If you are of a certain age, you will remember a television show from the 1970s called “Six Million Dollar Man”. The show was about an Air Force Colonel Steve Austin who is seriously injured when a spaceship he is testing crashes. He then has surgery where he receives bionic legs, a bionic left arm and a bionic eye. While the bionic limbs give him super strength and speed, the bionic eye allows him both telescopic and microscopic visual abilities.
Well, that was just a television show. Are there bionic eyes that provide vision to those who have varying degrees of blindness? The answer is yes. While not at the level of Steve Austin’s eye, there are bionic eyes that currently allow persons with retinitis pigmentosa to see light and high contrast objects. They include the Alpha-IMS and a suprachoroidal prosthesis developed by Bionic Vision Technologies.
Alpha-IMS
This prosthesis was developed by a company in Germany called Retina Implant. It consists of a 1/8 in square (3mm square) microchip that is implanted beneath the fovea. It consists of 1,500 light sensitive photodiodes that are connected to microelectrodes. What makes this prosthesis so great is that it doesn’t use an external camera. The photodiodes are connected to an external power module that is implanted under the skin behind the ear, similar to a cochlear implant. It amplifies the signals generated by the photodiode array.
Another great thing about the Alpha-IMS is that the person using this does not need to move his or her head to locate objects. Normal eye movements can be used to see objects within the person’s field of vision. A clinical trial of was done in 2015 that involved 29 late-stage retinitis pigmentosa and cone-rod dystrophy that had the Alpha-IMS prosthesis implanted and it was found that 25 patients had an improved ability to detect light. Also, half the patients reported that they were able to recognize shapes, identify facial features and some could read letters of the alphabet. While not currently available for use in the U.S., this prosthesis shows promise as a way to improve vision for those with retinitis pigmentosa.
Bionic Vision Technologies
Bionic Vision Technologies of Australia developed a device consisting of a suprachoroidal prosthesis that has an electrode array in a ¾ x ¼ inch (19 x 8 mm) silicone base. It has 33 stimulating electrodes and two return electrodes. Images from an external camera mounted on an eyeglass frame are transferred to the implant by way of a wireless interface located under the scalp. The stimuli are delivered to the retina, which in turn delivers the visual information to the brain. Like a hearing aid, this device can be turned on and off and external eyeglass frames can be easily removed.
Having this device located in the suprachoroidal area gives it two advantages. One, the surgery itself is less challenging than those for epiretinal or subretinal implants and does not penetrate the retinal tissue. Two, as a result of its position, the device has an excellent safety record.
A pilot study was done with this device on four patients with late-stage retinitis pigmentosa. Mobility testing was done after a two-month healing period and was followed by 16 weeks of vision rehabilitation training. The patients were asked to complete a series of six tests at 17 weeks following training, then at three monthly intervals from Week 20 with the device turned both on and off until Week 104. At Week 44, patients detected almost 75 percent of obstacles when the device was turned on, compared to only 4 percent when it was turned off. Also, patients were able to locate and touch a window 70 percent of the time when the device was on, compared to 24 percent of the time when it was turned off. In addition, the average touching distance improved from 30 inches (78 cm) to 5 inches (14 cm), showing improved accuracy. All of this shows that the more the patients use the system, the better they become at locating objects, recognizing doors and avoiding obstacles.
In September 2021, Bionic Vision Technologies formed a strategic partnership with a U.S. medical technology company, Cirtec Medical. This will help Bionic Vision Technologies to develop and manufacture the next generation bionic eye and help others with eye diseases, like retinitis pigmentosa, to be able to see.
While a bionic eye such as Steve Austin’s is the purview of television shows and movies, utilizing technology to help give some functional vision to those who are blind is a reality. As technology becomes more advanced, blindness as a result of eye disease will become a thing of the past.
Sources:
https://www.aao.org/eyenet/article/bionic-vision
https://bionicvis.com/products-technology/
https://bionicvis.com/wp-content/uploads/2020/03/BVT-interim-pilot-study-results-13-Jan-2020.pdf