Scientists in February had reported the first strong evidence that human embryonic stem cells can restore vision in two eye conditions - dry age-related macular degeneration and Stargardt disease.
In a publication in the Lancet
titled 'Human embryonic stem cell-derived retinal pigment epithelium in patients with age-related macular degeneration and Stargardt's macular dystrophy: follow-up of two open-label phase ― studies,' the authors showed that stem cells appear to have greatly improved the vision in more than half of the 18 blind people with these two incurable eye disease. This study was published online in Oct'14 but published in print in Feb'2015.
The scientists said that the results must be considered preliminary because the number of people cured was comparatively small and they have only been followed for only less than two years.
The patients with these two conditions were injected with either 50,000, 100,000, and 150,000 stem cells for each eye disorder and the patients were followed up for a median of up to 22 months by use of serial systemic, ophthalmic, and imaging examinations.
The authors found that the injection was safe with no adverse effects. Best-corrected visual acuity, monitored as part of the safety protocol, improved in ten eyes, improved or remained the same in seven eyes, and decreased by more than ten letters in one eye, whereas the untreated fellow eyes did not show similar improvements in visual acuity.
According to the scientists, 10 participants could see significantly better, seven participants saw better without losing any additional vision.
The results of this study provide the first evidence of the medium-term to long-term safety, graft survival, and possible biological activity of stem cells in individuals with such disease. The researchers turned the human embryonic stem cells that can become any type of cell in the body, into retinal pigment epithelial cells.
However confirmation of this study will require a phase 3 trial with larger number of patients. The medical world sees the results of this trial as a major breakthrough in using stem cells to cure chronic and degenerative diseases.
"The results are really promising. I'm astonished that the therapy is working in the way that it is - or seems to be working. I'm very excited about it. These are patients that didn't see better for 30 years and all of a sudden they're seeing better," said Steven Schwartz, an eye specialist at the University of California, Los Angeles (UCLA) who led the study.
The results were the first for any human embryonic stem cell trial approved by the US Food and Drug Administration (USFDA). Schwartz notes that the therapy will be ready in a few years.
Ref- Steven D Schwartz, Carl D Regillo, Byron L Lam, Dean Eliott, Philip J Rosenfeld, Ninel Z Gregori, Jean-Pierre Hubschman, Janet L Davis, Gad Heilwell, Marc Spirn, Joseph Maguire, Roger Gay, Jane Bateman, Rosaleen M Ostrick, Debra Morris, Matthew Vincent, Eddy Anglade, Lucian V Del Priore, Robert Lanza. Human embryonic stem cell-derived retinal pigment epithelium in patients with age-related macular degeneration and Stargardt's macular dystrophy: follow-up of two open-label phase 1/2 studies. The Lancet, October 2014 DOI: 10.1016/S0140-6736(14)61376-3