In July 2017, half a year has passed since the new IRIS®II retinal chip was implanted in the first recipient in our country, as part of a European clinical trial, in which the IMO participates as the only centre in Spain to test the efficiency of this bionic prosthesis. After undergoing surgery in January, carried out by Dr Borja Corcóstegui – the principal project investigator at the Institute –, Francisco Mulet, who had been blind for more than 30 years due to retinitis pigmentosa, completes the first stage of the study locating objects thanks to the perception of points of light. Meanwhile, he is still working on gradually identifying them through a demanding visual rehabilitation programme, which is expected to last 18 months, with the possibility of extending its follow-up stage another year and a half.
As emphasised by Carol Camino, an optometrist at the Institute in charge of this training programme, "we usually rehabilitate people with low vision, but making this possible in a blind patient is a great satisfaction, as well as a true challenge." The goal is for the patient to learn how to interpret the light stimuli he receives, so that he can "see" by means of the artificial vision system developed by the company Pixium Vision. It consists of a mini-camera installed on special glasses that mimic the operation of the human eye and send the information captured in the form of infrared rays to a processor, which allows to make adjustments in terms of zoom, brightness, etc., as well as to select different vision modes. From there, the data reaches the chip implanted in the retina, which, through the optic nerve, transmits the image signals to the brain.
To get the most out of this complex and advanced technology, we work in weekly sessions of about 5 hours at the Institute, during which we accurately monitor the direction of the patient's look and the activation of each of the 150 electrodes making up the chip (three times as many as in previous models), while performing exercises to distinguish materials of various shapes and sizes, with different types of contrast and movement. As a result, "flashes are more or less numerous and more or less intense,” Francisco Mulet explains.
Integration into everyday life
Since the ultimate purpose is to improve visual perception to achieve greater autonomy, during these sessions in the consultation room several elements of everyday life (glasses, plates, cutlery, etc.) are introduced, whereas, since May, the practical sessions at the IMO are combined with training dynamics at home and within the patient's environment, which we are going to focus on in the coming months. "In real life, everything is not black and white, there are many colours and shades, and this requires an adaptation,” according to Carol Camino, who adds that "Francisco already achieves good scanning levels and places the objects, so now efforts focus on helping him associate what he sees with what is actually there."
An important step in this direction has taken place in the month of June, with the first walk on the street while using the device. The walk took place at night in a place with lighting to obtain a greater contrast: the Montjuïc Magic Fountain, "a difficult objective, as this is not a compact thing,” the optometrist notes. However, according to Francisco Mulet, he managed to differentiate the various height levels of the fountains and perceive the water variations. The patient considers this a "positive" experience that tops off the first six months after the IRIS®II implant, not only because of the individual progress made, but, above all, for the door it opens for future generations.
The contribution and feedback of testimonials provided by people like Francisco Mulet is essential for marketing the IRIS®II solution, besides being key to optimising new models, which Pixium Vision is already working on. This was evidenced during the recent meeting held at the company's headquarters in Paris, which was attended by members of the IMO together with representatives from the other centres in France, Germany, United Kingdom and Austria that are part of the study, to share the evolution of the ten European patients on whom the bionic prosthesis is currently being tested.