Optometry and Vision Sciences - Research Publications

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    neuroBi: A Highly Configurable Neurostimulator for a Retinal Prosthesis and Other Applications
    Slater, KD ; Sinclair, NC ; Nelson, TS ; Blamey, PJ ; McDermott, HJ (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2015)
    To evaluate the efficacy of a suprachoroidal retinal prosthesis, a highly configurable external neurostimulator is required. In order to meet functional and safety specifications, it was necessary to develop a custom device. A system is presented which can deliver charge-balanced, constant-current biphasic pulses, with widely adjustable parameters, to arbitrary configurations of output electrodes. This system is shown to be effective in eliciting visual percepts in a patient with approximately 20 years of light perception vision only due to retinitis pigmentosa, using an electrode array implanted in the suprachoroidal space of the eye. The flexibility of the system also makes it suitable for use in a number of other emerging clinical neurostimulation applications, including epileptic seizure suppression and closed-loop deep brain stimulation. Clinical trial registration number NCT01603576 (www.clinicaltrials.gov).
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    Advances in implantable bionic devices for blindness: a review
    Lewis, PM ; Ayton, LN ; Guymer, RH ; Lowery, AJ ; Blamey, PJ ; Allen, PJ ; Luu, CD ; Rosenfeld, JV (WILEY, 2016-09)
    Since the 1950s, vision researchers have been working towards the ambitious goal of restoring a functional level of vision to the blind via electrical stimulation of the visual pathways. Groups based in Australia, USA, Germany, France and Japan report progress in the translation of retinal visual prosthetics from the experimental to clinical domains, with two retinal visual prostheses having recently received regulatory approval for clinical use. Regulatory approval for cortical visual prostheses is yet to be obtained; however, several groups report plans to conduct clinical trials in the near future, building upon the seminal clinical studies of Brindley and Dobelle. In this review, we discuss the general principles of visual prostheses employing electrical stimulation of the visual pathways, focusing on the retina and visual cortex as the two most extensively studied stimulation sites. We also discuss the surgical and functional outcomes reported to date for retinal and cortical prostheses, concluding with a brief discussion of novel developments in this field and an outlook for the future.
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    First-in-Human Trial of a Novel Suprachoroidal Retinal Prosthesis
    Ayton, LN ; Blamey, PJ ; Guymer, RH ; Luu, CD ; Nayagam, DAX ; Sinclair, NC ; Shivdasani, MN ; Yeoh, J ; McCombe, MF ; Briggs, RJ ; Opie, NL ; Villalobos, J ; Dimitrov, PN ; Varsamidis, M ; Petoe, MA ; McCarthy, CD ; Walker, JG ; Barnes, N ; Burkitt, AN ; Williams, CE ; Shepherd, RK ; Allen, PJ ; Mori, K (PUBLIC LIBRARY SCIENCE, 2014-12-18)
    UNLABELLED: Retinal visual prostheses ("bionic eyes") have the potential to restore vision to blind or profoundly vision-impaired patients. The medical bionic technology used to design, manufacture and implant such prostheses is still in its relative infancy, with various technologies and surgical approaches being evaluated. We hypothesised that a suprachoroidal implant location (between the sclera and choroid of the eye) would provide significant surgical and safety benefits for patients, allowing them to maintain preoperative residual vision as well as gaining prosthetic vision input from the device. This report details the first-in-human Phase 1 trial to investigate the use of retinal implants in the suprachoroidal space in three human subjects with end-stage retinitis pigmentosa. The success of the suprachoroidal surgical approach and its associated safety benefits, coupled with twelve-month post-operative efficacy data, holds promise for the field of vision restoration. TRIAL REGISTRATION: Clinicaltrials.gov NCT01603576.