World’s First Stem Cell Therapy to Restore Vision Shows Promising Long-Term Results

Researchers in Japan have reported a major breakthrough in treating severe vision impairment using stem cell therapy. The world’s first patients to undergo this innovative procedure demonstrated significant and lasting improvement in vision, with effects persisting for over a year. A fourth participant also experienced visual improvement, although the results were temporary.

This pioneering clinical intervention marks a turning point in ophthalmology, as it targets corneal diseases using induced pluripotent stem cells (iPS) derived from donor blood. These cells were reprogrammed into an embryonic-like state and then developed into a transparent epithelial layer of corneal cells, shaped for optimal surgical application.

The treatment was led by Dr. Koji Nishida, an ophthalmologist from Osaka University, along with his team. Between June 2019 and November 2020, the researchers treated four patients aged 39 to 72 with bilateral limbal stem cell deficiency (LSCD) — a condition where the eye loses its ability to naturally regenerate the corneal surface. LSCD can result from eye trauma, autoimmune diseases, or genetic disorders.

During the surgery, scar tissue was first removed from the surface of one eye. The lab-grown epithelial sheet was then stitched into place and covered with a soft contact lens for protection. Remarkably, none of the patients experienced severe side effects or signs of tissue rejection, even those who did not receive immunosuppressive medications. Furthermore, no tumor formation — a known risk of iPS-based treatments — was observed.

Following the transplants, all four patients showed immediate improvement in vision and a measurable reduction in the area affected by LSCD. The success of these early cases has encouraged the research team to proceed with larger-scale clinical trials, which are scheduled to begin in March 2025 to further assess the therapy’s safety and effectiveness.