title: Relationship Between Tissue Unscrolling Time and Endothelial Cell Loss.
abstract: OBJECTIVE
  To assess the relationship between intraoperative unscrolling time of the donor Descemet membrane endothelial keratoplasty (DMEK) tissue and 6-month postoperative endothelial cell loss (ECL), and to determine whether donor age, scroll tightness, and the presence of an S stamp are related to unscrolling time.
  
  
  METHODS
  Ninety-three consecutive uncomplicated DMEK surgeries performed on eyes with Fuchs endothelial dystrophy using our standardized technique (ie, prestripped tissue with or without a premarked S stamp from our eye bank, overstripping the recipient, Straiko glass injector, no-touch tap technique, and bubble of 20% SF6 gas) were evaluated. Intraoperative unscrolling times and 6-month endothelial cell densities were measured and analyzed.
  
  
  RESULTS
  Sixty-nine cases comprised the study cohort. The median unscrolling time was 4 minutes (range: 0.8-17.5 minutes), and the median ECL was 26.9% (range: -4.3% to 80.0%). There was no relationship between unscrolling time and ECL at 6 months by the Pearson correlation coefficient (r = -0.02, P = 0.89). Younger donor age, tighter scrolls, and absence of an S stamp had no correlation with longer unscrolling times (all P > 0.05). Only 2 of 4 cases of iatrogenic primary graft failure had unscrolling times available for analysis; in this limited sample, there was no association between iatrogenic primary graft failure and unscrolling time.
  
  
  CONCLUSIONS
  Once the DMEK tissue is safely in the anterior chamber, surgeons need not rush the "DMEK dance" because longer unscrolling times may not endanger the endothelium.
authors: *Ophthalmic Consultants of Boston, Boston, MA; †Devers Eye Institute, Portland, OR; ‡Massachusetts Eye and Ear Infirmary, Boston, MA; and §Lions VisionGift, Portland, OR.
authors: Christopher S
authors: CS
authors: Sáles
authors: Mark A
authors: MA
authors: Terry
authors: Peter B
authors: PB
authors: Veldman
authors: Zachary M
authors: ZM
authors: Mayko
authors: Michael D
authors: MD
authors: Straiko
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002452:Cell Count; D055954:Corneal Endothelial Cell Loss / Q000175:diagnosis / Q000503:physiopathology*; D057111:Descemet Stripping Endothelial Keratoplasty; D004728:Endothelium, Corneal / Q000473:pathology* / Q000637:transplantation; D005260:Female; D005642:Fuchs' Endothelial Dystrophy / Q000601:surgery*; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D014019:Tissue Donors