Age-related macular degeneration (AMD) is a leading cause of blindness that affects central vision and the ability to see fine details. AMD is progressive and primarily affects those over 50, with deposits accumulating beneath the retina in early stages. There are two advanced forms: wet AMD, where new blood vessels break through the retina and cause rapid vision loss; and dry AMD, where retinal cells in the central retina die off in a expanding area. Wet AMD can be treated through eye injections that block VEGF-A and new blood vessel growth, while there is currently no treatment for dry AMD.

1. WHAT IS AGE-RELATED
MACULAR
DEGENERATION?
Thomas Chalberg

2. INTRODUCTION
 Nearly 9 percent of the world’s blindness is attributed to age-related macular
degeneration, or AMD, a chronic disease of the retina that causes the sharp
central vision to blur. This results in an inability to see fine details when
looking straight ahead and can affect activities such as driving, looking at a
computer screen, and reading. Here is a look at this disease and its
treatments.
- AMD is progressive, can result in rapid loss of central vision, and can be
extremely debilitating. Primarily affecting people age 50 and older, its
prevalence is increasing as the world’s population ages.
- Early-stage AMD is when deposits (called "drusen") accumulate beneath
the retina. There are two advanced forms: exudative or "wet" AMD and
geographic atrophy (GA) or "advanced dry" AMD. In wet AMD, new blood
vessels begin to form, which can break through the retina and contribute to
rapid vision loss and fibrosis.

3. MACULAR DEGENERATION
 In GA, cells of the central retina begin to die, leaving an area that
cannot see; this area can expand, and central vision loss occurs as it
advances toward the central area of the retina (called the fovea).
- Wet AMD can be treated by injections into the eye, called
intravitreal injections or IVT. Currently approved therapies, such as
Lucentis and Eylea, work by blocking VEGF-A and the resulting
growth of blood vessels. In 2016, there were more than 6 million
IVT injections given in the US, making it one of the most common
procedures in all of medicine.
- Scientists have identified a genetic component of AMD, which
may prove helpful in developing therapies. As of now, there is no
treatment for GA, but therapies are available to slow visual
impairment and the progression of wet AMD.