After they received embryonic stem cell treatment, two people who were suffering from wet age-related macular degeneration had some of their vision restored. After the treatment, they could read again.
Macular degeneration can blur the vision or cause a blind spot because of abnormal blood vessels that leak fluids into the eye. It causes damage to the retinal pigment epithelium, a layer of cells, Agence France-Presse reported. The damage to the retina kills the light-sensing cells.
Human embryonic stem cells
The British-American team used human embryonic stem cells for the study to grow RPE cells on a thin plastic scaffold. They transported the engineered tissue into the eyes of two volunteers. Both volunteers were no longer able to read before the surgery.
Science Daily identified one of the patients as 86-year-old Douglas Waters who became part of a clinical trial that used stem cell-derived ocular cells developed by researchers at the University of California Santa Barbara. The retinal eyepatch was implanted at the Moorfields Eye Hospital, a National Health Service facility in London, England.
The other patient was a woman in her 60s who also suffered from a severe form of wet AMD. The two patients were monitored for 12 months. However, a year after they underwent the procedure, the two could read using normal reading glasses, but slowly at 60 to 80 words per minute. The embryonic stem cell can become any tissue of the body. It means it has the possibility of replacing limbs or organs lost to ailment, accident, or war.
Waters said that before the surgery, he was struggling to see things clearly, even when up-close. However, after the procedure, his eyesight improved to the point where he can now read the newspaper and help his wife out with the gardening, The Telegraph reported.
The safe and effective implantation of a specially engineered patch of retinal pigment epithelium cells that were derived from stem cells to treat patients with sudden severe sight loss from wet AMD was published in Nature Biotechnology. It is the first description of a completely engineered tissue that has been successfully used in this way, Science Daily reported.
Real progress in regenerative medicine
Peter Coffey, a professor at UCSB’s Neuroscience Research Institute and co-director of the Center for Stem Cell Biology in the campus, said the study represents real progress in regenerative medicine and opens the door to new treatment options for people with age-related macular degeneration.
But it can also provoke an immune response, be rejected by the body, or even cause cancer. Dusko Ilic, of King’s College London, said the study represents another step forward in materializing hopes of clinical implementation of hESC-based treatment of age-related macular degeneration in the not-so-distant future.
For stem cell transplants, the eye is thought to be a promising site because it is behind a shield called the blood-ocular barrier where there is a weaker immune response.
Researchers used embryonic stem cells four years ago to restore some vision in people with a more common and less severe form of macular degeneration which the dry type. There are other teams that are testing induced pluripotent stem cells which are adult human cells that have been reprogrammed to a youthful, versatile state.
Almost half of all the visual impairment in the developed world is macular degeneration. It usually affects people over 50 years old. The researchers hope that the new procedure will also help in the future to treat dry AMD. In Britain, more than 600,000 people suffer from AMD.
The treatments are injections into the eye or laser surgery. Both can slow the growth of blood vessels that harm the macula. But thesew will only partially restore sight and do not work for everyone.
The research investigated if the diseased cells at the back of the affected eye of the patients could be replenished using the stem cell patch. To insert the patch under the retina in the affected eye of each patient, a specially engineered surgical tool was used. The procedure lasted between one and two hours.
Coffrey said that he hopes the study will lead to an affordable off-the-shelf therapy that could be made available to NHS patients within the next five years.
Lyndon da Cruz, a consultant ophthalmologist at Moorfields Eye Hospital NHS Foundation Trust, said that the improved vision of the two patients will enable them to enhance their quality of life. While it is a small group of patients, Cruz said he hopes that what was learned from the study will benefit many more in the future.
Dr. Carmel Toomes, an associate professor at the Leeds Institutes of Molecular Medicine, said the results give the patients who suffer from AMD and other retinal degenerations real hope that stem cells replacement therapy may be a reality in the near future. It seems only a very early clinical trial, but the results are positive and show that the technology is moving along in the right direction.
[researchpaper 리서치페이퍼= Vittorio Hernandez 기자]