Extra-ocular surgery for implantation of an active subretinal visual prosthesis with external connections: feasibility and outcome in seven patients
- Dorothea Besch (dorothea.besch{at}med.uni-tuebingen.de),
- Helmut Sachs (helmut.sachs{at}klinik.uni-regensburg.de),
- Peter Szurman (peter.szurman{at}med.uni-tuebingen.de),
- Dirk Gülicher (dirk.guelicher{at}med.uni-tuebingen.de),
- Robert Wilke, Dr. (roberwilke{at}aol.com),
- Siegmar Reinert (siegmar.reinert{at}uni-tuebingen.de),
- Eberhart Zrenner (ezrenner{at}uni-tuebingen.de),
- Karl Ulrich Bartz-Schmidt (u.bartzschmidt{at}googlemail.com),
- Florian Gekeler (gekeler{at}uni-tuebingen.de)
- Center for Ophthalmology, University of Tübingen, Germany
- University-Eye-Hospital, Regensburg, Germany
- Center for Ophthalmology, University of Tübingen, Germany
- Department of Oral and Maxillofacial Surgery, University of Tübingen, Germany
- Center for Ophthalmology, University of Tübingen, Germany
- Department of Oral and Maxillofacial Surgery, University of Tübingen, Germany
- Center for Ophthalmology, University of Tübingen, Germany
- Center for Ophthalmology, University of Tübingen, Germany
- Center for Ophthalmology, University of Tübingen, Germany
- Published Online First 28 July 2008
Abstract
Background: Due to low energy levels in microphotodiode based subretinal visual prostheses external power supply is mandatory. We report on the surgical feasibility and the functional outcome of the extra-ocular part of an approach to connect a subretinal prosthesis to an extra-corporeal connector in the retro-auricular space via a trans-scleral, trans-choroidal cable.
Methods: Seven volunteers with retinitis pigmentosa received an active subretinal implant; energy was supplied by gold wires on a trans-sclerally, trans-choroidally 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, no serious adverse events occurred in the post-operative 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, trans-choroidal cable connection to an extra-corporeal connector.
