Retinitis Pigmentosa, Age-Related Macular Degeneration, Diabetic Retinopathy—they are all retinal diseases, and they can all lead to blindness. Thankfully, there are treatments that can manage the symptoms and slow the progression of these diseases. Can anything else be done to slow the progression? And more importantly, can anything be done to restore vision—not just maintain the status quo? Scientists are working to develop treatments that extend vision and possibly restore vision lost to retinal diseases.
A Drop A Day
Scientists at the National Institutes of Health (NIH) created eye drops that extend vision in animal models with retinitis pigmentosa. The drops contain a small piece derived from a protein known as pigment epithelium-derived factor (PEDF). PEDF helps sustain the cells in the retina.
These drops aren’t a cure. Still, the study shows that the drops can slow progression of retinal diseases, such as retinitis pigmentosa and dry age-related macular degeneration. What all retinal diseases have in common is cellular stress, and high levels of stress cause retinal cells to slowly lose function and die, which leads to vision loss and eventually blindness. Previous research showed that PEDF can help protect retinal cells from the effects of cellular stress.
Unfortunately, the full PEDF protein is too big to pass through the outer eye tissues. So, scientists developed short peptides from a region of PEDF that sustains cell viability. These peptides can move through the eye tissue.
Researchers created two eye drop formulations containing short peptides. The first peptide, called 17-mer, contains 17 amino acids found in the active region of PEDF. The second peptide, H105A, is similar to 17-mer but binds more strongly to the PEDF receptor.
The drops were applied to the eye surface of the mice. When dispensed once a day to young mice with a retinitis pigmentosa-like disease, the H105A peptide slowed photoreceptor degeneration and vision loss. When these drops were given to a group of mice bred to lose their photoreceptors shortly after birth, these mice kept up to 75 percent of their photoreceptors and continued to have strong responses to light.
These drops were also tested on human tissue. Retina-like tissues derived from human cells were grown in a lab and were exposed to chemicals that created high levels of cellular stress. Without the peptides, the cells died. With the peptides, the cells remained viable. Of course, more research is needed before clinical trials can begin.
Gold in Your Eye
Study done by researchers at Brown University suggests that gold nanoparticles might be used to restore vision in people with retinal diseases, like macular degeneration. Scientists demonstrated that injecting gold nanoparticles into the retina of mice can stimulate the visual system and restore vision. This implies that one day, a visual prothesis could be developed, where nanoparticles are used in combination with a small laser device worn in glasses to help people with retinal diseases to see.
The scientists injected the gold nanoparticles directly into the retina to circumvent the damaged photoreceptors. When infrared light is focused on the nanoparticles, they create a small amount of heat that triggers bipolar and ganglion cells in the same way that photoreceptor pulses do. Since vision diseases like macular degeneration affect the photoreceptors—not the bipolar or ganglion cells—this strategy could be utilized to restore vision.
This was tested in both mice retinas and in living mice with retinal diseases. A liquid nanoparticle solution was injected and researchers uses a patterned near-infrared laser light to project shapes onto the retinas. They confirmed via calcium signaling that the nanoparticles were triggering the bipolar and ganglion cells. They also used probes to confirm that the laser stimulation of the nanoparticles led to increased activity in the visual cortices of the mice’s brains—a sign that the visual signals were being transmitted and processed by the brain.
Another good thing about using nanoparticles is that the method is less invasive. They can be injected into the eye by an ophthalmologist. While more work is necessary before a clinical trial is conducted, this research shows that it may be possible to use gold nanoparticles to restore vision.
You may have heard the saying “Silence is golden”. Of course, blindness isn’t. Thanks to work done at NIH and Brown University, whether its peptide drops or gold nanoparticles, the future looks brighter for those living with retinal diseases.
https://www.brown.edu/news/2025-04-16/goldeneyes