Promising Advances in Using Adult Stem Cells to Treat Vision Loss from Macular Degeneration

In the United States, age-related macular degeneration (AMD) is a leading cause of irreversible vision loss among individuals aged 60 and older. This condition primarily affects the macula, the central part of the retina responsible for high-resolution color vision. Approximately 20 million adults in the U.S. live with some form of AMD, which progressively impairs central vision while leaving peripheral vision unaffected.

Current treatments for AMD focus on slowing disease progression but do not restore lost vision. Recent research, however, offers hope through innovative stem cell therapies. A study published in Cell Stem Cell reports the use of retinal pigment epithelial (RPE) cells derived from adult postmortem eye tissue in a phase 1/2a clinical trial. This trial aimed primarily to assess safety, marking an important step toward potential regenerative treatments.

There are two main types of AMD: dry and wet. The dry form, which constitutes over 90% of cases, results from dysfunction and eventual death of retinal pigment epithelial cells—a critical layer supporting the retina. In early stages, these cells lose function without dying, but as the disease advances, they die off entirely.

In this study, patients with advanced dry AMD received transplants of adult stem cells obtained from eye-bank tissues. These specialized cells could only grow into retinal pigment epithelial cells. Six participants received a low dose of 50,000 stem cells via a surgical eye procedure. Encouragingly, the treatment was safe, with no serious inflammation or tumor development reported.

Beyond safety, participants experienced significant improvements in vision. The most severely affected patients showed notable gains; for example, when tested with an eye chart, they could see 21 more letters after one year. The improvements in the transplanted eye, compared to the non-transplanted eye, suggested a direct benefit from the therapy.

Lead researcher Dr. Rajesh C. Rao expressed enthusiasm, stating, "We were surprised by the magnitude of vision gain in patients with advanced dry AMD. This kind of improvement has not been seen before in such cases." The research team is now monitoring additional patients who received medium and high doses of stem cells (150,000 and 250,000 cells respectively). If safety remains confirmed, further trial phases will be pursued.

This pioneering study signifies a critical step toward regenerative treatments for AMD, offering hope to millions affected by this currently irreversible disease. The ongoing research aims to expand these promising results and develop effective therapies to restore vision in patients with advanced retinal degeneration.

Source: https://medicalxpress.com/news/2025-09-adult-stem-cells-therapeutic-vision.html