title: A prospective study of endothelial cell loss during the 2 years after deep lamellar endothelial keratoplasty.
abstract: OBJECTIVE
  To report the endothelial survival over a 2-year period after 2 techniques of deep lamellar endothelial keratoplasty (DLEK) in the treatment of endothelial dysfunction.
  
  
  METHODS
  Prospective, noncomparative, interventional case series.
  
  
  METHODS
  One hundred eyes of 88 patients with corneal edema.
  
  
  METHODS
  One hundred consecutive eyes with endothelial failure were entered into a prospective study of endothelial keratoplasty, and the donor central endothelial cell density (ECD) was recorded postoperatively at 6 months (n = 98), 12 months (n = 96), and 24 months (n = 85) and then compared with the preoperative eye bank measurements. The subsets of eyes with large-incision DLEK (n = 36) and small-incision DLEK (n = 62) were also evaluated and compared.
  
  
  METHODS
  Preoperative and postoperative central ECDs were prospectively evaluated and the cell loss calculated for each postoperative time point.
  
  
  RESULTS
  The average (and standard deviation) ECD at 6 months was 2140+/-426 cells/mm(2), representing a mean cell loss from preoperative donor cell measurements of 25+/-15%. At 12 months, ECD was 2090+/-448 cells/mm2 (26+/-16% cell loss), and at 24 months, it was 1794+/-588 cells/mm2 (37+/-27% cell loss). The additional cell loss from 1 to 2 years was significant (P<0.001). In the subset of large-incision DLEK eyes (n = 36), the cell loss from preoperatively to 6 months was 23%; 12 months, 22%; and 24 months, 27%. In the subset of small-incision DLEK eyes (n = 62), the cell loss from preoperatively to 6 months was 25%; 12 months, 28%; and 24 months, 43%. The cell loss from small-incision DLEK surgery was significantly greater than that from large-incision DLEK surgery at the 12-month (P = 0.013) and 24-month (P<0.001) postoperative measurements.
  
  
  CONCLUSIONS
  Although the initial cell loss from DLEK surgery is minimally changed from 6 to 12 months postoperatively, there is an acceleration of cell loss from 1 year to 2 years postoperatively. The small-incision DLEK technique, which involves folding of the donor tissue, results in a significantly higher endothelial cell loss at 1 and 2 years than that found after large-incision DLEK surgery, wherein the tissue is not folded.
authors.affiliation: Devers Eye Institute, Portland, Oregon 97210, USA. mterry@deverseye.org
authors.forename: Mark A
authors.initials: MA
authors.lastname: Terry
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Wall
authors.forename: Karen L
authors.initials: KL
authors.lastname: Hoar
authors.forename: Paula J
authors.initials: PJ
authors.lastname: Ousley
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002452:Cell Count; D003316:Corneal Diseases / Q000601:surgery*; D016039:Corneal Transplantation / Q000379:methods*; D004728:Endothelium, Corneal / Q000473:pathology* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006085:Graft Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies