There is a possibility of reversing blindness. Scientists in the United Kingdom have shown that the part of the eye that detects light can be repaired with stem cells. And, now the team at University College London’s Moorfields Eye Hospital has claimed that it can be tested in humans.
In fact, it is already being tested in people where stem cells are used to replace the supporting cells in the eye that keep the photoreceptors alive. The function of these light-sensitive cells is to pass their electrical message to another cell so that it reaches the brain. This represents a breakthrough in the treatment of this type of vision disorder that, until now, seemed to have no solution.
Blindness
The main cause of vision loss in degenerative eye diseases such as age-related macular degeneration and diabetes-related blindness is the loss of light-sensitive nerve cells lining the back of the eye (photoreceptors). There are two types of photoreceptors in the eye, called cones and rods. The latter are essential for seeing in the dark because they are highly sensitive, even at low light levels.
Mouse trials
The team at Moorfiels Eye Hospital used a new method to make retinas in the laboratory. The aim was to collect thousands of stem cells, which were then treated to transform them into photoreceptors. These were injected into the eyes of blind mice, demonstrating that these cells can integrate into the existing architecture of the eye and develop properly. The London researchers found that integration had occurred in the retina and that the nerve connections needed to transmit visual information to the brain had been formed.
However, only about 1,000 cells out of 200,000 transplanted managed to attach to the rest of the eye. But, despite the low effectiveness, the fact that the first photoreceptor cell transplant has been successfully performed is good news because researchers now have a basis on which to work and continue studying to achieve a cure for blindness. The results suggest that embryonic stem cells may eventually provide an unlimited source of healthy photoreceptors for retinal cell transplants to treat blindness.