Geographic atrophy (GA), the late stage of age-related macular degeneration (AMD), may lead to vision loss. Here’s what to expect as the condition progresses.

About 1 million people in the United States have GA, the late stage of AMD. AMD is an eye condition that progressively damages the cells in the macula — the part of the eye that helps you see clearly straight in front of you.

Advanced AMD comes in two forms: Wet and dry. In wet AMD, leaky blood vessels cause scarring and damage to the macula. In dry AMD, cells on the macula gradually die, leaving behind patches of damage. GA is the late stage of dry AMD. It’s possible to have wet AMD and GA at the same time.

GA is progressive. At first, small areas of cells in the outer part of the retina die. Doctors refer to these areas of damage as “lesions.” The damage expands until it eventually covers the whole macula, leading to vision loss and potential blindness.

Syfovre (pegcetacoplan) and Izervay (avacincaptad) are approved treatments for GA. When these medicines are injected into the eye once per month or every other month, they can slow GA progression by about 14% to 21%. However, they can’t restore vision that has already been lost.

The destruction of cells in the macula is a slow process that takes years. However, the rate differs slightly for each person. A 2021 study estimated that GA growth varies from 0.02 to 4.05 millimeters (mm) per year, with an average rate of 1.09 mm per year.

These factors might make GA progress faster:

  • genes
  • the number of lesions
  • a high carbohydrate diet
  • the initial size of the lesions
  • smoking
  • age

Knowing what to expect as the condition progresses can help you prepare.

Geographic atrophy (GA) occurs during the late stage of dry AMD, in which cells in the macula become damaged and die. Without treatment, GA can progress to total vision loss.

Currently, two drugs have approval to treat GA. These medications can slow the progression of the condition by slowing the spread of atrophy across the macula. The drugs are injected into the eyes every month or every other month.

Research has shown that these drugs are more effective in people with atrophy away from their fovea. However, the drugs cannot restore vision in people who have already lost it.