London, August 12 (IANS) An international team of researchers, including from the All India Institute of Medical Sciences in India, has developed an implant made from collagen protein from pig skin that resembles the human cornea and has restored vision in blind and visually impaired people.
Bio-engineered implants act as an alternative to donated human corneal transplants, which are in limited supply in the countries where they are most needed.
“The results show that it is possible to develop biomaterials that meet all the criteria for use as human implants, which can be mass-produced and stored for up to two years and thus reach more people with vision health problems. around the issue of scarcity of donated corneal tissue and access to other treatments for eye diseases,” said Neil Lagali, professor in the Department of Biomedical and Clinical Sciences at Linkoping University (LiU) in Sweden.
In a pilot study, published in Nature Biotechnology, implants restored vision in 20 people in India and Iran with diseased corneas. Of the 20 participants, 14, including 3 Indians, were blind before receiving the implants.
Besides being safe, transplantation also restores normal corneal thickness and curvature. The participants’ vision also improved as much as after the corneal transplant with the donated tissue. After two years, none of the participants was blind. Three of the Indian participants who were blind before the study had perfect vision (20/20) after surgery, the researchers said.
The team also developed a new minimally invasive method to treat keratoconus, in which the cornea becomes so thin that it can cause blindness.
Currently, the cornea of patients with advanced keratoconus is surgically removed and replaced with a donated cornea, which is sutured in place using surgical sutures.
In contrast, the new surgical method does not require stitches. Corneal incisions can be made with great precision thanks to advanced lasers, but also, if necessary, by hand with simple surgical instruments. This method was first tested in pigs and has been found to be simpler and potentially safer than conventional corneal transplants.
Surgical methods and implants have been used by surgeons in Iran and India in 20 people who were blind or near vision loss due to advanced keratoconus; and receive biomaterial implants.
The operation was free of complications; tissue heals quickly; and eight weeks of treatment with immunosuppressive eye drops was sufficient to prevent implant rejection. With conventional corneal transplants, the medication must be taken for several years. The patients were followed for two years and no complications were noted during this period.
