Team finds clue to improve artificial vision for patients with retinitis pigmentosa



KIST finds clue to improve artificial vision for patients with retinitis pigmentosa
(A) Schematic illustration of retinal prosthesis displaying notion of the phrase ‘KIST’. Electric stimulation elicits spike trains in retinal ganglion cells (RGCs) for artificial visible percept. (B) Conceptual spike trains which will come up within the wholesome retina. High trial-to-trial consistencies are required for constant visible percepts throughout repeats of stimulation. (C) If RGCs within the degenerate retina produces extremely variable spiking actions throughout repeats, artificial visible percept could be inconsistent, confounding the mind. Credit: Korea Institute of Science and Technology (KIST)

A Korean analysis workforce has reported essential findings that might doubtlessly improve the efficiency of retinal prostheses, creating artificial vision for blind people. The Korea Institute of Science and Technology (KIST) introduced {that a} analysis workforce led by Dr. Maesoon Im of the Center for BioMicrosystems, Brain Science Institute had discovered that retinal neural indicators arising from electrical stimulation are altered relying on illness development in mice affected by outer retinal degeneration. This analysis was completed in collaboration with the lab of Professor Shelley Fried at Harvard Medical School, Massachusetts General Hospital.

Retinal degenerative illnesses, similar to retinitis pigmentosa and , primarily destroy , which convert gentle into electrochemical indicators, main to profound vision loss. Currently, there aren’t any accessible remedy for these illnesses.

Retinal ganglion cells are identified to survive these situations, making artificial vision attainable. An array of microelectrodes may be implanted in the back of the eyeball in order that electrical pulses utilized by these microelectrodes can stimulate ganglion cells to transmit visible to the mind once more. This is the essential working precept of retinal prosthetic units. Although a number of retinal prostheses have been commercialized, one among issues stopping broad software has been an enormous efficiency variation throughout patients due to unidentified causes.

The KIST analysis workforce had delved into the potential supply of the efficiency variation and has discovered the extent of could also be important. They designed a and carried out experiments utilizing mice at numerous levels of retinal degeneration. Those mice misplaced their vision step by step due to a genetic mutation related to folks with retinitis pigmentosa. The researchers recorded electrically evoked neural actions of from animals at various ages and tried to correlate these artificial vision indicators to the illness development. They found that each the magnitude and the consistency of the electrically evoked responses diminished as retinal degeneration superior.

The response consistency is especially essential for retinal prostheses as a result of they periodically refresh artificial visible percepts utilizing repetitive electrical stimuli. For instance, when a retinal prostheses consumer stares at a letter “K,” repeating electrical stimuli want to create neural indicators representing “K.” Otherwise, if the response consistency is simply too low, {the electrical} stimuli would possibly transmit neural indicators which means completely different letters similar to “L,” “R,” or “S,” thus making the prosthetic consumer unable to accurately interpret what she or he is seeing. Throughout a sequence of experiments to assess the diploma of similarities throughout completely different neural indicators arising from repeated electrical stimuli of a identical situation, they discovered that the response consistency significantly declined with the progressing retinal degeneration whereas regular retinas confirmed excessive consistencies.

Dr. Young-Jun Yoon and Dr. Jae-Ik Lee, the lead authors of the research, stated, “Even if a user fixes his/her gaze, their degenerate retina is likely to keep transmitting considerably different neural signals to the brain across repeats of electric stimuli, which may cause poor perception of electrically evoked artificial vision. Retinal degenerative diseases exhibit different patterns of progression across patients. Our results suggest that it is crucial to carefully select candidate patients of retinal implants by thorough examinations assessing the progression level of each patient’s retinal degeneration,” stated Dr. Maesoon Im. “We are studying hardware and software approaches for the improved quality of artificial vision for patients at the late-stage .”

Researchers pinpoint potential new therapeutic target for eye disease

More info:
Young Jun Yoon et al, Retinal Degeneration Reduces Consistency of Network-mediated Responses Arising in Ganglion Cells to Electric Stimulation, IEEE Transactions on Neural Systems and Rehabilitation Engineering (2020). DOI: 10.1109/TNSRE.2020.3003345

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National Research Council of Science & Technology

Team finds clue to improve artificial vision for patients with retinitis pigmentosa (2020, August 10)
retrieved 10 August 2020

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