title: Comparison of pneumatic dissection and forceps dissection in Descemet membrane endothelial keratoplasty: histological and ultrastructural findings.
abstract: OBJECTIVE
  To compare air and forceps dissection of Descemet membrane (DM) in regard to endothelial cell loss, apoptosis, and ultrastructural findings for transplantation in Descemet membrane endothelial keratoplasty.
  
  
  METHODS
  DM of 32 corneoscleral rims were separated using forceps dissection (group A) and air dissection (group B) and had been organ cultured for 1 week. The endothelial cell density (ECD) was evaluated before and immediately after DM dissection and during 1 additional week of organ culture. The presence of any residual stroma, thickness of the DM, thickness of banded and nonbanded layers, and smoothness of the lamella were analyzed. Apoptosis was evaluated by TUNEL (terminal dUTP nick-end-labeling) staining.
  
  
  RESULTS
  In group A, 15 of 16 usable DM were available, and in group B 14 of 16 usable DM were available. The duration of preparation was 19.7 minutes in group A and 8.8 minutes in group B. The mean ECD was 2050 ± 167 cells per square millimeter in group A and declined to 1846 ± 153 cells per square millimeter after 1 week of organ culture. The mean ECD in group B was 2038 ± 212 cells per square millimeter and declined to 1863 ± 211 cells per square millimeter. No evidence of adherent rests of corneal stroma in any specimens in either group was observed, demonstrating a stroma free separation with no differences in the smoothness of the lamellae. The rate of apoptosis positive cells was 0.37% in group A and 0.40% in group B.
  
  
  CONCLUSIONS
  Both separation methods seem to be equal in regard to the quality of the obtained DM. Finally, it depends on the preference of the surgeon which dissection method to use.
authors.affiliation: Department of Ophthalmology, Eberhard-Karls University, Tuebingen, Germany. efdal.yoeruek@med.uni-tuebingen.de
authors.forename: Efdal
authors.initials: E
authors.lastname: Yoeruek
authors.forename: Tarek
authors.initials: T
authors.lastname: Bayyoud
authors.forename: Johanna
authors.initials: J
authors.lastname: Hofmann
authors.forename: Peter
authors.initials: P
authors.lastname: Szurman
authors.forename: Karl-Ulrich
authors.initials: KU
authors.lastname: Bartz-Schmidt
mesh_terms: D000369:Aged, 80 and over; D000388:Air; D017209:Apoptosis; D002452:Cell Count; D055954:Corneal Endothelial Cell Loss / Q000473:pathology*; D003319:Corneal Stroma / Q000648:ultrastructure; D003886:Descemet Membrane / Q000648:ultrastructure*; D057111:Descemet Stripping Endothelial Keratoplasty; D004210:Dissection / Q000295:instrumentation / Q000379:methods*; D004728:Endothelium, Corneal / Q000648:ultrastructure*; D006801:Humans; D020287:In Situ Nick-End Labeling; D011312:Pressure; D014019:Tissue Donors