Age-related macular degeneration is the leading cause of irreversible blindness in people 50 years of age or older in the developed world. More than 8 million Americans have age-related macular degeneration, and the overall prevalence of advanced age-related macular degeneration is projected to increase by more than 50% by the year 2020.

Normal retinal architecture: The macula is the central, posterior portion of the retina. It contains the densest concentration of photoreceptors within the retina and is responsible for central high-resolution visual acuity, allowing a person to sec fine detail, read, and recognize theca/. Poatcrior to the photoreceptors lies the retinal pigment epithelium. It is part of the blood-ocular barrier and has several functions, including photoreceptor phagocytosis, nutrient transport, and cytokine secretion. Posterior to the retinal pigment epithelium lies Bruch's membrane, a semipermeable exchange barrier that separates the retinal pigment epithelium from the choroid, which supplies blood to the outer layers of the retina

Changes with age: With age, one change that occurs within the eye is the focal deposition of acellular, polymorphous debris between the retinal pigment epithelium and Bruch's membrane. These focal deposits, called drusen, are observed during ftmduscopic examination as pale, yellowish lesions and may be found in both the macula and peripheral retina.