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Behavioural responses to a photovoltaic subretinal prosthesis implanted in non-human primates


Retinal dystrophies and age-related macular degeneration related to photoreceptor degeneration can cause blindness. In blind patients, although the electrical activation of the residual retinal circuit can provide useful artificial visual perception, the resolutions of current retinal prostheses have been limited either by large electrodes or small numbers of pixels. Here we report the evaluation, in three awake non-human primates, of a previously reported near-infrared-light-sensitive photovoltaic subretinal prosthesis. We show that multipixel stimulation of the prosthesis within radiation safety limits enabled eye tracking in the animals, that they responded to stimulations directed at the implant with repeated saccades and that the implant-induced responses were present two years after device implantation. Our findings pave the way for the clinical evaluation of the prosthesis in patients affected by dry atrophic age-related macular degeneration.

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Fig. 1: Retinal prosthesis design and RGC responses on an in vitro NHP retina preparation.
Fig. 2: RGC responses to single pixel activations on an in vitro blind NHP retina.
Fig. 3: In vitro experiment on a human retina after full-field stimulation.
Fig. 4: Ophthalmological characterization and natural vision of implanted NHPs.
Fig. 5: Implant activation in behaving NHPs.
Fig. 6: Optimal parameters for NIR stimulations.
Fig. 7: Electro-optical characterization of the implant.

Data availability

All data supporting the results in this study are available in the Article and Supplementary Information. The raw and analysed datasets generated during the study are available for research purposes from the corresponding author on reasonable request.

Code availability

The custom codes used in this study are available from the corresponding author on request.


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This work was supported by BPIfrance (grant no. 2014-PRSP-15), the Foundation Fighting Blindness, the Fédération des Aveugles de France and LabEx LIFESENSES (grant no. ANR-10-LABX-65) and was managed by the French Agence National pour la Recherche as part of the first Investissements d’Avenir programme (grant no. ANR-11-IDEX-0004-02). This project also received funding from the European Union’s Horizon 2020 research and innovation programme for the European Graphene Flagship under grant agreement no. 785219. The content is solely the responsibility of the authors and does not necessarily represent the views of the funders. The authors had the final say over the data collection and analysis, decision to publish and preparation of the manuscript.

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Authors and Affiliations



P.-H.P., P.D., G.C., P.P., R.B. and S.P. planned the studies. M.L., M.V., K.B. and F.A. conducted the NHP behavioural experiments assisted by N.W. and M.W.; S.D. and V.F. conducted the in vitro experiments. E.D. and S.D. performed the histological analyses. K.G., H.A. and M.A.K. analysed the data. K.B. and O.O. coded the stimulations. P.L., E.E. and H.L. built the apparatus. Y.L., E.Bo., M.D. and R.H. designed the surgery procedure. E.Br., C.N.-J., P.H., J.D., C.-M.F. and Y.L. conducted the prostheses surgeries. E.Bo., M.D., R.H. and G.B. characterized and provided the implants. P.-H.P., S.P., P.P. and F.A. wrote the Article. J.-A.S. and S.P. obtained the funding. All authors reviewed, edited and approved the Article.

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Correspondence to Serge Picaud.

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Competing interests

J.-A.S., R.B. and S.P. were consultants and founders of Pixium Vision. Y.L. is a consultant for Pixium Vision. E.Bo., M.D., R.H. and G.B. are employees at Pixium Vision.

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Prévot, PH., Gehere, K., Arcizet, F. et al. Behavioural responses to a photovoltaic subretinal prosthesis implanted in non-human primates. Nat Biomed Eng 4, 172–180 (2020).

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