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Researchers have developed eye drops that extend vision in animal models of a group of inherited diseases that lead to progressive vision loss in humans, known as retinitis pigmentosa.
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. "While not a cure, this study shows that PEDF-based eye drops can slow progression of a variety of degenerative retinal diseases in animals, including various types of 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. "Given these results, we're excited to begin trials of these eye drops in people." All degenerative retinal diseases have cellular stress in common. While the source of the stress may vary -- dozens of mutations and gene variants have been linked to retinitis pigmentosa, AMD, and other disorders -- 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. In this new study, led by first author Alexandra Bernardo-Colon, 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. A second peptide, H105A, is similar but binds more strongly to the PEDF receptor. Peptides applied to mice as drops on the eye's surface 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. (ANI)
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