http://www.livemint.com/Opinion/ZRPkkwyacH5Tnq1QFE7EMK/The-now-and-the-next-of-Argus-II.html bionic ocular technology seems new, its development has been under way for over two decades. Research and experimentation on a bionic eye began in the early 1990s at Johns Hopkins University. By 1998, this work had demonstrated that a retinal prosthesis could use electricity to stimulate the retina and produce spots of light visible to blind patients. This created the potential for restoring sight in patients with advanced retinitis pigmentosa, a rare genetic disorder afflicting an estimated 1.5 million people worldwide. Second Sight Medical Products Inc. was founded in California to develop this prosthesis.
The technology from which Argus II developed was a natural extension of cochlear implant technology, though the building of miniature electrodes in greater numbers needed to be developed from the ground up. The research benefited from the development of cell phones and the miniaturization of computers and cameras. The first clinical trial began in 2002 with Argus I, a 16-electrode implant based on an established cochlear implant platform. After successful studies, a trial for Argus II, a 60-electrode device designed to be smaller and easier to implant, began in 2007. The trials were successful and Argus II has since been approved by the Food and Drug Administration (FDA). Argus II is approved for commercial utilization in both the US and outside. Outside of the US, the Argus II is indicated for individuals with severe to profound vision loss due to outer retinal degeneration. In the US, the product label restricts the use for patients with bare light perception or no light perception, caused specifically by the outer retinal degenerative disease of retinitis pigmentosa. Additionally, candidates must be aphakic, meaning they cannot have their natural lens in place. If their natural lens has not been previously removed in a prior cataract surgery, lens removal at the time of implantation is required. Argus II consists of three components; an implant that is surgically placed on the retina, a pair of glasses with an attached camera and a portable video processing unit (VPU). Images are captured by the camera, processed by the VPU and then transmitted wirelessly to the implant, which comprises an array of 60 electrodes. The implant converts the information into a series of small electrical pulses. The patient “sees” greyscale images—similar to how images appear on a digital scoreboard—which they learn to interpret. An extensive fitting period after implantation tailors the device to the optimal level for each individual. With Argus II, users can detect objects in their paths, or things such as doorways or the lines of a crosswalk. Movement and objects with greater light contrast tend to be easier to detect. From a patient’s perspective, the device can provide a greater degree of mobility. While they might not have “normal” sight, patients fitted with the Argus II have demonstrated the ability to track sidewalks, avoid obstacles, follow high-contrast lines on the ground, which in general helps them feel safer and more confident. For many, obstacles such as doorways and furniture no longer pose a problem and handling objects like glasses and utensils becomes less complicated. Some patients have even reported that activities such as archery or basketball become possible with the aid of lights strung on the targets. While Argus II does not restore “normal” vision, many patients describe looking into the night sky and locating the moon, or enjoying Christmas lights, fireworks and even sports on television as they can detect the movement on the screen. For many patients, regaining some form of sight is significant because it allows them greater social interaction, especially in being able to determine where people are around them. Blindness can be very isolating. For those who have been blind for many years, they get a great deal of enjoyment in discovering what they can do with the system. This technology is always being improved. Just like a phone or a computer, Argus II can be updated with software upgrades to improve the operating system. Such software developments will include combining computer vision, independent manipulation and a user interface to help decipher visual information, which will create a more natural experience. Efforts are also underway to reduce the cost of the device. Software improvements will aid in reduced costs. This therapy may also be expanded to include patients suffering from other forms of blindness, firstly patients with AMD (age-related macular degeneration), the leading cause of blindness in the western world which is estimated to affect 20 to 25 million people worldwide. More advances are potentially on the horizon, including the development of the Orion Cortical Prosthesis, an implant which will bypass the optic nerve and stimulate the visual part of brain, allowing treatment of almost all forms of blindness. Robert Greenberg, an expert in retinal prosthetics, is MD from John Hopkins School of Medicine, and was formerly the lead reviewer of medical devices for the US FDA. He is the president and CEO of Second Sight Medical Products, which developed Argus II. -- Avinash Shahi Doctoral student at Centre for Law and Governance JNU Register at the dedicated AccessIndia list for discussing accessibility of mobile phones / Tabs on: http://mail.accessindia.org.in/mailman/listinfo/mobile.accessindia_accessindia.org.in Search for old postings at: http://www.mail-archive.com/accessindia@accessindia.org.in/ To unsubscribe send a message to accessindia-requ...@accessindia.org.in with the subject unsubscribe. To change your subscription to digest mode or make any other changes, please visit the list home page at http://accessindia.org.in/mailman/listinfo/accessindia_accessindia.org.in Disclaimer: 1. Contents of the mails, factual, or otherwise, reflect the thinking of the person sending the mail and AI in no way relates itself to its veracity; 2. AI cannot be held liable for any commission/omission based on the mails sent through this mailing list..
