title: Penetrating keratoplasty versus deep anterior lamellar keratoplasty for the treatment of keratoconus.
abstract: OBJECTIVE
  To compare the outcome of penetrating keratoplasty (PKP) and deep anterior lamellar keratoplasty (DALK) in the surgical management of keratoconus (KC).
  
  
  METHODS
  A retrospective review was conducted of the medical records of all patients treated with PKP or DALK for KC at University of Iowa Hospitals and Clinics from January 1, 2000, to December 31, 2006. The main outcome measures were visual outcome, graft survival, and complications. Cases with a minimum follow-up of 6 months were included in the statistical analysis.
  
  
  RESULTS
  Of 41 eyes that met the inclusion criteria, 30 eyes were treated with PKP and 11 eyes were treated with DALK. The mean follow-up was almost identical for eyes treated with PKP or DALK (21.9 vs. 22.5 months, respectively). At the most recent examination, the mean best spectacle-corrected visual acuity (BSCVA) was 20/28 for the PKP group and 20/29 for the DALK group (P = 0.77). The percentage of eyes that achieved BSCVA of 20/25 or better was higher in the PKP group than in the DALK group (77.3 vs. 45.5%, respectively), but this difference was not statistically significant (P = 0.72). Endothelial rejection occurred in 4 (13.3%) eyes after PKP. Visually significant interface haze occurred in the early postoperative course in 2 (18.2%) eyes after DALK. No cases of late-onset endothelial failure were found in either group.
  
  
  CONCLUSIONS
  Treatment of KC with PKP or DALK is associated with similar visual outcomes, graft survival, and prevalence of sight-threatening complications.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Iowa Carver College of Medicine, University of Iowa Hospitals and Clinics, Pomerantz Family Pavilion, 200 Hawkins Drive, Iowa City, IA 52242-1091, USA.
authors.forename: Alex W
authors.initials: AW
authors.lastname: Cohen
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Goins
authors.forename: John E
authors.initials: JE
authors.lastname: Sutphin
authors.forename: George R
authors.initials: GR
authors.lastname: Wandling
authors.forename: Michael D
authors.initials: MD
authors.lastname: Wagoner
mesh_terms: D000328:Adult; D000368:Aged; D016039:Corneal Transplantation / Q000009:adverse effects / Q000379:methods*; D005139:Eyeglasses; D005260:Female; D006085:Graft Survival; D006801:Humans; D015994:Incidence; D007640:Keratoconus / Q000503:physiopathology / Q000601:surgery*; D015948:Keratoplasty, Penetrating / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000503:physiopathology; D016896:Treatment Outcome; D014792:Visual Acuity; D055815:Young Adult