- Researchers estimate that more than 10 million people worldwide live with corneal blindness caused by disease or injury to the eye’s cornea.
- Unilateral limbal stem cell deficiency (LSCD) is a type of corneal disease caused by certain injuries that can lead to vision loss.
- A new clinical trial is testing a potential new stem cell treatment for LSCD.
- Researchers reported that 50% of treated study participants experienced complete cornea restoration after 3 months.
As of 2019, researchers estimate that more than 10 million people globally live with corneal blindness due to disease or injury to the eye’s cornea.
The cornea is the outermost clear layer on the front of the eye. It is vital for clear vision, as it provides
Unilateral limbal stem cell deficiency (LSCD) is a corneal disease that occurs when there is a shortage of the limbal stem cells that typically regenerate the cornea as needed. This can lead to eye pain, blurred vision, and even vision loss.
LSCD can be caused by corneal injuries, such as
Currently, treatments for LSCD include surgical options, such as limbal stem cell transplants, as well as corneal scraping and amniotic membrane patching.
Ula Jurkunas, MD, associate director of the Cornea Service at Mass Eye and Ear, and professor of ophthalmology at Harvard Medical School, told Medical News Today that:
“Current treatment options for limbal stem cell deficiency caused by cornea injuries have considerable limitations, including injury to the healthy eye from removal of stem cells, or limited effectiveness. Because of this deficiency, they are unable to undergo a cornea transplant, the current standard of care, and they are often left blind in the affected eye and in great pain.”
Jurkunas is the principal investigator of a clinical trial testing a potential new stem cell treatment for LSCD.
She is also the lead author of a study recently published in the journal
This clinical trial revolved around an experimental stem cell therapy called cultivated autologous limbal epithelial cells (CALEC), which had reportedly been developed by researchers in the Mass General Brigham healthcare system.
“In the CALEC procedure, a very small biopsy is performed in a patient’s healthy eye, which removes a small amount of limbal cells,” Jurkunas explained. “Then, the cells are transported to a GMP (Good Manufacturing Practices) facility at Dana-Farber Cancer Institute, where they are expanded on a scaffold, a process that takes about two to three weeks.”
“The resulting stem cell graft is then brought back to Mass Eye and Ear, where it is transplanted into the patient’s damaged eye,” she continued. “After a brief recovery, the stem cell graft replenishes the limbal stem cells and restores the cornea’s surface. At this point, a patient can undergo a cornea transplant, or in the case of some patients in our study, do not need further cornea treatment.”
“We felt it was important to find new options for our patients that are safe to the donor and recipient eye, and effective,” Jurkunas added. “We feel the CALEC procedure fills some of these current gaps, and our study finds it was safe and feasible, and led to improvements in the cornea surface.”
At the study’s conclusion, researchers found the CALEC treatment completely restored the cornea of 50% of the 15 study participants recruited for this clinical trial at their 3-month follow-up.
Additionally, their complete success rate increased to 79% at the 12-month mark and 77% by 18 months after treatment.
“These findings are significant because it shows that CALEC’s effectiveness improved overtime, which can translate into a lasting benefit for patients who undergo these treatments,” Jurkunas said.
Researchers also reported a high safety profile for CALEC, with no serious issues occurring to either the donor or recipient eyes.
“Some existing methods to replenish limbal epithelial cells do not have as high of a safety profile; for example risking the healthy donor eye through the incision required to remove cells,” Jurkunas explained.
“CALEC, however, did have a high safety profile for patients. Only one infection occurred, and that was not due to the CALEC transplant itself. This is very important, because for a procedure to be widely used, it needs to be a safe option for patients,” she emphasized.
As for the next steps of this clinical trial, Jurkunas said they plan to expand to a phase 3 study of CALEC, that includes a randomized design testing it against a different treatment:
“Additionally, we are working to see [if] this stem cell transplant is feasible if it is allogenic (from a separate donor), rather than autologous (from the patient’s healthy eye). An allogenic approach may benefit patients who have sustained an injury, like a chemical burn, in both eyes.”
MNT had the opportunity to speak with Benjamin Bert, MD, a board-certified ophthalmologist at MemorialCare Orange Coast Medical Center in Fountain Valley, CA, about this study, who commented that any developments, especially in this area of treating corneal disease, is very important and very exciting.
“The limbal stem cells are cells that we are born with and then do not produce any additional during our lifetime, so if there’s damage to those, it’s somewhat irreversible,” Bert explained. “So the ability to repopulate those damaged cells using our own cells is a really exciting idea.”
“Previously, the only way to fix this was with a transplant from a cadaver donor,” he continued. “And there’s such a huge blood supply to this particular part of the cornea that people had to be on full systemic immunosuppression, as if they had a kidney transplant or a lung transplant, and we know that those medications have major side effects. So being able to repopulate these damaged cells using our own cells avoids all of those potential complications.”
For future research, Bert said he would like to see it continue to progress, and see how feasible it would be on a larger scale.
“The description of how they’re able to culture these cells requires pretty advanced technology, so it’s a question of can this be expanded so that it can be offered to many patients, or is it going to be limited just to these more academic centers where they have the laboratories and the capabilities to do it,” he added.
