You may have read the news about someone having a whole eye transplant, but what exactly does that mean? While one group of researchers hope to perform vision-restoring, whole eye transplants within a decade, it can't be done at this time. When someone receives a transplant today, they are probably having a corneal transplant. Donor corneas make this amazing, sight-saving surgery possible.
Your eye is a complex organ connected to your brain by the optic nerve. The optic nerve sends visual signals from the eye to the brain, which interprets them as images. The optic nerve is small. It is between 1.3 and 2.2 inches long and only a fraction of an inch wide. Yet the optic nerve has more than one million tiny nerve fibers, much like a fiber optic cable. Once these nerve fibers are cut, they cannot be reattached. The transplanted eye can't send signals to the brain through the optic nerve. That is why it is not currently possible to restore vision with a whole eye transplant.
Corneal Transplants
Corneal transplantation is not only possible, it has been used for nearly a century.
You need a healthy, clear cornea for good vision. If your cornea is injured or damaged by disease, it may become swollen or scarred. This can cause glare or blurred vision. In a corneal transplant, a surgeon removes the damaged cornea and replaces it with a clear donor cornea. There are several corneal transplant surgery options, depending on the case.
What Other Kinds of Eye Transplants Are There?
Corneal transplantation is the most common type of eye transplant. But it is not the only one.
Amniotic membrane transplantation (AMT)
Sometimes, doctors can use part of a human placenta, donated after childbirth, to heal the cornea. They can use the innermost layer of the placenta, called the amniotic membrane, to create a healing bandage. This bandage can be temporary or permanent. These membranes help heal and regrow surface tissues of the eye. Ophthalmologists have long used AMT to heal the sclera and the conjunctiva.
Eyelash transplants
Surgeons have succeeded in transplanting eyelashes. This can restore eyelashes lost due to burns, injury and other medical conditions.
Eyelid and tear duct transplants
Doctors continue to explore whether it is possible to transplant other parts of the eye. In July 2010, French doctors transplanted eyelids and tear ducts during a full-face transplant. Eyelids have been included in other face transplants in recent years as well.
The future of retina cell transplants
Today, researchers are replacing damaged retina cells with healthy transplants. In clinical trials, researchers have used human stem cells to grow retinal cells that are destroyed by conditions like macular degeneration or Stargardt disease. One day, surgeons may use these stem cells to replace damaged retinal cells and treat these conditions.