Japan performs world's first cornea transplant with iPS cells
A medical team at Osaka University has conducted the first-ever cornea transplant surgery using induced pluripotent stem cells (iPS cells), restoring partial eyesight to the patient, NHK reported.
Koji Nishida (西田幸二), a professor at Osaka University, announced the success of the transplant on Thursday (Aug. 29). According to Nishida, the transplant surgery took place July 23 and was conducted on the left eye of a female patient who was nearly blind due to corneal epithelial stem cell deficiency.
The team cultivated corneal epithelial cells from a donor's iPS cells provided by Kyoto University. It used millions of these to engineer a membrane 3 centimeters in diameter and 0.03 to 0.05 millimeters thick to replace the whitish, turbid part that precludes the patient from seeing clearly.
The patient showed no negative reaction to the transplant and was able to read text from newspapers or books. She left the hospital last Friday (Aug. 23).
“There is still much we do not know about cornea treatment with iPS cells, but we aim to popularize the method in five years,” said Nishida. The team plans to conduct another similar clinical surgery this year and two more in 2020 to ascertain the safety and effectiveness of the transplant.
Similar to the more well-known embryonic stem cells, iPS cells can propagate indefinitely and transform into any other type of cell, showing promise in the field of regenerative medicine. Furthermore, iPS cells are generated directly from adult cells, resulting in less controversy than embryonic stem cells, which involve the destruction of pre-implantation stage embryos.
Corneal epithelial stem cell deficiency is caused by natural imperfections or injury of the corneal epithelial, the tissue that covers the cornea. Patients experience degraded eyesight and even total blindness as the cornea becomes opaque.
Transplant surgery is the most effective method to treat cornea-related deficiency, but there is a shortage of donors and also substantial risk of rejection. iPS cell engineering may be able to solve both problems in the near future.
This is the third iPS cells-related clinical surgery in Japan. Medical teams at Kyoto University transplanted retina cells into a patient suffering from age-related macular degeneration in 2014 and nerve cells into a Parkinson's patient in 2018, both of whom are still being evaluated for safety and effectiveness.
By Taiwan News