title: Refractive outcome of keratoconus treated by combined femtosecond laser and big-bubble deep anterior lamellar keratoplasty.
abstract: OBJECTIVE
  To report 1-year follow-up in 11 of 13 eyes with keratoconus treated by deep anterior lamellar keratoplasty with a combined femtosecond laser lamellar resection followed by a big-bubble dissection.
  
  
  METHODS
  Thirteen eyes with keratoconus were treated. Recipient and donor were prepared with the 60-kHz IntraLase femtosecond laser (Abbott Medical Optics). In the recipient, the femtosecond laser, after performing a lamellar cut 100 μm above the thinnest corneal point (measured by Pentacam [Oculus Optikgeräte GmbH]), was used to make a mushroom-shaped resection (anterior diameter, 9 mm; posterior diameter, 8 mm) from the same depth. In the donor, the mushroom lamellar thickness was calculated according to an original model based on the recipient preoperative corneal thickness. Upon removal of the recipient lamella, air was injected into the residual stroma to achieve a big bubble. The keratectomy was continued up to Descemet membrane. The donor was fit into place and sutured using interrupted sutures, which were removed by 8 months postoperative. Corrected distance visual acuity (CDVA) and refractive astigmatism were calculated by manifest refraction, whereas topographic astigmatism and corneal thickness were measured by Pentacam.
  
  
  RESULTS
  A big bubble was successfully achieved in 11 eyes. Twelve months after surgery, mean CDVA was 0.52±1.2 (decimal), and refractive sphere and cylinder were -1.50±1.70 diopters (D) and 2.00±2.60 D, respectively. Three (27%) of 11 eyes at 1 year had a manifest refraction spherical equivalent within 1.00 D of emmetropia. Topographic astigmatism was 2.90±1.60 D. The thinnest corneal point was 519±27 μm.
  
  
  CONCLUSIONS
  This combination of a femtosecond laser lamellar dissection with a big-bubble technique can improve the standardization of deep anterior lamellar keratoplasty for keratoconus.
authors.affiliation: Ophthalmology Department, Children's Hospital, Rome, Italy. lucabuzzonetti@yahoo.it
authors.forename: Luca
authors.initials: L
authors.lastname: Buzzonetti
authors.forename: Antonio
authors.initials: A
authors.lastname: Laborante
authors.forename: Gianni
authors.initials: G
authors.lastname: Petrocelli
mesh_terms: D000293:Adolescent; D000328:Adult; D019781:Corneal Topography; D016039:Corneal Transplantation; D005500:Follow-Up Studies; D006801:Humans; D007431:Intraoperative Complications; D007640:Keratoconus / Q000601:surgery*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D011183:Postoperative Complications; D012029:Refraction, Ocular / Q000502:physiology*; D012189:Retrospective Studies; D013536:Suture Techniques; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult