03:09pm Monday 11 December 2017

After 16 Years of Blindness, ‘Bionic Eye’ Helps Bascom Palmer Patient See the Light

Last November, Carmen Torres, who has retinitis pigmentosa — a genetic disease that causes progressive degeneration of the retina in both eyes — became the first patient in Florida, and only the 70th in the world, to receive the Argus II Retinal Prosthesis System, which provides electrical stimulation of the retina to induce visual perception.

And last Friday, at a press briefing marked by laughter and joy, and joined by several members of the large team that performed her life-changing procedure, Torres told her story of emerging from the darkness back into light.

Torres was first diagnosed with retinitis pigmentosa (RP) at the age of 18 while growing up in Puerto Rico, but she thought little of it.

“I continued with my life, driving a car, going to college and raising my family,” she said.

By the time she was 45, however, she was completely blind.

“I had one daughter in college, another in high school and a son in kindergarten,” Torres said. “Then, one day, I couldn’t see myself in the mirror.”

As the years passed, Torres moved from Puerto Rico to Wisconsin to Tampa. Everywhere she moved, the ophthalmologists who treated her told her there was no cure for RP, but she refused to give up hope and began researching the possibility of getting an artificial eye.

“When I heard that the Argus II system had been approved in the U.S., I jumped up and cheered!” she said.

Currently, the Argus II system is only FDA-approved for “compassionate use” for patients with severe vision loss due to advanced RP, specifically with bare light perception or no light perception vision only.

The first step was for Torres’ local ophthalmologist to test her eye to see if it would be feasible to handle the new electrical input from the bionic eye. After getting the okay, Torres reached out to Bascom Palmer’s Byron L. Lam, M.D., professor of ophthalmology and the Robert Z. and Nancy J. Greene Chair in Ophthalmology.

“Dr. Lam conducted extensive testing and then told me I was the perfect candidate for the implant,” she said.

After learning more about the surgery and recovery, Torres gave the procedure a “thumbs up.”

“I completely trusted my excellent team of doctors at Bascom Palmer, and I told them I was ready to move forward,” she said.

The surgery and post-operative training were far from simple, however.

“Only institutions such as Bascom Palmer Eye Institute have the resources and ability to help patients with very difficult visual problems like Carmen,” said Eduardo C. Alfonso, M.D., Bascom Palmer’s chairman and holder of the Kathleen and Stanley J. Glaser Chair in Ophthalmology. “Bascom Palmer care is defined by providing this type of precision breakthrough procedure to each of our patients. No individual specialist could do a procedure of this magnitude or provide this type of precision medicine without an enormous amount of support from others.”

Alfonso estimates that more than 30 professionals at Bascom Palmer, including physicians, scientists, researchers, nurses and technicians, participated in some aspect of the bionic eye project.

“A huge infrastructure is needed,” said Janet L. Davis, M.D., professor of ophthalmology and Leach Chair in Ophthalmology. “A procedure like this requires a large, well-organized team.” Davis and Ninel Z. Gregori, M.D., associate professor of clinical ophthalmology and chief of the Ophthalmology Section at the Miami Veterans Affairs Medical Center, led the surgical team during the five-hour procedure.

“Carmen was the ideal patient for this surgery,” said Gregori. “She had realistic expectations and hoped to see shapes and objects and gain better mobility. She was extremely motivated to work with the device and undergo a long and continuous rehabilitation.”

The Argus II system includes several components, including hardware worn by the patient and a prosthesis surgically implanted around and inside the eye. A tiny photosensitive array of electrodes is implanted on the retina.

“The most complicated part is attaching the array over the retina,” said Gregori, “and it requires a technique that most retinal surgeons are not currently trained to do.”

After recovering from the surgery, the patient begins wearing special glasses with a miniature video camera that captures a visual scene.

The signals from that camera are sent to a small computer called a video-processing unit (VPU) that can be attached to a belt or carried in a pocket or purse. The reprocessed signal is then sent back to the glasses and transmitted wirelessly to an antenna in the retinal implant. That causes the implant to emit small pulses of electricity that bypass the damaged photoreceptors in the eye and stimulate the retina’s remaining cells, which transmit the visual information along the optic nerve to the brain, creating the perception of patterns of light. A video demonstrating how the system works can be seen here.

“Following the surgery, patients must learn to interpret visual patterns of light with their retinal implant – it is almost like learning a new language,” said Davis. “The patient has to be an active participant in the process, and Carmen has been an ideal patient from the very first day.”

“At first, it was very confusing,” said Torres. “It was all light with no detail.” Over time, however, she became more proficient in her new visual language.

What helped was that within days of the surgery, Torres began her visual training. Jean-Marie Parel, Ing. ETS-G, Ph.D., the Henri & Flore Lesieur Chair in Ophthalmology, along with biomedical engineers Mariela Aguilar and Alex Gonzalez of Bascom Palmer’s Ophthalmic Biophysics Center, were responsible for Carmen’s post-ARGUS II implantation “fitting” process following special training from Second Sight.

Torres also received extensive occupational and low vision therapy from the Miami Lighthouse. Then five months after the surgery, she received a software upgrade from Second Sight.

“Carmen’s vision is not the same as normal sight,” said Aguilar, “so we created a vision simulator to help family members see what she sees.”

Over the past eight months, Bascom Palmer’s biophysics team has also developed several digital techniques to assess her vision and created special software for her to test and provide feedback. With this personalized instruction, Bascom Palmer’s scientists were able to improve their understanding of what Torres really sees. Because Torres is able to accurately describe what she is seeing, she has also traveled to California to meet with Second Sight trainers and technicians to advise them on improvements of the device for her and other patients.

Reflecting on her experience, Torres says the bionic eye is not for everyone. “You have to retrain your eye to interpret the signals, and that takes long hours and many days. I think getting this implant is a personal decision for everyone. For me, it’s been a great improvement in my life and I’m very grateful to Bascom Palmer for making it happen.”

Torres still uses her cane in combination with the retinal implant, but she is now able to locate doors and windows, see sidewalks and buildings, and watch the stars outside her Tampa home at night. She described the joy she felt the first time she realized she could see again.

“It was very emotional, but I’m very strong,” she said. “I didn’t cry. I was laughing, I was just laughing like crazy. And the first time I could play with a ball with my grandson — watch him roll it across the carpet in my living room, catch it and roll it back to him — it made me feel very good.”

The best part, clearly, has been regaining something she feared was gone forever.

“With RP, you lose your vision one day at a time, and it feels like someone is constantly stealing something from you. What Bascom Palmer has given me back gives me great happiness, and I think I have a future with this.”

And like many Floridians, Torres is concerned with not only how she sees, but also how she looks.

“They’re cool,” she said, modeling her high-tech shades. “I look good. I also love the way my eyes look — there is no difference from the way they looked before I had the surgery.”

Argus II, which is made by Second Sight Medical Products, a California medical device manufacturer, also offers hope for patients with other retinal degenerations such as age-related macular degeneration, and has recently entered a clinical study phase for that condition in the United Kingdom. Meanwhile, Bascom Palmer has found its second RP patient through the Veterans Health Administration. Once the payment is approved, his procedure will be scheduled.

University of Miami


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