Over 12 million people in the world are waiting for a cornea transplant to be able to see again, but only one in 70 receives it: this is because most of those who need it live in low-income countries, where the access to treatment is very limited. Now a team of Swedish researchers seems to have found a possible solution to the problem: a bioengineering implant developed from collagen obtained from pig skin, which has managed to restore sight to twenty blind or nearly blind volunteers. The results of the pilot study were published in Nature Biotechnology.
Pig skin. The human cornea is mainly composed of collagen, the most abundant protein in mammals. For this the scholars have decided to try to use a collagen alternativeobtained from purified pig skin: to produce the implant, the team stabilized the collagen molecules to form a robust and transparent material capable of withstanding manipulations and transplantation into the eye: “The results are promising and give hope to those suffering from corneal blindness and low vision », underline the authors.
The cornea is a transparent membrane that represents the most powerful lens of the visual apparatus. The crystalline is the other lens that forms the diopter (i.e. the optical system) of the ocular.
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The operation. The study involved 20 volunteers suffering from keratoconus, a degenerative disease that deforms the cornea, of which 16 are totally blind and four with severely impaired vision. The implant was inserted into the patients’ eye through a minimally invasive surgical operation, making a small incision without the need for sutures. Following the operation, all volunteers had improved their vision skills, and three of the blind people had regained 10/10 vision.
If, as the researchers hope, this bio-implant can be mass-produced at a relatively low cost, many people living in the poorest countries will benefit: in Iran and India, for example, many people suffer from corneal blindness and low vision, but donations of human corneas and opportunities to treat the disease are lacking.
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The advantages. The positive aspects of this new technique are different: first of all the cost, which should be lower as collagen is derived from an industrial waste product (pig skin). Secondly, the fact that the plant thus produced can be stored for up to two years, while a human cornea lasts just two weeks. Finally, animal collagen appears to be well accepted by the human body, as it is a structured protein that does not have individual cells as well it is therefore not rejected by the immune system. People who receive a human cornea transplant must normally take drugs for several years to avoid rejection, while for volunteers who have been implanted with porcine collagen, an eight-week treatment based on eye drops with immunosuppressive properties was sufficient. Two years after the operation, none of the study participants reported any serious complications or adverse side effects.
Now all that remains is to wait for new clinical studies involving more volunteers, hoping that they will confirm these first, excellent results and that the treatment will soon be approved by the competent authorities.