title: Comparative evaluation of visual outcomes and corneal asphericity after laser-assisted in situ keratomileusis with the six-dimension Amaris excimer laser system.
abstract: OBJECTIVE
  To compare the visual and refractive outcomes after laser-assisted in situ keratomileusis (LASIK) surgery for correction of myopia or myopic astigmatism using a six-dimensional Amaris excimer laser.
  
  
  METHODS
  In this retrospective cohort study, we enrolled 47 eyes of 28 patients (age: 19-36 years) with myopia or myopic astigmatism. We used the Custom Ablation Manager protocol and performed ablations with the SCHWIND AMARIS system. LASIK flaps were cut with an iFS Advanced Femtosecond Laser. Mean static (SCC) and dynamic cyclotorsion (DCC) were evaluated. Visual and refractive outcomes were evaluated during 6 months' follow-up. Corneal asphericity (Q-value) was analyzed at 4 months postoperatively.
  
  
  RESULTS
  The spherical equivalent (SE) reduction was statistically significant reduce 1 day after refractive surgery (P < 0.001), with no additional significant changes during follow-up (P = 0.854). SCC registration rates were 81% in the Aberration-Free mode (AF) and 90% in the Corneal Wavefront mode (CW). SCC measurements were within ± 5 degrees in 57% (AF) and 68% (CW) of eyes. Mean DCC was within ± 1 degree in 96% (AF) or 95% (CW) of cases. At 6 months, the uncorrected distance visual acuity was 20/25 or better in all eyes. At last follow-up, both steep and flat keratometry values had significantly flattened in both groups (P < 0.001). Corneal asphericity also increased significantly during the postoperative period for an 8-mm corneal diameter (P < 0.001).
  
  
  CONCLUSIONS
  LASIK for myopia or myopic compound astigmatism correction using the six-dimensional AMARIS 750S excimer laser is safe, effective, and predictable. Postoperative corneal asphericity can be analyzed by linear regression to predict the changes in postoperative corneal asphericity with this approach.
authors.affiliation: Catholic Institute for Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: JunJie
authors.initials: J
authors.lastname: Piao
authors.affiliation: Department of Ophthalmology, Affiliated Hospital, Yanbian University Medical College, Jilin, China.
authors.forename: Ying-Jun
authors.initials: YJ
authors.lastname: Li
authors.affiliation: Department of Ophthalmology, Catholic Institute for Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Woong-Joo
authors.initials: WJ
authors.lastname: Whang
authors.affiliation: Department of Ophthalmology, Catholic Institute for Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Mihyun
authors.initials: M
authors.lastname: Choi
authors.affiliation: Department of Ophthalmology, Catholic Institute for Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Min Ji
authors.initials: MJ
authors.lastname: Kang
authors.affiliation: Department of Ophthalmology, Catholic Institute for Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jee Hye
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Flaum Eye Institute, Center for Visual Science, The Institute of Optics, University of Rochester, Rochester, New York, United States of America.
authors.forename: Geunyoung
authors.initials: G
authors.lastname: Yoon
authors.affiliation: Department of Ophthalmology, Catholic Institute for Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Choun-Ki
authors.initials: CK
authors.lastname: Joo
mesh_terms: D000328:Adult; D003316:Corneal Diseases / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D007834:Lasers; D008297:Male; D009216:Myopia / Q000601:surgery; D011183:Postoperative Complications / Q000453:epidemiology*; D014792:Visual Acuity