down. They also move the macula from its normal place at the back of the eye, distorting central vision.

Normal macula Dry AMD (few drusen) Wet AMD (drusen with bleeding and fluid)

Normal macula

Dry AMD (few drusen)

Wet AMD (drusen with bleeding and fluid)

What Are the Symptoms of Macular Degeneration?

While the rate of development and the severity of impairment differ greatly between wet AMD and dry AMD, the symptoms can be quite similar. Signs of AMD may include:

  • Central vision becomes dim, fuzzy, or less sharp.
  • Reading requires more light than in the past.
  • It's harder to see people's faces clearly.
  • Objects appear distorted or smaller than they really are.
  • A new blank or blind spot develops in your central field of vision.
  • You have a loss of central vision that does not go away or becomes worse over time.
  • Straight lines begin to appear wavy or curved. This is usually the first symptom of wet AMD.

The impact AMD has on one's life depends on lifestyle and the degree of vision loss. Even though AMD may affect central vision, it does not necessarily have to lead to complete blindness as most people retain side peripheral vision; however, it still has a devastating effect on the aging population. The ability to drive, the ability to negotiate stairs or other activities that require clear depth perception, and the ability to tolerate changes in light intensity are all compromised in individuals with AMD.

Who Does Macular Degeneration Affect?

The primary risk factor for AMD is advancing age, with incidence steadily increasing after 50 years of age with a greater increase in those more than 75 years old. Family history also appears to be associated with AMD, as 10 to 20 percent of patients with AMD have a close relative who has experienced AMD-related vision loss. AMD appears to be more prevalent in females, Caucasians, and in individuals with blue eyes, perhaps because they do not benefit from the protection that darker pigmentation provides to the retina.

Other risk factors that may be implicated in the development of AMD include cigarette smoking, excessive exposure to ultraviolet light (UV); a diet deficient in vitamins A, C, and E; and high blood pressure.

How to Avoid or Slow Progression of Macular Degeneration

There is no substitute for early detection. Many people give reasons for not having their eyes examined regularly, namely that they don't believe they have a vision problem. What most people do not realize is that AMD usually develops without affecting vision until it has progressed to such a state that treatment options are quite limited. The following are ways to avoid the onset and/or the progression of macular degeneration:

  • Have annual eye exams. Eye exams may help determine whether you are at risk for developing AMD or, if you have AMD, may detect it early. If it is treatable, early detection may help reduce or delay any loss of vision. If you have wet AMD you will need to be seen more frequently.
  • Do not smoke. People who smoke are more likely to develop AMD than those who do not smoke.
  • Eat plenty of fruits, fish, and nuts. Recent studies show that eating regular servings can reduce your chances of getting AMD.
  • People with AMD should check their vision daily or as often as the doctor recommends, using an Amsler grid. If any of the lines on the grid change or begin to appear wavy and curved, a doctor should be called immediately.
  • Protect your eyes from the sun.

How Is Macular Degeneration Treated?

Recent wonderful advancements have been made in the treatment of wet AMD. Treatment for Wet AMD is similar to a diabetic using and needing Insulin. We can control the leakage but you need to have frequent eye exams and frequent injections. Treatment is usually with injections of medications called Avastin or Lucentis.

Laser treatment is an outpatient surgical procedure where laser energy is applied to the retina to seal leaking blood vessels and reduce the growth of these blood vessels. This procedure has been shown to slow the progression of central vision loss in patients with wet AMD, and is reserved for leakage that does not directly involve the central area of vision.

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