Can save the vision of millions
A technique to create biosynthetic corneas can save the vision of millions. The first operations in the world were performed on ten patients in 2008 in Linköping.
A scratched windshield hinders the ability to see. And this is also true of the eye’s own windshield – the cornea.
Sometimes scars and illnesses impair vision so much that corneas need to be replaced, but donated corneas are in short supply, and world-wide it is estimated that about ten million people are waiting in line.
The solution may be the biosynthetic cornea that was operated into the eyes of ten patients in Linköping for the first time in the world.
It has now been ten years since May Griffith, researcher at the University of Ottawa in Canada, published her results in Science Magazine about a new material that could possibly be used for growing corneas using a patient’s own cells. Through her guest researcher, Lisha Gan from Sweden, she came into contact with ophthalmology professor Per Fagerholm at Linköping University.
“We decided to design the material, so that it could be adapted to surgical procedures and would function in the eyes of animals. The implants were sent from Ottawa to Linköping where I implanted them into the eyes. We found a good base that is safe and can now focus on refinement for different conditions”, says Per Fagerholm.
A biosynthetic cornea resolves two problems. Creating a safe, predictable and chemically well-defined material, and minimising the risk of transmitting illnesses and preventing the body’s immune system from rejecting the material.
The latest version that is now located in the eyes of ten people primarily consists of recombinant collagen. A human gene that regulates the production of collagen – a natural substance in the body’s connective tissue – is placed into a yeast cell that is then programmed to begin producing the substance on a continuous basis.
The result of this is collagen in the shape of long protein threads in solution. May Griffith has developed a chemical method of binding these together to form a hydrated, tough gel.
And it is in this structure that the basic idea lies. The diseased or damaged cornea is removed and implants are sewn in in their place. These bioactive implants stimulate the eyes’ own corneal cells and nerves to grow into them and form new tissue.
Of the ten pioneer patients, one had a scar after an accident, and the other nine suffered from an illness called keratoconus, which causes the cornea to thin out and become uneven. All of the patients were on the waiting list for corneas. When given the opportunity, they all volunteered to be the world’s first people with biosynthetic corneas. In January 2008, the material was sewn in place, and after five to six weeks the stitches were removed. The total rehabilitation time was about six months compared to one and a half years when donated corneas are used.
An examination of the ten patients’ status was carried out a year after the operation. The results have not been fully published yet. But in an article in Clinical and Translational Science, the research group writes that after six months, the new corneas were well integrated in all patients without side-effects or other complications. Visual acuity, surface quality and corneal sensitivity have steadily improved during the rehabilitation period.
“The results are sufficiently good to go further and develop the material and methods. Most of the patients have good vision in the eyes that have been operated on. One of them recently got their bus driver’s license back after being on sick leave for three years”, relates Per Fagerholm.
May Griffith is Professor of Regenerative Medicine. Her research is in the area of regenerative medicine, specifically tissue engineering. May Griffith arrival at Linköping University in 2009 marks the start of an undertaking in regenerative medicine at Linköping University.
Ophthalmologic (eye) surgery is a part of the undertaking, in which the new biosynthetic materials can also be used to repair and regenerate damaged parts of the eye, e.g. cornea, retina or eyelids. She also has ongoing projects in cardiovascular, spinal cord, nerve and cartilage repair.
Per Fagerholm, Professor of Ophthalmology at Linköping University. He has conducted research into artificial corneas since 2000. He is also an eye surgeon at the University Hospital, Linköping.
Last updated: Fri Jan 20 15:51:26 CET 2012