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Visual and Non-Visual Navigation in Blind Patients with a Retinal Prosthesis.

Garcia S, Petrini K, Rubin GS, Da Cruz L, Nardini M - PLoS ONE (2015)

Bottom Line: Participants completed a path reproduction and a triangle completion navigation task, using either an indirect visual landmark and non-visual self-motion cues or non-visual self-motion cues only.In both tasks, control participants showed better precision when navigating with reduced vision, compared to without vision.Additionally, all patients showed greater precision than controls in both tasks when navigating without vision.

View Article: PubMed Central - PubMed

Affiliation: Institute of Ophthalmology, University College London (UCL), London, United Kingdom.

ABSTRACT
Human adults with normal vision can combine visual landmark and non-visual self-motion cues to improve their navigational precision. Here we asked whether blind individuals treated with a retinal prosthesis could also benefit from using the resultant new visual signal together with non-visual information when navigating. Four patients (blind for 15-52 years) implanted with the Argus II retinal prosthesis (Second Sight Medical Products Inc. Sylmar, CA), and five age-matched and six younger controls, participated. Participants completed a path reproduction and a triangle completion navigation task, using either an indirect visual landmark and non-visual self-motion cues or non-visual self-motion cues only. Control participants wore goggles that approximated the field of view and the resolution of the Argus II prosthesis. In both tasks, control participants showed better precision when navigating with reduced vision, compared to without vision. Patients, however, did not show similar improvements when navigating with the prosthesis in the path reproduction task, but two patients did show improvements in the triangle completion task. Additionally, all patients showed greater precision than controls in both tasks when navigating without vision. These results indicate that the Argus II retinal prosthesis may not provide sufficiently reliable visual information to improve the precision of patients on tasks, for which they have learnt to rely on non-visual senses.

No MeSH data available.


The Argus II retinal prosthesis system (Second Sight Medical Products, Inc., Sylmar, CA).Used with permission from Second Sight Medical Products. The system consists of: (i) a pair of glasses fitted with a miniature video camera (510 x 492 resolution) for external image capture, (ii) an external Video Processing Unit (VPU) that processes the video signal into a 10 x 6 pixel image, matching the array’s field of view, and (iii) a 6 x 10 electrode epiretinal array (18 x 11 degrees) secured over the fovea.
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pone.0134369.g001: The Argus II retinal prosthesis system (Second Sight Medical Products, Inc., Sylmar, CA).Used with permission from Second Sight Medical Products. The system consists of: (i) a pair of glasses fitted with a miniature video camera (510 x 492 resolution) for external image capture, (ii) an external Video Processing Unit (VPU) that processes the video signal into a 10 x 6 pixel image, matching the array’s field of view, and (iii) a 6 x 10 electrode epiretinal array (18 x 11 degrees) secured over the fovea.

Mentions: The Argus II retinal prosthesis system (Second Sight Medical Products, Inc., Sylmar, CA) is a new treatment that aims to restore vision to patients blinded by outer retinal degenerative diseases, such as retinitis pigmentosa [19]. The device consists of a glasses-mounted miniature camera that sends live video data to an externally-worn processing unit that transforms it into electrical stimulation patterns. These patterns are sent wirelessly to an implant on the retina, directly stimulating preserved retinal cells (see Fig 1). Using the Argus II system, patients who have been visually deprived for a number of years are once again able to receive visual input. However, prosthetic vision is different to native vision and patients have to learn to interpret the pixelated phosphenes elicited by the implant. Furthermore, the direction of ‘gaze’ is defined by head position and not by eye position, and due to the small field the environment is explored by head scanning.


Visual and Non-Visual Navigation in Blind Patients with a Retinal Prosthesis.

Garcia S, Petrini K, Rubin GS, Da Cruz L, Nardini M - PLoS ONE (2015)

The Argus II retinal prosthesis system (Second Sight Medical Products, Inc., Sylmar, CA).Used with permission from Second Sight Medical Products. The system consists of: (i) a pair of glasses fitted with a miniature video camera (510 x 492 resolution) for external image capture, (ii) an external Video Processing Unit (VPU) that processes the video signal into a 10 x 6 pixel image, matching the array’s field of view, and (iii) a 6 x 10 electrode epiretinal array (18 x 11 degrees) secured over the fovea.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4520559&req=5

pone.0134369.g001: The Argus II retinal prosthesis system (Second Sight Medical Products, Inc., Sylmar, CA).Used with permission from Second Sight Medical Products. The system consists of: (i) a pair of glasses fitted with a miniature video camera (510 x 492 resolution) for external image capture, (ii) an external Video Processing Unit (VPU) that processes the video signal into a 10 x 6 pixel image, matching the array’s field of view, and (iii) a 6 x 10 electrode epiretinal array (18 x 11 degrees) secured over the fovea.
Mentions: The Argus II retinal prosthesis system (Second Sight Medical Products, Inc., Sylmar, CA) is a new treatment that aims to restore vision to patients blinded by outer retinal degenerative diseases, such as retinitis pigmentosa [19]. The device consists of a glasses-mounted miniature camera that sends live video data to an externally-worn processing unit that transforms it into electrical stimulation patterns. These patterns are sent wirelessly to an implant on the retina, directly stimulating preserved retinal cells (see Fig 1). Using the Argus II system, patients who have been visually deprived for a number of years are once again able to receive visual input. However, prosthetic vision is different to native vision and patients have to learn to interpret the pixelated phosphenes elicited by the implant. Furthermore, the direction of ‘gaze’ is defined by head position and not by eye position, and due to the small field the environment is explored by head scanning.

Bottom Line: Participants completed a path reproduction and a triangle completion navigation task, using either an indirect visual landmark and non-visual self-motion cues or non-visual self-motion cues only.In both tasks, control participants showed better precision when navigating with reduced vision, compared to without vision.Additionally, all patients showed greater precision than controls in both tasks when navigating without vision.

View Article: PubMed Central - PubMed

Affiliation: Institute of Ophthalmology, University College London (UCL), London, United Kingdom.

ABSTRACT
Human adults with normal vision can combine visual landmark and non-visual self-motion cues to improve their navigational precision. Here we asked whether blind individuals treated with a retinal prosthesis could also benefit from using the resultant new visual signal together with non-visual information when navigating. Four patients (blind for 15-52 years) implanted with the Argus II retinal prosthesis (Second Sight Medical Products Inc. Sylmar, CA), and five age-matched and six younger controls, participated. Participants completed a path reproduction and a triangle completion navigation task, using either an indirect visual landmark and non-visual self-motion cues or non-visual self-motion cues only. Control participants wore goggles that approximated the field of view and the resolution of the Argus II prosthesis. In both tasks, control participants showed better precision when navigating with reduced vision, compared to without vision. Patients, however, did not show similar improvements when navigating with the prosthesis in the path reproduction task, but two patients did show improvements in the triangle completion task. Additionally, all patients showed greater precision than controls in both tasks when navigating without vision. These results indicate that the Argus II retinal prosthesis may not provide sufficiently reliable visual information to improve the precision of patients on tasks, for which they have learnt to rely on non-visual senses.

No MeSH data available.