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Eyes Without a Face:
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Eyes Without a Face:
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I was nervous about my visit to the University Medical Center. I could sense that even John had some reserved optimism. Dr. Star had reviewed my medical records before we arrived. He began by explaining why my past cornea implants had failed.
"In the normal eye the epithelial cells of a cornea wear away through ordinary eye movements and are replaced by stem cells located in the corneal limbus. Lucy, your eyes were extensively damaged by the heat generated in the accident that destroyed your vision. You lack the necessary stem cells to maintain a healthy cornea. This is the reason cornea implants have been unsuccessful for you."
"But I could see for a while after I had the implants, then I would return to blindness," I responded puzzled.
"Initially you may have regained some sight, but after several weeks or months the epithelial cells on the donor cornea would slough off. Without stem cells, aging epithelial cells cannot be replaced on the donor cornea," Dr. Star continued. "In your situation, Lucy, stem cells will be needed, preferably from a close relative."
"Lucy's gone through a lot emotionally with the failure of the past cornea transplants," John interjected. "Why do you think this will work if all of the past transplants failed?"
"Research has shown that traditional corneal implants can never be successful in patients lacking the limbus stem cells. With this approach there is a fifty percent or better chance that Lucy will have some degree of success; however, the longevity of the benefits and future side effects are not known," Dr. Star said. "This procedure also has a distinct advantage. The cultured stem cells can be frozen for use at a later time. If the transplant should fail, the banked stem cells could be used so there would be no need for another donor."
"So you just take the stem cells and stick them in my eye?"
"Not exactly, it's a bit more complicated," Dr. Star explained. "We get the stem cells from a donor using a device called a Limbal Stem Cell Harvester. It was developed by Dr. Roy Chuck, an eye surgeon at the UCI Medical Center. This device is a modified microkeratome, which is used in LASIK surgery. By using this method, more stem cells can be gathered quickly and easily. One of the reasons that limbal stem cell transplants have failed in the past is the difficulty in identifying and obtaining an adequate amount of stem cells. To get enough of them we need to culture the stem cells on an amniotic membrane for about three to four weeks where they increase in number. Next, after the damaged corneal tissue from your eye is removed, the culture with the amniotic membrane is transplanted into your eye. This process will provide an epithelial cell layer with stem cells. Then about three months later a donor cornea is transplanted into your eye. With any luck it should restore a normal cornea surface on your eye."
"Dr. Star, these stem cells you're talking about culturing, do I understand you right; they don't come from an embryo?" John needed assurance that the procedure would be within his moral boundaries.
"Precisely, these are adult limbic stem cells. The exploration of adult stem cells is still in its infancy. The full potential, diversity, and problems associated with their use are only at the beginning stages of research, but early studies indicate great promise in this area," Dr. Star stated reassuringly.
John could sense how excited I was about this procedure. I just knew it would work. I would be able to see my daughter's smile and her pout. I would see the world again. We read over the literature that Dr. Star had given us and filled out the forms. As far as I was concerned, there was no down side. I was blind, so what did I have to lose?
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