Schwahn, Hartmut N. and Gekeler, Florian and Kohler, Konrad and Kobuch, Karin and Sachs, Helmut G. and Schulmeyer, Frank and Jakob, Wolfgang and Gabel, Veit-Peter and Zrenner, Eberhart (2001) Studies on the feasibility of a subretinal visual prosthesis: data from Yucatan micropig and rabbit. GRAEFES ARCHIVE FOR CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY, 239 (12). pp. 961-967. ISSN 0721-832X
Full text not available from this repository. (Request a copy)Abstract
Background: To estimate the feasibility of the subretinal concept of a visual prosthesis, animal models and prototypes, each representing a certain aspect of the final prosthesis, were utilised to test for requirements for such a medical device: (1) the ability to elicit - by electrical stimulation - event-related central activity in the central visual system. and (2) the long-term biocompatibility and biostability of the implant within the subretinal space. Methods: (1) In rabbit and Yucatan minipig, cortical evoked potentials were recorded with chronically implanted epidural electrodes during stimulation with light flashes as well as during electrical stimulation in the subretinal space. Voltage pulses ranging from -3 V to +3 V were applied via an acutely implanted electrode array on a wired prototype. (2) For biocompatibility studies a silicon-based micro-photodiode array (MPDA) was used that closely resembled the design and composition of the final prosthesis. Fourteen months after implantation, angiography was performed and the histological findings of the retina in the immediate vicinity of the implant were evaluated. Results: (1) In both rabbit and minipig, subretinal electrical stimulation resulted in evoked cortical potentials that were comparable to visual evoked potentials. The lowest threshold levels for the subretinal stimulation were 0.6 V for rabbits and 2 V for minipigs. (2) Long-term stability of an implanted MPDA and its biocompatibility were proven for a postoperative period of 14 months. Conclusions: Data from animal experiments with certain prototypes of the final prosthesis suggest the feasibility of the concept of a subretinal visual prosthesis: Both requirements were met: (1) the functioning of the subretinal stimulation and (2) the biocompatibility of the MPDA implant.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | ELECTRICAL-STIMULATION; DEGENERATED PHOTORECEPTORS; RETINITIS-PIGMENTOSA; MICROPHOTODIODES; BLIND; |
| Subjects: | 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Anästhesiologie Medicine > Lehrstuhl für Augenheilkunde Medicine > Lehrstuhl für Neurochirurgie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 24 Nov 2021 06:15 |
| Last Modified: | 24 Nov 2021 06:15 |
| URI: | https://pred.uni-regensburg.de/id/eprint/40898 |
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