Our vision relies on a multi-layered structure on the inner surface of the eye, the retina, bearing specialised light-sensitive neurons known as photoreceptors. Progressive degeneration of these cells leads to blindness, as in inherited diseases such as retinitis pigmentosa. While this cannot be reversed, transplanting healthy cells into the eye may provide a solution. Photoreceptor precursor cells are injected into the retina, where they mature into functional light detectors. In mice genetically modified to show symptoms of these diseases, transplants can restore normal responses to light. Pictured are donor cells (stained green), successfully integrating into the host retina (stained blue) of healthy mice (top left corner) and of mouse models of three different genetic diseases causing blindness in humans. Though the extent of integration still depends on the nature and progression of the disease, this technique raises hopes of recovering sight from a range of conditions.
Written by Emmanuelle Briolat
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