title: Modeling Endothelial Cell Loss After Descemet Stripping Endothelial Keratoplasty: Data From 5 Years of Follow-up.
abstract: OBJECTIVE
  To report 5-year outcomes for graft survival and endothelial cell survival after Descemet stripping endothelial keratoplasty (DSEK) including regression modeling for cell survival over time.
  
  
  METHODS
  This is a single-institution, retrospective, consecutive interventional series of 210 primary DSEK grafts operated for low-to-moderate risk indications, specifically Fuchs dystrophy and bullous keratopathy. Primary outcomes were cumulative graft survival and % endothelial cell loss from 3 months through 5 years; the secondary outcome was to trend endothelial cell density over time by least-squares and mixed nonlinear modeling.
  
  
  RESULTS
  Cumulative graft survival was high at 99%, 98%, and 94% at 1, 3, and 5 years, respectively. Mean endothelial cell loss was (mean ± SD) 44% ± 16%, 56% ± 17%, and 67% ± 13% at 1, 3, and 5 years. The trend in mean endothelial cell density over time by least square regression was accurately and parsimoniously described by a straight line taking earliest values (3 mo) through to 5 years, with a rate of cell loss of 148 ± 13 cells·mm·yr. Higher-order polynomial and exponential models did not provide a closer regression fit. Mixed nonlinear modeling using exponential decay equations confirmed a relatively stable rate of cell loss for DSEK from 3 months through to 5 years, in contrast to penetrating keratoplasty models using similar techniques in previous studies.
  
  
  CONCLUSIONS
  DSEK graft survival is high in our series through 5 years. Endothelial cell loss occurs at a relatively constant albeit low-grade rate from the earliest postoperative measurements through 5 years.
authors.affiliation: Department of Ophthalmology, King's College Hospital, London, United Kingdom.
authors.forename: Mark A P
authors.initials: MA
authors.lastname: Fajgenbaum
authors.forename: Emma J
authors.initials: EJ
authors.lastname: Hollick
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002452:Cell Count; D003316:Corneal Diseases / Q000473:pathology / Q000601:surgery*; D057111:Descemet Stripping Endothelial Keratoplasty; D042783:Endothelial Cells / Q000473:pathology; D004728:Endothelium, Corneal / Q000473:pathology; D005500:Follow-Up Studies; D005642:Fuchs' Endothelial Dystrophy / Q000601:surgery; D006085:Graft Survival; D006801:Humans; D008962:Models, Theoretical; D012044:Regression Analysis; D012189:Retrospective Studies