Lab-grown Corneas Improve Sight

B O S T O N, July 12 -- Eye surgeons — and some of their patients — may soon be seeing more light at the end of the tunnel.

In a pioneering technique, two separate research groups announced today they have successfully restored eyesight to patients with severely damaged corneas, using bioengineered tissue grown in a laboratory and then transplanted onto the eye.

The two teams of researchers — one out of Taiwan reporting in the New England Journal of Medicine and the other from University of California at Davis Medical Center reporting in the journal Cornea — announced they used the technique to improve vision in a total of 15 patients.

How to Grow a Cornea

They first took corneal stem cells, or immature cells that have the ability to generate mature cornea cells, and cultivated them in petri dishes to grow replacement corneas. Then they stitched the newly created corneas onto their patients’ eyes. A significant factor in the researchers’ success was growing the corneas on a scaffold of amniotic tissue, also known as afterbirth material.

“The real power of this technique is where it leads us,” says Dr. IvanSchwab, professor of ophthalmology and a co-author of the Cornea study. Schwab says that the cornea may be the next bio-engineered tissue in a list that already includes skin and cartilage, and could someday include the lungs, bladder, and intestines.

The cornea is the clear, dome-shaped surface that covers the eye and allows light to pass through. When it becomes damaged from disease, such as the rare Stevens-Johnson syndrome; an accident, such as a splash of acid to the face; or an infection, it can become scarred and cloudy, impairing vision.

Prior Donors: Corpses

Conventional corneal transplants, which use donated corneas from a corpse, are the most commonly performed transplant surgery, with almost46,000 done last year, according to the Washington D.C.-based Eye Bank Association of America. Eye banks nationwide collect corneas from donors upon their death, often by registries posted on the back of one’s driver’s licenses, and distribute them to needy patients within a few days.