title: Corneal flap morphological analysis using anterior segment optical coherence tomography in laser in situ keratomileusis with femtosecond lasers versus mechanical microkeratome.
abstract: OBJECTIVE
  To assess and compare the flap morphology using anterior segment optical coherence tomography (AS-OCT) in laser in situ keratomileusis (LASIK) with Femto LDV femtosecond lasers versus Hansatome mechanical Microkeratome.
  
  
  METHODS
  AS-OCT (Visante) was used to compare 1 month postoperatively the morphology of the flaps created with Femto LDV femtosecond lasers or Hansatome Microkeratome. The intended ﬂap thickness was 110µm and 160µm respectively. The thickness of twenty-five points across each flap, which were 0mm, 1.5mm, 2.5mm, and 3.5mm to the corneal vertex on the horizontal, vertical, 45° and 135° meridian respectively, was evaluated.
  
  
  RESULTS
  One month postoperative, the central flap thickness in the Femto LDV group was 107.43±4.70µm, while 125.90±17.50µm in the Hansatome group. The difference between the actual and the expected ﬂap thickness was 5.61±3.84µm and 31.52±12.27µm, respectively. The Hansatome group had presented a statistically signiﬁcant result (P<0.001). Flap morphology showed a more regular planar shape in the Femto LDV group and a meniscus shape in the Hansatome group.
  
  
  CONCLUSIONS
  AS-OCT is a direct and fast procedure to assess the flap morphology. The morphology by AS-OCT showed that the flaps created with Femto LDV femtosecond laser were more accurate and regular than the flaps created with Hansatome microkeratome.
authors.affiliation: Zhongshan Ophthalmic Center and State Key Laboratory of Ophthalmology, Sun Yat-sen University, Guangzhou 510060, Guangdong Province, China.
authors.forename: Xiao-Xiao
authors.initials: XX
authors.lastname: Zhang
authors.forename: Xing-Wu
authors.initials: XW
authors.lastname: Zhong
authors.forename: Jun-Shu
authors.initials: JS
authors.lastname: Wu
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.forename: Ke-Ming
authors.initials: KM
authors.lastname: Yu
authors.forename: Quan
authors.initials: Q
authors.lastname: Liu
authors.forename: Bin
authors.initials: B
authors.lastname: Yang