A team of scientists says they have found a new way to help people with damaged corneas: artisanal implants created from pig skin. In findings from a small clinical trial published this month, the implants were shown to restore sight to people for up to two years, including those who were legally blind. If it continues to show promise, the technology may one day provide a mass-produced alternative to donated human corneas for people with these conditions. The cornea is the transparent outer covering of the eye. In addition to protecting the rest of the eye, it helps us see by focusing the light that passes through it. Corneas can heal from mild abrasions fairly easily, but more serious injuries and certain diseases can leave behind permanently damaged corneas that begin to impair our vision. About 4 million people are believed to suffer from vision-related problems caused by damaged corneas, according to the World Health Organization, and it is one of the leading causes of blindness. For those with severely damaged corneas, the only truly effective treatment is to transplant a healthy cornea, also known as a corneal graft. Unfortunately, like many organs, human corneas must be used very soon after being donated and are often in short supply, especially for people living in poorer countries. This shortage has fueled researchers’ efforts to find other methods to replace or support damaged corneas. One such approach is the implant created by researchers from Linköping University (LiU) in Sweden, who also founded the company LinkoCare Life Sciences AB to develop it further. In their research, published last week in Nature Biotechnology, the team gave their implant to 20 patients from India and Iran with advanced keratoconus, a condition where the cornea progressively thins. Nineteen of the 20 patients experienced substantial improvements in their vision later, with the 14 who were legally blind no longer meeting this threshold. Patients who needed further corrective treatment were also now able to tolerate contact lenses again. And those gains remained stable two years later, with no adverse effects reported. “The results show that it is possible to develop a biomaterial that meets all the criteria for use as human implants, which can be mass-produced and stored for up to two years, thus reaching even more visually impaired people,” he said. the author of the study. Mehrdad Rafat, a professor in LiU’s Department of Biomedical Engineering and CEO of LinkoCare, in a university statement. G/O Media may receive a commission There are existing artificial corneas in use, as well as similar treatments in development. But the researchers say their implant should have some key advantages over those options. Many of these treatments still rely on donated corneas to reduce the risk of rejection by the body, while the team’s implant uses a relatively inexpensive biosynthetic material derived from purified pig skin. The material is then used to create a thin but durable layer of mostly collagen, the same basic component of the cornea. In the current study, patients received only eight weeks of transplant medication to ensure body acceptance, as opposed to the year or more of medication typically given to those with corneal transplants, and no signs of rejection were reported. They have also developed a less invasive surgical method to insert their implant that does not need to remove the original cornea, which will reduce the risk of complications and allow for wider use in places with fewer resources. And their other research shows that the materials in the implant should remain stable for at least eight years, if not longer. “We have gone to great lengths to ensure that our invention is widely available and affordable to everyone, not just the wealthy. That is why this technology can be used in all parts of the world,” said Rafat. Of course, these findings are still very small in scope. Successful results seen in many more patients will be needed before any country will consider approving this treatment. To that end, the researchers are planning larger clinical trials of their implant and may expand their work to see if the treatment might work for other cornea-related conditions.
