%0 Journal Article %T The very large electrode array for retinal stimulation (VLARS)—A concept study %+ Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH) %+ Dynamique corticale et prise de décision - Neural circuit dynamics and decision making %+ Jülich Research Centre %+ Universität Duisburg-Essen = University of Duisburg-Essen [Essen] %A Lohmann, Tibor Karl %A Haiss, Florent %A Schaffrath, Kim %A Schnitzler, Anne-Christine %A Waschkowski, Florian %A Barz, Claudia %A van Der Meer, Anna-Marina %A Werner, Claudia %A Johnen, Sandra %A Laube, Thomas %A Bornfeld, Norbert %A Mazinani, Babak Ebrahim %A Rössler, Gernot %A Mokwa, Wilfried %A Walter, Peter %Z The VLARS project was supported with a grant from the Jackstädt Foundation and with additional funding from the Hans Lamers Foundation. %Z Data and findings of this manuscript were partially shown at 'The Eye and the Chip 2016'. %< avec comité de lecture %@ 1741-2560 %J Journal of Neural Engineering %I IOP Publishing %V 16 %N 6 %P 066031 %8 2019-11-06 %D 2019 %R 10.1088/1741-2552/ab4113 %M 31480027 %K retinal stimulation %K retina implant %K multielectrode array %K cortical activation %K local eld potentials %K biocompatibility %K vitreoretinal surgery %Z Life Sciences [q-bio]/BioengineeringJournal articles %X Objective. The restoration of vision in blind patients suffering from degenerative retinal diseases like retinitis pigmentosa may be obtained by local electrical stimulation with retinal implants. In this study, a very large electrode array for retinal stimulation (VLARS) was introduced and tested regarding its safety in implantation and biocompatibility. Further, the array's stimulation capabilities were tested in an acute setting. Approach. The polyimide-based implants have a diameter of 12 mm, cover approximately 110 mm2 of the retinal surface and carrying 250 iridium oxide coated gold electrodes. The implantation surgery was established in cadaveric porcine eyes. To analyze biocompatibility, ten rabbits were implanted with the VLARS device, and observed for 12 weeks using slit lamp examination, fundus photography, optical coherence tomography (OCT) as well as ultrasound imaging. After enucleation, histological examinations were performed. In acute stimulation experiments, electrodes recorded cortical field potentials upon retinal stimulation in the visual cortex in rabbits. Main results. Implantation studies in rabbits showed that the implantation surgery is safe but difficult. Retinal detachment induced by retinal tears was observed in five animals in varying severity. In five cases, corneal edema reduced the quality of the follow-up examinations. Findings in OCT-imaging and funduscopy suggested that peripheral fixation was insufficient in various animals. Results of the acute stimulation demonstrated the array's ability to elicit cortical responses. Significance. Overall, it was possible to implant very large epiretinal arrays. On retinal stimulation with the VLARS responses in the visual cortex were recorded. The VLARS device offers the opportunity to restore a much larger field of visual perception when compared to current available retinal implants %G English %Z The authors thank Claudia Werner for her outstanding technical support. Rudolph Pivik supported the VLARS team with the rotational stereotactic frame. %2 https://pasteur.hal.science/pasteur-03291827/document %2 https://pasteur.hal.science/pasteur-03291827/file/Lohmann_2019_J._Neural_Eng._16_066031.pdf %L pasteur-03291827 %U https://pasteur.hal.science/pasteur-03291827 %~ PASTEUR