A new, stem cells-based treatment might come to help people with eye problems regain some of their sight as researchers have now achieved the first successful retinal transplants.
The retina is an important part of the eye. It is tissue layer situated on its back. It is the part responsible for sensing light. It also passes along signals to the brain. There, the signals get processed. As such, an image will be perceived.
People with retinal degeneration lose this capability. Their light-sensing cells start to gradually disappear. This, in turn, may eventually lead to blindness.
Macular degeneration is the most common such issue. It affects about 15 million U.S. citizens. And around 150 million at a global level. These type of eye problems can have debilitating effects.
But a team of scientists may have found a potential solution. They are part of the Japanese RIKEN Center for Developmental Biology. Research was led by Michiko Mandai. She is the study’s first author. And also a RIKEN Center deputy project leader.
Research results were released earlier this week. They were published in the Stem Cell Reports journal. The study was titled as follows. “iPSC-Derived Retina Transplants Improve Vision in rd1 End-Stage Retinal-Degeneration Mice”.
Tests were carried out with the help of mice. These suffered from serious eye problems. more exactly, they had end-stage diseases. Usually, such conditions bring about irreversible vision loss.
The researchers based their studies on stem cell therapies. These were used so as to grow new retinas in the lab. Such created tissues were then transplanted to the suffering mice.
Over 40 percent were seen to regain some of their vision. Or more exactly, they were able to see light. This is a first time ever result. Mandai, the lead, went to offer details. According to her, the results led to great excitement. The transplants were seen to respond to light robustly.
She states that they hope to raise the transplant’s abilities. This would allow the affected patients to also see movement or a large figure. Research could achieve this feat by increase the connections number.
The current transplant has successfully transferred light-sensing cells. These are the light receptors of the retina. Such cells connect to their host’s nervous system. As such, they can send signals to the brain. By increasing the number of such cells, one could also increase the retina – brain connections.
Transplant effectiveness was determined by using shuttle avoidance tests. Mice are specifically trained so as to recognize a simultaneous light and beep signal. This announces an electric shock.
After the retinal transplants, only the light signal was used. Reports state that 4 out of 10 mice responded to this light signal. All ten had transplants in both eyes.
11 mice with a single eye transplant were also tested. 5 out of them were seen to respond to the light warning. The ratio is quite notable when dealing with such severe eye problems.
Still, the technique is quite a long way from being tested on humans. According to the researchers, more studies would have to be carried out. And new tests would have to be made.
They also point out another fact. It is as yet unclear whether the formula will work on people. The human retina, for example, takes longer to mature when compared to mice. These were able to respond to light stimuli a month after the transplant.
In humans, the transplant could take up to 5 or 6 months before it starts responding. And that is if the same procedure will actually work for people.
Mandai states that the results are very promising. Still, the human eye has a different environment. As such, the possibilities of a retinal transplant remain to be determined. More exactly, their future connections. More tests will need to be carried out. And potentially also human trials. But such tests are still probably a long way off.
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