British scientist have been able to use stem cells from baby mice at a crucial stage of the stem-cell development to restore vision in blind mice in a stem-cell break through that might, some day in the future, help reverse blindness in humans. Stem cells can develop into any kind of cell in the body and when they do, they become precursors of a final cell type. Researchers at the University College London Institute of Ophthalmology and Child Health and Moorfields Eye Hospital used these precursor cells. To be precise, they transplanted immature photo-receptor cells, cells that are found in the retina into the retinas of mice that had visual impairments similar to the visual impairments suffered by humans. And it worked. The transplanted cells linked up to the retinas of the mice and the blind mice saw. Applying this technique to humans is not easy. The precursor cells needed for human retinas cannot be obtained in the same way as in mice. As an alternative, researchers are exploring the option of extracting cells from the edges of the human retina with similar self-renewal properties as stem cells. Harvesting those from a person and transplanting them back into that same person also reduces the risk of rejection.

Scientists suspect that blindness is not the only affliction that could potentially benefit from this research, but also caution against over-enthusiasm: It will take at least another ten years before we can expect human trials.

References

Helen Pearson (2006). Blind mice see after cell transplant. Study suggests newborn cells best for transfer. News@Nature.com. Available online at: http://www.nature.com/news/2006/061106/full/061106-10.html