Stem cell transplant shows promise for vision loss
A novel stem cell-based corneal graft has shown the potential to partially restore sight in patients with severe vision loss.
In a recent world first, a research team based at Osaka University Hospital (Osaka, Japan) has used stem cell-derived corneal epithelial cells to treat patients with significant vision loss due to limbal stem cell deficiency (LSCD).
LSCD is a rare eye disorder characterized by the failure of limbal stem cells to properly regenerate. Over time, this causes a buildup of fibrotic conjunctivital scar tissue over the cornea, resulting in progressive vision loss for LSCD sufferers. Treatment for severe LSCD involves the removal of scar tissue from the corneal surface, followed by transplantation of a healthy corneal tissue graft. In patients who are only affected by LSCD in one eye, an autologous graft from their healthy cornea can be used. But, for patients who suffer in both eyes, oral mucosal tissue or allogeneic donor tissue must be used. While often successful, these grafts carry many of the typical risks associated with transplant procedures, such as damage to the donor site and immunological rejection of allogeneic tissue, as well as a risk of neovascularisation of the eye, which can itself cause vision loss.
ALS research accelerated with new iPSC repository
The largest resource for amyotrophic lateral sclerosis (ALS) research has been made accessible to researchers worldwide.
As an alternative, the Osaka-based research team has developed a novel graft type based on human induced pluripotent stem cells (iPSC). To create the grafts, the researchers used iPSCs to create pure samples of corneal epithelial stem-progenitor cells. These were then cultured to generate iPSC-derived corneal epithelial cell sheets, which the team transplanted onto the corneas of four LSCD patients. The transplant recipients were monitored for 2 years to determine the safety and tolerability of the grafts and look for early indications of efficacy.
At the end of the study, the procedure was deemed successful and safe, with none of the patients experiencing severe adverse events during the monitoring period. Promisingly, the treatment also showed signs of working in all four treated eyes. Patients reported being able to see more clearly, with a reduction in obstructive scar tissue covering the cornea.
This study represents the first time iPSC-derived corneal epithelial cells have been used in eye transplants. The researchers hope to build on their successful results by taking their ‘groundbreaking’ methodology into a large multicenter trial.