title: Bubble technique for Descemet membrane endothelial keratoplasty tissue preparation in an eye bank: air or liquid?
abstract: OBJECTIVE
  To compare the big-bubble method using air and liquid as medium of separation for Descemet membrane endothelial keratoplasty (DMEK) lenticule preparation in an eye bank.
  
  
  METHODS
  Donor corneas (n=20) were immersed in liquid [tissue culture medium (TCM)]. Air and liquid was injected using a 25-gauge needle in the posterior stroma or as near to the stroma-Descemet membrane (DM) phase as possible to create a complete bubble of larger diameter. The endothelial cell density and mortality were checked pre- and postbubble after deflating the tissue. Four pairs of tissues were used to analyse the intracellular tight junctions and three pairs for histological examination and DNA integrity studies, respectively.
  
  
  RESULTS
  The yield obtained using air was 80%, whereas that with liquid was 100%. Single injection was required in six cases; twice in two cases; three and four times in one case each with air bubble, whereas seven cases required single injection; twice in two cases; and thrice in just one case with liquid bubble. The average diameter of the final lenticule was 9.12 (±1.71) mm for air bubble and 9.78 (±1.75) mm for liquid bubble with p=0.4362 (no statistical significance). Endothelial cell mortality postbubble preparation was 8.9 (±12.38)% for air and 6.25 (±9.57)% for liquid (p=0.6268).
  
  
  CONCLUSIONS
  DM and endothelium could be separated exclusively using air or liquid bubble. However, liquid bubble seems to have certain advantages over air such as the generation of yield, larger diameter and higher maintenance of endothelial cell density and integrity.
authors.affiliation: International Center for Ocular Physiopathology (ICOP), The Veneto Eye Bank Foundation, Zelarino, Venice, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ruzza
authors.forename: Mohit
authors.initials: M
authors.lastname: Parekh
authors.forename: Gianni
authors.initials: G
authors.lastname: Salvalaio
authors.forename: Stefano
authors.initials: S
authors.lastname: Ferrari
authors.forename: Davide
authors.initials: D
authors.lastname: Camposampiero
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Amoureux
authors.forename: Massimo
authors.initials: M
authors.lastname: Busin
authors.forename: Diego
authors.initials: D
authors.lastname: Ponzin
mesh_terms: D000368:Aged; D000388:Air; D002452:Cell Count; D003470:Culture Media; D057111:Descemet Stripping Endothelial Keratoplasty / Q000379:methods*; D004728:Endothelium, Corneal / Q000378:metabolism; D005125:Eye Banks / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D019108:Tight Junctions / Q000378:metabolism; D014019:Tissue Donors; D020858:Tissue and Organ Harvesting / Q000379:methods*; D062826:Zonula Occludens-1 Protein / Q000378:metabolism
chemical_list: D003470:Culture Media; C569042:TJP1 protein, human; D062826:Zonula Occludens-1 Protein
keywords: DMEK; big bubble; eye bank