The two, light detecting cell types vital for vision in the eye are the 'cone' cells, vital for colour vision and the 'rod' cells, highly sensitive to light detection in dim or dark conditions. Ultimately many forms of blindness result from loss of these cells. Jane Sowden and her team at University College London have been experimenting with the transplantation of these cells into blind mice. The hope is that that eventually human stem cells can be induced to develop into rod or cone cells which can then be transplanted to restore sight in blind people. The experiments have been aimed to establish whether a transplant would be viable.
Most recent results after injection of 200,000 isolated precursor cone and rod cells in the region of the retina showed that in 21 days the new cells settled into the normal photoreceptor (light sensitive) layer which was damaged in the blind mice and grew into proper rods and cones.
The results are exciting and pave the way for potential cure of many blindness causing conditions.