clear eyes. A biosynthetic cornea, shown here one day after implantation ( left , the lines are sutures) and two years later helped nerves in the eye to regenerate over time and left eye looking normal.
Per Fagerholm and Neil Lagali
at least 8 million people around the world saw again with new corneas, thin clear layer of cells collagen and at the front of the eye that allows him to concentrate. But most never get transplants. There are a few years, researchers have developed biosynthetic corneas and now, two years after implantation into patients, they seem safe and have helped many people see more clearly.
Millions of people worldwide suffer corneal opacification caused by infection or trauma to the eye that allow blind and visually impaired very. There are not enough corneas of dead donors for everyone, however, and those available are expensive: They cost about $ 2,500 each (which does not include the cost of surgery), in part because they must undergo extensive testing to viruses and other contaminants before being set. "In the developing world, which is frighteningly high," said Claes Dohlman, an ophthalmologist at the Massachusetts Eye and Ear Infirmary in Boston. Artificial corneas, which are made of plastic, are not easy for surgeons to work with, and carry a risk of complications such as glaucoma or infection.
"We wanted something that behaves like a human tissue, so the surgeon would be able to transplant without any additional training," says May Griffith, a cell biologist applied to the University of Ottawa in Canada and the University of Linköping in Sweden.
For this, Griffith and his colleagues turned to collagen provided by FibroGen company in San Francisco, California. In the laboratory, cast Griffith team collagen in the curved shape right then enlisted surgeon Per Fagerholm of Linköping University to implant these lab corneas made in 10 patients who had keratoconus, a disease that causes cornea to deteriorate, or scarring of the cornea.
The first big test was security, and achieved good results implants. the immune system of patients do not reject the new cornea, or no patients develop infections. The team also found that over time, the implants have helped the nerves in the regenerated area, leaving volunteers with what looked like a healthy eye tissue. Six patients had slightly better with their new corneas, on the basis of astigmatism and visual acuity as that measured in an exam, Griffith and his colleagues report online today in Science Translational Medicine .
Griffith said it is too early to say what the implants will cost. And there is still work to do to make them more effective. The sutures used to attach the implant causes the surface to be a little bumpy, which makes it more difficult to restore vision. Contact lenses have contributed to this problem and improve the vision of patients with an average of 20/42, similar to standard cornea transplants. Griffith and his colleagues are planning a larger study with what they hope will be better implants that do not require sutures.
Corneas "will, I think, of considerable use," said Dohlman, who was not part of the research team. They could be mass produced and would almost certainly be much cheaper than cornea donors. "You can build a square meter, the test once [for contamination], then hit hundreds and hundreds" of holes to create a lot of new corneas, he said.
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