Corneas Made From Pigskin Restore Vision

by Kevin Burton

   Fourteen blind people had vision restored after receiving cornea implants made from pigskin, according to published reports.

   Three of those people had perfect vision after undergoing a new surgical technique developed by Swedish researchers, wrote Sarah Kuta in Smithsonian Magazine.

   The cornea is the clear outer layer that protects and focuses light into the eyes.

   “Though corneas with mild damage can heal on their own, some people may need a human cornea transplant to regain their vision,” Kuta wrote.

   “In a small clinical trial, the implants led to eyesight improvements in 20 patients suffering from advanced keratoconus, a condition when the cornea thins and bulges, causing blurry, distorted vision.”

   “Fourteen of the 20 participants were blind before the procedure but regained some or all of their sight after receiving the implants; they were also able to wear contact lenses again. Three of the blind patients achieved perfect 20/20 vision after the transplants.”

   The researchers shared these and other results in a new paper published last week in the journal Nature Biotechnology.

   “Diseased corneas are a leading cause of blindness and a 2016 study found that an estimated 12.7 million people are on the waiting list to receive a cornea transplant,” wrote IG News. “The shortage of human donors means there is only one cornea available for every 70 needs.”

    “Like other types of donated organs, human corneas must be used quickly—within two weeks of the donor’s death—which can create logistical challenges. In many parts of the world, particularly in poorer areas, there aren’t enough cornea donations to go around,” Kuta wrote.

    “It is possible to develop a biomaterial that meets all the criteria for being used as human implants, which can be mass-produced and stored up to two years and thereby reach even more people with vision problems,” said Neil Lagali, an ophthalmologist at Linköping University and one of the study’s authors. “This gets us around the problem of shortage of donated corneal tissue and access to other treatments for eye diseases.”

   “To develop the cornea transplants, the researchers used medical-grade collagen derived from pig skin to create a transparent hydrogel. Surgeons then made a tiny incision in each patient’s cornea and inserted the hydrogel, which helped thicken and reshape the cornea to restore its functionality,” Kuta wrote.

   “This surgical method is an improvement on traditional transplant procedures, during which surgeons remove the patient’s original cornea and stitch the new one into place. The 30-minute hydrogel procedure is much faster than a typical cornea transplant, which can take several hours.”

   “All of the study’s participants continued to tolerate the implants two years after the procedure and did not experience any adverse effects, such as inflammation or scarring,” Kuta wrote. “Patients in the clinical trial used immunosuppressive eyedrops for just eight weeks after the procedure, compared to the several years of medication that follows traditional transplants. Their bodies did not reject the bioengineered corneas.”

   “The concept that we could have bioengineered corneas would be revolutionary,” said Marian Macsai, an ophthalmologist at the University of Chicago who was not involved in the study, speaking to NBC News.    “It would potentially eliminate the risk of rejection and potentially make corneas available to patients worldwide.”

   “Though it’s too soon to tell whether the bioengineered corneas could help patients suffering from other conditions, the technology is showing early signs of promise for those living with keratoconus, which affects one in 2,000 people worldwide, according to Johns Hopkins Medicine,” Kuta wrote.

   Next, researchers hope to trial the corneas in a study with 100 or more people, then continue toward regulatory approval, NBC News reports. They also hope to experiment with patients who have other eye conditions.

   “In the long run, their goal is to make bioengineered corneas available in parts of the world with limited resources. Though there is no waiting list for cornea transplants in the United States, according to the nonprofit group Eversight, that’s not the case elsewhere,” Kuta wrote.

   “We’ve made significant efforts to ensure that our invention will be widely available and affordable by all and not just by the wealthy,” says Mehrdad Rafat, a biomedical engineer at Linköping University, CEO of LinkoCare Life Sciences AB and one of the study’s authors. “That’s why this technology can be used in all parts of the world.”