Amniotic membrane grafts, fresh or frozen? A clinical and in vitro comparison

Background/aims - The use of fresh (hypothermically stored) and frozen amniotic membrane (AM) was compared in a patient with cicatricial pemphigoid with stem cell failure. The viability of both fresh and frozen AM epithelial cells was assessed after storage. Methods-AM was stored at either +4 degreesC (fresh) or at -80 degreesC (frozen). A fresh graft was applied to the cornea following superficial keratectomy. Subsequently, a further frozen graft was applied to the same eye. Viability of the stored AM epithelium was assessed by investigating membrane integrity and mitochondrial activity. Results-In both cases the cornea reepithelialised and visual acuity improved. Improvement, however, was not sustained. Conclusion-Although both procedures led to an improvement in visual acuity, fresh tissue performed no better than frozen in promoting re-epithelialisation. The authors suggest that logistical, safety, and cost considerations outweigh any benefits of using fresh as opposed to frozen graft material.