A Hair-Thin Implant Could Restore Vision in People With Advanced Macular Degeneration

Researchers at USC are launching a new clinical trial testing whether a hair-thin stem cell implant can restore vision in people with advanced dry age-related macular degeneration, a condition that affects roughly 20 million Americans. The implant, smaller than a strand of hair, contains lab-grown cells designed to replace damaged retinal tissue responsible for sharp, central vision. Earlier studies showed the treatment was safe, and 27% of participants experienced some level of vision improvement.

What Is Macular Degeneration and Why Does It Matter?

Age-related macular degeneration is the most common cause of vision loss and blindness among Americans age 65 and older. The disease damages the macula, a small area at the center of the retina essential for sharp, detailed vision. As it progresses, people experience blurry areas, dark patches, or blind spots in the center of their vision, making it difficult to read, recognize faces, or focus on objects directly ahead.

The dry form of the disease, which accounts for the majority of cases, currently has very limited treatment options. While a few treatments can slow the progression of macular degeneration, none can reverse damage that has already occurred. This is where the new stem cell implant offers genuine hope for patients who have exhausted other options.

How Does the Stem Cell Implant Work?

The implant being tested in the trial is created from embryonic stem cells grown in a laboratory and developed into retinal pigment epithelium (RPE) cells. These RPE cells play a critical role in maintaining healthy vision, and their loss directly leads to visual decline in macular degeneration. During an outpatient surgical procedure, eye surgeons place a thin layer of these lab-grown cells directly into the retina.

"The study will explore if the lab-engineered implant will take over for the damaged cells, function as normal RPE cells would, and improve vision for patients who may currently have no other options for improvement," said Dr. Rodrigo Antonio Brant Fernandes, an ophthalmologist with Keck Medicine and the study surgeon.

What Did Earlier Research Show?

The new phase 2b clinical trial builds on encouraging results from earlier research conducted by USC Roski Eye Institute specialists. That initial study found the implant was safe, remained securely positioned in the eye, and was successfully absorbed into the retinal tissue. Most notably, 27% of participants experienced some level of vision improvement, suggesting the treatment has genuine potential to help patients.

"We are hoping to determine if the stem-cell based retinal implant can not only stop the progression of dry age-related macular degeneration, but actually improve patients' vision," said Dr. Sun Young Lee, a retinal surgeon with Keck Medicine and principal investigator of the Keck Medicine study site. "The findings could be groundbreaking because while there are a few treatments available that delay the progress of macular degeneration, there are none able to reverse the damage already done".

Steps to Understand the Clinical Trial Process

• Trial Design: The study is masked, meaning some participants will receive the actual implant while others will undergo a simulated procedure to ensure unbiased results.
• Patient Eligibility: Participants must be between ages 55 and 90 and have advanced dry age-related macular degeneration along with geographic atrophy, a condition in which RPE cells are damaged or no longer function properly.
• Study Duration and Monitoring: Participants will be followed for at least one year so researchers can evaluate how well the implant is tolerated and track any changes in vision.
• Enrollment Goals: The study aims to enroll 24 patients in total across five sites nationwide, with Keck Medicine serving as one of the participating centers.

What Makes This Treatment Different?

Unlike treatments that slow disease progression, this stem cell implant is designed to actively restore function by replacing damaged cells. For people living with advanced dry macular degeneration, this represents a fundamentally different approach to treatment. The implant's ultra-thin design allows it to be inserted during a minimally invasive outpatient procedure, reducing recovery time compared to traditional eye surgery.

The bioengineered RPE retinal implant is produced by Regenerative Patch Technologies LLC, a clinical-stage company focused on developing stem cell-based implants for retinal diseases. The technology is exclusively licensed to the company by the University of Southern California, the California Institute of Technology, and the University of California Santa Barbara.

What's Next for Stem Cell Eye Treatments?

"Stem cell-derived retinal implants may offer one of the greatest possibilities for helping patients with dry age-related macular degeneration and one day, may offer a cure," said Dr. Mark S. Humayun, co-director of the USC Roski Eye Institute and director of the USC Ginsberg Institute for Biomedical Therapeutics. This phase 2b trial represents a critical step toward bringing this technology from the laboratory to patients who desperately need new treatment options.

For those interested in learning more about the trial or potentially participating, interested individuals can contact Mariana Edwards or Kimberly Rodriguez at Keck Medicine. The results of this study could reshape how doctors approach advanced macular degeneration treatment and offer hope to millions of Americans struggling with age-related vision loss.