Optogenetics is a technology that was developed a decade ago though only used in robotics. Currently, doctors are just beginning to use it in therapy that will create light-sensitive cells in patients suffering from retinitis pigmentosa. In this type of disease, light-sensitive cell of the retina, gradually die off resulting in blindness.
The technology uses a combination of light and gene therapy to precisely control nerves. It is the only alternative to the retinal prosthesis, which uses an implanted chip to stimulate cell at the back of the eye. If the therapy is successful, it will be good news to 1 in every 4000 people in the world, who are expected to suffer from the disease.
A Texas woman who suffers from blindness in her eye is the first person to undergo the therapy. If successful, the treatment will create a light-sensing cell in her eye called ganglion cell to be light sensitive enabling her to see again. During the procedure, the eye was injected with viruses carrying DNA from light-sensitive algae. If effective, the new cells will do what a healthy retina does – produce an electric signal in response to light, restoring vision.
Retina Foundation doctors who conducted the therapy will monitor the patient for the next year. They will check for light sensitivity as they administer potentially three additional doses of the gene therapy. They will also check for any side effects that might result from the procedure. The primary aim of the treatment is not to give the patient a 20/20, full-color vision but to endow the eye, which currently has zero light perception with some degree of vision. David Birch, one of the doctors conducting the therapy notes that small things the like of being able to note the presence of a person in the room or the ability to cross the road is a big deal.
If the therapy is successful, the vision, which will work through light-sensitive ganglion cells, will most definitely be different from the vision that relies on a healthy retina. Light degrees in various locations do vary. For instance, out in the sunshine, light can be about 10,000 times brighter than inside a room. Healthy retinas typically adapt their sensitivity to adjust this, but light sensing cell created from the therapy will not likely be able to adjust. Due to this, it might be necessary for the RetroSensce therapy to be coupled with some kind of video projection glasses that can perform the adjustment and tailor incoming light to the treated eye.
The trial is being watched closely by neuroscience community with the aim of establishing if it can be used as a potential therapy for patients suffering from schizophrenia and Parkinson’s.
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