Researchers from Sweden's Lin Xueping University and linkocare Life Sciences Co., Ltd. jointly developed an implant similar to human cornea made of collagen in pig skin.
In a pilot study, the implant restored vision in 20 patients with corneal lesions, most of whom were blind before receiving the implant. This study, published in Nature Biotechnology, uses bioengineering implants as an alternative to human corneal transplantation donation, bringing hope to patients with corneal blindness and low vision.
The cornea is mainly composed of collagen. To create a substitute for human cornea, researchers used collagen molecules derived from pig skin, which were highly purified and produced under strict human use conditions. The pig skin used is a by-product of the food industry, which is easy to obtain and has economic advantages.
In the process of constructing the implant, researchers stabilized the loose collagen molecules to form a solid and transparent material that can withstand treatment and implantation into the eye. Donated corneas must be used within two weeks, while bioengineered corneas can be stored for up to two years before use.
Researchers have also developed a new minimally invasive method to treat keratoconus. The patient's cornea becomes very thin, which may lead to blindness. At present, patients with advanced keratoconus need surgery to remove the cornea, instead of donating the cornea and suturing it in place with surgical sutures. This procedure is invasive and can only be performed in larger university hospitals.
The new surgical method does not require suturing. It can perform high-precision corneal incision surgery with advanced laser technology, and can also be performed manually with simple surgical instruments when necessary. The method was first tested in pigs, and the results showed that it was simpler and safer than traditional corneal transplantation.
Surgeons in Iran and India conducted pilot clinical studies using this surgical approach and implant. Twenty people who were blind or near blind due to advanced keratoconus participated in the study and received biomaterial implants. There were no complications and the tissue healed quickly; Treatment with immunosuppressive eye drops for 8 weeks is sufficient to prevent rejection of the implant. The two-year follow-up of the patients showed that no complications were found during this period.
The results of the pilot clinical study showed that the thickness and curvature of the cornea returned to normal. Participants' visual acuity improved to the same extent as after corneal transplantation using donated tissue. Before surgery, 14 of the 20 participants were blind. Two years later, they were no longer blind. Three Indian participants who were blind before the study had near perfect vision after surgery.