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

Purpose. To bioengineer a corneal surface replacement using ex vivo expande d, cultured corneal epithelial stem cells seeded on a matrix derived from a mniotic membrane and use this bioengineered graft to manage difficult ocula r surface disease. Methods. Fourteen patients with ocular surface disease u nresponsive to standard medical and surgical treatments, including seven pa tients with presumed limbal stem cell deficiency were chosen for transplant ation of a bioengineered composite corneal surface in eye each. Presumed co rneal 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 a mniotic membrane. The resulting composite cultured tissue was transplanted to the ocular surface of the diseased eye, from which the abnormal tissue h ad been surgically removed. Ten patients received autologous grafts, and fo ur received allogeneic grafts. Results. A successful outcome, defined as re storation or improvement of vision, along with maintenance of corneal re-ep ithelialization and absence or recurrence of surface disease was obtained i n 6 of the 10 patients with autologous procedures and in all 4 allogeneic t ransplants. Follow-up ranged 6-19 months with a mean of 13 months. Conclusi ons, This novel technique documents that presumed corneal epithelial stem c ells can be harvested safely from the limbus, expanded successfully in vitr o, and grown on denuded amniotic membrane. The resultant composite cultured tissue can be transplanted and appears to successfully manage eyes with di fficult ocular surface disease, including those with stem cell deficiency. This technique minimizes the threat of damage or depletion to the contralat eral or donor limbus.