A new procedure reported in the current issue of Nature Biotechnology has been shown to be a safe and effective method for introducing stem cells into the retina. Implantation of a specially engineered patch of retinal pigment epithelium (RPE) cells derived from stem cells has restored some vision in two people with sight loss from wet age-related macular degeneration (AMD). Researchers hope the new procedure will also help in the future to treat dry AMD and similar diseases of the retina.
The study investigated whether the diseased cells at the back of the patients’ affected eye could be replenished using the stem cell patch. A specially engineered surgical tool was used to insert the patch under the retina in the affected eye of each patient in operations lasting one to two hours.
The patients were monitored for 12 months and reported improvements to their vision. They went from not being able to read at all to reading 60 to 80 words per minute with normal reading glasses.
This is a major milestone for the London Project to Cure Blindness, a research effort of Moorfields Eye Hospital, the University College London Institute of Ophthalmology, and the National Institute for Health Research. The stem cell-derived ocular cells were developed in part by researchers at UC Santa Barbara.
“This study represents real progress in regenerative medicine and opens the door on new treatment options for people with [AMD],” said Peter Coffey, who founded the London Project more than a decade ago. “We hope this will lead to an affordable ‘off-the-shelf’ therapy that could be made available to NHS patients within the next five years.”
It is important to remember that only the retinal pigment epithelial (RPE) cells are being treated in this study. The RPE is the layer of cells that nourish the photoreceptor (cone and rod) cells, meaning that, in order for vision to be restored, the photoreceptors themselves must be healthy. Science has not yet been able to replace those, so until that becomes possible, stem cell treatment will be limited to a specific set of patients who meet the criteria.
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SOURCE: University of Southern California-Santa Barbara press release
