| Myopic degeneration is an uncommon
condition characterized by progressive stretching of the
eye that damages the retina, the layer of light-sensitive
cells that lines the back of the eye. People with severe
nearsightedness (high myopia) are at greater risk for
myopic degeneration.
Myopic degeneration commonly occurs during young adulthood
with a gradual decrease in central vision. Vision can
decrease more abruptly, but typically vision loss is
gradual. Although central vision may be lost, side (peripheral)
vision usually remains unaffected. Remaining sight can
still be very useful and with the help of low-vision
optical devices, people can continue many of their normal
activities.
The causes of myopic degeneration are not clearly understood
but may include biomechanical abnormalities or hereditary
factors. The biomechanical theory assumes that the retina,
in a myopic eye, is stretched over a larger than normal
area because the eye is longer than usual. Over time,
the outer coat of the eye, known as the sclera, also
stretches in response to forces like internal eye pressure.
This stretching of the sclera is thought to lead to
retinal degeneration. In the hereditary theory, the
retinal changes are thought to be an unavoidable, inherited
process.
The only treatment for myopic degeneration is surgery
to reinforce the scleral wall. This has been performed
with varying degrees of success. |