In development for more than a decade, biosynthetic corneas implanted in 10 Swedish patients over a two-year clinical trial are helping most of those patients see again, according to researchers in Canada and Sweden.
"This study is important because it is the first to show that an artificially fabricated cornea can integrate with the human eye and stimulate regeneration," senior author May Griffith of the Ottawa Hospital Research Institute said. "With further research, this approach could help restore sight to millions of people who are waiting for a donated human cornea for transplantation."
Griffith and colleagues began developing the biosynthetic cornea using collagen they produced in their lab that they molded into the shape of a cornea. After extensive testing, Griffith and eye surgeon Per Fagerholm at Linkoping University in Sweden initiated the trial for 10 patients with advanced keratoconus, or central corneal scarring.
The cornea is a thin and transparent layer of collagen and cells that allow light to enter the eyeball. Because the clouding of the cornea prevents light from entering the eyeball and is a leading cause of blindness across the globe, repairing it with a synthetic one could help restore vision to many.
In this study, each patient underwent surgery in one eye to replace the damaged corneal tissue with synthetically cross-linked recombinant human collagen. Over a two-year period, the cells and nerves from the patients' own corneas grew into the implant, without any cases of rejection often associated with human donor tissue.
Moreover, the biosynthetic corneas eventually became sensitive to the touch and produced tears to oxygenate the eyes. Actual vision improved in 6 of the 10 patients, a percentage the team finds promising from an early clinical trial:
"We are very encouraged by these results," Fagerholm says. "Further biomaterial enhancements and modifications to the surgical technique are ongoing, and new studies are being planned that will extend the use of the biosynthetic cornea to a wider range of sight-threatening conditions requiring transplantation."