Bioengineered Cornea Restores Sight

Scientists at Linköping University in Sweden have developed a collagen-based corneal implant that can restore sight to blind patients with corneal disease. The breakthrough could pave the way for such patients to receive effective treatment for corneal disease without requiring a corneal transplant from a human donor. There is a shortage of donor corneas, so creating an off-the-shelf alternative could be very useful. The bioengineered cornea was created using highly purified collagen derived from pig skin, a byproduct of the food industry. The researchers developed a method to double crosslink the purified collagen, using both chemical and photochemical crosslinking techniques, resulting in a stabilized and robust implant that can significantly improve sight in recipients.

Almost 13 million people are blind worldwide because of corneal disease, but obtaining a donor cornea to restore sight is challenging because there is a shortage. There is a critical need to develop bioengineered alternatives to help address this underserved patient population. This latest study appears to have achieved just that.

The collagen constructs were made through a double crosslinking process that helped to stabilize the loose collagen fibers used in the implants, meaning that they have the correct mechanical and biochemical properties for use as a corneal replacement. Excitingly, unlike donor corneas, which must be used within two weeks, the new collagen implants are stable for up to two years, meaning they represent a true “off-the-shelf” solution.

“The results show that 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, one of the lead creators of the new implants. “This gets us around the problem of shortage of donated corneal tissue and access to other treatments for eye diseases.”

So far, the Linköping team have tested the implants in 20 patients with keratoconus, a corneal disease in which the cornea becomes very thin, affecting sight. At the start of the study 14 of 20 patients were blind, with the remaining 6 suffering poor sight. At the study end-point, 2 years after implantation of the bioengineered corneas, none of the patients were blind and three participants had 20/20 vision.

“Safety and effectiveness of the bioengineered implants have been the core of our work,” said Mehrdad Rafat, another researcher involved in the study. “We’ve made significant efforts to ensure that our invention will be widely available and affordable by all and not just by the wealthy. That’s why this technology can be used in all parts of the world.”

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