Is it possible to transplant a retina with modern medicine? The answer is no.
While retinal transplantation is often cited as a solution to various retinal diseases that cause vision loss, modern medicine has not advanced to the point where it is possible to remove the retina from someone else's eye and place it in the eye of a person with retinal disease.
Why is it that the cornea, the outermost part of the eye, can be transplanted, but the retina, the inner part of the eye, cannot?
"The retina itself is not a candidate for transplantation because it has a lot of nerve tissue and blood vessels," said Kim Yoon-jeon, professor of ophthalmology at Asan Medical Center (AMC) in Seoul.
Although it is technically possible to transplant an artificial retina, it is difficult in Korea because the manufacturer of the artificial retina device has suspended the production of the device.
A retinal transplant involves implanting a chip that provides electrical stimulation to the inner retinal nerve. After the chip is inserted through the conjunctiva, a device similar to glasses is worn from the outside, and light stimulation is received through a camera attached to the device, and the device converts video signals into electrical signals, which are transmitted to the chip in the eye through a magnetic field. The 3-4mm-sized chip then directly stimulates the nerves in the inner retina, which is how the brain perceives light.
Since 2017, five patients with retinitis pigmentosa have undergone retinal transplantation surgery at AMC and have been freed from total blindness with only wide-angle vision or no vision at all. But now, there is no way some patients can avoid total blindness.
Will retinal transplants be possible in the future when medical technology is more advanced than now?
If the technology to create and transplant perfect eye tissues through "organoids," which are human-like substances that reflect tissue morphology and genetic characteristics, is developed, retinal organoids could be transplanted.
"It may be possible to differentiate stem cells to grow an organoid like an eye and implant it later," Kim said.