The elimination of eye diseases has taken a step closer after experts in the US reported that an experimental treatment for blindness was a success. The therapy, developed from a patient's skin cells, was seen to improve the vision of blind mice in a study conducted by Columbia University ophthalmologists and stem cell researchers.
According to the results, induced pluripotent stem (iPS) cells – which are derived from adult human skin cells but have embryonic properties – could soon be used to restore vision in people with macular degeneration and other diseases that affect the retina.
Study principal investigator study’s principal investigator, Dr Stephen Tsang, associate professor of ophthalmology and pathology and cell biology at Columbia University Medical Centre, explained the findings. "With eye diseases, I think we're getting close to a scenario where a patient's own skin cells are used to replace retina cells destroyed by disease or degeneration," he noted.
"It's often said that iPS transplantation will be important in the practice of medicine in some distant future, but our paper suggests the future is almost here."
The creation of human iPS cells in 2007 was greeted with enthusiasm by scientists, who hailed the development as a way to avoid the ethical complications of embryonic stem cells and create patient-specific stem cells.
As with embryonic stem cells, iPS cells can develop into any type of cell, with thousands of different iPS cell lines from patients and healthy donors created in the last few years, though they are almost always used in research or drug screening.
The cells have not yet been transplanted into people, but many ophthalmologists say the eye is the ideal "testing ground" for iPS therapies.
In the study, researchers injected the iPS-derived retina cells into the right eyes of 34 mice that had a genetic mutation that caused their retina cells to degenerate.
In many animals, the human cells assimilated into mouse retina without disruption and functioned as normal retina cells well into the animals' old age, while controls that received injections of saline or inactive cells showed no improvement in retina tests.
"Our findings provide the first evidence of life-long neuronal recovery in a preclinical model of retinal degeneration, using stem cell transplant, with vision improvement persisting through the lifespan," Dr Tsang commented. "And importantly, we saw no tumours in any of the mice, which should allay one of the biggest fears people have about stem cell transplants: that they will generate tumours."