gms | German Medical Science

Artificial Vision 2017

The International Symposium on Visual Prosthetics

01.12. - 02.12.2017, Aachen

Development of a cortical visual prosthesis for the blind: pre-clinical studies

Meeting Abstract

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  • Eduardo Fernandez - Bioengineering Institute, Miguel Hernández University of Elche, Elche, Spain; CIBER-BBN, Madrid, Spain
  • A. Alfaro - CIBER-BBN, Madrid, Spain; Department of Neurology, Hospital Vega Baja, Orihuela, Spain

Artificial Vision 2017. Aachen, 01.-02.12.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. Doc17artvis33

doi: 10.3205/17artvis33, urn:nbn:de:0183-17artvis332

Published: November 30, 2017

© 2017 Fernandez et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

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Objective: A cortical prosthesis is the only treatment available for blindness caused by glaucoma, end-stage retinitis pigmentosa, optic atrophy, trauma to the retinas and/or optic nerves or by diseases of the central visual pathways such as brain injuries or stroke. We are now facing the challenge of creating a cortical visual neuroprosthesis, based on intracortical microelectrodes, which will allow to provide a limited but useful visual sense to profoundly blind.

Materials and Methods: We implanted the Utah Electrode Array (UEA) in the visual cortex of several animal models and humans. We collected histological and physiological data. Furthermore we performed electrical stimulation in patients with a diagnosis of intractable epilepsy that had to undergo a surgical resection. Electrical stimulation was applied through implanted subdural electrodes or using penetrating micro-electrodes.

Results: All study subjects perceived phosphenes and tolerated the procedure without complications. The probability of detecting phosphenes or scotoma varied with the position of the electrodes. Stimulation of early visual areas induced visual perceptions but stimulation of extrastriate occipital cortex was also able to induce phosphenes with retinotopic representation. These results are being used for a pre-clinical trial and for effective patient selection.

Discussion: Electrical stimulation of visual areas in humans provides a unique opportunity to study the qualitative properties of induced perceptions, which can offer insights about the functional organization of human visual cortex and help to the development of new rehabilitative strategies for profoundly blind based on multiple cortical microelectrodes.

Acknowledgment: This work was supported by the Bidons Egara's Research Chair in Retinitis Pigmentosa and by the National Organization of the Spanish Blind (ONCE).