Dry Macular Degeneration
Updated January 01, 2014.
Written or reviewed by a board-certified physician. See About.com's Medical Review Board.
Dry age-related macular degeneration (AMD) is the most common type of the disease, accounting for about 90% of all AMD cases. In dry AMD, an observable change in the pigmented cells of the eye occurs, leaving areas of depigmentation, pigment clumping and drusen.
Dry AMD usually progresses very slowly. Amount of vision loss with dry AMD varies, but it rarely progresses to legal blindness. Some patients may develop macular tissue atrophy and mild scarring.
Dry AMD occurs in three stages referred to as early, intermediate and advanced AMD.
Most people with early AMD do not have reduced vision. In fact, vision in many cases is still 20/20.
Scarring may create significant distortion in the central vision. Central blind spots become much larger, making it extremely difficult or impossible to read or use straight-ahead central vision.
People with advanced stage dry AMD begin to make more use of their peripheral vision, which remains intact.
Sources:
Alexander, Larry J. Primary Care of the Posterior Segment, Second Edition. Appleton & Lange, 1994.
Written or reviewed by a board-certified physician. See About.com's Medical Review Board.
Dry age-related macular degeneration (AMD) is the most common type of the disease, accounting for about 90% of all AMD cases. In dry AMD, an observable change in the pigmented cells of the eye occurs, leaving areas of depigmentation, pigment clumping and drusen.
Dry AMD usually progresses very slowly. Amount of vision loss with dry AMD varies, but it rarely progresses to legal blindness. Some patients may develop macular tissue atrophy and mild scarring.
Dry AMD occurs in three stages referred to as early, intermediate and advanced AMD.
Early Stage Dry AMD
The most common observation in the early stage of dry AMD is the presence of drusen. Drusen is made up of small yellow material that builds up within the retina. Drusen is easily detectable by your eye doctor during a dilated eye examination.Most people with early AMD do not have reduced vision. In fact, vision in many cases is still 20/20.
Intermediate Stage Dry AMD
Intermediate AMD occurs with the presence of one or more large drusen or an irregularly shaped drusen. People in the intermediate stage typically have more symptoms than those in the early stage, often complaining of blurred vision and needing more light to read. Objects may sometimes appear distorted in the central vision and a scotoma (blind spot) may also develop.Advanced Stage Dry AMD
Advanced AMD is also called geographic AMD. In this stage, pigmentary changes begin to appear in the retina, and the light sensitive layer of the retina breaks down.Scarring may create significant distortion in the central vision. Central blind spots become much larger, making it extremely difficult or impossible to read or use straight-ahead central vision.
People with advanced stage dry AMD begin to make more use of their peripheral vision, which remains intact.
Sources:
Alexander, Larry J. Primary Care of the Posterior Segment, Second Edition. Appleton & Lange, 1994.
Source...