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Artificial corneas restore sight for the first time

Fri, 07/20/2012 - 11:12 -- admin

Scientists hope the breakthrough will also slash the cornea transplant waiting list which every year falls short by more than 500 in Britain alone.

The new technique involves growing human tissue or collagen in the laboratory and then shaping it using a contact lens mould.
 
Damaged and scarred tissue from the front of the eye is then removed and the "biosynthetic" replacement is stitched in its place.

Eventually existing cells and nerves in the eye grow over the artificial cornea incorporating it fully into the eye.

The first trials of the operation have shown that it is just as successful as live tissue transplantation and in some cases patients have had their sight fully restored.

Dr May Griffiths, of Linköping University, in Sweden, said: "We were very excited by the results.

"This study is the first to show an artificially fabricated cornea can integrate with the human eye and stimulate regeneration.

"With further research, this approach could help restore sight to millions of people who are waiting for a donated human cornea for transplantation.

"There is a shortage of donors and this could solve that problem. It can also be done at a fraction of the cost."

The cornea is a vulnerable shield or lens protecting the eye and plays a key role in creating vision.

It consists of three main layers – the endothelium, stroma and epithelium.

But many are damaged by scarring or disease causing blurring and even complete vision loss very much like a lens of a camera being scratched.

A clinical trial of 10 patients with damaged corneas whose damaged tissue was operated on and replaced with the artificial cornea, found vision improved in six of them.

After contact lens fitting their sight was comparable to conventional corneal transplantation with human donor tissue, according to the findings published in Science Translational Medicine.

Humans are currently the only source of corneas for transplantation, and the supply of donor tissue is limited.

In addition, the artificial corneas may actually work better than human versions because they avoid the chance of infection or rejection.

Patients did not experience any rejection reaction or require long-term immune suppression, which are serious side effects associated with the use of human donor tissue.

The biosynthetic corneas also became sensitive to touch and began producing normal tears to keep the eye oxygenated.

Globally, diseases that lead to clouding of the cornea affect more than 10 million people worldwide making them the most common cause of blindness.

More than a decade ago, Dr Griffith and her colleagues began developing biosynthetic corneas using collagen produced in the laboratory and moulded into the shape of a cornea.

After extensive laboratory testing Dr Griffith began collaborating with eye surgeon Dr Per Fagerholm, also at Linköping University, to provide the first human experience with biosynthetic cornea implantation.

Dr Fagerholm, said: "We are very encouraged by these results and by the great potential of biosynthetic corneas.

"Further biomaterial enhancements and modifications to the surgical technique are ongoing, and new studies are being planned that will extend the use of the biosynthetic cornea to a wider range of sight-threatening conditions requiring transplantation."

Category: 
Month of Issue: 
August
Year of Issue: 
2 010
Source: 
http://www.telegraph.co.uk/health/healthnews/7964264/Artificial-corneas-restore-sight-for-the-first-time.html
Place: 
N.A.
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International

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