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February 8, 2013
Dr. Fernando Arevalo and his surgical team, performing the first retinal implant surgery in the Middle East.
While Baltimore residents focused their attention on the Super Bowl this past weekend, a 44-year-old patient on the other side of the world with an advanced form of retinitis pigmentosa (RP) was receiving an implant that may restore some of his vision. On February 2, Dr. Fernando Arevalo, adjunct professor of ophthalmology at Wilmer Eye Institute and chief of the vitreoretinal division at King Khaled Eye Specialist Hospital (KKESH) in Riyadh, Saudi Arabia, implanted the Argus II Retinal Prosthesis System, known to many as “the bionic retina.” This is the first retinal implant surgery in the Middle East, according to Dr. Arevalo.
The Argus II is 3 x 5 mm in size, which corresponds to the size of a letter on a page, and provides images to the brain that could allow for improved mobility. It consists of a 60-electrode grid, about 200 micrometers in diameter – a little over the width of a hair – surgically implanted on the retina, where the electrodes transmit information taken from an external video camera mounted on a pair of eyeglasses worn by the user. A series of small electrical pulses are transmitted wirelessly to an array of electrodes on the surface of the retina. These pulses are intended to stimulate the retina's remaining cells, resulting in the corresponding perception of patterns of light in the brain. Patients then learn to interpret these visual patterns, ultimately regaining some visual function. The device has enabled clinical trial participants who are profoundly blind due to damaged photoreceptors to see shapes, locate objects and recognize large letters.
The device offers some hope to patients with RP, currently an incurable disease that often leads to blindness. There are an estimated 1.2 million people worldwide with RP, including 100,000 in the United States. Numerous strategies to treat RP have been investigated, but none so far have been definitively effective at maintaining or improving vision. Less than a week after surgery, Dr. Arevalo reports that the patient is doing well, with no inflammation. After several weeks of training and rehabilitation, the patient may be able to start using the device at home.
“We have known of several patients who have been implanted with the Argus II and can perceive color; future generations of the device may be upgraded one day to restore color vision for these blind patients” said Dr. Arevalo. Dr. Arevalo added “As I was implanting the first device in this area of the world, I could only think about all the hard work by my team to get us here, and how many patients, in Saudi Arabia and worldwide, will benefit from this implant.”
The first generation of the Argus II device was initially developed at Wilmer and the implant procedure has been performed multiple times by Wilmer retina specialists. “Dr. Arevalo’s historic operation in the Kingdom of Saudi Arabia is a perfect example of how Wilmer’s groundbreaking research is being translated into clinical practice. It also exemplifies the wonderful collaboration between Hopkins and KKESH in clinical care, research and education,” said Dr. Neil Bressler, the James P. Gills Professor of Ophthalmology and chief of the retina division of the Wilmer Eye Institute, where Dr. Arevalo will continue to work when completing his efforts at KKESH next year. Dr. Bressler is a member of the FDA Ophthalmic Devices Panel whose members advise the FDA on the device, but was not involved with any of the research related to the device.