Abstract
Purpose: :
To assess techniques for harvesting donor tissue for Descemet’s membrane endothelial keratoplasty (DMEK).
Methods: :
Various techniques for harvesting Descemet's membrane and endothelium from human eyebank corneas were assessed. Techniques included: 1) Partial trephination with bimanual blunt forceps peeling. 2) Lamellar dissection with a blunt spatula. 3) Artificial anterior chamber mounting followed by partial trephination and intrastromal air injection. 4) Sub-Descemet's membrane injection of saline. Assessment of endothelial morphology and viability were performed with alizarin red and trypan blue staining. Histologic examination of successfully harvested tissue was performed. Donor factors (including age and time in storage) associated with successful or failed harvesting were assessed.
Results: :
Partial trephination with bimanual blunt forceps peeling produced an unacceptably high rate of tearing Descemet's membrane. Lamellar dissection also resulted in a high rate of incomplete dissection with tearing of the donor tissue. Artificial anterior chamber mounting followed by partial trephination and intrastromal air injection produced incomplete separation of Descemet's membrane from adjacent stroma and the resulting stromal emphysema hindered subsequent attempts to manually separate these layers. Sub-Descemet's membrane injection of saline allowed reliable and complete separation of Descemet's membrane from the adjacent stroma which allowed subsequent trephination and intact removal of a circular donor disc consisting of Descemet's membrane and endothelium. Histology and endothelial cell morphology and viability of tissue harvested using the saline injection method will be presented.
Conclusions: :
Of the four methods assessed, only sub-Descemet's membrane injection of saline followed by trephination consistently yielded an intact donor Descemet's membrane/endothelium suitable for subsequent DMEK surgery. The reliability of this method is sufficient to warrant additional studies and potential modification for use in patient surgery.
Keywords: cornea: endothelium • cornea: clinical science • transplantation