Researchers have developed an implant made from pig skin that resembles the human cornea and could restore sight to the blind and partially sighted, according to a study.
In a pilot study, the implant – made of collagen protein from the animal – restored the sight of 20 people with diseased corneas, most of whom were blind before receiving the implant.
Researchers say their promising results offer hope to those suffering from corneal blindness and low vision.
The bioengineered implant is an alternative to transplants of donated human corneas, which are scarce in countries where the need for them is greatest.
The cornea is the transparent part of the eye that covers the iris and the pupil, and allows light to enter the eye – essential for the ability to see.
Neil Lagali, professor at the Department of Biomedical and Clinical Sciences at Linköping University, Sweden, was one of the researchers behind the study.
He said: “The results show that it is possible to develop a biomaterial that meets all the criteria to be used as human implants, which can be mass-produced and stored for up to two years and thus reach even more people with vision problems.
“This gets us around the problem of a shortage of donated corneal tissue and access to other treatments for eye diseases.”
Experts estimate that 12.7 million people worldwide are blind due to damaged or diseased corneas, but only one in 70 patients receives a cornea transplant.
And those who need cornea transplants tend to live in low- and middle-income countries where access to treatments is very limited.
Mehrdad Rafat is the researcher and entrepreneur behind the design and development of the implants, and CEO of LinkoCare Life Sciences AB, which manufactures the bioengineered corneas used in the study.
He said: “We have made a significant effort to ensure that our invention will be widely available and affordable to everyone and not just the wealthy.
“That’s why this technology can be used in any part of the world.”
To create an alternative to the human cornea, the researchers used collagen molecules derived from pig skin, which is a by-product of the food industry, making it readily available.
The researchers have also developed a new, minimally invasive method for treating the disease keratoconus, where the cornea becomes so thin that it can lead to blindness.
Transplantation usually involves the patient’s cornea being surgically removed and replaced with a donated one, which is sewn into place using surgical sutures.
Prof Lagali, who led the research team that developed this surgical method, said: “A less invasive method could be used in more hospitals, helping more people.
“With our method, the surgeon does not have to remove the patient’s own tissue.
“Instead, a small incision is made, through which the implant is inserted into the existing cornea.”
No stitches are needed with this new method of surgery.
The surgical method and implants were used by surgeons in Iran and India, two countries where many people suffer from corneal blindness and impaired vision, but where there is a significant shortage of donated corneas and treatment options.
Twenty people who were either blind or on the verge of losing their vision due to advanced keratoconus received the biomaterial implant.
According to the study, the operations were free of complications, the tissue healed quickly, and an eight-week treatment with immunosuppressive eye drops was enough to prevent rejection of the implant.
With conventional cornea transplants, medication must be taken for several years.
The patients were followed for two years, and no complications were recorded during that time.
Before the procedure, 14 of the 20 participants were blind.
After two years, none of them were blind anymore, and three of the Indian patients who had been blind before the study had perfect (20/20) vision after the operation.
The research is published in Nature Biotechnology.