GA

Geographic Atrophy

Geographic atrophy (GA) is an advanced form of age-related macular degeneration (AMD). GA primarily affects the macular region of the retina, and is characterized by the gradual, progressive loss of photoreceptors, retinal pigment epithelium (RPE), and underlying choriocapillaries. The progressive loss of retinal cells is associated with a gradual and irreversible loss of central visual function, that can affect one or both eyes.

GA is a leading cause of visual impairment in the elderly, affecting more than 5 million people worldwide. A study in people with European ancestry showed the prevalence of GA (% of people with GA in the population) rises sharply with age, increasing approximately 4-fold with every decade of life beyond the age of 50 years; from 0.7% in people aged 70 years, to 2.9% in people aged 80 years and 11.3% at 90 years of age.

Several studies have also estimated the incidence of GA (new cases of GA diagnosed in a population over a specified time period). One of these studies evaluating the incidence of AMD in the US white population reported annual GA incidence rates of 1.9 per 1000 aged ≥50 years; rates increased significantly with age, rising from 0.3 per 1000 in individuals aged 60-64 years, to 3.0 per 1000 in those aged 75–79, to 22.0 per 1000 in those aged >90 years.⁵

As a result of population growth and ageing, the number of people affected by AMD and GA are expected to increase considerably over the next few decades.

GA is responsible is for approximately 20% of all cases of legal blindness in the United States¹ and 26% of cases in the United Kingdom. With no approved treatments to prevent or slow its progression and the number of people affected expected to increase, GA represents a significant unmet medical need.