Wet vs Dry: Age-Related Macular Degeneration

Learn the Differences

Wet or dry AMD
Wet vs Dry AMD. Image © A.D.A.M.

Age-related macular degeneration (AMD) is the leading cause of blindness in people aged 65 and older. AMD damages the macula, the part of the retina responsible for our sharp central vision and our ability to see fine details. If you are diagnosed with AMD, it is important to understand the differences between the wet and dry forms of the eye disease.

  • Dry AMD:  Dry AMD is also referred to as non-exudative macular degneration. Most people with AMD have the dry form. This type is usually less severe and tends to progress slowly. In dry AMD, changes occur in the pigmented cells of the macula. Also, yellow-colored deposits called drusen may be detected by your eye doctor during a dilated eye examination.
  • Symptoms of dry AMD may include blurred vision, a need for more light when reading, difficulty with seeing in low light levels, trouble with distinguishing people's faces, and a blind spot in the center of vision. Dry AMD usually affects both eyes, but vision can be lost in one eye while the other eye seems unaffected. The dry form of AMD can turn into the wet form, even during the early stages.

  • Wet AMD:  Wet AMD is also referred to as exudative macular degeneration or neovascular macular degeneration. Wet AMD is also known as "advanced" AMD. The wet form of AMD leads to more vision loss than the dry form, but only accounts for about 10% of all cases. In wet AMD, abnormal blood vessels can bleed. As blood builds up, it may lift the macula and cause visual distortions.

    Symptoms of wet AMD include straight lines that appear crooked or wavy and the sensation that objects are further away than they really are. Wet AMD can quickly lead to loss of central vision, as it does not have stages like the dry form of AMD.

    What is Geographic Macular Degeneration?

    Geographic macular degeneration is an advanced form of dry macular degeneration. In geographic macular degeneration there is a general, larger area of loss of the RPE or retinal pigment epithelial cells. The RPE gives the back of the eye its characteristic red-orange color and helps to nourish the photoreceptors, such as rods and cones.

    As a result, anything that causes disease in the RPE will eventually affect the rods and cones in the retina. Doctors call it geographic because the large areas of lost RPE appear like continents surrounded by a sea of healthy retina. Sometimes it is described as RPE dropout. Typically, there is no fluid leakage or bleeding and the loss of vision occurs very slowly. Doctors are studying gene therapy and RPE transplantation as treatment because the dramatic changes in the RPE. 

    Who is at risk for macular degeneration?

    Risk factors for macular degeneration are:

    • Smoking
    • Poor diet
    • Light complexion
    • Family history
    • Cardiovascular disease
    • Excessive sun exposure

    If I have macular degeneration, does that mean I will get glaucoma too?

    No, glaucoma is a completely different type of eye disease that affects the optic nerve. Glaucoma is usually, but not always, due to increased pressure inside the eye. Having glaucoma does not put you at increased risk for also developing macular degeneration. 

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