Duane Geruschat, Ph.D. specializes in rehabilitation research with persons who are blind and visually impaired. His primary interest is in low vision orientation and mobility. He is a certified orientation and mobility specialist (COMS) and a certified low vision therapist (CLVT).
Dr. Geruschat began his career working at a school for children with multiple disabilities and blindness. After several years, he moved to the Pennsylvania College of Optometry (now part of Salus University), where he worked in the William Feinbloom Vision Rehabilitation Center providing low vision instruction to patients. His research on low vision mobility encompasses studies on how visual impairment affects the ability to cross streets safely, including studies on eye movements and the perceptual judgments of time/distance of moving vehicles while attempting street crossings.
His involvement with prosthetic [i.e., artificial] vision began in 2004 with a product developed by Optobionics. Since 2009, Dr. Geruschat has been involved with Second Sight Medical Products, Inc., helping them to develop functional assessments and a rehabilitation curriculum that low vision therapists and orientation and mobility instructors can use when teaching patients to use the Argus II Retinal Prosthesis System.
Dr. Geruschat served as the Editor-in-Chief of the Journal of Visual Impairment & Blindness from 2005-2012. He is the recipient of numerous awards, including the Corinne Kirchner Award from the American Foundation for the Blind for lifetime achievement in blindness and low vision research, and the Outstanding Contributions in Research and Literature in Low Vision Award from the Association for Education and Rehabilitation of the Blind and Visually Impaired (AER).
Maureen Duffy: Hello, Dr. Geruschat. Thank you very much for taking the time to speak with us about the Argus II Retinal Prosthesis System. We have been following the development and testing of the Argus II at VisionAware and are interested to learn more about it. To start, can you explain what the Argus II is and what it is designed to do? Many people call it the “bionic eye,” but the Argus II is so much more than that.
Duane Geruschat: The Argus II is a retinal chip that is implanted into the eye, specifically on to the retina. A camera is mounted at the bridge of the nose of a pair of glasses. This camera captures images. The images are processed by a video processing unit (VPU) and sent through a wireless transmission to the retinal chip.
The information provided by the Argus II is light of varying intensities. It is this light and the patterns of light that a recipient experiences that are interpreted by the Argus II user.
MD: Can you tell us more about your role in the latest phase of the Argus II development?
DG: Second Sight Medical Products, the company that designed and manufactures the Argus II, recognizes that their system is not simply implanted with the patient making an immediate adaptation. There is a process of adaptation, learning to use the VPU, and learning to interpret the light patterns.
Since the company employees are mostly engineers and scientists, they have engaged me as a consultant to help them develop a rehabilitation curriculum that includes assessment and training. I have also developed an online continuing education program for orientation and mobility specialists and low vision specialists who will be providing the rehabilitation services.
MD: When I attended your presentation about the Argus II at the American Foundation for the Blind Leadership Conference in February 2014, I was very interested to learn about the training program that Second Sight has developed to “reintroduce” vision to users of the Argus II. Can you tell us more about that?
DG: The instructional program follows the foundational principles of all types of rehabilitation. Specifically, we assess, implement a program of rehabilitation, and measure the effects. In the clinical trial, it became obvious that some patients would naturally adapt to the technology, while most patients benefited from some instruction, with a few patients who would not have had any benefit without instruction.
Think of this as being analogous to blind rehabilitation that occurs all over the country on a daily basis. There are some people who become blind and, through their own abilities and motivation, figure things out for themselves, but this is rare. Most people start to figure a few things out (marking things, folding money) but they experience tremendous benefit from attending a structured program of rehabilitation. The Argus II patients are the same.
As for reintroduction of vision, the “sight” is actually light of varying intensities and possibility patterns. This information has no connection to the user’s original native vision, so the user must learn what the light and the light patterns mean. The rehabilitation curriculum is designed to improve their skills with this new vision.
MD: How do you see the Argus II developing in the future?
DG: Well, the most obvious answer is better resolution, meaning the ability to increase visual acuity and visual field.
The second hope is that the technology will be of use with other eye pathologies. Right now the Argus II system is only approved for retinitis pigmentosa (RP). While this has the potential to be of great benefit to those with RP, this pathology is a relatively small portion of the blind and visually impaired in our country. Hopefully, with time, the technology will prove to be of benefit to a wider range of users with varying pathologies.
MD: What do you regard as the next great frontier in vision science? I’m always interested in what practicing vision scientists have to say about the future of vision research.
DG: Right now there is a lot of exciting work going on with gene therapy for Leber congenital amaurosis, which shows a lot of promise.
The other exciting area is the use of advanced optics and computer chips that allow for rather incredible real-time manipulations of a scene and with a large field of view. Imagine having low vision and wearing a head-mounted display with a large field of view that allows you to modify the visual environment to minimize the negative effects of an eye pathology!
We thank Dr. Geruschat for his support of VisionAware and for his research on behalf of blind and visually persons worldwide. You can read more about the Argus II Retinal Prosthesis System at VisionAware, including a first-person account from an Argus II pioneer.
June is Vision Research Month
Optogenetics: The Next Frontier in Vision Research? The Foundation Fighting Blindness Explains
Dr. Sheila Nirenberg: A MacArthur Foundation “Genius” Award for Artificial Retina Research
Meet Aries Arditi, Ph.D., Founder and Principal Scientist of Visibility Metrics, LLC
Argus II images provided by Second Sight Medical Products, Inc. Used with permission.