Pig Skin Protein Restores Vision of 14 Blind People in Study

When we encounter pig skin, oftentimes, we think of the crispy delectable dish used as a topping or eaten as a snack on its own. As for researchers from Linköping University in Sweden, pig skin has paved the way to restore the sight of 14 blind people.

As published on Nature Biotechnology Journal’s website this August, the research team’s study, “Bioengineered corneal tissue for minimally invasive vision restoration in advanced keratoconus in two clinical cohorts”, made use of dissolved pig tissue to form a purified Type I collagen solution turned into a hydrogel that mimics the cornea to treat keratoconus.

Keratoconus is an eye disease that affects the eye’s corneal structure and its ability to focus light, resulting to vision loss, and eventually requiring corneal transplantation.

Traditional corneal transplantations utilize human tissue. However, the study states that the severe shortage of donor corneas poses more burden of blindness especially to low- and middle-income countries in Asia, Africa and the Middle East. According to the research, the incidence of new cases of corneal blindness annually is over 1 million, with only 1 cornea available for every 70 needed.

A main objective therefore of the study is to provide a substitute that can be mass-produced, to give wider and easier access to corneal transplantation (as these can be stored up to 2 years unlike human tissue), that is less invasive as well.

The procedure which uses the porcine-derived hydrogel only takes around 30 minutes, whereas human tissue corneal transplantation needs several hours and requires stitches.

Surgeons created an incision in the patient’s cornea to serve as the insertion point of the hydrogel, which will “thicken the cornea” and “reshape it so that it can restore the cornea’s function”, explains Neil Lagali, professor of experimental ophthalmology at Linköping University and co-author of the study, in his interview with NBC.

The patients were given immunosuppressive eyedrops to lower risk of implant rejection. No adverse effects were reported from the 20 subjects from India and Iran (14 of whom were already blind, and 6 were on the verge of losing their sight prior to the study).

After two years, significant improvements were noted among the participants – the 14 blind patients had their visions restored, and 3 subjects even had clinically perfect vision.

The pilot study was limited to patients with only the central layer of the cornea affected, and did not include cases where there is corneal scarring due to bacterial/viral infection. However, further studies are being pursued by the team, with the goal of eventually gaining regulatory approval.

“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, and one of the study’s authors. “That’s why this technology can be used in all parts of the world,” Rafat adds.

-with reports from Smithsonian Magazine and NBC News