title: [Subretinal visual implants].
abstract: Visual implants are medical technologies that replace parts of the visual neuronal pathway. The subretinal implant developed by our group is being used in a human trials since 2005 and replaces the function of degenerated photoreceptors by an electronic device in blind patients. The subretinal implant consists of a 70-µm thin microchip with 1500 microphotodiodes each with an amplifier and an electrode with area of 3 mm × 3 mm. The power supply is provided by a subdermal power supply cable. The microchip is implanted under the macula and transforms the light signal into an electrical one, which is referred directly to the bipolar cells. Requirements for a good function of the implant are a preserved function of the inner retina, as well as clear optic media and a good visual acuity in the earlier life. The current technology can mediate a visual field of 10 - 12° and a computed resolution of up to 0.25° visual angle (corresponding to a visual acuity of 63 / 1000 - 80 / 1000) in blind patients. The so far best results from our studies reached a visual acuity of 21 / 1000 in blind retinitis pigmentosa patients. This overview is intended to inform the ophthalmologist about the current state of the technology and help him/her to advise interested patients.
authors.affiliation: Department für Augenheilkunde, Universitätsklinikum Tübingen, Tübingen. katarina.stingl@med.unituebingen.de
authors.forename: K
authors.initials: K
authors.lastname: Stingl
authors.forename: U
authors.initials: U
authors.lastname: Greppmaier
authors.forename: B
authors.initials: B
authors.lastname: Wilhelm
authors.forename: E
authors.initials: E
authors.lastname: Zrenner
mesh_terms: D001766:Blindness / Q000534:rehabilitation*; D011211:Electric Power Supplies; D006801:Humans; D011474:Prosthesis Design; D012160:Retina / Q000503:physiopathology*; D057488:Visual Prosthesis