title: Comparison of corneal and total ocular aberrations before and after myopic LASIK.
abstract: OBJECTIVE
  To assess the compensation of total ocular and corneal wavefront aberrations after conventional myopic LASIK.
  
  
  METHODS
  This study comprised 57 eyes of 57 patients. Total and corneal aberrations were measured preoperatively and 3 months postoperatively using the OPD-Scan (NIDEK Co Ltd) aberrometer. Total and corneal aberrations root-mean-square (RMS) was calculated out to the 6th Zernike order for a 6.0-mm pupil diameter. The percentage increase postoperatively was defined by the ratio of RMS pre- and postoperatively for each corneal and total eye group. The compensation between corneal and internal aberrations for a given aberration group was defined as: (corneal aberration group RMS - total eye aberration group RMS)/corneal aberration group RMS.
  
  
  RESULTS
  Postoperatively, higher order aberrations increased by a factor of 1.77+/-1.26 (total) and 2.47+/-2.25 (corneal) (P<.05). Coma aberration increased by a factor of 2.43+/-2.61 (total) and 2.56+/-2.66 (corneal). Spherical aberration increased by a factor of 1.46+/-1.83 (total) and 2.64+/-2.24 (corneal). The values of the ratio of compensation did not change significantly before and after LASIK for individual aberrations (P>.05).
  
  
  CONCLUSIONS
  Although myopic LASIK induced significant corneal aberrations, the level of partial compensation of corneal aberrations by internal structures remained unchanged. These results suggest that the previously described emmetropization that is effective during development may also be effective with acquired variations in corneal shape.
authors.affiliation: AP-HP Bichat Claude Bernard Hospital, Paris, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Gatinel
authors.forename: Pierre-Alexandre
authors.initials: PA
authors.lastname: Adam
authors.forename: Slim
authors.initials: S
authors.lastname: Chaabouni
authors.forename: Jacques
authors.initials: J
authors.lastname: Munck
authors.forename: Maud
authors.initials: M
authors.lastname: Thevenot
authors.forename: Thanh
authors.initials: T
authors.lastname: Hoang-Xuan
authors.forename: Stefan
authors.initials: S
authors.lastname: Pieger
authors.forename: Masanao
authors.initials: M
authors.lastname: Fujieda
authors.forename: Harkaran S
authors.initials: HS
authors.lastname: Bains
mesh_terms: D057128:Aberrometry; D000328:Adult; D057108:Corneal Wavefront Aberration / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000009:adverse effects*; D054018:Lasers, Excimer / Q000627:therapeutic use; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D055815:Young Adult