Age-Related Macular Degeneration

Macular Degeneration (AMD) is a common eye condition and the leading cause of vision loss among people age 50 and older – more than cataracts and glaucoma combined. It affects over 10 million North Americans and at present is considered an incurable eye disease.[i]

 

Cause:

 

AMD is caused by the deterioration of the central portion of the retina, the inside back layer of the eye that we need for sharp, central vision letting us see what is straight ahead. The human eye can be compared to a camera. When it is working properly, the retina’s central portion, known as the macula, is responsible for focusing the eye’s central vision. It controls our ability to read, drive a car, recognize faces or colors and see objects in fine detail. It records the images we see and sends them via the optic nerve from the eye to the brain.

 

When the cells of the macula deteriorate, images are not received correctly. In early stages, macular degeneration does not affect vision. In some people AMD advances so slowly that vision loss does not occur for a long time, while in others it can progress faster and may lead to a loss of vision in one or both eyes.

 

Research into this little understood disease is limited, but cause includes both heredity and environment. It is not known what causes the cells of the macula to deteriorate. It has been stated that “as the ‘baby boom’ generation ages and in the absence of further prevention and treatment advances, the prevalence of AMD is estimated to reach epidemic proportions of 6.3 million Americans by 2030”.[ii]

 

Risk Factors:

 

The biggest risk factor for Macular Degeneration is age. Your risk increases as you age and the disease is most likely to occur in those 55 and older.

Other risk factors include:

 

  • Genetics – people with a family history of AMD are at a higher risk.
  • Race – Caucasians are more likely to develop the disease than African- Americans or Hispanics/Latinos.
  • Smoking – Smoking doubles the risk of AMD.

 

Symptoms:

 

As the disease progresses, a person may experience wavy or blurred vision or a blurred area near the center of vision. If the condition continues to worsen, central vision may be completely lost. People with very advanced macular degeneration are considered legally blind. Even so, because the rest of the retina is still working, they retain their peripheral vision, which is not as clear as central vision.

 

Over time the blurred area may grow larger and objects may not appear to be as bright as they used to be. The loss of central vision will interfere with normal daily activities.

 

Diagnosis:

 

The first signs of AMD are typically discovered during a regular dilated eye exam. Standard screening tests include the visual acuity exam using the “Snellen” letter chart with an E at the top. Also used is the Amsler grid, which looks like graph paper with a dot in the middle. The grid is used to check whether lines look wavy or distorted or if any lines of the graph appear to be missing.

 

Most of the advanced diagnostics to detect or study the progression of AMD involve taking images of the inside back of the eyeball (fundus) and the retina.

 

Treatments:

 

There are two types of AMD – “dry” and “wet”. The treatment for early dry AMD is generally nutritional with a healthy diet high in antioxidant to support the cells of the macula. If the disease is further advanced, but still dry then supplements may be recommended to add higher quantities of certain vitamins and minerals, which may increase healthy pigments and support cell structure.

 

Until recently the only available treatment to seal leaking blood vessels associated with wet AMD was with Laser Photocoagulation to reduce the risk of severe visual loss. A number of clinical trials were conducted between 1979 and 1994 using this procedure.

 

Later treatments used an intravenously injected drug to help direct the laser to the affected area to seal off leaking vessels while leaving healthy ones intact. These treatments cannot restore what vision is lost, but seem to slow down the progression of the disease. Currently, the most common and effective clinical treatment for wet Age-related Macular Degeneration is anti-VEGF therapy – which is periodic injections into the eye with a chemical called an “anti-VEGF” to support the growth of new blood vessels.[iii] There can be serious side effects from this treatment and consultation with your eye doctor is needed to understand how they may affect you.

 

Macular degeneration treatment breakthroughs inspire hope that someday we may see a cure to this disease.

 

Periodic examination of your spine by your chiropractor is also another good health habit to keep you physically agile. Look after your body and it will look after you!

[i] American Macular Degeneration Foundation, http://www.macular.org

[ii] Kupfer, Dr. Carl, former Director of the National Eye Institute, National Institutes of Health

[iii] National Eye Institute, http://www.nei/nih

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