Purpose: To investigate the effect of a wider field-of-view (FOV) of a retinal prosthesis on the users’ performance in locating objects. Methods: One female and four male subjects who were blind due to end-stage retinitis pigmentosa and had been implanted with the Argus II retinal prosthesis participated (aged 63.4 ± 15.4). Thermal imaging was captured by an external sensor and converted to electrical stimulation to the retina. Subjects were asked to localize and to reach for heat-emitting objects using two different FOV mappings: a normal 1:1 mapping (no zoom) that provided 188 ☓118 FOV and a 3:1 mapping (zoom out) that provided 498 ☓358 FOV. Their accuracy and response time were recorded. Results: Subjects were less accurate and took longer to complete the tasks with zoom out compared to no zoom. Localization accuracy decreased from 83% (95% confidence interval, 75%, 90%) with no zoom to 76% (67%, 83%) with zoom out (P ¼ 0.07). Reaching accuracy differed between the two mappings only in one subject. Response time increased by 43% for the localization task (24%, 66%; P < 0.001) and by 20% for the reaching task (0%, 45%; P ¼ 0.055). Conclusions: Argus II wearers can efficiently find heat-emitting objects with the default 188 ☓118 FOV of the current Argus II. For spatial localization, a higher spatial resolution may be preferred over a wider FOV. Translational Relevance: Understanding the trade-off between FOV and spatial resolution in retinal prosthesis users can guide device optimization.
Bibliographical noteFunding Information:
The authors thank Jessy Dorn for her generous help in critically reviewing the manuscript. Sponsorship and article processing charges for this study were funded by the Center for Applied Translational Sensory Science at the University of Minnesota, the Minnesota Lions Vision Foundation, the VitreoRet-inal Surgery Foundation, and an unrestricted grant to the Department of Ophthalmology and Visual Neurosciences from the Research to Prevent Blindness (RPB), New York, NY, USA.
© 2019 The Authors.
- Spatial resolution
- Ultralow vision
- Visual prosthesis