A small (n=10) Phase 1 study published in Science Translational Medicine this week shows that synthetic corneas performed as well as cadaver harvested corneas over a 24 month followup.
From the abstract:
The biosynthetic implants remained stably integrated and avascular for 24 months after surgery, without the need for long-term use of the steroid immunosuppression that is required for traditional allotransplantation. Corneal reepithelialization occurred in all patients, although a delay in epithelial closure as a result of the overlying retaining sutures led to early, localized implant thinning and fibrosis in some patients. The tear film was restored, and stromal cells were recruited into the implant in all patients. Nerve regeneration was also observed and touch sensitivity was restored, both to an equal or to a greater degree than is seen with human donor tissue. Vision at 24 months improved from preoperative values in six patients.
While there are enough cadaver corneas to go around in the US (some are exported as well) they require immunosuppresion and the rest of the world, for various reasons, does not have as ready a supply. The study was an international effort, with the collagen produced by FibroGen in the US, shaped into corneas by University of Ottawa Eye Institute in Canada, and implanted into patients in Sweden.
Abstract in Science Translational Medicine: A Biosynthetic Alternative to Human Donor Tissue for Inducing Corneal Regeneration: 24-Month Follow-Up of a Phase 1 Clinical Study
Press release: FibroGen Announces Results of 2-Year Study Demonstrating that Biosynthetic Corneas Formulated with Recombinant Human Type III Collagen Restore Vision and Promote Nerve Regeneration
Image credit: BlakJakDavy