Researchers have developed eye drops that extend vision in animal models of retinitis pigmentosa (RP), a group of degenerative eye diseases that leads to progressive vision loss in humans.
The eye drops contain a small fragment derived from a protein made by the body and found in the eye, known as pigment epithelium-derived factor (PEDF). PEDF helps preserve cells in the eye’s retina. A report on the study is published in Communications Medicine.1
In a media release,2 the National Institutes of Health’s National Eye Institute (NEI) in the United States said all degenerative retinal diseases have cellular stress in common. While the source of the stress may vary, high levels of cellular stress cause retinal cells to gradually lose function and die. Progressive loss of photoreceptor cells leads to vision loss and eventually, blindness.
The study’s senior author, Dr Patricia Becerra, from the NEI, said while PEDF-based eye drops were “not a cure”, they can slow progression of “a variety of degenerative retinal diseases in animals”, including various types of RP and geographic atrophy.
“Given these results, we’re excited to begin trials of these eye drops in people.”
Previous research from Dr Becerra’s lab revealed that, in a mouse model, the natural protein PEDF can help retinal cells stave off the effects of cellular stress. However, the full PEDF protein is too large to pass through the outer eye tissues to reach the retina, and the complete protein has multiple functions in retinal tissue, making it impractical as a treatment.
With this knowledge, Dr Becerra’s team then developed a series of short peptides.
Given these results, we’re excited to begin trials of these eye drops in people
Mice Retained Sight
In this new study, led by first author Alexandra Bernardo-Colón, Becerra’s team created two eye drop formulations, each containing a short peptide. The first peptide candidate, called ‘17-mer’, contains 17 amino acids found in the active region of PEDF. The second peptide, H105A, is similar but binds more strongly to the PEDF receptor. When the peptides were applied to mice as drops on the eye’s surface, they were found in high concentration in the retina within 60 minutes, slowly decreasing over the next 24 to 48 hours. Neither peptide caused toxicity or other side effects.
When administered once daily to specially bred mice with RP-like disease, H105A slowed photoreceptor degeneration and vision loss.
When given peptide eye drops through that one-week period, mice retained up to 75% of photoreceptors and continued to have strong retinal responses to light, while those given a placebo had few remaining photoreceptors and little functional vision at the end of the week.
“For the first time, we show that eye drops containing these short peptides can pass into the eye and have a therapeutic effect on the retina,” said Ms Bernardo-Colón. “Animals given the H105A peptide have dramatically healthier-looking retinas, with no negative side effects.”
To see whether the eye drops could work in humans, the researchers worked with Dr Natalia Vergara, from the University of Colorado, to test the peptides in a human retinal tissue model of retinal degeneration. Without the peptides, the cells of the tissue model died quickly, but with the peptides, the retinal tissues remained viable. These human tissue data provide a key first step supporting human trials of the eye drops.
References
- Bernardo-Colón A, Bighinati A, Becerra SP, et al. H105A peptide eye drops promote photoreceptor survival in murine and human models of retinal degeneration.” Commun Med. 2025 Mar; 5:81. doi: 10.1038/s43856-025-00789-8.
- National Eye Institute, NIH researchers develop eye drops that slow vision loss in animals (media release, 21 March 2025) available at: nei.nih.gov/about/news-and-events/news/nih-researchers-develop-eye-drops-slow-vision-loss-animals [accessed March 2025].
