Imagine trying to focus on a friend's face in a photo, or on the road ahead while driving, but everything you see appears blurry and indistinct. This is what millions of adults with age-related macular degeneration experience, where the central field of vision gradually weakens, and details become difficult to distinguish.
Current treatments can only slow the progression of the disease or partially improve vision, while blurriness continues to worsen.
In this regard, a recent clinical trial has shown that stem cell transplantation may reverse the cumulative damage to the macula, the part of the retina responsible for direct central vision.
This is the first trial of its kind on humans, focusing on testing the initial safety and effectiveness of the treatment.
The trial involved six volunteers aged between 71 and 86 years, all diagnosed with age-related dry macular degeneration, the most common type, accounting for approximately 80% of cases. Three of them had severe visual impairment, while the other three had moderate to poor visual acuity.
Dry macular degeneration is caused by the accumulation of fatty and protein deposits that lead to the destruction of retinal pigment epithelial cells (RPEs), which are cells that support the light-sensitive tissues of the eye.
The treatment involved transplanting stem cells taken from an eye bank, capable of producing new pigment epithelial cells. Each eye received a relatively low dose of 50,000 stem cells, implanted under the retina of the superior macular region of the more affected eye.
The results showed that the treatment was safe, with no signs of immune problems or tumors, and no side effects related to the transplanted cells were recorded, despite some common surgical complications.
All patients experienced significant improvement in vision in the transplanted eye, while no improvement was shown in the other eye, indicating the treatment's effectiveness. One year after treatment, the three participants with the worst vision were able to read approximately 21 more letters on the eye chart compared to the start of the trial.
"We were surprised by the extent of the improvement in the most severely affected patients, and this level of improvement has not been observed in this category of patients with advanced dry macular degeneration," said Rajesh Rao, an ophthalmologist and researcher at the University of Michigan Medical School.
The trial continues to monitor patients who received higher doses (150,000 and 250,000 cells), and if deemed safe, this will allow for the expansion of human trials.
The results were published in the journal Cell Stem Cell.
