Some scientists have been searching for ways to help the blind see. Now, a group of researchers recently made the attempt to use a microelectrode array to help the blind perceive letters and shapes.
The implant made is quite small, roughly the size of a penny. Once inserted, it’s been designed to bypass the optic nerve. Rather, it directly stimulates to the brain’s visual cortex to make seeing easier. At the end of the research, the volunteer was able to identify several letters of the alphabet, something that they consider a tremendous breakthrough.
According to the studies made by the experts from Centers for Disease Control and Prevention (CDC), they estimated that around 1 million people in the United States over the age of 40 are considered blind. To date, there is no cure for blindness. Much has yet to be done, but they hope that this new implantable device may one day become a vital way to make blind people a lot more independent in life. The implant they created makes use of an electrode that is designed to provide artificial vision.
This innovative device is still in its teething stages of clinical development and it’s still too early to tell what lies ahead. However, the first experiment in the human participant was considered a victory. The details and the results of the study made are now available in The Journal of Clinical Investigation.
This latest breakthrough was conducted by researchers in Spain. They worked together with the scientists at the Netherlands Institute for Neuroscience in Amsterdam and the University of Utah in Salt Lake City.
All about Phosphenes
Blind people experience a phenomenon called spontaneous phosphenes. Phosphenes are what blind people “see” when random flashes of light appear without any light entering the eye.
Sighted people can also experience phosphenes. For example, pressure phosphenes occur when a person rubs their eye. Certain drugs, ionizing radiation, and electrical and magnetic stimulation can also triggerTrusted Source phosphenes.
Although spontaneous phosphenes do not provide any functional vision, their manipulation played a vital role in the recent study.
The Brain Implant Used
In the study made, the researchers implanted what they call a Utah electrode array (UAE). This was placed directly into the visual cortex of the patient’s brain. Why? Because the visual cortex is the one in charge of processing visual information. The UAE consisted of 96 microelectrodes that is projected out from a silicon base.
“A long-held dream of scientists is to transfer information directly to the visual cortex of blind individuals, thereby restoring a rudimentary form of sight,” wrote the authors of the study. They elaborated, “However, no clinically available cortical visual prosthesis yet exists.”
The study took around 6 months to complete. They only used one participant for this: a 57-year-old lady who became blind 16 years before they started the actual study. In order for her to regain her vision, the scientists had implanted the device. They then have her a few weeks to recover from the procedure. Before they began testing the device used, they worked closely with the participant. This was to make sure that she is able tell the difference between spontaneous phosphenes and the phosphenes the team wanted to induce as part of them providing the patient’s functional vision.
The good news is that they were able to discover that the woman was actually able to identify the induced phosphenes with a 95 percent accuracy rate. After which, the team started training and presenting her with a variety of visual challenges. The training sessions conducted had to be done often, which took place on 5 days on a weekly basis. Then, once or twice each day, and for as long as 4 hours per session. They continued with this routine for the next 6 months. The scientists synced a pair of special glasses to work with the implant. This was made in order to track the movements that happen in her eyes.
During the time of the study, the woman was able to successfully recognize phosphenes in a certain space. The researchers also realized that it was actually easier for her to perceive the spots of light when they simultaneously stimulated more than two electrodes in the process. They also noticed that the results were much better when it comes to space and shape recognition if they spaced out the stimulating electrodes beforehand.
“This suggests that the phosphene’s size and appearance is not only a function of the number of electrodes being stimulated, but also of their spatial distribution,” said the authors of the study. By the time they reached the conclusion, when the researchers had simultaneously stimulated up to 16 electrodes that came in different patterns, the woman had successfully identified multiple letters. She was even able to tell apart the uppercase and lowercase letters.
Lead study author Dr. Eduardo Fernández talked to Medical News Today in detail and this was what he said about the research, “I would like to emphasize that although our preliminary results are very encouraging, we should be aware that this is still research and not yet a clinical treatment.”
The doctor further stated, “In this context, the scientific and technological problems associated with safe and effective communication with the brain are very complex, and many problems have to be solved before a cortical visual neuroprosthesis can be considered a viable clinical therapy or option.”
Dr. Fernández is considered an expert as he is a professor of cellular biology. He is also the chairman of the Department of Histology and Anatomy at University Miguel Hernández (UMH) in Alicante, Spain. Moreover, he serves as the director of the Neuroengineering and Neuroprosthesis Unit at the Bioengineering Institute at UMH.
Implications of Study Made
The purpose of the implant they created was not to restore full vision. At this point in time, this kind of technology has yet to be studied and created. Rather, the implant serves to provide a degree of functional vision for the recipient. Senior study author Dr. Richard Normann, a bioengineer from the University of Utah, said, “One goal of this research is to give a blind person more mobility.”
“It could allow them to identify a person, doorways, or cars easily. It could increase independence and safety. That’s what we’re working toward,” Dr. Normann further expounded.
Dr. Fernández also went into detail as he talked about trying to provide functional vision for the user with the implant. He said, “We are not trying to provide [full vision], that right now is not feasible, but just to provide […] useful vision, for tasks such as orientation, mobility, reading big characters, etc.”
“We have to go step by step and […] not create false expectations or underrate the challenges that still remain to be resolved,” Dr. Fernández also said. “In this framework, we propose that increased collaborations among clinicians, basic researchers, engineers, and associations of blind [people] [are] key to advance in this field.”
John Nosta is the founder of NostaLab, He is also a member of the Digital Health Roster of Experts at the World Health Organization (WHO). MNT conducted an interview about the implant with him where he said, “[This is] certainly an important step forward that builds upon the existing brain interface technologies, like the cochlear implant and deep brain stimulation for movement disorders.”
Conflict of Interest in the Study Conducted
The study comes with a few conflicts. Hence, it’s crucial to know that two of the study authors who were involved in the research, Pieter R. Roelfsema and Xing Chen, are co-founders of and shareholders in a neurotechnology start-up company they aptly named Phosphoenix.
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