title: Comparison of the change in posterior corneal elevation and corneal biomechanical parameters after small incision lenticule extraction and femtosecond laser-assisted LASIK for high myopia correction.
abstract: OBJECTIVE
  To compare posterior corneal elevation (PCE) changes and corneal biomechanical changes post fematosecond laser-assisted laser in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE) procedures using the Pentacam system and the Ocular Response Analyzer (ORA).
  
  
  METHODS
  Retrospective observational case series study.
  
  
  METHODS
  106 patients with bilateral myopia who underwent either FS-LASIK (56 patients) or SMILE (50 patients) were reviewed, only the right eye was used in the analysis. Inclusion criteria include a spherical equivalent of -6.00DS and completion of 12 months follow up. The main outcome evaluated was change in PCE at 3 months, 6 months and 12 months post-operation using the Pentacam system. Corneal biomechanical parameters were evaluated at 6 and 12 months with the ORA.
  
  
  RESULTS
  PCE change at 3 and 6 months were not significantly different between the two procedures (p=0.064, p=0.109 respectively). At 12 months, PCE change was greater in FS-LASIK than SMILE (p=0.048). One-way ANOVA showed that for either procedure, the change in PCE did not differ at 3, 6 or 12 months post operation. CH and CRF values were reduced after both procedures, with FS-LASIK demonstrating a greater reduction in CRF than SMILE at 6 and 12 months (p=0.037 and p=0.001). Both CH and CRF reduction correlated with PCE increase at 6 and 12 months.
  
  
  CONCLUSIONS
  FS-LASIK demonstrated a greater increase in PCE than SMILE only at 12 months, as well as a greater reduction of CRF than SMILE. There were no significant differences in PCE change over time within either group.
authors: Key Myopia Laboratory of Chinese Health Ministry, Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 83, Fenyang Road, Shanghai 200031, China.
authors: Bingjie
authors: B
authors: Wang
authors: Department of Ophthalmology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Meiling North Road 409, Shanghai 200062, China.
authors: Zhenyong
authors: Z
authors: Zhang
authors: The University of Sydney, Camperdown, NSW 2006, Australia.
authors: Rajeev K
authors: RK
authors: Naidu
authors: Key Myopia Laboratory of Chinese Health Ministry, Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 83, Fenyang Road, Shanghai 200031, China.
authors: Renyuan
authors: R
authors: Chu
authors: Key Myopia Laboratory of Chinese Health Ministry, Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 83, Fenyang Road, Shanghai 200031, China.
authors: Jinhui
authors: J
authors: Dai
authors: Key Myopia Laboratory of Chinese Health Ministry, Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 83, Fenyang Road, Shanghai 200031, China.
authors: Xiaomei
authors: X
authors: Qu
authors: Key Myopia Laboratory of Chinese Health Ministry, Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 83, Fenyang Road, Shanghai 200031, China.
authors: Zhiqiang
authors: Z
authors: Yu
authors: Key Myopia Laboratory of Chinese Health Ministry, Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 83, Fenyang Road, Shanghai 200031, China. Electronic address: zheent@139.com.
authors: Hao
authors: H
authors: Zhou
mesh_terms: D001251:Astigmatism / Q000503:physiopathology* / Q000601:surgery*; D003315:Cornea / Q000503:physiopathology* / Q000601:surgery*; D019781:Corneal Topography; D055119:Elastic Modulus; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D008137:Longitudinal Studies; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D054140:Refractive Surgical Procedures / Q000379:methods*; D016896:Treatment Outcome
keywords: Corneal hysteresis; Corneal resistance factor; FS-LASIK; Posterior corneal elevation; SMILE