title: Clinical outcomes of penetrating keratoplasty performed with the VisuMax femtosecond laser system and comparison with conventional penetrating keratoplasty.
abstract: OBJECTIVE
  To assess the clinical outcomes of femtosecond laser-assisted keratoplasty (FLAK) using the VisuMax femtosecond laser system, and to compare them with those of conventional penetrating keratoplasty (PK).
  
  
  METHODS
  We retrospectively examined 20 eyes of 20 consecutive patients undergoing FLAK and 20 eyes of 20 age- and diagnosis-matched patients undergoing conventional PK. We quantitatively assessed corneal astigmatism, refractive astigmatism, and corrected visual acuity, 1, 3, and 6 months postoperatively, and endothelial cell density 6 months postoperatively.
  
  
  RESULTS
  Corneal and refractive astigmatism after FLAK were significantly lower after FLAK than that after conventional PK at 3 and 6 months postoperatively (p = 0.04 and p = 0.03, respectively, Mann-Whitney U test). FLAK provided significantly faster visual recovery than conventional PK at 1 month postoperatively (p = 0.02), but not at 3 and 6 months postoperatively (p = 0.52 and p = 0.80, respectively). We found no significant differences in the change in endothelial cell density between the two groups (p = 0.30).
  
  
  CONCLUSIONS
  FLAK using the VisuMax femtosecond laser system induces significantly less corneal and refractive astigmatism than conventional PK, and provides significantly faster visual recovery in the early postoperative period, possibly because the geometry of the donor-recipient matching is more physiological and requires less tight sutures. It is suggested that FLAK has advantages over conventional PK, in terms of astigmatism and fast visual recovery.
authors.affiliation: Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Kamiya
authors.affiliation: Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan.
authors.forename: Hidenaga
authors.initials: H
authors.lastname: Kobashi
authors.affiliation: Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan.
authors.forename: Kimiya
authors.initials: K
authors.lastname: Shimizu
authors.affiliation: Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan.
authors.forename: Akihito
authors.initials: A
authors.lastname: Igarashi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001251:Astigmatism / Q000209:etiology*; D004728:Endothelium, Corneal / Q000473:pathology; D005260:Female; D006801:Humans; D015948:Keratoplasty, Penetrating / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity; D055815:Young Adult