title: Contralateral assessment of sub-Bowman keratomileusis (SBK) microkeratome suction duration on laser-assisted in-situ keratomileusis (LASIK) flap characteristics.
abstract: OBJECTIVE
  To describe the effect of prolonging the standard suction duration during laser-assisted in-situ keratomileusis (LASIK) and its effect on flap thickness and hinge length using sub-Bowman keratomileusis (SBK) microkeratome.
  
  
  METHODS
  Fifty-six eyes (28 patients) were included and divided into 2 groups; Group-A: eyes with flatter corneas (36 eyes, 18 patients) and mean keratometric readings ranging from 40.13 to 43.71 diopters (D). Group-B: eyes with steeper corneas (20 eyes, 10 patients) with mean keratometric readings ranging from 43.85 to 46.72 D. One-Use-Plus SBK microkeratome was used for flap creation. For right eyes, flap was created immediately once suction was built up. In left eyes, the surgeon waited for 10 s after suction was built up before flap creation. Flap hinge length and flap thickness were measured using surgical caliper and ultrasonic pachymetry, respectively.
  
  
  RESULTS
  Statistically significant differences were observed in corneal flap hinge size between right eyes versus left eyes, with a mean of 3.98 ± 0.48 vs. 3.78 ± 0.55 mm (p < 0.001). Mean flap thickness in both eyes did not prove to be statistically significantly different with either surgical technique (90.2 ± 1.68 vs. 90.07 ± 1.44 μm, p = 0.8). Sub-group analysis of Group-A vs. Group-B revealed hinge sizes that were significantly larger in steeper corneas (p < 0.01 and p < 0.05, respectively). However, flap thickness in both groups was unaffected by surgical procedure (p = 0.5).
  
  
  CONCLUSIONS
  Increasing suction duration increases flap hinge length and stabilizes the flap, especially in steeper corneas.
authors.affiliation: Ophthalmology Department, Faculty of Medicine, Ain Shams University, Egypt.
authors.forename: Mohamed Omar
authors.initials: MO
authors.lastname: Yousif
authors.affiliation: Doheny Eye Institute, University of California Los Angeles, Los Angeles, CA, USA; Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Nizar Saleh
authors.initials: NS
authors.lastname: Abdelfattah
authors.affiliation: Department of Surgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: Amira A
authors.initials: AA
authors.lastname: Zayed
authors.affiliation: Ophthalmology Department, Faculty of Medicine, Ain Shams University, Egypt.
authors.forename: Ashraf H
authors.initials: AH
authors.lastname: Soliman
keywords: Corneal flap; LASIK; Laser-assisted in-situ keratomileusis; Suction