The world’s first transplantation of induced pluripotent stem (iPS) cells into the eye of a human patient took place on September 12, 2014, in Japan. The recipient of the experimental treatment, a Japanese woman in her 70s, suffers from age-related macular degeneration. The transplanted cells were derived from the patient’s own skin cells. Masayo Takahashi, an ophthalmologist at the RIKEN Center for Developmental Biology, harvested the patient’s skin cells, coaxed them to become iPS cells, and then differentiated them into retinal cells. This thin sheet of retinal pigmented epithelium cells was then transplanted into the patient’s eye during a two-hour surgical procedure. RIKEN has reported that, as of yet, the patient has not experienced any serious problems. Although it is unlikely that the procedure will restore the patient’s vision, the hope is that the transplanted cells will prevent any further retinal destruction without causing negative side effects.
Around the world, stem cell researchers and clinicians are watching to see how the newly transplanted cells will behave. Will they cause an immune response, even though the transplanted cells are derived from the patient herself? Will they begin to proliferate and grow into a cancerous mass? Will they begin to degenerate? Or, will they have the desired protective effect? Stem cell researchers have long been asking these questions, and years of testing in cell cultures and experimental animals have provided plenty of evidence to support their safety and efficacy. However, they have not yet confirmed that this kind of treatment is equally good in human patients, so it’s really crucial that now they can finally start getting some answers. It’s not surprising, therefore, that this surgery is being hailed as a critical step in the development of regenerative medicine.
Here at the Foundation Fighting Blindness, we are watching this story closely. We will be updating our community as we learn what this experimental surgery will teach us about the future of retinal regeneration and stem cell therapies, like those we’ve been funding for years.