Could a Tiny Eye Implant Reverse Macular Degeneration?

A clinical trial is investigating whether a stem cell-derived patch can replace disease-damaged cells and restore vision.

Age-related macular degeneration is a steadily worsening eye disease and the leading cause of vision loss and blindness among Americans age 65 and older. It damages central vision, making it increasingly difficult to see faces, read text, or clearly view objects directly ahead as blurred, dark, or missing areas appear over time.

A new clinical trial is now providing renewed optimism for people with advanced “dry” age-related macular degeneration, the most common form of the condition.

Scientists at the USC Roski Eye Institute, part of Keck Medicine of USC, are beginning a phase 2b clinical trial to test whether specially engineered stem cells can replace damaged retinal cells and help restore vision lost to macular degeneration. These lab-grown cells are secured to an extremely thin implant that is even finer than a human hair, allowing the cells to remain in the correct position inside the eye.

“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 Sun Young Lee, MD, PhD, 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.”

The clinical trial follows early research conducted by USC Roski Eye Institute experts on a small patient population that showed the implant was well-tolerated, stayed put in the eye, and was successfully absorbed into the tissue of the retina. Additionally, 27% of patients had some improved vision.

“The earlier phase of the clinical trial showed the treatment to be safe with the potential to benefit patients’ vision; this next phase will investigate whether the therapy can achieve clinically significant improvements in vision,” said Lee, who is also an associate professor of ophthalmology and physiology & neuroscience at the Keck School of Medicine of USC.

How the retinal implant works

Approximately 20 million Americans live with age-related macular degeneration. This number also includes cases of wet macular degeneration, which is a less common but more serious form of the disease.

Age-related macular degeneration affects the eye’s macula, which is located in the center of the retina and is responsible for central vision. In advanced cases, the retinal pigment epithelium (RPE) cells, which line the macula and are key in helping the retina produce clear vision, become damaged or destroyed, which leads to vision loss.

The retinal implant used in the clinical trial is derived from embryonic stem cells grown into RPE cells in a lab. During an outpatient surgical procedure, Keck Medicine eye surgeons will implant a tiny layer of the lab-produced RPE cells 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 Rodrigo Antonio Brant Fernandes, MD, PhD, an ophthalmologist with Keck Medicine and the study surgeon.

Details of the clinical trial

Keck Medicine is one of five locations in the nation enrolling patients in the clinical trial. The study is masked — some of the enrolled participants will receive the implant, while others receive a simulated implant.

Eligible patients must be between ages 55-90 with advanced dry age-related macular degeneration and a diagnosis of geographic atrophy, meaning their RPE cells are damaged or not functioning.

Patients will be monitored for at least one year to determine how the implant is tolerated and for any changes in vision. The trial is hoping to enroll 24 patients.

Those interested in learning more about the trial can contact Mariana Edwards at [email protected] or Kimberly Rodriguez at [email protected].

“The USC Roski Eye Institute is dedicated to furthering innovative treatments to help improve lives by restoring vision,” said Mark S. Humayun, MD, PhD, co-director of the USC Roski Eye Institute, director of the USC Ginsberg Institute for Biomedical Therapeutics and the Dennis and Michele Slivinski Chair in Macular Degeneration Research at the Keck School. “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.”

The bioengineered RPE cell retinal implant is manufactured by Regenerative Patch Technologies LLC, a clinical-stage company developing stem cell-based implant technologies for the treatment of retinal diseases. Humayun co-invented the implant and is a co-founder of the company.

The technology to produce the cell implant is exclusively licensed to Regenerative Patch Technologies from the University of Southern California, the California Institute of Technology ,and the University of California Santa Barbara.

The clinical trial is in part funded by the California Institute for Regenerative Medicine, a California state-funded organization dedicated to accelerating the development of innovative cell and gene therapies, the Marcus Foundation, a biomedical research philanthropic organization, and USC.

Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.