Family Inspiration Led Retina Specialist to Develop the World’s First 'Bionic Eye'
Wednesday, June 5, 2013
On February 14, 2013, the US Food and Drug Administration (FDA) approved the Argus II Retinal Prosthesis System, manufactured by Second Sight® Medical Products, Inc. (Sylmar, CA). This is the first implanted device—or “bionic eye”—to treat adults with vision loss caused by advanced retinitis pigmentosa, an inherited disorder that affects about 1 in every 4000 people.
This life-changing medical breakthrough, which has caught the attention of the world, is the brainchild of American Society of Retina Specialists leader Mark S. Humayun, MD, PhD, who devoted 25 years to its development.
Figure 1: Mark S. Humayun, MD, PhD, devoted 25 years to the development of the Argus II retinal prosthesis system
Although he comes from a family of physicians, Dr. Humayan wasn’t planning to be an ophthalmologist. It was his grandmother who inspired his career choice when she became blind as a result of diabetic retinopathy. This had a profound impact and made him rethink his career path and pursue ophthalmology and a PhD in biomedical engineering.
“If it hadn’t been for her, I wouldn’t have been an ophthalmologist or a biomedical engineer and certainly would not have pursued this field,” Dr. Humayan says.
A breakthrough paves the way for the bionic eye
The breakthrough came when Dr. Humayan discovered that patients with certain retinal diseases, such as retinitis pigmentosa or macular degeneration, still had the neural paths the retina uses to send signals to the brain. These neural paths carry the electrical “picture” impulses from the retina to the brain for processing. Think of it as the wire connecting your cable box to your television.
How does the retinal implant system work?
Figure 2: The retinal implant consists of a small electronics package and antenna placed around the eye
Each person who uses the Argus II retinal prosthesis system has an implant placed around their eye (Figure 2). This implant consists of a small electronic device and antenna which receives signals from a digital video camera mounted inside a special pair of sunglasses (Figure 3).
As the camera captures images, such as a person, mailbox, or doorway, it sends a signal to the electronics array on the implant.
The array on the implant mimics the job of the retina by converting the video images into electrical impulses, which are sent through the optic nerve to the brain for processing. The brain reads these signals of patterns and lights and displays them for the person, who can then perceive the image.
Figure 3: The Argus II system
The system consists of several components, as shown in Figure 3:
- Small video camera
- Transmitter mounted on a pair of eyeglasses
- Video processing unit (VPU) worn on the patient’s belt
- Implanted retinal prosthesis with a 60-electrode epiretinal array (Figure 2)
What can a person see with the bionic eye system?
People using the system can:
- Distinguish light from dark
- Recognize movement and detect the direction of a motion
- Recognize large letters, words, or sentences
- Identify shapes such as doorways, curbsides, and trees
Some patients have even been able to sort black, grey, and white socks when doing laundry.
Says Dr. Humayan, “A tall patient of mine said he would get hit in the head and shoulders with tree branches and other things because the cane could tell him only what was down below. Argus II can be used in conjunction with a cane or other mobility aids that these patients are already using to get about.”
How the bionic eye system is changing lives
Kathy Blake, Dr. Humayan’s patient and the first person in the US to be implanted with the bionic eye device, had her sight restored after more than 2 decades of blindness because of retinitis pigmentosa. According to Dr. Humayan, “She has talked about using the Argus II device in doing chores, but also for the fun things in life like being able to see fireworks and the lights on a Christmas tree.”
Watch Kathy Blake’s story, which was featured on:
The New York Times also spotlighted the case of Barbara Campbell, who was blind for 20 years before receiving the Argus II implant.
Who is the Argus II system for?
The Argus II is FDA approved for patients age 25 and older with severe to profound retinitis pigmentosa. It has the potential of helping thousands of retinitis pigmentosa patients improve their quality of life and will blaze a path for similar medical technologies.