Retinal implants have shown potential in restoring vision in blind mice, indicating that they may eventually help those with conditions like age-related macular degeneration, where photoreceptor cells in the retina deteriorate over time.

Shuiyuan Wang from Fudan University in China and his team developed a retinal prosthesis composed of metal nanoparticles that replicate the function of lost retinal cells, converting light into electrical signals to be sent to the brain.

In their experiments, the researchers administered nanoparticles into the retinas of mice that had been genetically modified to be nearly completely blind.

They restricted water access for three days to both the modified blind mice and those with normal vision. Subsequently, they trained all mice to activate a 6cm wide button on a screen to receive water.

Following training, each mouse underwent 40 testing rounds. The fully sighted mouse pressed the button successfully 78% of the time. Mice with implants achieved a 68% success rate, while untreated blind mice only managed 27%. “That presents a very noticeable effect,” stated Patrick DeGenard, who wasn’t involved in the research but is affiliated with Newcastle University in the UK.

After 60 days, researchers observed minimal signs of toxicity from the implants in the mice. However, Degenaar emphasized the need for long-term safety data, stating, “For clinical application, extensive animal testing lasting approximately five years will be necessary.”

“Patients with age-related macular degeneration and retinitis pigmentosa could benefit from this prosthetic,” noted Leslie Askew from the University of Surrey, UK, who was not part of the study.

Degenaar also remarked that justifying this solution for age-related macular degeneration patients is complex, as they possess a degree of vision that may not warrant the risks associated with implanting prosthetics.

Furthermore, he noted that mice generally have inferior vision compared to humans, raising uncertainty about how beneficial the findings will be for people until comprehensive clinical trials are conducted.