Today, Nature Medicine published a paper which describes the first-ever reported partial recovery of sight by a patient with retinitis pigmentosa (RP), after treatment with an optogenetics therapy.
Optogenetics is an innovative technique whereby light can be used to control neurons in the brain. This is possible due to a light-detecting protein found on a specific alga, that, when exposed to light of a specific colour, opens an ion channel, causing the neuron to “turn on” and transmit a signal.
With recent advances in gene therapies, it is now possible to inject the DNA for this light-detecting protein into human cells, and for those cells to subsequently grow and use that protein. This has major potential for use in those living with retinal degenerative conditions, where the light-detecting cells in the retina become damaged and stop working with time.
Gene therapies are now entering the market, and there are many more in the clinical trial pipeline. However, a major drawback with these therapies is that each gene therapy is specific to treating one mutated gene. With nearly 300 IRD-causing genes described so far, it is not feasible to create a separate gene therapy for each mutation. One particular benefit of optogenetics is that it is mutation-independent. This means that this technique could, in theory, be used to treat any retinal degenerative condition, no matter what gene mutation is causing the vision loss.
In this study, a patient living with RP was treated with an optogenetics therapy, by injection into the retina of one eye. The treated cells were then stimulated when the patient wore a pair of engineered goggles. These goggles detect changes in light in real-time, and project these changes onto the back of the eye as light pulses in the specific colour needed to stimulate the light-sensing protein in the treated cells. In this case, the treated cells were stimulated enough by these light pulses to send a signal to the brain that could be interpreted as a visual image.
A quote from the paper, authored by Dr. José-Alain Sahel details that “The patient testified to a major improvement in daily visual activities, such as detecting a plate, mug or phone, finding a piece of furniture in a room or detecting a door in a corridor but only when using the goggles.”
This is the first reported case of partial sight recovery after optogenetic therapy, and is a significant milestone step towards developing therapies that have meaningful benefit for those living retinal degenerative conditions.
Click here to view the full paper on the Nature Medicine website