An eye implant developed by USC — the first FDA approved implant of its kind — is helping people with a rare type of vision loss regain some sight and is paving the way for more "bionic eyes" to treat other forms of blindness in the future.
Dubbed the Argus II, it was designed to treat retinitis pigmentosa, a genetic disorder that slowly robs a person of sight by destroying photoreceptors in the eye.
(An illustration of the Argus II implanted in an eye)
The Argus II is a two-part device: Patients wear dark sunglasses outfitted with a small camera powered by a battery back, which wirelessly sends a visual signal to an implant in the eye.
That implant then converts the signal into a series of electrical impulses that stimulate the retina, creating a rudimentary form of vision. (The video below, from the company that makes the implant, explains how it works.)
Lisa Kulik, 55, is the first person west of the Mississippi to receive the commercial version of this device. She describes the vision it provides as a series of flashing lights.
"If you close your eyes real tight, and then open them, have you ever seen like dots or wiggly lines? It’s kind of like that," she said.
Kulik was in her early teens when she first showed signs of retinitis pigmentosa, which affects one in 4,000 people in the United States.
From darkness to light
At first, Kulik slowly lost her ability to read fine print, then her ability to read at all. Next went faces and shapes. By the time she reached her 30s, Kulik was considered legally blind. She says it was frustrating relying on others to help her get around.
When she found out about the Argus implant, she was told to keep her expectations low. It wouldn't allow her to read or see her grandchildren’s faces, but it might help her gain back some independence.
She had it installed four months ago, and Kulik remembers seeing intense bursts of light the first time she turned it on.
"It was overwhelming, all the flashes and the activity," she recalled.
(Ed Kulik guides Lisa as she walks using the Argus II system)
Now, Kulik is able to walk down a hall and notice doorways and stairs.
It's a crude sort of vision, she admits. She can only make out broad outlines of shapes.
"You know, you are use to seeing how you were born to see," she said. "Now, it’s almost like a foreign language. You’ve got to learn it all over in a different way."
Kulik is confident that with time she'll get better at interpreting these visions, allowing her to navigate through the world more independently.
The implant itself is a silver case about the size of a watch battery. It holds the electronics that communicate with the camera mounted in the sunglasses Kulik wears. The case was attached to the inside of her eye. A group of gold electrodes extend from it, and during surgery those electrodes are pressed up against the eye's retina.
When the electrodes receive a signal from the camera - they send a jolt of electricity to the retina, creating a rudimentary kind of vision.
A pixel problem
James Weiland, a professor with USC’s Eye Institute, helped develop the Argus II and said the technology is limited by the number of electrodes it can store in the small device, "which is 60 electrodes or 60 pixels. Only 60," he said.
By comparison, a modern camera has 10 million pixels, and the human eye has about 100 million photoreceptors.
If scientists could pack more electrodes safely in the eye implant, patients like Lisa Kulik might be able to see much more. But that's tricky given the limits on the size of the device.
Still, Weiland said for those suffering from severe blindness, even 60 points of light can make a huge difference.
"If you can’t see anything at all, that can potentially improve your vision fairly dramatically."
(An image of the Argus II's electrode array on the retina of an eye)
More to come
William Freeman is the director of the Jacobs Retina Center at UC San Diego, and he’s worked on retinal implant designs himself.
He says there's no question the Argus provides some benefit.
"But it seems to be pretty limited," he said.
Freeman said the Argus can only help people with damaged photoreceptors in otherwise healthy eyes. That means it works for patients with retinitis pigmentosa but not other common types of blindness.
It’s also expensive, costing almost $150,000, though it is covered by Medicare.
Still, Freeman said the device is a start.
"The good thing is that now there’s a path so that people with other ideas know the path to follow."
He said several other labs are working on improved devices and implantation techniques that could provide patients with even more sight.
The company making the Argus, Second Sight, is also hoping to expand its research to help people with macular degeneration, which is a more common disorder.
In the meantime, Kulik is training with her Argus implant to improve her limited vision.
She said it's already paying off.
Earlier this summer she wore the Argus system out to a Fourth of July celebration where she was able to see fireworks for the first time in nearly 30 years.
"I didn't know how much I'd see, but there was a lot, ... it was very exciting," she said.