title: Donor corneas for transplantation: a scanning electron microscopic study of the epithelium.
abstract: OBJECTIVE
  Donor corneas are processed in eye banks and used for transplantation as a standard routine. The maximum time limit post-mortem for harvesting donor tissue varies greatly between eye banks. This study aimed to examine the corneal epithelium for structural changes post-mortem.
  
  
  METHODS
  A total of 51 corneas harvested between 14 and 163 hours post-mortem were examined using scanning electron and light microscopy.
  
  
  RESULTS
  Cell loss occurred through desquamation of flat superficial cells during the first days. In corneas with a post-mortem time of more than 2-3 days, large superficial cell sheets and deeper cells detached, starting centrally. Deep peripheral cells remained. The loss of the superficial cells revealed the 3-dimensional structure of the epithelium and the membrane characteristics of deeper cells.
  
  
  CONCLUSIONS
  The longer the time post-mortem, the greater the epithelial cell loss. However, a rim of peripheral cells remained, even after 7 days. The superficial cell layer showed signs of strong lateral attachment and broke up in a sheet-like fashion. The intercellular adhesion between deeper cells and adhesion between the basal cells and the basement membrane appeared to be weak post-mortem. The cell membrane structures of the remaining cells were surprisingly well retained. The clinical implication of the study is discussed.
authors.affiliation: Center for Eye Research, Department of Ophthalmology, Ullevaal University Hospital, Oslo, Norway. jon.klokk.slettedal@gmail.com
authors.forename: Jon Klokk
authors.initials: JK
authors.lastname: Slettedal
authors.forename: Torstein
authors.initials: T
authors.lastname: Lyberg
authors.forename: Hanne
authors.initials: H
authors.lastname: Ramstad
authors.forename: Bjørn
authors.initials: B
authors.lastname: Nicolaissen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016039:Corneal Transplantation; D019573:Epithelium, Corneal / Q000648:ultrastructure*; D005125:Eye Banks; D005260:Female; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D011180:Postmortem Changes; D013997:Time Factors; D014019:Tissue Donors