Age Related Macular Degeneration Amd: Eye Care

Content provided by the Faculty of the Harvard Medical School

Age-related macular degeneration (AMD)

Unlike glaucoma, which first affects peripheral vision, age-related macular degeneration (AMD) strikes at the macula, the heart of the eye's vision center. This small part of the retina, which measures only about 3 by 5 millimeters (less than one-quarter inch square), is responsible for sharp, central vision (see Figure 9). People with AMD often develop blurred or distorted vision and cannot clearly see objects directly in front of them. Eventually they may develop a blind spot in the middle of their field of vision that increases in size as the disease progresses.

Figure 9: When central vision is damaged When the macula is damaged, people may first experience blurred or distorted vision and see straight lines as wavy. As the condition progresses, they may notice a black or dark space at the center of their visual field. An ophthalmologist may ask the patient to focus on a dot on a visual grid (Amsler grid). If the lines near the dot appear wavy, macular degeneration may be responsible.

Although the disorder eventually can become debilitating, in the earliest stages of AMD, there are no warning symptoms. If the condition progresses to intermediate AMD, some people begin to notice blurring in the center of their vision. At the advanced stage, the blurred area increases, making it hard to read or even recognize people. More than 7 million Americans have intermediate AMD, while 1.7 million have an advanced form that has progressed to the point of visual impairment.

As age-related macular degeneration progresses, you may notice a blind spot develop in your central vision. Photograph courtesy of the National Eye Institute.

Last updated:	June 19, 2007