Stem Cell Therapy Shows Promise in Treating Severe Corneal Damage
A groundbreaking study has unveiled promising results for a novel stem cell therapy aimed at restoring vision in individuals with severe corneal injuries that are otherwise untreatable. The research, led by scientists at Mass Eye and Ear, suggests that transplanting stem cells from a patient’s healthy eye to their damaged cornea can effectively regenerate the corneal surface and improve vision.
The cornea, the clear front layer of the eye, plays a vital role in protecting the eye and focusing light onto the retina, enabling clear vision. When the cornea is severely damaged by injury or infection, it can lead to scarring and vision impairment. In many cases, corneal transplantation, involving the replacement of damaged corneal tissue with healthy tissue from a donor, can restore vision.
However, some injuries are so extensive that they deplete the cornea’s supply of limbal epithelial cells, which are stem cells responsible for replenishing the cells on the cornea’s surface. This condition, known as limbal stem cell deficiency, results in permanent damage to the corneal surface, rendering traditional corneal grafts ineffective as the donated cornea deteriorates without the support of stem cells.
"When people have a corneal stem cell deficiency, which is a very devastating condition, they can have a really white cornea and no vision. And there’s a lot of pain and discomfort. There are really no good ways to treat that," explained lead study researcher Ula Jurkunas, associate director of the Cornea Service at Mass Eye and Ear.
Recognizing the challenges in treating these complex cases, researchers have been exploring alternative approaches, including stem cell therapy. Jurkunas and her team at Mass Eye and Ear have developed a technique to safely harvest and cultivate healthy stem cells from a patient’s uninjured cornea. These cells, known as cultivated autologous limbal epithelial cells (CALEC), are then assembled into a cellular tissue graft and transplanted onto the patient’s damaged cornea.
In a Phase I/II clinical trial involving 14 patients with severe corneal damage, the researchers evaluated the safety and efficacy of CALEC transplantation. The results, published in Nature Communications, revealed that 92% of patients experienced at least a partial restoration of their corneal surface within 18 months of the procedure, while 77% achieved complete restoration. Furthermore, all patients demonstrated improvement in their visual acuity.
Importantly, the CALEC transplant appeared to be well-tolerated, with no serious adverse events directly related to the procedure reported. One patient experienced a bacterial infection several months later, but this was attributed to chronic contact lens use.
"A lot of them have had a great transformative change in their symptoms. And these were really severe injuries with no current treatment beforehand. But now they’re able to function," Jurkunas said. "I had one patient tell me, ‘I actually got my life back.’"
The success of CALEC transplantation in this study represents a significant advancement in the treatment of severe corneal damage. It offers hope for individuals who have been left with limited or no vision due to limbal stem cell deficiency.
"I think that this is a very big stepping stone for stem cell therapy in general. Again, we’re not using stem cells from embryonic cells. These are adult-derived stem cells that already exist in our bodies, but we’re able to harness them and to create products where we treat the person’s own body with their own stem cells," Jurkunas said.
While the findings are encouraging, it is important to note that CALEC transplantation is still an experimental procedure. Further research is needed to confirm its long-term safety and efficacy. Additionally, many patients who respond to CALEC transplantation may still require a subsequent corneal graft to achieve substantial improvement in their vision.
The researchers are currently working to initiate larger clinical trials at multiple eye centers to broaden access to this promising therapy. They are also exploring ways to enhance the technology, such as developing methods to cultivate and transplant stem cells from other donors, which would extend the benefits of this treatment to individuals with damage to both corneas.
If future studies continue to demonstrate the safety and efficacy of CALEC transplantation, it has the potential to become a new standard of care for patients with severe corneal damage and limbal stem cell deficiency, offering renewed hope for vision restoration and improved quality of life. This innovative approach highlights the transformative potential of stem cell therapy in addressing previously untreatable conditions.
