Aug 16, 2022 13:00:00

20 patients who were transplanted with ``artificial corneas made from pig skin'' regained their eyesight

Vision loss is a significant quality-of-life problem, with an estimated 12.7 million people worldwide suffering from vision loss due to

corneal damage or disease. A clinical trial was successful in restoring vision by transplanting an 'implant made from pig skin' to a person who lost vision due to such a corneal problem.

Bioengineered corneal tissue for minimally invasive vision restoration in advanced keratoconus in two clinical cohorts | Nature Biotechnology
https://www.nature.com/articles/s41587-022-01408-w

Bioengineered cornea can restore sight impaired to the blind and visually | EurekAlert!
https://www.eurekalert.org/news-releases/961194

Clinical Trial Restored Sight to 20 People With Corneas Made From An Unlikely Source : ScienceAlert
https://www.sciencealert.com/clinical-trial-restored-sight-to-20-people-with-corneas-made-from-an-unlikely-source

For those who suffer from blindness or reduced vision due to corneal damage or disease, donor corneal transplant surgery is almost the only way to regain vision. However, donated corneas can only be stored for two weeks, and surgery to remove the damaged cornea and replace it with a new cornea is invasive and can only be performed at well-equipped hospitals. As a result, only about 1 in 70 people can receive a corneal transplant, and there is also the problem that access to treatment is very limited in low- and middle-income countries.

Therefore, an international research team such as Sweden's Linköping University has developed an artificial cornea that chemically and photochemically processed ``pig skin-derived collagen molecules'' purified under strict conditions. Pig skin is readily available as a by-product of the meat industry, and a specially developed packaging and sterilization process allows the artificial cornea to be stored for up to two years.

The research team conducted a clinical trial in which artificial corneas made from pig skin were transplanted to 20 subjects suffering from blindness or decreased vision due to a disease called

keratoconus . Keratoconus is a disease in which the thickness of the central part of the cornea becomes thin and the cornea protrudes forward in a conical shape. Although the exact cause is unknown, it is genetic, eye trauma, hay fever, asthma, Down syndrome, Ehlers, and Danlos . Syndromes may increase the chances of developing the disease. Clinical trial subjects were recruited in India and Iran, and 14 out of 20 were completely blind.

In addition to the development of an artificial cornea, the research team is a relatively simple operation in which the eye is incised about 2 mm and an artificial cornea is inserted to compensate for the thickness of the cornea, rather than the usual invasive surgery involving removal and suturing of the cornea. I devised a law. The less invasive surgery can preserve the nerve and cell layers of the cornea, and the incision wound heals quickly, and the patient recovered after eight weeks of treatment with immunosuppressive eye drops and bandages. thing.

In clinical trials, all patients, including 14 who had been blind, recovered their vision to the same extent as regular corneal transplants, and the effects continued two years after surgery. In particular, three of the Indian participants who were blind before the experiment reportedly had a visual acuity of '1.0' two years after surgery. The patient did not show any immune rejection due to transplantation, and no scars or other adverse events were observed.

“We have invested a lot of money into ensuring that this invention is widely available and affordable by everyone, not just the wealthy,” said Mehrdad Rafat, a biomedical engineer at Linköping University. We've put in a lot of effort, and that's why this technology can be used in all regions of the world.'

Neil Lagali, also an ophthalmology researcher at Linköping University, said, 'This study circumvents the problem of scarcity of donated corneal tissue and access to other treatments for eye diseases.' The lower method can be used in more hospitals, so more people can be helped.Our method does not require the surgeon to remove the patient's tissue, instead a small incision is made and The implant is inserted into the cornea from' 'The result is that we have developed a biomaterial that meets all the criteria to be used as a human implant, can be mass-produced and stored for up to two years, and this can lead to further vision impairment. It shows that it reaches a lot of people,' he commented.

In the future, a large-scale clinical trial to transplant an artificial cornea derived from pig skin is planned, and the research team expects to meet regulatory approval in the future.