In the sterile environment of the womb, infection is not a factor. Wounds therefore can heal more slowly, without inflammation or scarring or excessive blood-vessel formation. New cells simply fill in the gap left by the wound. Recently, eye surgeons have tried to duplicate the fetal environment, by using amniotic membrane removed with the baby during C-section delivery. The tissue is processed into thin, transparent sheets, Wang said.
Doctors also transplant immature stem cells from the limbus.
These cells normally migrate into the cornea to replace cells lost to minor injury or damage. Protecting the cornea Like the amniotic membrane, the stem cells can prevent the growth of new blood vessels to keep the cornea clear as it heals. If the limbus has been injured along with the cornea, the corneal transplant may fail because there are few if any stem cells left to protect it. That's why Wang transplants amniotic membranes and, later, donated stem cells from the limbus, to aid scar-free healing and to improve the chances of successful corneal transplant, even in the most severely injured eye. Sixteen years ago, the Gallatin man was mixing concrete when the cement powder flew into his eyes.