title: Anterior segment optical coherence tomography measurement of flap thickness after myopic LASIK using the Moria one use-plus microkeratome.
abstract: OBJECTIVE
  To analyze the accuracy and consistency of corneal flap thickness created in myopic LASIK using the Moria One Use-Plus microkeratome compared with the Moria M2 Single Use 90-microm microkeratome.
  
  
  METHODS
  Bilateral LASIK was performed in 68 myopic patients. Flaps were created using the One Use-Plus microkeratome in 82 eyes (41 patients) and the M2 90-microm microkeratome in 54 eyes (27 patients). Flap complications and visual outcomes were evaluated. Horizontal "High Res. Corneal" scan pattern of anterior segment optical coherence tomography (AS-OCT) was applied to measure flap thickness at five locations (0, +/-2, and +/-3.5 mm from the corneal vertex) on the first postoperative day.
  
  
  RESULTS
  No significant differences were noted in flap complications and visual outcomes between groups. The central flap thickness was dramatically thinner in the One Use-Plus group (114.7+/-10.1 microm and 109.4+/-11.0 microm for right and left eyes, respectively) than in the M2 group (155.6+/-14.8 microm and 151.6+/-12.5 microm for right and left eyes, respectively) (P<.001). The One Use-Plus did not show a markedly better uniformity than the M2; the variation was mainly observed in the periphery. Multiple linear regression showed that for the One Use-Plus, the steeper the preoperative keratometry, the thicker the flap thickness, and for the M2, the thicker the preoperative pachymetry, the thicker the flap (P<.1).
  
  
  CONCLUSIONS
  The One Use-Plus and M2 microkeratomes have similar safety and efficacy. The flap created by the One Use-Plus was much thinner than the flap created with the M2; however, the One Use-Plus can not realize a fully planar-shaped flap.
authors.affiliation: Peking University Third Hospital, Peking University Eye Center, Beijing, China.
authors.forename: Hui-Jin
authors.initials: HJ
authors.lastname: Chen
authors.forename: Ying-Jie
authors.initials: YJ
authors.lastname: Xia
authors.forename: Yan-Ying
authors.initials: YY
authors.lastname: Zhong
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Song
authors.forename: Yue-Guo
authors.initials: YG
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D001699:Biometry; D003319:Corneal Stroma / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000295:instrumentation*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D009929:Organ Size; D011446:Prospective Studies; D015203:Reproducibility of Results; D013524:Surgical Flaps / Q000473:pathology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult