title: Laser in situ keratomileusis flap-thickness predictability with a pendular microkeratome.
abstract: OBJECTIVE
  To assess flap-thickness predictability with a pendular microkeratome (130 μm head).
  
  
  METHODS
  Eye Institute of Thrace, Democritus University of Thrace, Alexandroupolis, Greece.
  
  
  METHODS
  Clinical trials.
  
  
  METHODS
  The study comprised 263 eyes (132 patients). Laser in situ keratomileusis was performed using the 130 μm head of the Carriazo pendular microkeratome; right eyes were treated first. Ultrasound pachymetry and topography were used for central corneal thickness (CCT) and keratometry (K) measurements. Evaluation included flap thickness, flap diameter, and flap shape.
  
  
  RESULTS
  The mean flap thickness was 125 μm ± 22 (SD) (range 74 to 187 μm) in right eyes and 112 ± 21 μm (range 61 to 190 μm) in left eyes. Flap thickness was significantly correlated with preoperative CCT (r = 0.271; P<.001) but not with K values or the manifest refraction spherical equivalent (P>.15). Right eyes had thicker flaps than left eyes (P<.001); both were significantly below the 130 μm head thickness (mean flap thickness 119.2 ± 22.8 μm; P<.001). The mean achieved flap diameter was 9.2 mm using the 9.0 ring and 9.8 mm using the 10.0 mm ring. Flap-thickness stabilization and convergence between right eyes and left eyes occurred after 100 consecutive flap cuts.
  
  
  CONCLUSIONS
  Flap-thickness predictability was influenced by preoperative CCT only. All cuts were significantly thinner than the head thickness regardless of the suction ring size. Second surgical eyes had thinner flaps, possibly from blade deterioration from the first cut. Approximately 100 flaps were required as a learning curve.
authors: Department of Ophthalmology & Eye Institute of Thrace, Democritus University of Thrace, Alexandroupolis, Greece. epaschalis@hotmail.com
authors: Eleftherios I
authors: EI
authors: Paschalis
authors: Georgios
authors: G
authors: Labiris
authors: Antonis P
authors: AP
authors: Aristeidou
authors: Nikitas C
authors: NC
authors: Foudoulakis
authors: Stavrenia C
authors: SC
authors: Koukoula
authors: Vassilios P
authors: VP
authors: Kozobolis
mesh_terms: D000293:Adolescent; D000328:Adult; D003319:Corneal Stroma / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D019781:Corneal Topography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006956:Hyperopia / Q000601:surgery*; D020731:Keratomileusis, Laser In Situ / Q000295:instrumentation*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D012029:Refraction, Ocular / Q000502:physiology; D015203:Reproducibility of Results; D013524:Surgical Flaps; D014463:Ultrasonography; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult