Argus retinal prosthesis "bionic eye" significantly improves vision in blind patients

Feb 22nd– A total of 15/28 (54%) patients had a significant improvement in their ability to detect spatial motion with the use of the Argus II retinal prosthesis. 

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1. A total of 15/28 (54%) patients had a significant improvement in their ability to detect spatial motion with the use of the Argus II retinal prosthesis.

2. From this group, 91% of patients had a significant improvement in spatial motion detection with normal spatial mapping versus scrambled spatial mapping.

The Argus II retinal prosthesis was developed over several decades as an attempt to provide vision to those blinded by photoreceptor disease. In this study, the Argus II was shown to allow most individuals who are legally blind due to retinitis pigmentosa to visualize spatial motion. This is the first trial in which an artificial, electric apparatus has been used to convey meaningful visual data to the brain in blind patients. Strengths of this study include the large sample size, given the complexity of the implantation process. In addition, the use of a second control (scrambled spatial mapping) further corroborates the value of this intervention. Limitations include the use of only one shape; perhaps testing block letters and their orientation would have provided further insight into the efficacy of the system. Nonetheless, the importance of this medical engineering achievement is immense, as it provides tangible hope for the development of prostheses for other retinal diseases.

Click to read the study in JAMA Ophthalmology

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1. A total of 15/28 (54%) patients had a significant improvement in their ability to detect spatial motion with the use of the Argus II retinal prosthesis.

2. From this group, 91% of patients had a significant improvement in spatial motion detection with normal spatial mapping versus scrambled spatial mapping.

This study: A total of 30 legally blind patients with retinitis pigmentosa had the Argus II prosthesis implanted. All patients met the requirements of visual acuity less than 20/15887 but with light perception. The prosthesis was surgically inserted in the eye, which wirelessly communicated with a camera positioned on a pair of glasses worn by the patients. Patients were seated and instructed to focus their face towards a flatscreen monitor, upon which a white bar moved across the screen at various angles. Patients reported the direction and general angle of movement. Their responses to 80 trials were recorded both with the prosthesis system on and off. For those patients in whom a difference was noted, the experiment was repeated with the system on but all spatial structure electronically scrambled to serve as a second control.

Further reading:  

1. Retinal prosthesis: an encouraging first decade with major challenges ahead.

2. Visual perception elicited by electrical stimulation of retina in blind humans.

In sum: The Argus II retinal prosthesis was developed over several decades as an attempt to provide vision to those blinded by photoreceptor disease. In this study, the Argus II was shown to allow most individuals who are legally blind due to retinitis pigmentosa to visualize spatial motion. This is the first trial in which an artificial, electric apparatus has been used to convey meaningful visual data to the brain in blind patients. Strengths of this study include the large sample size, given the complexity of the implantation process. In addition, the use of a second control (scrambled spatial mapping) further corroborates the value of this intervention. Limitations include the use of only one shape; perhaps testing block letters and their orientation would have provided further insight into the efficacy of the system. Nonetheless, the importance of this medical engineering achievement is immense, as it provides tangible hope for the development of prostheses for other retinal diseases.

Click to read the study in JAMA Ophthalmology

By Swarup Swaminathan and Andrew Bishara

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