Corneas made from porcine collagen have enabled blind or visually impaired subjects to regain their sight. During the two years following the operations, no serious complications or adverse side effects were observed.
Promising alternatives to human corneas
More than 12 million people worldwide are affected by blindness corneal, usually occurring when the transparent, protective outer layer of the eye becomes cloudy or distorted as a result of damage or disease. The transplants of cornea currently requiring a human donor, only one in 70 people in need of such care receive one. And it turns out that the prohibitive cost of such a surgical procedure in many low-income countries further complicates access to treatment.
In the context of work published in the journal Nature BiotechnologyMehrdad Rafat and his colleagues at Linköping University (Sweden) have developed a dome that is both flexible and resistant similar to a contact lens, by extracting and purifying collagen from porcine skin tissue. After successful preclinical trials, the team began testing the artificial corneas on human volunteers.
The twenty people taking part suffered from keratoconus, a condition in which the cornea becomes thin and deformed. Fourteen of them were officially recognized as blind before the operation, while the sight of the other six was described as severely impaired. Following the operation, all saw their vision improve significantlywith a visual acuity of 10/10 observed in three of the previously blind patients.
The use of collagen proteins also involves a much lower risk of rejection by the recipient’s immune system. While people receiving a human cornea transplant usually have to take medication for several years to avoid rejection, the twenty subjects only used immunosuppressive eye drops for eight weeks.
A lower total cost than a classic corneal transplant
Good that the total cost of the new procedure remains rather vague at this stage, Rafat considers that he will be lower than that of a classic corneal transplant, varying from a few thousand to several tens of thousands of euros depending on the country. His team is currently planning new clinical trials, which will pave the way for wider use of this approach.
As promising as these results are, Esen Akpek, of Johns Hopkins University, points out that people with keratoconus can often benefit from personalized contact lenses and that various alternatives to human corneas had been previously developed without however taking off. ” It will not cure people who cannot be cured with currently available technology. “, emphasizes the researcher.