Age-related Macular Degeneration (AMD)

What is Age-related Macular Degeneration (AMD)?

Age-related Macular Degeneration (AMD) is the leading cause of vision loss and blindness among those above the age of 65. AMD is the degeneration of the macula, which is part of the retina or nerve fibre layer of the eye (similar to the “film” in a camera) responsible for the sharp, central vision needed to read or drive. Progressive degeneration of the macula leads to loss of central vision and irreversible vision loss.

What are the different types of AMD?

There are 2 main types of AMD.

1. Dry or non-exudative AMD

This is the most common type (about 85 to 90%) of AMD. In dry AMD, ageing and thinning of the macula together with the deposition of waste materials (called drusen) causes deterioration of central vision. Fortunately, the progression of dry AMD is slow and visual loss is usually not severe. Severe visual loss can occur if disease progresses to late-stage geographical atrophy.

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2. Wet or exudative AMD

Wet AMD is the more serious type and about 10% of patients with AMD have this. In wet AMD, new abnormal (and fragile) blood vessels grow beneath the retina and leak blood and fluid. This can cause sudden visual loss and lead to permanent damage as a result of scarring.

Who is at risk of having AMD?

  • Elderly
  • Those with family history of AMD
  • Unprotected over-exposure to sunlight
  • Smoker
  • Obesity and high dietary fat
  • Lack of physical exercise
  • High blood pressure (hypertension)
  • Lighter eye colour

Dry AMD usually produces a slow, painless loss of central vision. Patients may complain of shadowy areas in central vision or fuzzy vision. However, patients with wet AMD can present with sudden onset of loss of central vision or distorted vision.

Can we prevent AMD?

As there is no cure for AMD, screening and early treatment may be beneficial. Nutrients such as zinc, lutein, vitamins A, C and E help to lower the risk of AMD or slow down the progression of dry AMD. This is supported by results from the Age-related Eye Disease Study (AREDS) released in 2001. In addition, increase physical exercise, usage of sunglasses, smoking cessation and control of blood pressure can also be beneficial.

How is AMD treated?

Treatment will depend on the type and severity of the disease. There is no effective treatment for dry AMD although nutritional supplements may help prevent its progression to wet AMD.

For wet AMD, the aim of treatment is to stop the growth of abnormal of blood vessels without damaging the surrounding retina. This can be done by injection of drugs (such as Lucentis or Avastin) into the vitreous of the eye or usage of laser together with injection of special dye (photodynamic therapy).

The visual loss from AMD is usually irreversible. Those with severe visual loss will benefit from low vision devices.