The liquid artificial retina also works in the advanced stages of retinitis pigmentosa- breaking latest news

The effectiveness of the liquid artificial retina presented in 2020 by the Italian Institute of Technology, San Martino Polyclinic Hospital (Genoa) and IRCCS Sacro Cuore Don Calabria Hospital in Negrar (Verona) now also demonstrated in the most advanced and irreversible stages of retinitis pigmentosa. The successful outcome of the experiment, just published in the scientific journal Nature Communications by the research teams of the institutes, represents a further approach to the feasibility of future human clinical trials.

How does it work

The biocompatible liquid retinal artificial prosthesis, with high resolution and consisting of a aqueous component in which nanoparticles are suspended polymeric fotoattive made ad hoc about 1/100 of the diameter of a hair, which take the place of damaged photoreceptors. The surgical procedure forsubretinal injection minimally invasive photoactive nanoparticles and potentially replicable over time.

The retinitis study

For research on retinitis pigmentosa, preclinical tests were conducted on experimental models showing the same conditions of the human being in the later stages of the disease: not only with the retina completely devoid of photoreceptors, but also with profound alterations of the retinal nervous circuits which, although spared from degeneration, no longer receive any signal. In these models the visual cortex was initially completely silent, but following the injection of the photoactive polymer nanoparticles, new physiological signals were recorded: the visual cortex reactivated, reacquired acuit and visual memories returned to form. These results demonstrate that the biocompatible high-resolution artificial retina-based approach is a winner and lays a solid foundation for the next steps aimed at conducting the first tests on humans, estimated around 2025-2026.

Results and potential

There are 5.5 million patients with retinitis pigmentosa worldwide. Our recent study – says Simona Francia, IIT researcher and first author of the work – a further important step towards the therapy of pathologies such as retinitis pigmentosa and age-related macular degeneration. Not only do these nanoparticles distribute themselves to large retinal areas allowing to gain a wide field of view, but thanks to their small size they are able to ensure a recovery of visual acuity. Polymer nanoparticles – adds Guglielmo Lanzani, Director of the IIT center in Milan – 250 times smaller than the thickness of a hair, act like photovoltaic microcells, converting light into an electrical signal and do not cause any negative reaction. Having reduced the retinal prosthesis to a suspension of nanoparticles reduces the implantation procedure of the prosthesis to a simple injection much less invasive. Having demonstrated – says Dr. Grazia Pertile, director of the Eye Clinic of the IRCCS Sacro Cuore Don Calabria Hospital – that photovoltaic nanoparticles they remain effective in stages of advanced degeneration of the retina opens the door to the application of this strategy to human pathologies.