gms | German Medical Science

Artificial Vision 2017

The International Symposium on Visual Prosthetics

01.12. - 02.12.2017, Aachen

Development and evaluation of a wide-field dual-array suprachoroidal-transretinal stimulation (STS) prosthesis system

Meeting Abstract

  • Takeshi Morimoto - Department of Applied Visual Science, Osaka University Graduate School of Medicine, Osaka, Japan
  • H. Kanda - Department of Applied Visual Science, Osaka University Graduate School of Medicine, Osaka, Japan
  • K. Hozumi - Department of Ophthalmology, Osaka University Graduate School of Medicine, Osaka, Japan
  • K. Nishida - Department of Ophthalmology, Osaka University Graduate School of Medicine, Osaka, Japan
  • T. Fujikado - Department of Applied Visual Science, Osaka University Graduate School of Medicine, Osaka, Japan

Artificial Vision 2017. Aachen, 01.-02.12.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. Doc17artvis16

doi: 10.3205/17artvis16, urn:nbn:de:0183-17artvis165

Published: November 30, 2017

© 2017 Morimoto 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

Purpose: To report the development of a wide-field dual-array suprachoroidal-transretinal stimulation (STS) prosthesis system and results of the implantation of this system into dogs.

Methods: This STS prosthesis system consisted of two arrays of 25 electrodes each and an extraocular microstimulator. We developed three types of STS systems (2014ver, 2015ver, 2016ver) and applied them for the implantation. Six healthy beagle dogs were used in this study. Under systemic general anesthesia, the array was implanted into the left eye of each dog. Color fundus photography, fluorescein angiography (FA), electroretinography (ERG) were performed postoperatively. The dogs were euthanatized 3 to 6 months after the implantation, and the eyes were evaluated histologically.

Results: All the prostheses were successfully implanted without complications, and no serious complications occurred during the postoperative period. The fixation of the implant was stable throughout the experimental period. Fundus photographs and FA revealed no serious damage in the retina and choroid around the arrays. ERGs recorded from the eyes with the prosthesis did not differ significantly from those recorded from control eyes. Histologic evaluations showed good preservation of the retina over the electrode array. However, in some dogs, the wound dehiscence around the microstimulator in the head and/or the malfunction of this device due to the repeated scratches by the dogs in the kennel were observed.

Conclusions: Implantation of a wide-field dual-array STS retinal prosthesis system into the dogs is surgically feasible and can be performed without significant damage to the retina or the animal. The biocompatibility and stability of the system were good for the observation period, except for the scratch damage which is specific to dogs. These findings indicate that it might be possible to implant more STS electrode arrays to cover a larger area of the retina to activate a larger visual field.