Researchers have discovered that an eye injection of stem cells may reverse or slow down the effects of age-related macular degeneration in the condition's early stages. No treatment exists at the moment to slow down the progression of the disease, which is a major cause of loss of vision in people 65 years old and up.

At least 15 million people in the United States are affected by age-related macular degeneration, a disease that occurs when the retina's small central portion, the macula, starts deteriorating. Aside from aging, genetic predisposition and environmental factors also contribute to the development of macular degeneration.

According to Shaomei Wang, a research scientist from the Cedars-Sinai Board of Governors Regenerative Medicine Insitute's Eye Program and lead author for the research published in the journal STEM CELLS, their work is the first to show that vision can be preserved after injecting just a single dose of adult-derived human cells into rats with age-related macular degeneration. After receiving just one shot, rat models exhibited preserved vision for 130 days, which is equivalent to about 16 human years.

After an injection, researchers observed that healthy cells started migrating to the retina, forming a protective layer that kept ongoing degeneration at bay. To come up with induced neural progenitor stem cells, the researchers first converted some adult human cells into induced pluripotent stem cells and then made them into the desired human cell.

Clive Svendsen, Ph.D., Board of Governors Regenerative Medicine Institute director and a contributing author for the study, said that the induced neural progenitor stem cells provide a unique source for cells capable of slowing down macular degeneration and the vision loss associated with it.

Additional pre-clinical data is still needed but research is close to making it possible to offer adult stem cells as a personalized method of treatment for macular degeneration and other diseases.

After the promising results produced by the study, researchers are moving on testing safety and efficacy of stem cell injections in pre-clinical studies involving animals as a means of investigating a new drug. Clinical trials will also be designed for testing potential benefit of injecting stem cells in age-related macular degeneration in the later stages.

The study was supported by the David and Janet Polak Foundation Stem Cell Core Laboratory, the Simon and Beathrice Apple Stem Cell fund for Eye Research, the Department of Defense, the National Institutes of Health, the Knights Templar Eye Foundation Inc. and the Foundation Fighting Blindness. Other authors include: Anais Sahabian, Ph.D., Sergey Girman, Ph.D., Benjamin Bakondi, Ph.D., Bin Lu, M.D., Ph.D., Yuchun Tsai, Ph.D. and Dhruv Sareen.

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