title: Artificial vision with wirelessly powered subretinal electronic implant alpha-IMS.
abstract: 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 mm(2) 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.
authors: Centre for Ophthalmology, University of Tübingen, Schleichstraße 12-16, Tübingen, Germany.
authors: Katarina
authors: K
authors: Stingl
authors: Karl Ulrich
authors: KU
authors: Bartz-Schmidt
authors: Dorothea
authors: D
authors: Besch
authors: Angelika
authors: A
authors: Braun
authors: Anna
authors: A
authors: Bruckmann
authors: Florian
authors: F
authors: Gekeler
authors: Udo
authors: U
authors: Greppmaier
authors: Stephanie
authors: S
authors: Hipp
authors: Gernot
authors: G
authors: Hörtdörfer
authors: Christoph
authors: C
authors: Kernstock
authors: Assen
authors: A
authors: Koitschev
authors: Akos
authors: A
authors: Kusnyerik
authors: Helmut
authors: H
authors: Sachs
authors: Andreas
authors: A
authors: Schatz
authors: Krunoslav T
authors: KT
authors: Stingl
authors: Tobias
authors: T
authors: Peters
authors: Barbara
authors: B
authors: Wilhelm
authors: Eberhart
authors: E
authors: Zrenner
mesh_terms: D000328:Adult; D001766:Blindness / Q000601:surgery*; D005260:Female; D006801:Humans; D020007:Implants, Experimental; D008297:Male; D008875:Middle Aged; D058117:Neural Prostheses; D010775:Photic Stimulation; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology; D011474:Prosthesis Design; D014792:Visual Acuity; D014796:Visual Perception; D057488:Visual Prosthesis