Retinitis pigmentosa (RP) is a rare inherited condition that causes the gradual death of photoreceptors (light-sensing cells) in the eye, leading to vision loss. There is currently no cure.
Imagine a future where vision loss from inherited diseases could be slowed with just a daily drop in the eye. Researchers at the National Institutes of Health (NIH) have developed eye drops extending vision in animal retinitis pigmentosa models.
These groundbreaking drops contain a tiny fragment of a natural protein found in the eye called pigment epithelium-derived factor (PEDF). PEDF helps protect and sustain the retina’s fragile cells.
“While these drops aren’t a cure, the study shows PEDF-based eye drops can slow the progression of degenerative retinal diseases in animals, including retinitis pigmentosa and dry age-related macular degeneration (AMD),” said Patricia Becerra, Ph.D., chief of NIH’s Section on Protein Structure and Function at the National Eye Institute, and senior author of the study.
“The next step is human clinical trials, and we’re excited to begin.”
The research addresses a common challenge across degenerative retinal diseases: cellular stress. Retinitis pigmentosa and AMD stem from gene mutations and other factors that cause retinal cells to weaken, lose function, and eventually die. This results in photoreceptor loss, vision impairment, and ultimately blindness.
Previous studies from Becerra’s lab found that PEDF protects retinal cells against stress but is too large to pass through the eye’s outer tissues. So her team developed short peptides—tiny fragments derived from PEDF—that not only preserve retinal cells but also reach the retina efficiently when delivered as eye drops.
Model of PEDF protein alongside the 17-mer and H105A peptides. Amino acid 105, which is changed from histidine in PEDF and the 17-mer peptide to alanine in the H105A peptide, is shown in green. Image credit: NEI. Alt tag: 3D image of a model PEDF protein. NEI
The study, led by Alexandra Bernardo-Colón, tested two peptide-based formulations, “17-mer” and H105A. These small peptides penetrate the retina within an hour of application and remain active for up to 48 hours with no harmful side effects.
Daily H105A eye drops in mouse models preserved up to 75% of photoreceptor cells, compared to placebo-treated mice that lost nearly all photoreceptors within a week.
“For the first time, we show these peptide eye drops can reach the retina and have a therapeutic impact,” Bernardo-Colón noted. “The results are dramatic—healthier retinas and no adverse effects.”
With several gene-specific therapies in the works for diseases like retinitis pigmentosa, these eye drops could serve as a crucial interim treatment, preserving retinal cells until new therapies are ready. The researchers also tested the compatibility of preserved cells with gene therapy in mice, which successfully maintained vision for six additional months.
To explore human applications, the team collaborated with Natalia Vergara, Ph.D., at the University of Colorado Anschutz to test the peptides on human retina-like tissues grown in a lab. When exposed to stress, untreated tissues died quickly, while those treated with peptides stayed viable, offering a promising first step toward human trials.
“This approach could transform treatment for degenerative retinal diseases,” Becerra said. “We’re optimistic about bringing these eye drops closer to real-world use.”
The research was supported by the NEI Intramural Research Program and funding from organizations such as the Prevention of Blindness Society and Fondazione Telethon.
Journal Reference
- Bernardo-Colón, A., Bighinati, A., Parween, S. et al. H105A peptide eye drops promote photoreceptor survival in murine and human models of retinal degeneration. Communications Medicine 5, 81 (2025). DOI: 10.1038/s43856-025-00789-8
