Extraocular surgery for implantation of an active subretinal visual prosthesis with external connections: feasibility and outcome in seven patients
- D Besch1,
- H Sachs2,
- P Szurman1,
- D Gülicher3,
- R Wilke1,
- S Reinert3,
- E Zrenner1,
- K U Bartz-Schmidt1,
- F Gekeler1
- 1Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
- 2Department of Ophthalmology, University of Regensburg, Regensburg, Germany
- 3Department of Oral and Maxillofacial Surgery, University of Tübingen, Tübingen, Germany
- Dr F Gekeler, Centre for Ophthalmology, University of Tübingen, Schleichstraße 12–16, 72076 Tübingen, Germany; gekeler{at}uni-tuebingen.de
- Accepted 15 July 2008
- Published Online First 28 July 2008
Abstract
Background: Due to low energy levels in microphotodiode-based subretinal visual prostheses, an external power supply is mandatory. We report on the surgical feasibility and the functional outcome of the extraocular part of an approach to connect a subretinal prosthesis to an extracorporeal connector in the retro-auricular space via a trans-scleral, transchoroidal cable.
Methods: Seven volunteers with retinitis pigmentosa received an active subretinal implant; energy was supplied by gold wires on a trans-sclerally, transchoroidally implanted polyimide foil leading to the lateral orbital rim where it was fixated and connected to a silicone cable. The cable was implanted subperiostally beneath the temporal muscle using a trocar to the retro-auricular space where it penetrated the skin for connection to a stimulator. To avoid subretinal movement of the implant, three tension relief points have been introduced.
Results: All implantations were performed as planned without complications, and no serious adverse events occurred in the postoperative period. Fixation of the implants was stable throughout the entire study duration of 4 weeks; permanent skin penetration proved to be uncomplicated. Motility was minimally restricted in downgaze and ab-/adduction. Explantation was uneventful.
Conclusion: The above-described procedure provides a method for stable fixation of a subretinal device with a trans-scleral, transchoroidal cable connection to an extracorporeal connector.
Footnotes
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Competing interests: According to the journal’s guidelines, the authors declare the following: (1) the retinal implant was manufactured and delivered by Retina Implant AG (RIAG), Gerhard-Kindler-Straße 8, D-72770 Reutlingen, Germany; (2) RIAG covered the direct costs of the study; (3) HS, EZ and FG are shareholders of RIAG; none of them receives payment or is employed by RIAG.
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Ethics approval: The ethics committee of the Medical Faculty of the University of Tübingen provided the approval.
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Patient consent: Obtained.
