A research team from Osaka University said Thursday it had conducted the world’s first transplant of corneal tissues using artificially derived stem cells in July.

The university’s team, led by Koji Nishida, may have created a new treatment for those suffering from corneal disease, as current treatment procedures involve waiting for corneal donations from deceased donors. A total of around 1,600 patients in the country are waiting for corneal donations, according to an estimate by the health ministry.

The patient in the July surgery, a woman in her 40s who suffered from corneal epithelial stem cell deficiency, was discharged from the hospital Aug. 23 after receiving the operation on her left eye on July 25. Her eyesight has improved considerably and there have been no problems detected so far, the team said.

“We have only conducted the first operation and we are continuing to monitor the patient carefully,” Nishida said at a news conference, adding that the team hopes to make the treatment practical in about five years.

Corneal disease is caused by losing cells in the eye that produce the cornea due to illness or injury, leading to worsening eyesight and loss of vision.

The team transplanted extremely thin sheet-like corneal tissues produced from another individual’s induced pluripotent stem cells, or iPS cells, that had been stored at Kyoto University.

The team believes that one transplant should remain effective throughout a patient’s life. The researchers will continue to monitor the patient to observe the transplant’s effectiveness and safety and will look for any signs of a tumor.

The health ministry in March approved the research team’s clinical studies on four adult patients. The team plans to conduct another transplant this year.

The transplanted cells are expected to keep making more corneal cells, and therefore contribute to sight recovery.

Conventional corneal transplant operations are prone to rejection because immune cells get implanted along with the rest of the cornea.

The sheets of corneal cells used by the team do not contain immune cells, so the team believes that they are unlikely to be rejected.

IPS cells, which can grow into any type of body tissue, were identified by Kyoto University’s Shinya Yamanaka, who won the 2012 Nobel Prize in physiology or medicine for his work. The world’s first clinical study using iPS cells was conducted in 2014 by the government-backed Riken institute, transplanting retina cells into a woman with age-related macular degeneration.