title: Deep anterior lamellar keratoplasty in patients with keratoconus: big-bubble technique.
abstract: OBJECTIVE
  To evaluate the visual and refractive outcomes after deep anterior lamellar keratoplasty (DALK) using the big-bubble technique in eyes with keratoconus.
  
  
  METHODS
  In this case series, eyes with moderate to advanced keratoconus underwent DALK. All of them had unacceptable spectacle-corrected visual acuity or were contact lens intolerant. DALK was performed using the big-bubble technique. Full thickness donor cornea without Descemet's membrane (DM) was sutured to the recipient bed with three different suturing techniques. The visual acuity (presented in logMAR), refractive status, intraoperative and postoperative complications were evaluated.
  
  
  RESULTS
  A total of 129 consecutive eyes of 121 patients were included. In 3 eyes, the operation was converted to penetrating keratoplasty. Therefore, 126 eyes (79 male) were enrolled in the study. Mean patient age at the time of surgery was 26.08 +/- 7.6 years. Mean follow-up period was 21.62 +/- 9.0 months. Mean preoperative corrected visual acuity was 1.27 +/- 0.4 logMAR, increasing to 0.25 +/- 0.2 logMAR at final follow-up examination (P < 0.001). Postoperative mean spherical equivalent refractive error, refractive and keratometric astigmatism were -3.41 +/- 3.1 D, 3.04 +/- 2.3 D, and 3.67 +/- 2.1 D, respectively. Bared DM was achieved in 103 eyes, whereas in 23 eyes pre-Descemet dissection was performed. DM perforation occurred in 5 eyes. The main complications encountered were filamentary keratitis, subepithelial graft rejection, and astigmatism.
  
  
  CONCLUSIONS
  : DALK using the big-bubble technique appears to be a safe and effective procedure for eyes with moderate to advanced keratoconus. In case of extensive intraoperative DM perforation, it does not pose any limitation to ongoing penetrating keratoplasty.
authors.affiliation: Department of Ophthalmology, Shahid Beheshti University, Tehran, Iran. sepehrfeizi@yahoo.com
authors.forename: Sepehr
authors.initials: S
authors.lastname: Feizi
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Javadi
authors.forename: Hossein
authors.initials: H
authors.lastname: Jamali
authors.forename: Firooz
authors.initials: F
authors.lastname: Mirbabaee
mesh_terms: D000293:Adolescent; D000328:Adult; D003319:Corneal Stroma / Q000637:transplantation*; D019781:Corneal Topography; D016039:Corneal Transplantation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007431:Intraoperative Complications; D007640:Keratoconus / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult