The treatment of four patients with severe chemical burns in one eye, in phase one of a clinical trial with a method based on stem cells, had positive results. According to a team of American researchers, two of these 4 patients had a significant improvement in their vision after one year without further treatment. Two other patients were also able to perform corneal transplant surgery; An option that was not possible before this treatment due to the severity of the injuries.
“Our preliminary results suggest that this treatment may offer hope to patients with intractable blindness and pain associated with major corneal damage,” said Ola Jurkunas, senior author of the paper.
to report ScienceAlertIn a new method called autologous limbal epithelial cell culture (CALEC), a small sample of stem cells from the patient’s healthy eye is transplanted into the damaged eye. This method is not associated with the risk of rejection; Because the transplanted cells are taken from the patient’s own body.
Transplanted CALEC cells are harvested from the limbus (outer border of the cornea) of the patient’s healthy eye. Limbal stem cells play a very important role in protecting the cornea. The cornea is the protective and clear outer layer of the eye through which light first passes. The smoothness of this layer is necessary to have a clear vision.
Patients who suffer chemical burns in their eye area often face permanent damage to the limbal area, which makes it impossible for the natural regeneration of new cells. Treatment of eye damage usually involves transplanting a healthy cornea from a donor eye. Due to the necessity of limbal stem cells and a healthy corneal surface to support the new tissue, corneal transplantation is not possible for people with high eye injuries.
Transplantation of donated limbal tissue, which is associated with the possibility of eye infection, or direct transplantation of a larger part of cells from the patient’s healthy eye to the damaged eye, are among the alternative methods that are used to treat eye injuries. Removing a larger amount of healthy eye tissue may damage the growth of limbal cells in the healthy eye, and for this reason, it does not seem to be a suitable method.
The new treatment approach uses a minimal amount of stem cell tissue from a healthy eye, and this small amount is transformed into a larger layer of cells that can facilitate the regeneration of healthy tissue after transplantation into the damaged eye.
After restoring the healthy surface of the eye, it is possible to perform a conventional corneal transplant for patients; Of course, some of the patients present in the phase one clinical trial did not need a corneal transplant. Four treated patients were men aged 31 to 52 years, one of whom did not improve his vision after CALEC transplantation; But the surface of his cornea improved and opened the way for him to undergo a corneal transplant.
In the second patient, the initial biopsy failed to produce a stable stem cell graft; But this patient had a successful transplant three years later and in the second attempt at CALEC. This patient’s vision improved to such an extent that he was able to recognize hand movements, count fingers and perform cornea transplant surgery.
Two other patients experienced a significant improvement in vision of 20/30 and did not need corneal transplantation. Tissue sampling was done from healthy eyes of five patients; Of course, one of the patients was not able to perform the CALEC transplant due to the non-expansion of the stem cells. The important point in the feasibility and short-term safety of the new method was that the tissue-removed eyes of all five patients recovered without any complications and their vision returned after 4 weeks.
