Amniotic membrane surgery

Human amniotic membrane (AM) is composed of three layers: a single epithelial layer, a thick basement membrane, and an avascular stroma. Amniotic membrane has anti-adhesive properties and is felt to promote epithelialization and decrease inflammation, neovascularization, and fibrosis. Amniotic membrane transplantation (AMT) is currently being used for a continuously widening spectrum of ophthalmic indications. Amniotic membrane transplantation has been shown to be effective in the reconstruction of the corneal surface in the setting of persistent epithelial defects, sterile corneal ulcerations, and partial limbal stem cell (LSC) deficiency states, including those secondary to chemical or thermal burns. Amniotic membrane transplantation also has been used in conjunction with limbal stem cell transplantation (LSCT) both in a concurrent fashion as well as in preparation for LSCT. Amniotic membrane transplantation also has been used in place of conjunctival autografting after pterygium excision and to reconstruct the conjunctival surface after removal of conjunctival lesions. Most recently, ex vivo cultivation and expansion of limbal epithelial cells has been performed utilizing AM as a matrix. However, the superiority of AMT over other treatment modalities in many of these settings needs to be substantiated by controlled clinical trials. (C) 2001 Lippincott Williams & Wilkins, Inc.