Eyesight Restored in Blind Mice

An innovative surgery has restored sight in blind mice, and offers the promise of a cure for humans suffering from blindness due to common conditions such as macular degeneration and diabetic eye damage.

A research team from University College London (UK), Moorfields Eye Hospital (London, UK), and the University of Michigan (Ann Arbor, MI, USA) implanted mice with genetic defects--loss of photoreceptors--with immature retinal cells, similar to stem cells. The retinal cells had been extracted from newborn mice whose eyesight was developing. The transplanted cells developed into fully functioning photoreceptors that successfully connected to nerves leading to the brain. Tests confirmed that the photoreceptors were functioning and that the animals' vision had been restored to about one-fourth of the normal level.

The initial tests involved "rod” cell transplants, cells that control peripheral and night vision. The researchers suggested that transplanting "cone” cells--those that control color and detail--would greatly improve results. Using differentiated cells may be the key to the success of the procedure, according to the research team, since previous attempts to achieve the same result using undifferentiated stem cells have failed. It may also be possible to grow precursor photoreceptor cells using cells similar to stem cells that are found at the margins of the adult retina. Using the patient's own cells would also avoid the possibility of donor cells being rejected by the body. The study was published in the November 8, 2006, edition of Nature.

"Rather than focusing on stem cells, we believed that if we could understand how cells develop and become photoreceptors...our transplantation efforts would meet with greater success,” said co-author Professor Anand Swaroop, Ph.D., of the University of Michigan Medical School. "This technique gives us new insights in repairing damage to the retina and possibly other parts of the central nervous system.”



Related Links:
University College London
Moorfields Eye Hospital
University of Michigan