February 15, 2013
High-Tech Artificial Retina Gets FDA Approval
Jason Pierce, MSN, MBA, RN for redOrbit.com — Your Universe Online
Today the US Food and Drug Administration (FDA) approved an artificial retina that is the first device of its kind to treat a form of progressive blindness that begins in young adulthood. The device will not completely restore vision, but it does allow the wearer to detect differences in light patterns and some shapes from their environment. The Argus II Retinal Prosthesis System, developed by Second Sight Medical Products, treats a form of blindness known as retinitis pigmentosa (RP).
The retina is a layer of tissue on the inner portion of the eye responsible for converting light into electrical signals that the brain can interpret. This is where photoreceptor cells, commonly referred to as rods and cones, detect light entering the eye. Neurons in the retina then process the information received from the rods and cones, and send the data to the brain.
Approximately 100,000 people in the US have been diagnosed with RP, a progressive disease that involves the deterioration of the retina. Night blindness is often the first symptom, with vision continuing to worsen over the next few decades. Complete blindness is a common result. Dr. Robert Greenberg, CEO and founder of Second Sight Medical Products says of the condition: "It's like looking down a tunnel that gradually narrows until it disappears entirely.”
The Argus II device consists of a pair of glasses with a small video camera and transmitter attached. The camera converts visual input into electronic data, which is then transmitted to electrodes implanted on the patient´s retina. From there the electronic data is carried to the brain via the optic nerve. The brain is able to interpret the data in the form of a picture.
Prior studies on patients with RP who use the artificial retina found that most were able to participate in daily activities better than they could prior to treatment. Participants in the study demonstrated an improved ability to navigate sidewalks and curbs, match socks by color and recognize large print words.
The FDA authorized the device to be used to treat patients who are 25 and older with advanced retinitis pigmentosa, and some remaining retinal function. The patients must have little to no light perception in both eyes, and have previously been able to make out basic shapes and forms.
The FDA approved the Argus II under the category of “humanitarian devices.” This level of approval is designed for products that have significant research and development costs, but initially benefit fewer than 4,000 people. Second Sight Medical hopes to eventually get approval to market the device to treat a broader range of visual disorders.