In a small pilot study, the implants were able to restore corneal thickness and curvature to normal levels, and vision outcomes were as good as if human-donated corneas had been used.
Scientists from the Linköping University in Sweden have successfully developed implantable corneas from pig skin collagen that restored sight to 14 previously-blind patients.
In a small pilot study of 20 patients from sites in Iran and India, the implants were able to restore corneal thickness and curvature to normal levels, and vision outcomes were as good as if human-donated corneas had been used. Fourteen patients entered the pilot study blind, and after two years, all had regained vision. Two patients even reached 20/20 eyesight after the procedure.
The implants were safe to use. Using a new, minimally invasive approach, which they developed with pig skin-derived corneas, the researchers detected no surgical complications, and all wounds healed quickly. An eight-week course of immunosuppressive eye drops was enough to prevent implant rejection, much shorter than the regimens typically used following a human corneal transplant.
The study, published Thursday in Nature Biotechnology, was co-led by researchers from the Swedish bioengineering company LinkoCare Life Sciences AB.
“Safety and effectiveness of the bioengineered implants have been the core of our work,” Mehrdad Rafat, adjunct associate professor at the Department of Biomedical Engineering at Linköping University, said in a statement. Rafat was the brain behind the design and development of these novel implants and is also the founder and CEO of LinkoCare.
“We’ve made significant efforts to ensure that our invention will be widely available and affordable by all and not just by the wealthy. That’s why this technology can be used in all parts of the world,” he added. This was also part of the motivation to conduct the pilot in Iran and India, where corneal blindness is prevalent, but there are few donors and treatment options.
More than 12 million people worldwide are blind due to damaged, weak or diseased corneas. While there are medicines to slow the blinding, the only way to restore vision is to take out the old cornea and replace it with a new, healthy one. But such transplants are expensive and can only be performed in large, specialized centers. Finding donor corneas is also challenging, and only one in 70 patients eventually receive a transplant.
The Linköping team used pig skin sourced from the food industry to address the supply shortage and high barriers to access. The extracted collagen underwent a stringent purification process and was produced under tightly controlled conditions in order to make it suitable for human use. The loose collagen molecules were then stabilized and arranged into a transparent film to create a robust corneal transplant.
Whereas donated corneas last for only two weeks, the pig-derived implants can withstand storage for up to two years.
If established as safe and effective in larger, more expansive clinical studies, these novel corneal implants will join a fast-growing therapeutic space. According to analytics firm Vision Research Reports, the corneal implants market is sitting at around $420 million this year but is expected to reach nearly $700 million by 2030. This growth is driven mainly by the rising prevalence of corneal diseases and industry interest in bioengineered, 3D-printed and stem cell-derived corneas.
