Laboratory-made “biosynthetic” corneas can spur damaged tissue and broken nerves to regenerate, restoring vision in human eyes just as well as donor corneas, according to a two-year study of 10 patients reported in Science Translational Medicine.
A worldwide shortage of donated corneas leaves millions of people likely to go blind each year. Now, researchers in Sweden show that these biosynthetic corneas made with human collagen may allow patients who need corneal transplants but do not have donors to regain normal sight.
The implants also avoid some of the drawbacks of using regular human corneal tissue, such as the possibility of disease transmission from the donor.
Human sight depends on the cornea, a tiny piece of transparent, film-like tissue that covers the surface of our eyes. Constructed from parallel strands of the protein collagen, the cornea refracts light to focus images on the retina. Although the fragile film is easily destroyed by trauma or infection, replacement human corneas can be inserted and reliably restore vision.
An informal conversation with Dr. Per Fagerholm.
Per Fagerholm and colleagues at Linköping University removed diseased tissue from the corneas of 10 patients and replaced them with biosynthetic implants designed to mimic the largely collagen-containing normal human cornea.
An informal conversation with Dr. Per Fagerholm.
The patients were followed for two years after surgery, to monitor how the implants were incorporated into the eye. The researchers observed that eventually, the cells and nerves from nine of the 10 patients regrew completely and packed themselves into the implant, resulting in a “regenerated” cornea that resembled normal, healthy eye tissue.
Overall vision improved in six of the 10 patients. After contact lens fitting, all of the patients had vision that was equivalent to conventional corneal transplantation with human donor tissue.
Moreover, patients did not experience any bodily rejection or require long-term immune suppression; both are serious side effects associated with the use of human donor corneas. Next, further studies plan to extend the use of the biosynthetic cornea to a wider range of sight-threatening conditions.
Science Translational Medicine, the newest journal from Science, focuses on outstanding science with promise to improve human health and quality-of-life. Under the direction of Elias Zerhouni, chief scientific adviser and former director of the National Institutes of Health, and Editor Katrina Kelner, the journal aims to publish groundbreaking research from basic biology that will help make significant advances in medical care, along with commentary on the latest issues in translational medicine.
Watch an informal conversation with Dr. Per Fagerholm.
Read the abstract for “Restoring Vision with Biosynthetic Corneas.”
Watch a video of surgeons implanting a biosynthetic cornea in a patient with advanced keratoconus. (Because this video shows a surgery, portions of it are graphic.)