An upcoming human trial will attempt to use optogenetics to treat conditions such as retinitis pigmentosa:
In the next month, scientists from RetroSense Therapeutics will inject a virus deep into the retina of legally blind human volunteers. The virus will carry what is perhaps the most monumental payload in modern neuroscience history: DNA that codes for channelrhodopsin-2, a light-responsive protein isolated from algae that — under blue light — activates cells in the retina, thereby transmitting visual information to the brain.
Forget electronic implants. If all goes well, these volunteers will be able to see again using their own eyes — but in no way a human being has ever experienced sight before. Whoa.
But the stakes are even higher: if this works, it means that optogenetics — a revolutionary neuroscience technique using channelrhodopsin-2 and other light-activated proteins — is feasible in humans as therapy. Considering optogenetics has been used in mice to implant false memories, treat cocaine addiction, attenuate OCD symptoms, trigger sexual advances and aggression and reverse motor deficits in Parkinson's disease — just to name a few feats— the technique could completely transform the face of neurology. "This is going to be a gold mine of information about doing optogenetics studies in humans," said Dr. Antonello Bonci, the scientific director of the intramural research program at the National Institute on Drug Abuse, to MIT Technology Review.
[...] If it works, what will the patients see? No one can say for sure. After all, this will be the first time humans experience the visual world through the light sensor of algae. But studies with blind lab mice may give us a hint. In one previous study, after optogenetics treatment, previously blind mice could swim out of a chamber in which the escape route was brightly lit. On average, they escaped as fast as mice with normal vision.
(Score: 2, Informative) by pTamok on Tuesday March 01 2016, @10:02AM
If you look here:
"Retinitis pigmentosa (RP) is a group of retinal degenerative diseases in which there is a slow and progressive loss of photoreceptors. " (http://www.ncbi.nlm.nih.gov/pubmed/11249772). It's a bit like 'cancer' in that we give a single name to a large variety of problems, so there isn't a single cause, and therefore, there is unlikely to be a single treatment. The genetics of RP are complicated.
So, my reading of this article is that it is an attempt to sidestep a lot of the complicated issues - the approach is to replace photoreceptors by something completely different genetically, rather than try and repair photoreceptors that may have gone wrong in one or several of many different ways. The method is to ignore the photoreceptors (rods and cones) in place, and instead make the nerve cells directly sensitive to (blue) light.
Simple anatomy of retina here: http://webvision.med.utah.edu/book/part-i-foundations/simple-anatomy-of-the-retina/ [utah.edu]