Researchers combined gene therapy and event cameras to fragment restore vision in a blind person.


Imagine, if you will, slowly going blind over the course of forty years-waking up every morning with a tiny bit of peripheral gray vision, your world disappearing behind a shrinking vision hole. well, that is finally lost in the abyss altogether. blindness as faulty photoreceptive cells in your eyes fail. Such was the supposed fate of a 58-year-old sufferer Retinitis Pigmentosa over the past four decades. He chose to participate in a new study conducted by researchers from the University of Basel, University of Pittsburgh Medical Center and startup GenSight Biologics. Instead of sinking further into the pitch -black darkness of the night, this patient was actually unexpected, there is a part of his vision that has been restored thanks to a cutting-edge hybrid biological-technological therapy known as optogenetics.

“I think a new field has been born,” University of Basel professor and researcher Botond Roska told reporters in a recent conference call announcing the team’s results.

Optogenetics, as the name implies, fused optics and genetics, enabling researchers to control individually, in vitro neurons using visible light. The light beam molecules are first introduced by brain cells and then activated by pulse light from fiber optic threads. The molecule converts the light into an electrical salpot that causes the neuron that it also attaches to fire, allowing the researchers to activate the specific neurons in question and possibly influence the subject’s behaviors and responses.

it neuromodulation used the method of neurology for many decades to study the functions of the central nervous system in millcards hours in millimeters (a big step up from the days and months used to capture the noticeable results of traditional genetic techniques). In recent years, optogenetics has been reintroduced as a method of treatment to help treat – and possibly transfer – hereditary diseases such as RP, which afflicts 1 in 4,000 people. born in the US every year.

The University of Basel-UPMC team took the basic theories behind optogenetics and applied them to the retinal part of their PIONEER 1 / 2a study, using tech developed in GenSight Biologics. It is a two -pronged approach that uses both biologic and technologic components. On the bio side, the researchers first targeted the patient’s retinal ganglion cells to receive a genetic therapy that would make them inactivated. Normal ganglion cells are not photosensitive – that’s a job for sticks and cones – and they simply carry the electrical charge generated by the photoreceptive cells up to the optic nerve. But because the RP has already damaged and destroyed the patient’s canes and cones, these ganglions need to be replaced to get a double duty.

To do this, it is inserted into the content of the research (read: injected) a gene isolated from a light-sensing species of green moss in one of the patient’s eyes. That gene encodes for photoactivatable channelrhodopsin called ChrimsonR and targeted ganglion cells using a modified adenovirus vector.

GenSight Biologics

“These proteins are especially special,” Drs. José-Alain Sahel, Distinguished Professor and Chairman of the Department of Ophthalmology at the University of Pittsburgh School of Medicine, co-founder of Gensight Biologics and co-lead investigator for the PIONEER study, told Engadget. “They were discovered in the late 90s and early 2000s. These proteins exist in algae, capture light and cause an electrical response that allows the algae to move toward or away from light, and it a protein so it’s a quickest response. ”

It took a few months for the ganglions to produce a sufficient amount of ChrimsonR and for it to remain inside the cells. Once that happens, the ganglion cells detect the same light and carry the next electricity up to the optic nerve, bypassing the useless rods and cones.

This is where the tech side comes in. ChrimsonR is most responsive to light at 590nm wavelength (amber) and that light needs to be bright to activate the protein – much brighter than natural light can in general. “It doesn’t respond to short light levels and it doesn’t adapt to different light levels in the normal retina,” Sahel laments.

Thus, Gensight has created a proprietary set of goggles that collects image data from a included activity camera and bright, 590nm wavelength light directly into the patient’s eyes. “We created a bioinspired camera that works on every pixel by detecting any changes in light sensitivity,” Sahel explains. “These cameras can detect the shortest levels of changes, can operate at short levels applied and high levels of light. We move pixel by pixel and we process the image in real time. . ”

The patient began training with the headset five months after receiving the injection. “The first step is to train the patient to adjust the retinal lenses, to make sure the beam is well aligned,” he continues, “and to train the patient to understand what he sees when he sees.”

Seven months later began to see noticeable improvements in his visual acuity. Using his glasses, the patient correctly saw and touched a large notebook and small pencil case placed on a table in front of him 92 percent and 36 percent of the time, respectively. He also counted the number of tumblers placed on the table with 63 percent accuracy. Without the help of his or her mirror, the patient successfully completes these tasks zero percent of the time.

In addition, EEG readings taken in these tests showed increased activity in the patient’s visual cortex, suggesting that his brain actually “saw” what he was looking at. The patient even said he recognized white stripes on a crosswalk when the headset was tested outside the lab.

“A lot of people don’t think it will work on people,” Sahel said. “Many eminent scientists in the field of optogenetics are being considered [this technique] very good as a tool to understand how the brain works and how [neural] the connections work, but they don’t think it will work with patients … It’s a really important factor, it tells us we’re on the right track. ”

The current PIONEER study is a preliminary start to the development of therapy. At this point researchers are mostly looking for standard safety measures and dialing the highest biologic dose. Many other patients have received their vector injections but, due to issues stemming from the COVID pandemic, have not yet been trained in headsets. Sahel hopes to fix that soon as GenSight works to test the improvements to the headsets themselves. The event camera used in today’s bottle glasses is hampered by its low resolution, “so we’re working on higher resolution glasses,” says Sahel, as well as looking to include a eye tracking system “to better align the eye.”

However, if you’re a little upset about having a genetically modified version of the common cold injected into adapted fragments of your inner eye, don’t panic because it’s just one of many technological treatments being made to address RP. and so on. inherited diseases. the The Orion Visual Cortical Prosthesis System, developed by Second Sight Medical Products offers a similar camera-goggle setup-with predator vision is not diminished-even if it requires thin examinations to be inserted into your brain and a control unit placed in your skull. Yeah, suddenly that shooting doesn’t look bad anymore, does it?

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