gms | German Medical Science

Artificial Vision 2017

The International Symposium on Visual Prosthetics

01.12. - 02.12.2017, Aachen

Measurement of visual cortex activity with near infrared spectroscopy after endoscope assisted ARGUS II epiretinal prosthesis implantation in retinitis pigmentosa patients

Meeting Abstract

  • Emin Özmert - Ankara University Department of Ophthalmology and Brain Research Center, Ankara University, Ankara, Turkey
  • B. Baskak - Ankara University Department of Ophthalmology and Brain Research Center, Ankara University, Ankara, Turkey
  • R. Arslantaş - Ankara University Department of Ophthalmology and Brain Research Center, Ankara University, Ankara, Turkey
  • Y. Kır - Ankara University Department of Ophthalmology and Brain Research Center, Ankara University, Ankara, Turkey
  • A. Kuşman - Ankara University Department of Ophthalmology and Brain Research Center, Ankara University, Ankara, Turkey
  • Z. Baran - Ankara University Department of Ophthalmology and Brain Research Center, Ankara University, Ankara, Turkey

Artificial Vision 2017. Aachen, 01.-02.12.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. Doc17artvis27

doi: 10.3205/17artvis27, urn:nbn:de:0183-17artvis272

Published: November 30, 2017

© 2017 Özmert 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

Text

Objective: To assess the visual cortex activity changes using near-infrared spectroscopy (NIRS), which is a non-invasive and ready method compare to functional magnetic resonans imaging (fMRI), after Argus II implantation surgery.

Method: In order to decrease the incidence of pars plana sclerotomy incision-related complications, inadequate placement of the electrode array over the fovea, Argus II epiretinal prosthesis implantation in 3 retinitis pigmentosa (RP) patients were done under endoscopic control. We used the near-infrared spectroscopy (f-NIRS) device (ETG-4000; Hitachi Medical, Japan) to measure cortical activity during the visual cortex stimulation, 2 and 6 months later after the surgery. Four different paradigms were used (Static checkerboard, On-off checkerboard, Alternating checkerboard, Moving ball). Visual cortex activity was recorded in two conditions; namely the bionic eye-on condition and the bionic eye off- condition. All paradigms were presented in four blocks. The mean activity represents the grand average of these blocks.

Results: We did not observe activity difference in the checker board conditions. However there was a marked activity difference in the moving ball paradigm between the bionic eye-on and off conditions.

Discussion: The NIRS instrument measures relative changes in oxygenated and deoxygenated haemoglobin through optodes (emitters and detectors) of 2 wavelengths (695 and 830 nm). NIRS method can be used in implanted RP patients to assess the visual cortex activity easily instead of fMRI.

Acknowledgement: This work was supported by Second Sight Inc.