People with cornea-related blindness may be able to have their vision restored without having to wait for a human donor cornea, thanks to a newly engineered corneal transplant derived from pig skin.
Scientists at Linköping University in Sweden bioengineered a tissue implant that restored sight in severely visually impaired and blind people. The approach was as successful as with a donated cornea.
"This was beyond our expectations," study authors Mehrdad Rafat, PhD, and Neil Lagali, PhD, told Medscape Medical News. "What surprised us was how well the implant worked to restore the thickness and shape of the diseased cornea and how this translated into excellent vision for the patients, in some cases resulting in perfect 20/20 vision."
The pilot study included 20 people with advanced keratoconus, 14 of whom were blind. In advanced cases of keratoconus, the cornea thins and weakens, damaging sight. Two years after the implantation, vision was restored for all the patients.
An estimated 12.7 million people worldwide are waiting for a cornea transplant. There is only one human-donor cornea for every 70 that are needed. The shortfall lands heavily on low- and middle-income countries, where there is limited or no access to corneal transplants.
"Donor tissue is in short supply," the study authors say. "We show that bioengineered tissue" can be made "using sustainable raw materials ― in our case collagen extracted from pig skin, which is a byproduct from the food industry."
The researchers improved the surgical procedure to make it "simpler and safer," they say. No sutures are needed with the new method; it can be performed with either surgical lasers or hand instruments, allowing the technology to reach people who do not have access to advanced eye care.
"We wanted to develop a solution that would avoid the need for organ donation and that would be simple to implement and could be brought to even remote areas," said Rafat and Lagali.
The highly purified collagen used in the bioengineered corneas has been approved by the US Food and Drug Administration and is used for other medical applications. The researchers also developed a new method that stabilizes the collagen that forms the implants, allowing it to be packaged, shipped, and stored for up to 2 years.
The innovation can be used for other applications, the researchers say, including treating other types of ectasia, or corneal thinning, and corneal scarring or dystrophy.
Raft and Lagali have their eyes set on the future to further the access of their technology. "Our next step is to conduct larger randomized clinical trials in Europe and the US to be able to show safety and efficacy data to regulatory agencies, which would then give us the green light to market and distribute the bioengineered corneas on a wide scale."
Rafat and Lagali report no relevant financial relationships.
Nat Biotechnol. Published online August 11, 2022. Full text
Lead image: Thor Balkhed/Linköpings universitet
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Cite this: Bioengineered Corneas Made of Pig Skin Could Help Millions See Again - Medscape - Aug 19, 2022.