Credit: Image courtesy Virginia Commonwealth University
If the center of your vision is blurry or missing, you could have age-related macular degeneration (AMD). AMD is the leading cause of serious vision loss in people over 50 years of age. Until recently, some types of AMD have had no successful treatment. Now some patients with end-stage AMD can receive improve vision thanks to a tiny implanted telescope.
Age-related macular degeneration is a progressive condition that causes the gradual deterioration of central vision. The inside lining of the back of the eye is made up of light-sensitive tissue called the retina.
Light enters the eye through the pupil and is focused by the lens onto the retina. Special cells in the retina convert the light into electric signals that are sent to the brain as visual images through the optic nerve.
The central portion of the retina is known as the macula. The macula receives the images that are directly in front of you.
The light recepters in the macula are much more sensitive to fine detail than the outer or peripheral portions of the retina. The macula is the part of the eye that allows you to read road signs, see the computer screen, or thread a needle. It also allows you to see facial features clearly so you can recognize people.
As you age, the cells in the macula can start to degenerate which can cause AMD. Common symptoms include the gradual inability to see objects clearly, distorted vision, loss of color vision, or a dark or empty area in the center of vision.
One treament for advanced-stage AMD bypasses the non-functioning portions of the macula. During surgery, a telescope the size of a pea is inserted into the eye in place of the lens.
The telescope uses a wide-angle lens to enlarge central visual images two to three times. The images are then projected onto healthy tissue in the retina alongside the damaged cells of the macula where vision has been lost. Because the images have been enlarged, the less sensitve cells of the retina are able to help overcome the blind spot caused by AMD.
The implantable telescope was designed by Dr. Isaac Liphitz and is produced by VisionCare Ophthalmic Technologies.