title: Comparison of three different techniques of corneal transplantation for keratoconus.
abstract: OBJECTIVE
  To compare the visual outcomes following deep anterior lamellar keratoplasty (DALK), penetrating keratoplasty (PK), and manual top-hat PK (TH-PK) in subjects undergoing corneal transplantation for keratoconus (KC).
  
  
  METHODS
  A retrospective comparative case series.
  
  
  METHODS
  settings: Cornea clinic at the Toronto Western Hospital. study population: Fifty patients who underwent corneal transplantation for KC: 17 eyes underwent DALK, 20 eyes underwent traditional PK, and 13 had TH-PK. main outcome measures: Preoperative and postoperative uncorrected and best spectacle-corrected visual acuity (UCVA, BSCVA), high-order aberrations (HOA), complication rate, and endothelial cell counts.
  
  
  RESULTS
  The median BSCVA at 12 months follow-up was 20/40 in the DALK eyes and 20/30 in the traditional PK and TH-PK eyes. The mean final spherical equivalent power in the three groups was less than -1 diopter (D). The median astigmatism was less than 3.5 D in the three groups. Complication rates were similar for three groups, although the DALK group tended toward more complications. Although DALK and TH-PK procedure results in significantly shorter time to suture removal (P < .01), they caused increased levels of HOAs (P = .02). Endothelial cell counts at 12 months were significantly higher in DALK and TH-PK eyes when compared to the traditional PK eyes (P < .001).
  
  
  CONCLUSIONS
  DALK, PK, and TH-PK provide comparable visual outcomes in keratoconus patients. Although DALK and TH-PK induce more HOA, they speed up the time to suture removal and provide higher endothelial cell density at one year of follow-up.
authors: Ophthalmology Department, Toronto Western Hospital, University of Toronto, University Health Network, Toronto, Ontario, Canada. iritbahar@yahoo.com
authors: Irit
authors: I
authors: Bahar
authors: Igor
authors: I
authors: Kaiserman
authors: Sathish
authors: S
authors: Srinivasan
authors: Jin
authors: J
authors: Ya-Ping
authors: Allan R
authors: AR
authors: Slomovic
authors: David S
authors: DS
authors: Rootman
mesh_terms: D000328:Adult; D002452:Cell Count; D003315:Cornea / Q000601:surgery*; D016039:Corneal Transplantation / Q000379:methods*; D004728:Endothelium, Corneal / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000503:physiopathology / Q000601:surgery*; D015948:Keratoplasty, Penetrating / Q000379:methods; D008297:Male; D011183:Postoperative Complications; D012030:Refractive Errors / Q000503:physiopathology; D012189:Retrospective Studies; D014019:Tissue Donors; D014021:Tissue Preservation / Q000379:methods; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology