A Vision of the Impossible

A first look at Second Sight 

Back in 1998, it was estimated that throughout the world, over 45 million people were living with blindness, and 135 million were visually disabled. While around 80% of blindness conditions are preventable or curable,* for those not living with cataracts, trachoma, onchocerciasis, or other treatable blindnesses, there needed to be another solution.

It was around this time, in the mid-1990s, when Johns Hopkins University medical and graduate student Bob Greenberg was experimenting with the idea of a retinal prosthesis—a tiny implantable device which could be used to restore vision in blind patients. During his graduate studies, Greenberg was involved in the early science demonstrating the promise of a retinal implant in a few patients.

After graduation, following a stint at the FDA, Greenberg went on to take a job with The Alfred Mann Foundation, where his interest in retinal implants persisted while work on other Foundation projects continued.

Stars in our eyes align

And then, a moment of serendipity occurred in the form of Sam Williams, a jet engine entrepreneur who was blind from retinitis pigmentosa, the ideal candidate for a retinal implant. Williams approached the Foundation to see whether implantable technology could be developed for use in the eye, not just the ear (see the Foundation’s cochlear implant technology) — and fortunately, Greenberg and the Foundation were the types to say “I bet it could be.”

Sam Williams had donated money to universities to promote medical technology development, but was frustrated by these projects' inability to get out of the “research” phase and into the realm of real patient impact. This time around, Williams wanted to establish a company to develop and commercialize a retinal implant—the idea being that stock incentives would keep development focused and rapidly pushing forward. 

And this was the beginning of Second Sight. Williams, Al Mann and another investor pooled resources, licensed Bob Greenberg’s IP from his time at JHU, and set up business at the Foundation’s headquarters. As is encouraged at the Foundation, Greenberg left operations at the Foundation in order to head up Second Sight as its founding CEO.

With a company formed, a leader at the helm, and an eager team in place, it was time to work on their vision to cure blindness. Just how that would happen was still a question.

Seeing the solution through challenges  

Sometimes, not knowing something is impossible to do is precisely what makes it possible. As Second Sight soon learned, it’s this wide-eyed, fresh perspective that often leads to incredible innovation.

While hiring engineers for this new project, Dr. Greenberg looked for young graduates and eager engineers who didn’t already have preconceived ideas that something “wasn’t possible.” After all, the big ask for this retinal implant was to dramatically increase the volume of electrodes from cochlear prototypes, while simultaneously shrinking the design to fit in a tiny, flexible footprint.

A new generation of curious engineers and Ph.D. scientists rose to the task and got to work. A number of these brilliant individuals still work at huMannity Medtec today.

Most of the technical challenges we had to solve involved the placement of the implant: on the retina; the light-sensitive part in the back of the eye. In some forms of blindness, the retina is partially deteriorated. Since the retina is so thin, even in healthy eyes, placing a prosthesis on it was a very delicate and complicated process. We needed to find biocompatible materials that were very thin, light, flexible and soft—while still being able to host all the electrodes, and withstand the corrosive saltwater environment of the body…and stay in place even if someone ran a marathon (which one of Second Sight’s patient’s did).

Our materials science team had candidate materials to house the electrodes and electronics—but the practicalities of miniaturizing and installing the electrical components was a significant challenge.

To pattern the electrodes, a micro-electromechanical systems (MEMS) process called photolithography was used to expose the electrodes using light—much like using an enlarger in a photography darkroom. Part of our experimentation was finding the right biocompatible materials and figuring out how to pattern them on a micro scale.

One material tested was platinum. The team liked its inert properties, but it proved challenging to pattern on a micro scale.More problematic—when an electrical current was run through the platinum, the platinum would dissolve. That wouldn’t work.

After testing 30 different materials that failed, Dr. Greenberg and the team developed a new material we called platinum gray—our term for “roughed up” platinum using electricity in order to create a higher surface area. This allowed more current to run through it, which made the material more stable than even the very inert ‘plain’ platinum.

With the materials issue behind us, we were able to build our first working retinal implant prototype. 

Medical breakthroughs take bravery

But how do you know if a prototype actually works to restore sight in humans? You need a brave human to step up and test it.

Harold Churchy from North Carolina was a key figure in the development of the retinal implant, dating back to the early days of experimentation during Bob Greenberg’s time at JHU. Back then, he was the first patient to test the rudimentary prototypes Dr. Greenberg and his colleagues created at the university. Harold suffered blindness from retinitis pigmentosa. As an older man, he was motivated by the belief that he could help advance science and help others afflicted with his condition in the generations to come. He did not expect to see a solution in his lifetime.

During the early Argus 1 trials, where Second Sight used a modified Advanced Bionics cochlear implant to test chronic stimulation of the retina, once again Harold bravely stepped forward to demonstrate that the concept of electrode stimulation worked, in practice, to restore the perception of light in blind patients. While Argus 1 only had 16 electrodes, Harold was able to perceive a handful of bright lights, and even read large letters—which proved that the concept had legs. A few weeks after implanting the prototype prosthesis at the University of Southern California (USC), Second Sight invited Harold back to USC to test the device. Scientists, physicians, and engineers assembled in the room of the ophthalmology clinic, eager to know what Harold could see. The first test was to illuminate an oversized letter “L” on the wall of the dark room. The team turned on the device, and asked Harold what he could perceive. To everyone’s disappointment, Harold just shook his head—it seemed in that moment that the implant had failed, but then Harold said all he could see was “a line that went up, and a line that went sideways…like a letter L.” 

The room erupted in cheers. And that was the moment Harold Churchy became a pioneer for all those living with blindness. 

Bringing Second Sight to the world. 

Thanks to Harold Churchy and five other trial patients after him who also received the Argus 1, we knew Second Sight’s retinal implant prototype could restore vision to blind patients. This clinical success became the inflection point which attracted outside investor interest—interest which enabled Second Sight to prepare to bring the implant to market. Second Sight’s first commercial product, the Argus II, built on the experience of the Argus 1, but had 60 electrodes and fit entirely in the eye socket - dramatically shortening surgical complexity and time. Following a 30 patient international clinical trial, The Argus 2 obtained FDA clearance in 2014 and not long after received Medicare reimbursement.

Following the success of the Argus 2, which was implanted in around 400 patients globally, Dr. Greenberg led the development of Second Sight’s next product, the Orion: a direct brain interface which has the potential to treat all blindness. The Orion was implanted in six patients prior to Dr. Greenberg’s return to the Foundation in 2018.

Following a restructuring after Dr. Greenberg’s departure, Second Sight was renamed Cortigent to emphasize the focus on the Orion cortical implant. The company is continuing to pursue its commercialization and even has plans to seek other potential applications of the technology, including the possibility of aiding in the recovery of stroke.