Successful transplantation of bioengineered tissue replacements in patients with ocular surface disease

Purpose. To bioengineer a corneal surface replacement using ex vivo expanded, cultured corneal epithelial stem cells seeded on a matrix derived from amniotic membrane and use this bioengineered graft to manage difficult ocular surface disease. Methods. Fourteen patients with ocular surface disease unresponsive to standard medical and surgical treatments, including seven patients with presumed limbal stem cell deficiency were chosen for transplantation of a bioengineered composite corneal surface in eye each. Presumed corneal stem cells were harvested from either the patient's or related donor's limbus, expanded ex vivo, and cultivated on a carrier of modified human amniotic membrane. The resulting composite cultured tissue was transplanted to the ocular surface of the diseased eye, from which the abnormal tissue had been surgically removed. Ten patients received autologous grafts, and four received allogeneic grafts. Results. A successful outcome, defined as restoration or improvement of vision, along with maintenance of corneal re-epithelialization and absence or recurrence of surface disease was obtained in 6 of the 10 patients with autologous procedures and in all 4 allogeneic transplants. Follow-up ranged 6-19 months with a mean of 13 months. Conclusions, This novel technique documents that presumed corneal epithelial stem cells can be harvested safely from the limbus, expanded successfully in vitro, and grown on denuded amniotic membrane. The resultant composite cultured tissue can be transplanted and appears to successfully manage eyes with difficult ocular surface disease, including those with stem cell deficiency. This technique minimizes the threat of damage or depletion to the contralateral or donor limbus.