For the first time ever, scientists in Japan have repaired a damaged cornea using induced pluripotent stem cells. According to the surgeon, the patient’s vision has improved since the breakthrough procedure.
Scientists created induced pluripotent stem (iPS) cells by reprogramming adult cells through a process that converts the cells into embryonic-like cells that can be developed into any other type of human cells such as nerve, pancreatic, liver, and corneal cells.
Though iPS cells have great potential to treat a wide range of medical conditions, the implementation from the laboratory to the clinic has been slow. By carrying out this new groundbreaking procedure, ophthalmologist Kohji Nishida from Osaka University in Japan has made a big leap in the field.
The cornea is the transparent front section of the eye, covering the iris and pupil. Stem cells in the cornea safeguard that it becomes refreshed and repaired when needed, keeping it clear for light to enter. But, if these stem cells get damaged due to disease or injury, maintenance of the cornea will no longer be possible, and can consequently lead to corneal blindness.
Patients with damaged corneas must wait for donor tissue to become available, and like any other organ transplant, this can be a lengthy process. Dr. Nishida’s patient who underwent the recent surgery suffered from a genetic condition that affects the stem cells of the cornea resulting in blurry vision and eventually loss of sight.
In the procedure, the researchers implanted thin sheets of iPS cells into the patient’s eye in the hope that they would take root and fill in the gaps made by her missing corneal stem cells.
The Importance Of iPS Cells
Japan is the leader in iPS technology with Shinya Yamanaka first presenting his research on these experimental cells back in 2006. While stem cells had caused excitement in medical circles, iPS cells seemed to promise more. Scientists could not unleash stem cells from the ethical concerns related to fetal tissue, but iPS cells can be derived from adult skin cells, sidestepping that issue entirely.
Moreover, as scientists derive iPS cells from the patient’s own tissue, there are no issues with transplant rejection. In contrast, preventing the rejection of embryonic stem cells has posed a significant challenge.
In 2012, Yamanaka shared the Nobel Prize in Physiology or Medicine for his pioneering role in the discovery and advancement of iPS cells. In Japan, researchers have already tested iPS cells for a number of conditions in clinical trials such as spinal cord injuries and Parkinson’s disease.
More Procedures To Come
After successful research in an animal trial, the Japanese health ministry gave the signal to Nishida to carry out the corneal repair procedure in four people. Up to now, the first treatment appears to be a success. Nishida says, the person’s cornea is still clear, and her vision has improved in the month since the operation.
He now plans to carry out the second procedure later this year and expresses hope that the surgery will be available to more people within 5 years.
A recent global survey of corneal transplantation has determined that there is “only one cornea available for 70 needed.” With any luck, this groundbreaking technology will, in due course, close that gap.