Matthew A Petoe1, Chris D McCarthy2, Mohit N Shivdasani1, Nicholas C Sinclair1, Adele F Scott3, Lauren N Ayton4, Nick M Barnes5, Robyn H Guymer4, Penelope J Allen4, Peter J Blamey1. 1. Bionics Institute of Australia, East Melbourne, Victoria, Australia 2Department of Medical Bionics, University of Melbourne, Parkville, Victoria, Australia. 2. Computer Vision Research Group, Data61, Canberra, Australian Capital Territory, Australia 4Department of Computer Science and Software Engineering, Swinburne University of Technology, Hawthorn, Victoria, Australia. 3. Computer Vision Research Group, Data61, Canberra, Australian Capital Territory, Australia. 4. Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia 6Department of Surgery (Ophthalmology), University of Melbourne, Parkville, Victoria, Australia. 5. Computer Vision Research Group, Data61, Canberra, Australian Capital Territory, Australia 7College of Engineering & Computer Science, Australian National University, Canberra, Australian Capital Territory, Australia.
Abstract
Purpose: With a retinal prosthesis connected to a head-mounted camera, subjects can perform low vision tasks using a combination of electrode discrimination and head-directed localization. The objective of the present study was to investigate the contribution of retinotopic electrode discrimination (perception corresponding to the arrangement of the implanted electrodes with respect to their position beneath the retina) to visual performance for three recipients of a 24-channel suprachoroidal retinal implant. Proficiency in retinotopic discrimination may allow good performance with smaller head movements, and identification of this ability would be useful for targeted rehabilitation. Methods: Three participants with retinitis pigmentosa performed localization and grating acuity assessments using a suprachoroidal retinal prosthesis. We compared retinotopic and nonretinotopic electrode mapping and hypothesized that participants with measurable acuity in a normal retinotopic condition would be negatively impacted by the nonretinotopic condition. We also expected that participants without measurable acuity would preferentially use head movement over retinotopic information. Results: Only one participant was able to complete the grating acuity task. In the localization task, this participant exhibited significantly greater head movements and significantly lower localization scores when using the nonretinotopic electrode mapping. There was no significant difference in localization performance or head movement for the remaining two subjects when comparing retinotopic to nonretinotopic electrode mapping. Conclusions: Successful discrimination of retinotopic information is possible with a suprachoroidal retinal prosthesis. Head movement behavior during a localization task can be modified using a nonretinotopic mapping. Behavioral comparisons using retinotopic and nonretinotopic electrode mapping may be able to highlight deficiencies in retinotopic discrimination, with a view to address these deficiencies in a rehabilitation environment. (ClinicalTrials.gov number, NCT01603576).
Purpose: With a retinal prosthesis connected to a head-mounted camera, subjects can perform low vision tasks using a combination of electrode discrimination and head-directed localization. The objective of the present study was to investigate the contribution of retinotopic electrode discrimination (perception corresponding to the arrangement of the implanted electrodes with respect to their position beneath the retina) to visual performance for three recipients of a 24-channel suprachoroidal retinal implant. Proficiency in retinotopic discrimination may allow good performance with smaller head movements, and identification of this ability would be useful for targeted rehabilitation. Methods: Three participants with retinitis pigmentosa performed localization and grating acuity assessments using a suprachoroidal retinal prosthesis. We compared retinotopic and nonretinotopic electrode mapping and hypothesized that participants with measurable acuity in a normal retinotopic condition would be negatively impacted by the nonretinotopic condition. We also expected that participants without measurable acuity would preferentially use head movement over retinotopic information. Results: Only one participant was able to complete the grating acuity task. In the localization task, this participant exhibited significantly greater head movements and significantly lower localization scores when using the nonretinotopic electrode mapping. There was no significant difference in localization performance or head movement for the remaining two subjects when comparing retinotopic to nonretinotopic electrode mapping. Conclusions: Successful discrimination of retinotopic information is possible with a suprachoroidal retinal prosthesis. Head movement behavior during a localization task can be modified using a nonretinotopic mapping. Behavioral comparisons using retinotopic and nonretinotopic electrode mapping may be able to highlight deficiencies in retinotopic discrimination, with a view to address these deficiencies in a rehabilitation environment. (ClinicalTrials.gov number, NCT01603576).
Authors: Samuel A Titchener; Jessica Kvansakul; Mohit N Shivdasani; James B Fallon; D A X Nayagam; Stephanie B Epp; Chris E Williams; Nick Barnes; William G Kentler; Maria Kolic; Elizabeth K Baglin; Lauren N Ayton; Carla J Abbott; Chi D Luu; Penelope J Allen; Matthew A Petoe Journal: Transl Vis Sci Technol Date: 2020-12-18 Impact factor: 3.283
Authors: Lewis Karapanos; Carla J Abbott; Lauren N Ayton; Maria Kolic; Myra B McGuinness; Elizabeth K Baglin; Samuel A Titchener; Jessica Kvansakul; Dean Johnson; William G Kentler; Nick Barnes; David A X Nayagam; Penelope J Allen; Matthew A Petoe Journal: Transl Vis Sci Technol Date: 2021-08-12 Impact factor: 3.283
Authors: Matthew A Petoe; Samuel A Titchener; Maria Kolic; William G Kentler; Carla J Abbott; David A X Nayagam; Elizabeth K Baglin; Jessica Kvansakul; Nick Barnes; Janine G Walker; Stephanie B Epp; Kiera A Young; Lauren N Ayton; Chi D Luu; Penelope J Allen Journal: Transl Vis Sci Technol Date: 2021-08-12 Impact factor: 3.283