Using a new low-vision assessment tool developed specifically for patients implanted with retinal prostheses, investigators showed that Second Sight's Argus II improves the ability of blind individuals to perform everyday tasks.
The Argus II is the first artificial retina to receive widespread approval, and is offered in Canada, France, Germany, Italy, Netherlands, Saudi Arabia, Spain, Switzerland, Turkey, United Kingdom and the United States.
The surgically implanted epiretinal prosthesis provides electrical stimulation that bypasses the defunct retinal cells and stimulates remaining viable cells, inducing visual perception in individuals with severe to profound retinitis pigmentosa.
The Argus II works by converting images captured by a miniature video camera mounted on the patient's glasses into a series of small electrical pulses, which are transmitted wirelessly to an array of electrodes implanted on the surface of the retina. These pulses are intended to stimulate the retina's remaining cells, resulting in the perception of patterns of light in the brain. The patient then learns to interpret these visual patterns, thereby regaining some visual function.
At the request of the U.S. FDA, investigators developed the Functional Low-vision Observer Rated Assessment (FLORA) to evaluate the impact of the Argus II on subjects' everyday lives. Prior to FLORA, there were no accepted, standardized assessments of functional vision or quality of life that could be used to assess the kind of vision that is restored by a retinal prosthesis.
The results from the 3-year FLORA study, which was published in Clinical and Experimental Optometry, showed that 24 of 35 tasks (69%) had a statistically significant improvement when the device was turned on. Patients reported the most significant improvement in sorting light to dark laundry and finding doorways. Two tasks, travel within the home independently and identifying the top or bottom step, were significantly worse with the device. This suggests that Argus II provides its greatest advantage in environments with maximum light contrast, according to researchers
"We are thrilled, yet not surprised, with the results of this study," said Will McGuire, president and CEO of Second Sight. "Since the beginning, we have heard from the majority of individuals with the Argus II that our technology has changed their life and greatly enhanced their ability to perform tasks and activities of daily life. This study validates the positive feedback we've been receiving from our recipients all along."