title: Trends in penetrating and anterior lamellar corneal grafting techniques for keratoconus: a national registry study.
abstract: OBJECTIVE
  Keratoconus is a progressive disorder and one of the primary indications for corneal transplantation. Anterior lamellar keratoplasty offers several advantages over other techniques, including endothelial preservation and longer graft survival. In this study, we examined the recent trend of using lamellar techniques for keratoconus at a national level.
  
  
  METHODS
  Data were obtained from the Dutch national organ transplant database regarding corneal transplants for keratoconus performed in 2005 through 2014. Baseline characteristics for patients undergoing various techniques were obtained, and temporal trends were analysed.
  
  
  RESULTS
  A total of 1041 operations were performed, including 736 penetrating keratoplasties (PKPs) and 297 anterior lamellar keratoplasties (ALKs). The mean age of the total surgical group was 37.4 ± 13.4 years, and 68% of patients were male (p = 0.0001). Preoperative patient characteristics were reported in all 1041 cases. The relative proportion of ALKs increased from 2005 (19% of cases) to 2010 (39% of cases) and remained approximately 30-40% thereafter. Descemet baring or deep anterior lamellar keratoplasty (DALK) was increasingly applied and was the predominant anterior lamellar technique performed from 2009 onwards.
  
  
  CONCLUSIONS
  The number of corneal transplantations performed annually for keratoconus decreased during the past 10 years. Lamellar techniques were increasingly performed, accounting for approximately 35% of keratoplasties in 2010 and thereafter. Among ALK techniques, maximal depth DALK is the most prevalent keratoplasty performed for keratoconus in most recent years. Penetrating keratoplasty (PKP) is still common, with a stable frequency from 2010 onwards.
authors.affiliation: Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Godefrooij
authors.affiliation: Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Renze
authors.initials: R
authors.lastname: Gans
authors.affiliation: Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Saskia M
authors.initials: SM
authors.lastname: Imhof
authors.affiliation: Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Robert P L
authors.initials: RP
authors.lastname: Wisse
mesh_terms: D000328:Adult; D016039:Corneal Transplantation / Q000639:trends*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000453:epidemiology / Q000601:surgery*; D015948:Keratoplasty, Penetrating / Q000639:trends*; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D012042:Registries
keywords: DALK; anterior lamellar keratoplasty; cornea; keratoconus; keratoplasty; penetrating keratoplasty