The first patient to receive a CALEC cell transplant in 2018 is pictured with doctors. (Photo credit: Mass Eye and Ear)
A new stem cell therapy reversed blinding corneal damage in 93% of participants in an early clinical trial.
The cornea is a clear dome that covers the front of the eye and helps focus light, allowing you to see clearly. On the outer edge of the cornea are stem cells known as limbal epithelial cells, which can transform into any other type of corneal epithelial cell. This means that these stem cells can replace damaged corneal cells caused by injury or normal wear and tear over time.
However, severe injuries such as chemical burns or infections can completely destroy these stem cells, as can Stevens-Johnson syndrome, which can cause blisters to form on the mucous membranes of the eye. In such cases, the cornea is damaged beyond repair, which can lead to blindness in the affected eye. Patients with this type of eye injury cannot be treated with traditional corneal transplants, as they use donor tissue to replace only the central portion of the damaged cornea, while the stem cells at the outer edges, which are vital for repair, are missing.
One possible solution is to restore the lost supply of stem cells in a patient’s damaged eye using healthy cells from his remaining, healthy eye. In this procedure, known as “cultured autologous limbal epithelial cell transplantation,” doctors extract stem cells from the healthy eye, grow them into cell sheets in the lab, and then surgically transplant them into the damaged eye.
The treatment was initially tested in 2018 in a small clinical trial at Massachusetts Eye and Ear Infirmary in Boston. The study involved four patients, each with a chemical burn in one eye. It was the first-ever stem cell therapy for the eye in the U.S., the team said at the time. The patients were followed for a year after the transplant, during which time the procedure was shown to be feasible, safe, and potentially effective.
Now, the same research team has published the results of a larger study that included 15 patients followed for 18 months after treatment. According to the paper, published Tuesday (March 4) in the journal Nature Communications, the patients had blinding corneal injuries due to a variety of causes, such as chemical burns, thermal burns, or viral eye infections.
Treatment was successful in 14 of 15 patients after 18 months.
“Success” of the treatment in the trial was defined by three criteria, trial leader Dr. Ula Jurkunas, associate director of the cornea service at Massachusetts Eye and Ear Infirmary, told Live Science. This meant that the surface of the damaged cornea was repaired, that the blood vessels that had previously obscured vision in the affected eye had receded, and that patients experienced less eye pain and discomfort. There were also no serious side effects from the transplant itself. However, one patient developed a bacterial infection unrelated to the treatment.
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Sourse: www.livescience.com
