Injecting “precursor” photoreceptor cells into the eyes of totally blind mice resulted in the reconstruction the entire light-sensitive layer inside the eye, restoring the experimental animals’ vision. While the quality of vision was not easy to evaluate, the mice ran away from bright light, had pupils that responded to light, and had brain activity showing they were processing visual information.
Researchers at the University of Oxford studied mice that had retinas without any light-sensing photoreceptor cells. Unable to distinguish between dark and light, these mice were completely blind. The precursor cells they used were designed to develop into retinal building blocks after getting injected into the eye. Just two weeks after receiving the injection of cells, each eye developed a retina.
Similar studies in the past had results in mice with a partially-functioning retina. Also, studies like this have been effective at treating night blindness in animals.
The study was designed to resemble treatments that could help people with degenerative eye disease. Significant vision loss and blindness can result from eye diseases including retinitis pigmentosa. Patients with retinitis pigmentosa lose light-sensing cells gradually in their retina, usually starting in youth. Being able to rebuild the retina may help retinitis pigmentosa and perhaps other types of eye disease sufferers if this technique is shown to be effective in humans.
Research into the quality of the restored vision is crucial. The post-operative tests on the mice showed eye and brain activity. However, these tests were not sensitive enough to show what sense the brain makes of the visual input it is receiving from the new retinas.
Note: At Natural Eye Care, we offer supplements to support retinitis pigmentosa, including complete RP Combo package designed expressly for this condition.
Study: “Reversal of end-stage retinal degeneration and restoration of visual function by photoreceptor transplantation.” M. S. Singha et. al. Proceedings of the National Academy of Sciences of the United States of America. Dec 7 2012.