title: Femtosecond laser arcuate keratotomy for the correction of high astigmatism after keratoplasty.
abstract: OBJECTIVE
  To determine the feasibility and initial outcomes of using a femtosecond laser to perform arcuate keratotomies to correct high post-keratoplasty astigmatism.
  
  
  METHODS
  Prospective noncomparative interventional case series.
  
  
  METHODS
  Twelve eyes of 12 consecutive patients (mean age 44.9+/-9.5 years) who presented with a high degree of astigmatism, noncorrectable with spectacles or contact lenses (10 post-penetrating keratoplasty, 2 post-deep lamellar keratoplasty), and were candidates for relaxing incisional corneal surgery.
  
  
  METHODS
  The Femtec (20/10 Perfect Vision, GmbH, Heidelberg, Germany) femtosecond laser performed paired 90-degree angled arcuate incisions on the graft button. The incision sites and depths were programmed at 1.00 mm inside the graft edge and at 90% of the corresponding local graft thickness, whereas the angular lengths of the cuts were determined by analyzing the locations and extents of the steepest meridians in the topographic map.
  
  
  METHODS
  Changes in uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), mean subjective and topographically determined astigmatism; imaging of incisions by anterior segment optical coherence tomography (AS-OCT); and wound healing by in vivo confocal microscopy (IVCM).
  
  
  RESULTS
  Postoperative follow-up extended to 6 months. Mean uncorrected logarithm of the minimum angle of resolution (logMAR) BSCVA and UCVA improved from preoperative values of 0.25+/-0.16 and 1.05+/-0.18 to 6-month values of 0.11+/-0.12 (standard deviation) and 0.55+/-0.34, respectively (P<0.05). Mean subjective astigmatism was 7.16+/-3.07 diopters (D) preoperatively and 2.23+/-1.55 D at 1 month after surgery (P = 0.002) and remained stable to the end of follow-up. Anterior segment optical coherence tomography image analysis showed that the depth and location of the incisions were consistent with the preoperative surgical plan. In vivo confocal microscopy showed mild edema and keratocyte activation along the incision edges, together with initial epithelial ingrowth inside the wound, followed by subsequent moderate fibrotic scarring.
  
  
  CONCLUSIONS
  Arcuate keratotomies performed with the femtosecond laser were effective in reducing post-keratoplasty astigmatism. Laser-generated incisions within the graft button presented precise geometry and reliable depth of incision, with a wound healing pattern characterized by epithelial ingrowth and mild fibrosis.
  
  
  BACKGROUND
  The author(s) have no proprietary or commercial interest in any materials discussed in this article.
authors.affiliation: Department of Medicine and Ageing Science, Ophthalmic Clinic, University G. D'Annunzio of Chieti and Pescara, Italy. m.nubile@unich.it
authors.forename: Mario
authors.initials: M
authors.lastname: Nubile
authors.forename: Paolo
authors.initials: P
authors.lastname: Carpineto
authors.forename: Manuela
authors.initials: M
authors.lastname: Lanzini
authors.forename: Roberta
authors.initials: R
authors.lastname: Calienno
authors.forename: Luca
authors.initials: L
authors.lastname: Agnifili
authors.forename: Marco
authors.initials: M
authors.lastname: Ciancaglini
authors.forename: Leonardo
authors.initials: L
authors.lastname: Mastropasqua
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D016039:Corneal Transplantation / Q000009:adverse effects*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D015948:Keratoplasty, Penetrating / Q000009:adverse effects*; D007646:Keratotomy, Radial / Q000379:methods*; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D011183:Postoperative Complications; D011446:Prospective Studies; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology