title: Scanning Electron Microscope Analysis of Stromal Surface Regularity in DSAEK Using Manual or Automated Microkeratomes or DMEK.
abstract: OBJECTIVE
  To analyze differences in the stromal bed according to the method used to obtain the disc for endothelial transplant with 1) an automated microkeratome for Descemet stripping automated endothelial keratoplasty (DSAEK), 2) homogeneous dissection of Descemet membrane (Descemet membrane endothelial keratoplasty [DMEK]), or 3) a manual microkeratome used for DSAEK.
  
  
  METHODS
  We analyzed the stromal bed of 25 consecutive corneas used for endothelial transplantation, divided into 3 groups: 1) 11 samples cut with an automated microkeratome, 2) 5 samples used for DMEK, 3) 9 samples cut with a manual microkeratome. A scanning electron microscope was used to obtain an image of the center of the stromal bed. The irregularity index of the surface complementary to the stromal surface of the disc obtained for grafting was calculated with the Canny algorithm (0: completely smooth; 1: completely irregular).
  
  
  RESULTS
  At all thresholds studied (20, 30, 50, and 70), the mean irregularity index for group C (35.2, 24.4, 13.7, and 8.8, respectively) was higher than that of group A (26.2, 14.8, 6.7, and 4.0, respectively), which in turn was higher than that of group B (7.0, 4.2, 2.4, and 1.8, respectively). Differences were statistically significant among all groups and for all thresholds.
  
  
  CONCLUSIONS
  Irregularity of the stromal bed after any dissection can be quantified using the Canny method. The use of an automated microkeratome for DSAEK reduces irregularity and helps obtain a surface more similar to that obtained with DMEK than with a manual microkeratome.
authors.affiliation: *Instituto de Oftalmología La Arruzafa, Córdoba, Spain; †Departamento de Informática, Universidad de Córdoba, Córdoba, Spain; ‡Departamento de Genética, Universidad de Córdoba, Córdoba, Spain; §Hospital GermansTrias i Pujol, Badalona, Barcelona, Spain; ¶Hospital General La Mancha-Centro, Alcázar de San Juan, Ciudad Real, Spain; ‖Hospital Universitari Mútua Terrassa, Terrasa, Barcelona, Spain; and **Hospital Universitario Infanta Cristina de Badajoz, Badajoz, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Villarrubia
authors.forename: Enrique
authors.initials: E
authors.lastname: García
authors.forename: Antonio
authors.initials: A
authors.lastname: Cano-Ortiz
authors.forename: Alberto
authors.initials: A
authors.lastname: Membrillo
authors.forename: Antoni
authors.initials: A
authors.lastname: Sabala
authors.forename: Javier
authors.initials: J
authors.lastname: Celis
authors.forename: Antoni
authors.initials: A
authors.lastname: Salvador
authors.forename: Jorge
authors.initials: J
authors.lastname: Solana
authors.forename: Alexandra
authors.initials: A
authors.lastname: Arango
authors.forename: Irene
authors.initials: I
authors.lastname: Sassot
mesh_terms: D003319:Corneal Stroma / Q000648:ultrastructure*; D003886:Descemet Membrane / Q000601:surgery*; D057111:Descemet Stripping Endothelial Keratoplasty / Q000379:methods*; D004728:Endothelium, Corneal / Q000637:transplantation*; D005642:Fuchs' Endothelial Dystrophy / Q000601:surgery; D006801:Humans; D008855:Microscopy, Electron, Scanning; D012189:Retrospective Studies; D020858:Tissue and Organ Harvesting / Q000379:methods*