Medical Update. What is Geographic Atrophy?

The yellow areas in this illustration show the progression of geographic atrophy.

Geographic atrophy (GA) is the scientific term for late stage dry age-related macular degeneration (MD). It is called geographic atrophy, as the damage to the macula tends to start as patches of damage (or atrophy) that look like islands on a map when a doctor looks at the back of the eye.

Age-related MD is a progressive disease which goes through different stages. Not everyone will reach late-stage age-related MD, as the disease develops at different rates for different people.

Age-related MD starts off as early AMD, when an optometrist may notice small fatty deposits called drusen when looking at the back of the eye. As age-related MD develops to the intermediate stage, often these drusen get bigger or more abundant, and small patches of the macula may change colour. With early AMD and intermediate AMD, sight is not usually affected. However, with intermediate AMD you may start to notice issues such as having difficulty adjusting to changing light conditions. Late-stage AMD manifests in two ways, either wet age-related MD (also called choroidal neovascularisation) or geographic atrophy (often referred to as dry age-related MD). Wet and dry age-related MD can occur together.

In geographic atrophy cells in the macula become damaged and die which leads to sight loss.

Treatments for dry macular degeneration are being developed and have featured in the two most recent issues of Viewpoint – issues 21 and 22. It is encouraging to note research and studies continue to be pursued in the search for effective and affordable treatments.

Thank you to the Macular Society, UK for this content.