Researchers have learned how to restore the vision of patients using stem cells. The almost completely blind patient was able to ride a horse. The woman who has not seen a single line of the standard visual acuity test can now distinguish the letters of the top four lines. Other subjects regained their ability to perceive colors.
A total of 18 people with degenerative eye diseases took part in the clinical trials approved by Data Safety Monitoring Board (DSMB). All of them received injections of specialized retinal cells, which eventually replaced the cells that were lost as a result of the disease. Scientists believe that this type of treatment is another promising technique based on human embryonic stem cells.
“We learned about the potential of stem cells more than a decade ago, but then we only saw successful results from experiments involving rodents. No one had yet proven that they were safe and effective for humans in the long term,” says Robert Lanza, who is currently working on stem cell therapies. “We have now proven that they are safe and that you can actually recover with this technology.”
A decade ago, researchers announced that they had successfully transformed human embryonic stem cells into retinal pigment epithelial cells. These cells help keep the photoreceptors – the rods and cones of the eye – healthy. But when the condition of the retinal pigment epithelium worsens, a person can go blind. This occurs, as a rule, with age-related macular degeneration and Stargardt macular degeneration – a genetic disease that can affect not only the elderly but also young people.
Lanza’s team tried to reverse this process. Scientists injected retinal cells into one eye of 18 volunteers, half of whom were diagnosed with age-related macular dystrophy, and the other half with Stargardt’s disease. A year later, the condition of the eyes of 10 patients improved, and in three more they stabilized. Each of these 13 people showed an increase in pigmentation, meaning that the transplanted cells are working.
Since only one eye of each person was treated (for ethical reasons, there was no separate control group in the study), it was possible to follow the dynamics of the disease in the second. In all cases, his condition continued to deteriorate.
On average, the patients’ vision improved by three lines on the standard visual acuity test.
During the treatment (and it began back in 2012), no serious side effects were identified, including no signs of the appearance of tumors, the main potential risk in stem cell therapy.
For 12 weeks, patients received immunosuppressants as a precautionary measure in order to prevent possible rejection of stem cells by the body.
“The aim of the study was to stop further deterioration in vision, so the improvement in visual ability was an unexpected pleasant bonus for us,” Lanza admits. Their work resumes after adding new cells. ”
In the near future, сell еechnology specialists are going to begin a large-scale study, during which it is planned to help hundreds of people with Stargardt macular degeneration and macular degeneration.
Research is also underway to prove the effectiveness of human embryonic cells in the treatment of patients with type 1 diabetes, heart failure, and paralysis.
A research paper by Lanza and colleagues was published in The Lancet.