title: Changes to corneal aberrations and vision after Presbylasik refractive surgery using the MEL 80 platform.
abstract: OBJECTIVE
  To investigate changes to corneal surface aberrations and vision between PresbyLASIK and LASIK for correction of presbyopia using the MEL 80 platform (Carl Zeiss Meditec, Jena, Germany).
  
  
  METHODS
  The retrospective data of 31 patients who underwent PresbyLASIK (the PresbyLASIK group) between January 2009 and November 2011 and 20 matched patients who underwent LASIK (the LASIK group) were analyzed for changes to refraction, corrected distance visual acuity, and corneal surface wavefront aberrations calculated over 4- and 6-mm pupils. Outcomes at the 3-month follow-up visit were compared to data collected immediately prior to surgery and between PresbyLASIK and LASIK correction. Associations between induced corneal aberrations and best spherical equivalent refraction were explored.
  
  
  RESULTS
  PresbyLASIK and LASIK significantly reduced refractive error in both myopes and hyperopes. Residual refractive error was not significantly different between treatment groups, except for spherical equivalent refraction, which was significantly more myopic following LASIK treatment compared to PresbyLASIK in myopes. There was no significant difference in postoperative corrected distance visual acuity between groups. LASIK and PresbyLASIK induced positive spherical aberration in myopes and negative spherical aberration in hyperopes, with significant differences between treatments only apparent in myopes when analyzed over a 4-mm pupil (PresbyLASIK group: 0.07 ± 0.06 µm; LASIK group: 0.03 ± 0.04 µm, P < .05). In hyperopes, induced spherical aberration was more highly associated with refractive change after LASIK (r = 0.82, P < .05) than PresbyLASIK (r = 0.64, P < .001); instead PresbyLASIK led to a more consistent shift of approximately 0.3 µm independent of induced change to refraction.
  
  
  CONCLUSIONS
  PresbyLASIK using the MEL 80 platform induced significant changes in spherical aberration in myopes and hyperopes. PresbyLASIK appears to offer an improved response over LASIK when correcting myopes due to an apparent increase in depth of focus resulting from changes in spherical aberration. For hyperopes, PresbyLASIK provides a more consistent spherical aberration effect independent of refractive change.
authors.forename: Paul
authors.initials: P
authors.lastname: Gifford
authors.forename: Pauline
authors.initials: P
authors.lastname: Kang
authors.forename: Helen
authors.initials: H
authors.lastname: Swarbrick
authors.forename: Patrick
authors.initials: P
authors.lastname: Versace
mesh_terms: D000328:Adult; D000368:Aged; D019781:Corneal Topography; D057108:Corneal Wavefront Aberration / Q000503:physiopathology*; D005500:Follow-Up Studies; D006801:Humans; D006956:Hyperopia / Q000503:physiopathology / Q000601:surgery*; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011305:Presbyopia / Q000503:physiopathology / Q000601:surgery*; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult