Blind World


Michigan hospitals participate in clinical trial.
Tiny telescope implanted in eye saves patients' sight.





December 8, 2003.

By Daniel Mears,
The Detroit News.




Lyle Graf participated in a clinical trial of the implantable miniature telescope for the eye. She covers her right eye and looks at her hand with her left eye, in which the IMT has improved her vision. "It's much clearer," she says.


Lyle Graf watches her granddaughter, Magnolia Kittle, learn to read. Despite her surgery, Graf can't see well enough to read.


Lyle Graf could barely make out the words printed on a book page. The letters were fuzzy and ran together, but she thought her eyes were blurry from a cold.


Gradually, however, her vision further deteriorated.


For Graf, 79, of Ann Arbor, sewing, reading and watching television ultimately became impossible. She was diagnosed with macular degeneration.


The disease, which affects central, or "straight ahead" vision, is among the leading causes of vision loss in the United States, especially for those older than 50. It does not cause total blindness since it does not affect peripheral vision, but there is no cure, and the exact cause is unknown.


But now a tiny microscope implanted in one eye -- a "bionic eye" -- is showing promise in improving vision for those with the disease.


The pea-size implantable miniature telescope is part of a revolution in medical bioengineering devices, where biology meets technology. It is bringing the bionic man of TV's "The $6 Million Man" closer to reality.


"I still can't read, but I can see so much better than I could before," said Graf, who is part of a clinical trial for the eye device. "I can watch television and go to the movies with no problems."


The IMT was implanted in the eyes of 220 participants during the three-year clinical trial, which included doctors from Beaumont Hospital in Royal Oak and the University of Michigan's Kellogg Eye Center in Ann Arbor. Now, doctors are compiling data and studying the results.



Macular degeneration affects an estimated 1.6 million Americans. Michigan ranks eighth in the nation, with 57,268 cases; California leads with 165,476. P>
The macula, the central part of the retina directly opposite the lens, is about one-eighth inch in diameter. It is supplied with blood, which nourishes the cells. If the macula is intact, we see the fine details of whatever is directly in front of us. When the macula deteriorates or breaks down, central vision becomes blurred or disappears. Straight lines look wavy or broken. People with the disease see the edges of images, but not what is in the middle.


P>
In time, the sense of color is diminished. Although the patient does not experience total blindness, vision may be reduced to legal blindness -- 20/200 or less. Perfect vision is 20/20. P>
Doctors caution that the telescope is not a panacea. P>
"A patient who starts with not perfect vision will be left with vision that is not perfect after the surgery," said Dr. Paul Lichter, director of the Kellogg Eye Center, who performed Graf's surgery. "But compared to before, it is a lot better."


He explained that the telescope takes the image of an object, like a face, and magnifies it two to three times its normal size, then projects it like a movie projector beyond the scarred macula so it can be seen and recognized. But "seeing" takes extensive training.


"They have to learn to see again," said Dr. G. Robert Lesser of Beaumont Hospital in Royal Oak, who also performed implants in the clinical trial. "Patients must work with a low-vision specialist because it's like learning to write with your left hand if you're right-handed."


Once the telescope is implanted, the eyes no longer work together because the brain cannot merge the magnified image in one eye with the normal image in the other eye. It is similar to walking around with a binocular attached to one eye.


The one-hour surgery involves removing the eye lens and placing the telescope into the patient's eye with the poorest vision. It is not a complete telescope, but rather a set of lenses encased in a plastic-like covering that allows the cornea of the eye to serve as the forward lens of the telescope.


The telescope was implanted only in patients with "dry" macular degeneration, as opposed to "wet." Dry, the most common form, involves fatty deposits forming in the layers of the retina, which normally converts light to electrical impulses and sends them to the brain to allow vision.


Wet macular degeneration is more threatening to vision. Blood vessels under the retina leak fluid or break open. The wet form can be treated with lasers in some cases.


The eye telescope is one of the newest developments in the bionic revolution, in which plastic, metal and polymers are used to create artificial muscles, ears and other organs that researchers hope will improve the quality of life.


Mechanical heart valves, replacement hips and cochlear ear implants long have been part of the landscape.


"There's no question there will be a tremendous number of advances in the future that will include devices, whether electrical or mechanical, which will enhance the function of our organs," said Steve Goldstein, Henry Ruppenthal family professor of orthopedic surgery and bioengineering at the University of Michigan.


Goldstein said right now, replacement parts may not look like the original organs -- such as the eye telescope, which replaces the lens.


But "eventually, what will happen more and more is that the ceramics, polymers and metals being used now will be replaced by proteins that make up normal tissues and will actually be made of skin and bone."


For Graf, the bionic revolution came just at the right time.


The surgery "didn't hurt a bit, and it feels like my normal eye," she said. "I don't have to use a magnifying glass to see anymore, and I can go to ball games."



You can reach Shawn D. Lewis at (313) 222-2296 or slewis@detnews.com.



Copyright 2003 The Detroit News.






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