This week a couple of patients came through that have suffered severe damage to one of their eyes and asked about a transplant. Can we transplant an entire eye? The answer is no. It has been tried with 100% failure. The biggest obstacle is getting the nerve tissue to start functioning again. The large nerve that connects the brain to the back of the eye, the optic nerve, is really over a million nerve fibers bundled together.
The good news is stem cell research has been successful in re-populating damaged nerves with new functioning nerve fibers! So far there have only been animal studies on the optic nerve, but they are using the same techniques that have been successful in spinal cord injuries. The new studies will include a few human beings.
How does this relate to dry eyes? Healthy nerves are needed to keep the front part of the eye, the cornea, well protected, which includes stimulating adequate tear production. Stem cells have recently been used to re-populate a damaged cornea with healthy corneal cells that have the ability to reproduce. That is how a corneal abrasion will usually heal in a day or two. Unhealthy corneas (dry eye corneas) lose the ability to heal properly or sometimes will not heal at all. The ability to re-populate an eye with healthy corneal cells by applying stem cells to the front of the eye is very exciting!