An international research team has shown that optogenetic therapy has 
helped to partially regain visual function in a patient with retinitis 
pigmentosa. This is a milestone towards a gene therapy that could 
restore vision. 
 
   A Media Snippet accompanying this announcement is available by clicking 
on the image: 
 
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   Paris, Pittsburgh, Basel, May 24(th) , 2021- Clinical trial results 
announced today show for the first time that optogenetic methods can 
partially restore vision in a blind human patient. The achievement marks 
a milestone towards developing mutation-independent therapies for 
inherited photoreceptor diseases. It was reported in Nature Medicine by 
an international research team led by José-Alain Sahel and Botond 
Roska including members from the Institut de la Vision and Hôpital 
National des Quinze-Vingts, Paris, the University of Pittsburgh, the 
Institute of Molecular and Clinical Ophthalmology Basel (IOB), StreetLab, 
and GenSight Biologics (Euronext: SIGHT). 
 
   "Enabling a patient to regain partial vision by optogenetics could not 
have happened without the engagement of the patient, the efforts of our 
multidisciplinary team at the Institut de la Vision and GenSight, and 
the longstanding collaboration with Botond Roska, which was at the 
origin and core of all this project " says first and corresponding 
author José-Alain Sahel, Distinguished Professor and Chairman of 
Ophthalmology at the University of Pittsburgh, Professor at Sorbonne 
University and Hôpital National des Quinze-Vingts, and Founding 
Director of the Institut de la Vision. 
 
   "The findings provide proof-of-concept that using optogenetic therapy to 
partially restore vision is possible" says last and corresponding author 
Botond Roska, Founding Director at IOB and Professor at the University 
of Basel. 
 
   Optogenetics involves genetically altering cells so that they produce 
light-sensitive proteins called channelrhodopsins. The technique has a 
nearly 20-year history in neuroscience but, so far, clinical benefit of 
optogenetics had not been demonstrated. A collaboration between the 
teams of José-Alain Sahel and Botond Roska culminated in the 
findings reported today that reflect 13 years of multidisciplinary 
effort. 
 
   The goal of the research is to treat inherited photoreceptor diseases, 
which are widespread causes of human blindness. Photoreceptors are 
light-sensing cells in the retina that use proteins called opsins to 
deliver visual information to the brain via the optic nerve. 
Photoreceptors progressively degenerate, and then blindness sets in. To 
restore light-sensing capability, the team uses gene therapy methods to 
deliver channelrhodopsins into the retina's ganglion cells. 
 
   For the current study, the team delivered the gene coding for a 
channelrhodopsin called ChrimsonR. This particular protein senses amber 
light, which is safer for retinal cells than the blue light used for 
other types of optogenetic research. The team also developed specialized 
goggles outfitted with a camera that captures and projects visual images 
onto the retina at amber light wavelengths. 
 
   Training with the goggles began nearly five months after the injection, 
thus giving ChrimsonR expression time to stabilize in ganglion cells. 
Seven months later, the patient began reporting signs of visual 
improvement. 
 
   Test results showed he could locate, touch and count objects on a white 
table placed in front of him, but only with the aid of the goggles. 
Without the goggles, he was unable to perform these exercises. One test 
involved perceiving, locating, and then touching a large notebook or a 
smaller staple box. The patient touched the notebook during 36 of 39 
separate evaluations (in other words, 92% of the time), but could pick 
out the smaller staple box only 36% of the time. In a second test, the 
subject correctly counted glass tumblers on the table 63% of the time. 
 
   During a third test, the subject wore a skull-cap affixed with 
electrodes that took non-invasive electroencephalography (EEG) readings 
of his brain activity.  A tumbler was alternately taken on or off the 
table, and the subject had to press a button indicating whether it was 
present or absent. Importantly, EEG readings showed that correlated 
changes in activity during this testing were concentrated in the visual 
cortex. 
 
   The team also trained a software decoder to evaluate the EEG readings. 
By simply measuring neuronal activity, the decoder could tell with 78% 
accuracy if the tumbler was present or not in a given trial. This last 
evaluation, Roska says, helped to confirm that brain activity is indeed 
related to a visual object, and "therefore that the retina is no longer 
blind." 
 
 
 
   "Importantly, blind patients with different kinds of neurodegenerative 
photoreceptor disease and a functional optic nerve will potentially be 
eligible for the treatment. However, it will take time until this 
therapy can be offered to patients" commented Sahel. 
 
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Link to publication in Nature Medicine: 
https://dx.doi.org/10.1038/s41591-021-01351-4 
 
   Contact first and corresponding author: 
 
   José-Alain Sahel, sahelja@upmc.edu 
 
   Media contacts: 
 
   Anastasia Gorelovaa: gorelovaa@upmc.edu (University Pittsburgh, 
Pittsburgh) 
 
   Emanuela de Luca: emanuela.de-luca@institut-vision.org (Institut de la 
Vision, Paris) 
 
   Contact last and corresponding author: 
 
   Botond Roska, botond.roska@iob.ch 
 
   Media contact: Sandra Schlüchter, sandra.schluechter@iob.ch 
 
   Links to institutional web pages 
 
 
   --  https://www.medschool.pitt.edu https://www.medschool.pitt.edu 
 
   -- https://iob.ch 
 
   -- https://www.institut-vision.org 
 
   -- https://www.15-20.fr 
 
   -- http://www.streetlab-vision.com 
 
   -- https://www.gensight-biologics.com 
 
   About IOB 
 
   At the Institute of Molecular and Clinical Ophthalmology Basel (IOB), 
basic researchers and clinicians work hand in hand to advance the 
understanding of vision and its diseases, and to develop new therapies 
for vision loss. IOB started its operations in 2018. The institute is 
constituted as a foundation, granting academic freedom to its 
scientists. Founding partners are the University Hospital Basel, the 
University of Basel and Novartis. The Canton of Basel-Stadt has granted 
the institute substantial financial support. 
 
   Follow us on social media 
 
 
   -- Twitter @IOB_ch 
 
   -- YouTube IOB Basel Switzerland 
 
 
   Attachments 
 
 
   -- Botond Roska, Director at the Institute of Molecular and Clinical 
      Ophthalmology Basel. At the IOB we are working on the next generation of 
      optogenetic vision restoration. 
      https://ml-eu.globenewswire.com/Resource/Download/ffef37b2-33a1-479d-a4cb-aacf330f512c 
 
 
   -- Blind patient during extracranial multi-channel electroencephalography 
      (EEG) recording. 
      https://ml-eu.globenewswire.com/Resource/Download/2028527a-8882-49db-9cd3-73eee642ad67 
 
 
   -- Blind patient touching an object 
      https://ml-eu.globenewswire.com/Resource/Download/206b95d3-9298-4e3b-bbe2-84d039099b09 
 
 
   -- Blind patient touching an object 
      https://ml-eu.globenewswire.com/Resource/Download/63242c9c-81d0-4d67-9a33-14696cb091f9 
 
 
   -- José-Alain Sahel, M.D. 
      https://ml-eu.globenewswire.com/Resource/Download/ee28809a-bf93-4451-9ae2-701cf4f8cac4 
 
 
   -- "The retina of a blind person is made light sensitive using optogenetic 
      therapy and is illuminated by light-stimulating goggles that capture 
      images from the visual world using a neuromorphic camera" 
      https://ml-eu.globenewswire.com/Resource/Download/ca78d8f8-5484-4117-8098-5784788425e2 
 
 
   -- The retina of a blind person is made light sensitive using optogenetic 
      therapy and is illuminated by light-stimulating goggles that capture 
      images from the visual world using a neuromorphic camera 
      https://ml-eu.globenewswire.com/Resource/Download/2e5bc031-058e-45f5-84a2-b805b77cbb10 
 
 
   -- The retina of a blind person is made light sensitive using optogenetic 
      therapy and is illuminated by light-stimulating goggles that capture 
      images from the visual world using a neuromorphic camera 
      https://ml-eu.globenewswire.com/Resource/Download/be051f56-3bb0-4422-a63e-1b519d328827 
 
 
   -- Botond Roska in his laboratory at the Institute of Molecular and Clinical 
      Ophthalmology in Basel (IOB) 
      https://ml-eu.globenewswire.com/Resource/Download/50fbdd58-34b8-41eb-aad6-2292acb48e29 
 
 
   -- José-Alain Sahel, M.D. (in the laboratory) 
      https://ml-eu.globenewswire.com/Resource/Download/916a1c02-b1ea-4380-bb12-1adc2c5b95cb 
 
 
   -- José-Alain Sahel, M.D. 
      https://ml-eu.globenewswire.com/Resource/Download/f928d6b6-cc05-466c-a140-3c8f9595001c 
 
 
   -- Botond Roska, Director at the Institute of Molecular and Clinical 
      Ophthalmology in Basel. From an idea that was born when I was a graduate 
      student, I was fortunate to contribute to technologies that could restore 
      some visional function in a blind 
      https://ml-eu.globenewswire.com/Resource/Download/de7fe088-ce1a-4bf3-93ac-668d86cde640

(END) Dow Jones Newswires

May 24, 2021 11:00 ET (15:00 GMT)