Artificial vision with wirelessly powered subretinal electronic implant alpha-IMS

This study aims at substituting the essential functions of photoreceptors in patients who are blind owing to untreatable forms of hereditary retinal degenerations. A microelectronic neuroprosthetic device, powered via transdermal inductive transmission, carrying 1500 independent microphotodiode-amplifier-electrode elements on a 9 mm2 chip, was subretinally implanted in nine blind patients. Light perception (8/9), light localization (7/9), motion detection (5/9, angular speed up to 35 deg s−1), grating acuity measurement (6/9, up to 3.3 cycles per degree) and visual acuity measurement with Landolt C-rings (2/9) up to Snellen visual acuity of 20/546 (corresponding to decimal 0.037 or corresponding to 1.43 logMAR (minimum angle of resolution)) were restored via the subretinal implant. Additionally, the identification, localization and discrimination of objects improved significantly (n = 8; p < 0.05 for each subtest) in repeated tests over a nine-month period. Three subjects were able to read letters spontaneously and one subject was able to read letters after training in an alternative-force choice test. Five subjects reported implant-mediated visual perceptions in daily life within a field of 15° of visual angle. Control tests were performed each time with the implant's power source switched off. These data show that subretinal implants can restore visual functions that are useful for daily life.

[1]  E. Zrenner,et al.  Electrical multisite stimulation of the isolated chicken retina , 2000, Vision Research.

[2]  Thomas Guenther,et al.  Bionic vision: system architectures – a review , 2012, Expert review of medical devices.

[3]  S. Trauzettel-Klosinski,et al.  [Rehabilitation of lesions in the visual pathways]. , 2009, Klinische Monatsblatter fur Augenheilkunde.

[4]  P. Fromherz,et al.  Silicon-Neuron Junction: Capacitive Stimulation of an Individual Neuron on a Silicon Chip. , 1995, Physical review letters.

[5]  T Fujikado,et al.  Laboratory investigation of microelectronics-based stimulators for large-scale suprachoroidal transretinal stimulation (STS) , 2007, Journal of neural engineering.

[6]  Eberhart Zrenner,et al.  Solar cells for the blind , 2012, Nature Photonics.

[7]  E. Zrenner,et al.  Long-term survival of retinal cell cultures on retinal implant materials , 1999, Vision Research.

[8]  Joseph F. Rizzo,et al.  Overview of the boston retinal prosthesis: Challenges and opportunities to restore useful vision to the blind , 2011, 2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[9]  Jean Delbeke,et al.  Measurement of evoked potentials after electrical stimulation of the human optic nerve. , 2010, Investigative ophthalmology & visual science.

[10]  K. Kohler,et al.  Histologische Untersuchungen zur Netzhautdegeneration und zur Gewebeverträglichkeit subretinaler Implantate , 2001, Der Ophthalmologe.

[11]  E. Zrenner,et al.  Compound subretinal prostheses with extra-ocular parts designed for human trials: successful long-term implantation in pigs , 2007, Graefe's Archive for Clinical and Experimental Ophthalmology.

[12]  Alfred Stett,et al.  Subretinal electronic chips allow blind patients to read letters and combine them to words , 2010, Proceedings of the Royal Society B: Biological Sciences.

[13]  Alice K. Cho,et al.  Retinal prostheses: current clinical results and future needs. , 2011, Ophthalmology.

[14]  E Zrenner,et al.  [Histological studies of retinal degeneration and biocompatibility of subretinal implants]. , 2001, Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft.

[15]  Michael Bach,et al.  Safety and efficacy of subretinal visual implants in humans: methodological aspects , 2013, Clinical & experimental optometry.

[16]  D Besch,et al.  [What can blind patients see in daily life with the subretinal Alpha IMS implant? Current overview from the clinical trial in Tübingen]. , 2012, Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft.

[17]  Jessy D. Dorn,et al.  Interim results from the international trial of Second Sight's visual prosthesis. , 2012, Ophthalmology.

[18]  Michael Bach,et al.  Testing Visual Functions in Patients with Visual Prostheses , 2007 .

[19]  C. Kufta,et al.  Feasibility of a visual prosthesis for the blind based on intracortical microstimulation of the visual cortex. , 1996, Brain : a journal of neurology.

[20]  E. Zrenner.  Will Retinal Implants Restore Vision ? , 2002 .

[21]  K. Stingl,et al.  Was können blinde Patienten mit dem subretinalen Alpha-IMS-Implantat im Alltag sehen? , 2012, Der Ophthalmologe.

[22]  N Drasdo,et al.  Non-linear projection of the retinal image in a wide-angle schematic eye. , 1974, The British journal of ophthalmology.

[23]  . Bartz-Schmidt,et al.  Subretinal electronic chips can restore useful visual functions in blind retinitis pigmentosa patients , 2010 .

[24]  D Besch,et al.  Extraocular surgery for implantation of an active subretinal visual prosthesis with external connections: feasibility and outcome in seven patients , 2008, British Journal of Ophthalmology.

[25]  Michael Bach,et al.  Basic quantitative assessment of visual performance in patients with very low vision. , 2010, Investigative ophthalmology & visual science.

[26]  E Zrenner,et al.  Retinal prosthesis: an encouraging first decade with major challenges ahead. , 2001, Ophthalmology.

[27]  U. Klose,et al.  Positioning of electronic subretinal implants in blind retinitis pigmentosa patients through multimodal assessment of retinal structures. , 2012, Investigative ophthalmology & visual science.

[28]  Christine A. Curcio,et al.  The spatial resolution capacity of human foveal retina , 1989, Vision Research.

[29]  M. Bach,et al.  The Freiburg Visual Acuity test--automatic measurement of visual acuity. , 1996, Optometry and vision science : official publication of the American Academy of Optometry.

[30]  B Wilhelm,et al.  Subretinale visuelle Implantate , 2010, Klinische Monatsblatter fur Augenheilkunde.

[31]  A. Sher,et al.  Photovoltaic Retinal Prosthesis with High Pixel Density , 2012, Nature Photonics.

[32]  Eberhart Zrenner,et al.  Studies on the feasibility of a subretinal visual prosthesis: data from Yucatan micropig and rabbit , 2001, Graefe's Archive for Clinical and Experimental Ophthalmology.

[33]  Roland Thewes,et al.  Electrical stimulation of retinal neurons in epiretinal and subretinal configuration using a multicapacitor array. , 2012, Journal of neurophysiology.

[34]  Ava K. Bittner,et al.  The artificial silicon retina in retinitis pigmentosa patients (an American Ophthalmological Association thesis). , 2010, Transactions of the American Ophthalmological Society.