Abstract
Macular degeneration also called as Age related macular degeneration (ARMD) is an age
associated chronic eye disease and is a very common cause of reduced vision among
older individuals over the age of55 years. The condition is characterized by degeneration
of light-sensing cells of the central region of the retina – the rnacula which malfunction
and eventually die, resuhing in a gradual decline and loss of central vision, while
peripheral vision is retained. MD is the main cause of blindness in the United States and
accounts for blindness in approximately 80 percent of people who are 75 or older. The
condition affects more than 10 million Americans and this number is predicted to
increase as the ”baby boomers” age.
Eyes, Vision and Macular Degeneration
The retina, which is situated at the back of the eye, contains an extraordinary
photosensitive array ofcells that line the back ofthe eye. The light fulling onto these cells
in the retina is transfurmed into electrical signals which arc transmitted to the brain
centers !bat process and interpret them. The retina has two main parts – the macula and
the peripheral retina 1-3.
The rnacula is the part of the retina that is responsible fur seeing line detail (see fig
below), such as reading, seeing fueial features and interpreting different colors. The
macula is made up of densely packed light-sensitive cells called cones and rods. These
cells, particularly the cones, are essential for central vision. The cones are responsible for
color vision, and the rods enable the individual to see shades ofgray 1-3
The choroid is an underlying layer of blood vessels that noutishes the cones and rods of
the retina. A layer of tissue furming the outermost surfuce of the retina is callcd the
retinal pigment epithelium (RPE). The RPE is a eritical passageway fur nutrients from the
choroid to the rerina and helps remove waste products from the retina to the choroid. It is
this part of the retina that is affected by age-related macular degeneration and results in
debilitating loss ofvital central or detail vision 1-3.
Types of Macular Degeneration
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