Dry AMD

Dry AMD is most common type of macular degeneration and affects 85-90% of people who have the condition. In the dry form, there is a breakdown or thinning of the layer of retinal pigment epithelium (RPE) in the macula. These RPE cells support the light sensitive photoreceptor cells that are critical to vision. When we look at something, photoreceptor cells (rods and cones) in the retina gather the images and send them to the brain, where vision information is processed.

  • Dry AMD is characterized by the presence of drusen and thinning of the macula. Dry AMD reduces central vision and can affect color perception. Generally, the damage caused by the dry form is not as rapid as that of wet AMD. However, over time, it can cause profound vision loss. The degeneration or death of these cells is called atrophy.  Hence, dry AMD is often referred to as atrophic AMD.  The more advanced stage of dry AMD is called geographic atrophy, where entire patches of photoreceptor cells die leaving dark grayish patches in the central vision.

What Are Drusen?

  • Drusen are tiny yellow or white protein deposits in a layer of the retina called Bruchs membrane. They are the most common early sign of dry AMD.  They may be the result of a failure of the blood vessels to dispose of waste products produced by retinal cells. 
  • There are several types of drusen with different levels of risk. Drusen can be small, hard and scattered far apart from each other. They are round and have distinct edges. These drusen may not create vision problems for a long time and may not even be an indication of macular degeneration.
  • Other drusen are larger, softer and closer together.  Their edges are less distinct. When these drusen are observed, there is a greater risk for developing wet AMD.  They can also disrupt the layers of the retina and can lead to a detachment of the RPE.   
  • Your doctor can see drusen during a dilated eye exam, even if you are not aware of changes to your vision.  That is one reason why regular eye exams are so important.  If you have the larger, soft drusen your doctor will probably want you to come for check-ups more often.  If they do lead to wet AMD, early treatment is essential.

 

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