[Nfbf-l] Fw: [acb-l] Restoring sight with new type of artificial cornea

[Patricia A. Lipovsky]

----- Original Message ----- 
From: "Kim Lookingbill" <seadolphink at comcast.net>
To: <acb-l at acb.org>
Sent: Wednesday, August 25, 2010 8:44 PM
Subject: [acb-l] Restoring sight with new type of artificial cornea


> Restoring sight with new type of artificial cornea
> August 25, 2010 - 4:49pm
> By LAURAN NEERGAARD
> AP Medical Writer
>
> WASHINGTON (AP) - Scientists have created a new kind of artificial cornea,
> inserting a sliver of collagen into the eye that coaxes its own natural
> corneal cells to regrow and restore vision.
>
> It worked in a first-stage study of 10 patients in Sweden, researchers
> reported Wednesday. And while larger studies are needed, it's a step 
> toward
> developing an alternative to standard cornea transplants that aren't
> available in much of the world because of a shortage of donated corneas.
>
> "We're trying to regenerate the cornea from within," said Dr. May 
> Griffith,
> senior scientist at the Ottawa Hospital Research Institute in Canada and a
> professor of regenerative medicine at Linkoping University in Sweden.
>
> Vision depends on a healthy cornea, the film-like covering of the eye's
> surface that helps it focus light. Corneas are fragile, easily harmed by
> injury or infection, and about 42,000 people in the U.S. receive
> transplanted corneas every year. While that's considered an adequate 
> supply
> in this country, donated corneas aren't available in many countries for 
> the
> estimated 10 million people worldwide with corneal blindness. Transplants
> also bring risk of rejection.
>
> In addition, researchers are working to improve plastic-like artificial
> corneas and to create stem-cell treatments that could spur corneal growth.
>
> The new work, published in the journal Science Translational Medicine, is 
> a
> bioartificial cornea _ an attempt to use the same natural substances that
> make up a real cornea to induce healing.
>
> "I characterize this work as a major advance in the direction that we need
> to go," said Dr. Alan Carlson, cornea transplant chief at Duke 
> University's
> eye center, who wasn't involved in the research. To "make this mimic donor
> tissue to the extent that your own cells ultimately become incorporated in
> this tissue, I think that's the most exciting aspect."
>
> A cornea's structure is made up of a tissue called collagen. First,
> researchers took human collagen grown in yeast, made by San 
> Francisco-based
> FibroGen Inc., and molded it into a contact lens-looking shape _ the
> scaffolding, essentially, for a cornea.
>
> Then Griffith, working with Linkoping University eye surgeon Dr. Per
> Fagerholm, studied the bioartificial cornea in 10 patients with severe
> vision loss from damage to a corneal layer. Damaged tissue in one eye was
> removed, and the new biosynthetic cornea implanted. Soon, cells that line 
> a
> healthy cornea started growing in the collagen. Tear production 
> normalized,
> and even corneal nerves regrew, something researchers could test by
> measuring sensitivity. There was no rejection, and patients didn't need
> immune-suppressing medication.
>
> Two years later, six of the patients had significantly improved vision 
> with
> glasses and two were no worse. When implanted with contact lenses that
> previously they couldn't tolerate, patients saw as well as a similar group
> of patients who had received standard corneal transplants.
>
> Duke's Carlson cautioned that these weren't full-thickness corneal
> transplants _ the lowest layer of the patients' original corneas wasn't
> replaced. People with these more upper-layer corneal problems make up 
> about
> 10 percent of transplant cases, he said, while the bigger hurdle is 
> creating
> therapy for harder-to-treat full-thickness damage to what's called
> endothelial cells.
>
> But he called the experimental technology a step toward that goal, and
> Griffith said she is planning larger studies and will try to extend the
> therapy to a wider range of vision loss.
>
> ___
>
> Online:
>
> Science Translational Medicine: http://stm.sciencemag.org/
>
>
> Share your yesterdays, Dream of tomorrow, but Live for today!
>
> Kim Lookingbill
> seadolphink at comcast.net
> Twitter:  seadolphin1
>
>
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