Injections of gold particles restore vision in blind mice, study finds
A recent study that proposes injecting gold nanoparticles directly into the eye could be the first step toward a virtual cure for certain types of blindness, particularly those caused by retinal deterioration, such as age-related macular degeneration and retinitis pigmentosa.
In the study, published in the journal ACS Nano , researchers demonstrated that injections of gold powder can stimulate the visual system and restore vision in mice with retinal disorders.
The discovery suggests a possible visual prosthesis system, combining the intravitreal injection (between the lens and the retina) of gold nanoparticles, with a laser device in glasses that, by projecting beams of light into the eye, activate the nanoparticles which, in turn, stimulate the remaining neural cells in the retina.
In a statement, first author Jiarui Nie from Brown University in the US said: “This is a new type of retinal prosthesis that has the potential to restore vision lost due to retinal degeneration, without the need for any type of complex surgery or genetic modification.”
Led by researchers at Brown University in Providence, USA, the research revolutionizes the way we treat blindness by offering an alternative to traditional electronic prosthetics. The technique uses gold nanoparticles as mini-converters of light into heat.
Testing the injection of gold particles into the retina
Retinal diseases, such as macular degeneration and retinitis pigmentosa, affect millions of people worldwide, destroying photoreceptors (rods and cones), specialized cells that capture light and convert it into electrical impulses. Without them, the brain cannot receive visual information.
The new technique uses tiny gold particles injected into the retina that, when exposed to infrared light, gently heat and stimulate the still-functioning nerve cells. Bypassing the photoreceptors, the process reactivates the neural pathway of vision in people with the remaining retinal cells intact.
To test the effectiveness of their system, the authors performed the approach on mouse retinas and also on live animals with retinal disorders. Using an infrared laser, the researchers projected visual patterns onto retinas already treated with the gold particles.
The results proved that the nerve cells responded exactly according to the designed patterns , suggesting functional visual reception, with no side effects observed, either in the nanoparticle solution or in the laser stimulation, according to specific markers.
Using probes, the researchers observed increased activity in the visual cortex of the treated rodents, indicating that visual signals were being captured and processed by the brain. The result suggests a partial restoration of vision , with potential for future application in humans.
How to use new technology in humans?
To enable human use, the authors integrated the nanoparticles into the retina and the lasers into glasses with cameras. These capture external images, converting them into light pulses to stimulate the particles. The idea is to create a visual prosthesis, replacing traditional surgical methods.
Less invasive than ocular implants already approved by the FDA , the new technology eliminates surgically implanted electrodes, replacing them with intravitreal injections, currently a common procedure in ophthalmology. The solution eliminates surgical risks and increases accessibility.
In addition, the new system has some functional advantages: while older implants were limited to 60 pixels, the nanoparticles cover the entire retina , fully restoring the visual field. And, because they respond to infrared light, they do not interfere with the user's remaining vision.
In preliminary tests, the particles proved stable in the retina for months, without significant toxicity. “We have shown that they successfully stimulate the visual system,” Nie said. The next step is clinical trials to validate the technology in humans, the authors promise.
Nie acknowledges that, despite the promising results, some adjustments are needed before practical applications. For the biomedical engineer, if successful, the integration between hardware and biology could redefine the treatment of visual impairments in a practical and revolutionary way.
CNN Brasil
