BY THE OPTIMIST DAILY EDITORIAL TEAM

For millions living with age-related macular degeneration, seeing the world head-on becomes an exercise in frustration. Faces blur, road signs fade, and once-clear scenes dissolve into a grey smudge at the center of vision. Existing treatments can only slow the damage, but sadly not reverse it.

That may soon change.

In a first-of-its-kind clinical trial, researchers have successfully tested a stem cell-based treatment that could potentially restore central vision in patients with advanced dry age-related macular degeneration (AMD), the most common form of the disease.

The early results are promising. Though still in its early stages, the phase 1/2a trial suggests that surgically transplanted stem cells cannot only halt but possibly improve vision. This is a development that scientists and ophthalmologists have long been striving for.

What’s new about this treatment?

Unlike ‘wet’ macular degeneration, which progresses rapidly, the more common ‘dry’ form is a slow breakdown of the retinal pigment epithelial (RPE) cells, which support the system for the eye’s light-sensing tissues. Over time, tiny deposits of fat and protein damage the macula, the central part of the retina responsible for sharp, focused vision.

The new approach involves transplanting eye bank-sourced RPE stem cells under the retina. These cells are intended to replace the damaged ones and restore the support system that allows the eye to function properly.

The procedure, tested in a small group of patients aged 71 to 86, involves injecting 50,000 RPE stem cells into the worst-affected eye through a single surgical injection targeting the upper macula.

A cautious trial yields surprising results

As a phase 1/2a trial, the primary goal was safety. And on that front, the treatment passed with flying colors.

Researchers observed no immune rejection, no tumor formation, and no serious side effects directly linked to the stem cells themselves. Some minor complications arose, but only ones typical for retinal surgeries, and none were cause for concern.

What surprised researchers most, however, was the unexpected vision improvement.

“Although we were pleased with the safety data, the exciting part was that their vision was also improving,” said Rajesh Rao, ophthalmologist and physician-scientist at Michigan Medicine. “We were surprised by the magnitude of vision gain in the most severely affected patients who received the adult stem cell-derived RPE transplants.”

That magnitude was significant. Among the three participants with the poorest baseline vision—measured between 20/200 and 20/800—each could see an average of 21 more letters on a standard eye chart one year after treatment.

In contrast, their untreated eyes saw no improvement, strongly suggesting that the stem cell transplant was responsible for the visual gains.

Who was involved in the study?

From an initial group of 18 screened individuals, six patients were selected based on the severity of their dry AMD. The trial included two subgroups: three with more advanced vision loss and three with moderate impairment.

The study was published in the peer-reviewed journal Cell Stem Cell, marking a milestone in ophthalmic regenerative medicine.

Earlier lab studies had already demonstrated that the transplanted stem cells retained their retinal identity, meaning they were likely to perform the tasks of natural RPEs. The cells also showed no signs of toxicity, which helped clear the way for human testing.

Next steps: testing higher doses

While the initial round used a relatively low dose of 50,000 cells, the team has begun monitoring patients receiving higher doses (150,000 and 250,000 cells) to determine whether the vision gains scale with cell count and remain safe.

If successful, these results could accelerate the path to phase 3 clinical trials, the final step before potential regulatory approval.

The hope, Rao says, is that the therapy might one day be widely available to the millions affected by AMD, many of whom currently have few or no options once the disease progresses past a certain point.

“This level of vision gain has not been seen in this group of patients with advanced dry AMD,” Rao added.

A potential paradigm shift in treating vision loss

Age-related macular degeneration is one of the leading causes of blindness worldwide, particularly among older adults. Until now, treatment options for dry AMD have focused on slowing progression, not reversing it.

This stem cell therapy could transform how ophthalmologists approach retinal degeneration by offering not just management but actual improvement.

While more research is needed, especially with larger and more diverse populations, these early results represent a hopeful step forward for millions whose central vision has faded, but whose world may still come back into focus.

Source study: Cell Stem Cell—Safety and tolerability of RPESC-RPE transplantation in patients with dry age-related macular degeneration: Low-dose clinical outcomes