Clinical study results with new wireless electronic subretinal implant alpha‐ims

Abstract

AbstractPurpose Restitution of vision in blind Retinitis Pigmentosa patients by the new wireless implant Alpha‐IMS (Retina Implant AG, Tübingen, Germany).Methods Each of the 1500 subfoveal photodiodes within an 11 by 11 deg field controls an amplifier that ejects light evoked currents onto bipolar cells via TiN electrodes (Zrenner et al. Proc. R. Soc. B 2011, 278: 1489ff). Power and control signals are transmitted transdermally via retroauricular inductive coils connected to a subdermal cable to the eye.Results Ten patients received implants since 2010 (average age 46±84). In 8 patients the chip was at the desired subfoveal position; in 2 patients slightly parafoveal. All patients were able to perform the function tests except one due to loss of inner retina function after surgery. Results in all other patients were: light perception 9/9; light localization 8/9; motion recognition 5/9; grating resolution 8/9 (up to 3,3 cycle/degree); Landolt C rings 3/9 (up to 0,036); recognition of geometric objects 8/9; recognition of objects in table setup 8/9; letter reading 4/9; clock hands reading 3/9; grey scale differentiation 6/9; improved outdoor mobility 5/9. Patients` experiences: recognition of unknown objects, facial or clothes’ characteristics, moving objects in nature and traffic, small objects (glasses, telephone, doors, door handles, washing basin, dices).Conclusion The wireless Alpha‐IMS implant can restore useful visual abilities in blind RP‐patients. Subretinal surgery for positioning chips subfoveally is safe and the multicenter part of the study has been started in Oxford, London and Hongkong. Commercial interest