Oct 14, 2014
A New Kind of Vision
How would you describe what it feels like to see something? We have lots of language to help us with this. We can talk about colours, textures, shadows, scenery, and movement. We can talk about faces, objects, and silhouettes. The central role that vision plays in shaping our perception of the world is reflected in how we describe our daily experiences. Language, therefore, limits our ability to talk about the effects of the Argus II retinal implant (often referred to as the Bionic Eye) and the impact that it is having on patients who are “seeing again” after years of blindness.
Today is a very exciting day at the Foundation Fighting Blindness because we are finally able to start sharing stories from the first Canadian patients to receive the Argus II implant, which used our valuable patient registry to identify the pioneering candidates: Orly Shamir and Ian Nichols. The successful early results of the ongoing observational study were announced yesterday. Dr. Robert Devenyi, Ophthalmologist-in-Chief and Director, Retinal Services at the University Health Network, performed the implantation surgeries while Dr. Samuel Markowitz, a low-vision rehabilitation specialist at Toronto Western Hospital, has been helping these patients to learn how they can use the device to see.
There is much excitement about retinal implants because they offer an innovative approach, and at present, the only available option, for restoring sight in some patients who suffer from degenerative retinal diseases. In degenerative eye diseases, such as retinitis pigmentosa (RP) and age related macular degeneration (AMD), photoreceptors (the cells in the retina that capture light and pass along a message towards the brain) progressively stop working. Eventually, a significant loss of photoreceptors leads to blindness. Interestingly, although photoreceptors are lost, the rest of the retina seems to stay largely intact, at least for a while. Because of this, various retinal prostheses approaches have been developed that aim to activate and make use of the remaining visual pathway.
Argus II was the first retinal implant to be approved in both the US and Europe. It is currently pending approval from Health Canada, which has approved its use in the ongoing trial in Toronto. By design, the Argus II bypasses missing photoreceptors by attaching a microelectrode array (chip) directly to the retina. The tiny electrodes stimulate the eye’s nerve cells, providing them with visual information from an external camera that is worn by the patient. This small video camera is attached to special glasses, which are also connected to a pocket-sized computer. The computer processes and transforms images from the camera into signals that can be sent to the microelectrode array. After the microelectrodes receive these signals, they emit pulses of electricity signifying that there is light in the corresponding area seen by the camera. This stimulates activity in the ganglion cells (nerve cells), which then travels as nerve impulses through the optic nerve and into the brain. With training and practice, the patient learns to translate this information into visual cues about the environment.
Sharing their stories of regaining vision, however, is not going to be easy to do with words because their unique experiences are unprecedented. What is like to see with “Argus vision”? (Imagine trying to tell an alien being, that has only senses of hearing and smell, what it is like to see anything!) Certainly, the Argus II recipients are experiencing sensations that they have never felt before and these sensations are enabling them to gain a new and better orientation in their surroundings.
Over dinner a few weeks ago, Orly Shamir, who has been learning how to use her new Argus II implant since June 5, 2014, described how the Argus glasses enabled her to feel that there was light on her left side. She proceeded to talk about what it felt like to approach a doorway with Argus vision: the door frame felt different to her than the opening and rehabilitation had taught her how to walk through the opening rather than into the frame. Receiving the Argus II implant has dramatically changed the way Orly feels the world around her; there is no doubt about that! She can point to bright squares as they appear on a dark screen — something that she could never have done before receiving the implant. Indeed, she is scoring incredibly well on all of the rehabilitation tests that are designed to evaluate her vision. Hopes are exceedingly high that these scores will continue to improve; Orly’s feelings of light will gradually be translated into an ability to recognize 3-dimensional shapes. This ability will transform how Orly senses and navigates her environment. Here at the Foundation Fighting Blindness, we are on this journey with Orly, which is sure to be full of ups and downs and detours. We are so grateful that she has agreed to try and find the words to explain her experiences as she makes her way through largely unchartered territory.
Check back in with us to follow Orly’s story of learning a new kind of vision. Also on this journey is Ian Nichols, who was the second Canadian to receive the Argus II implant on September 4, 2014. By talking with Orly and Ian, who are both long-time members of the Foundation Fighting Blindness community, we will have a personal window into this futuristic medical development.
Unissons nos forces
Découvrez comment votre soutien peut contribuer à tracer un avenir sans cécité! Soyez informé en exclusivité des dernières percées de la recherche en santé de la vision et des événements dans votre région en vous abonnant à notre infolettre.