Nearly three months after receiving an artificial retina and the special equipment that makes it work, Linda Kirk is beginning to see the world around her for the first time in 50 years.
Kirk, 67, who lives in Port Jefferson, is the recipient of a sophisticated system often called a bionic eye. Although legally blind and biologically incapable of eyesight on her own, technology is enabling a form of visual perception.
“It’s a long learning curve and I am still getting used to it,” said Kirk, who has a degenerative disorder of the retina and underwent a surgical procedure at Stony Brook University Hospital as a first step in a vision-restoring process.
Her doctor placed an infinitesimal implant directly onto the retina of one eye. It is part of a complex three-part system that provides a rudimentary form of eyesight — shapes, movement and contrasting shades of darkness and light.
Some doctors refer to it as artificial vision.
And while artificial vision seems straight from the pages of science fiction, the company that makes the system is testing a newer one that involves implanting a chip directly into the brain.
The visual system Kirk received, which is the only federally approved artificial retina on the market, allows neither colors nor sharp images. But it is a major milestone toward a useful form of vision for Kirk, a retired social worker who has been legally blind since her late teens. She is participating in research involving the system at Stony Brook and hopes her experience with the device helps other patients whose vision loss has shrouded their worlds in darkness.
“These patients can now see open doorways and windows,” said Dr. Khurram Chaudhary, the Stony Brook retinal surgeon who performed the implant operation. “They can see the shape of a person standing in front of them. Before they weren’t seeing anything at all. It’s all about contrasts: Very white and dark.
“If there is a white plate on a dark table they can see the contrast, so they can eat,” Chaudhary said.
Kirk hopes to use the white lines that define crosswalks as her guides as she makes her way across streets and enjoys long strolls in Port Jefferson. For now, she is getting used to seeing the world by way of her bionic eye.
“It’s really learning how to interpret electrical impulses,” produced by the visual system, Kirk said.
“So I know that if I am getting white [coloration] over there, then that is a window; that’s where the bay window is,” she said of learning about her home in a new way.
“I am practicing with white squares, arcs and other shapes on a black magnetic board, trying to get used to them.”
The system has three parts: the implant, a video camera attached to special dark glasses, and a small computer worn on a belt, about the size of a 1990s-era cellphone, Chaudhary explained.
A miniature video camera in the patient’s glasses captures a scene. That image is transmitted to the computer where it is transformed into electrical instructions and sent back to the glasses via a cable. These impulses are transmitted wirelessly to an antenna in the retinal implant, which also has a 60-electrode array that emits small pulses of electricity. These pulses bypass damaged retinal tissue but stimulate the retina’s remaining cells, transmitting the captured scene along the optic nerve to the brain.
Kirk has Leber’s congenital amaurosis. The device was designed for people with severe retinal conditions, particularly retinitis pigmentosa, which also can result in loss of eyesight.
These conditions are marked by the irreversible loss of cells in the retina, made up of highly specialized light-sensitive tissue at the rear of the eye. Common early symptoms of retinal disorders of this magnitude include difficulty seeing at night and a gradual loss of peripheral vision.
Vision loss and serious sight impairment of all kinds are major global health concerns affecting nearly 300 million people, according to the World Health Organization. The loss of eyesight can affect independence and make it difficult to perform simple tasks, such as reading, traveling even short distances, or performing routine domestic chores.
The implant and associated prosthetic devices that Kirk received hail from the evolving field of optoelectronic technology. Her device is the Argus II Retinal Prosthesis System, also known as an artificial retina, manufactured by Second Sight Medical Products Inc. in California. It encompasses 25 years of scientific research and was approved by the U.S. Food and Drug Administration in 2013.
Nearly 1,000 patients have received the device worldwide. Stony Brook is the first hospital to implant the device on Long Island, although the device has been implanted in patients by doctors in Manhattan.
For Chaudhary, an assistant professor of vitreoretinal surgery at Stony Brook’s school of medicine, walking and crossing streets are laudable goals because the contrast between the blacktop of the street and white lines of the crosswalk help people like Kirk navigate areas they previously could not see.
“They can use the visual stimuli to become more independent,” Chaudhary said.
Dr. Stephen Rose, chief research officer at the Foundation Fighting Blindness, a leading nonprofit that supports research aimed at restoring sight, said the Argus II is a key advance.
“It provides functional mobility in most cases,” Rose said, adding that black-and-white-only vision is not a handicap. “I grew up with a black-and-white TV, which compared to nothing at all was not a bad thing to have.
“They can go into a room and see a big black spot in front of them and know that’s probably the couch. It reduces the chances of accidents.”
Even though Kirk is excited about taking long walks in her community, she will not give up a key symbol of her blindness: “I will still use my cane,” she said.