title: Does dilated wavefront aberration measurement provide better postoperative outcome after custom LASIK?
abstract: OBJECTIVE
  To compare outcomes after custom LASIK based on non-pharmacologically dilated (natural mesopic pupil) and pharmacologically dilated wavefront aberration measurement.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  The study group included 81 myopic eyes from 81 patients (mean preoperative spherical equivalent [SE], -4.15+/-1.97 diopters [D]). The control group consisted of 87 myopic eyes from 87 patients (mean preoperative SE, -4.98+/-2.00 D).
  
  
  METHODS
  The 81-eye study cohort was treated based on nonpharmacological low mesopic dilated wavefront aberration measurement (Zywave aberrometer), and the postoperative outcome was compared with that of the control group of 87 eyes treated, based on pharmacologically dilated (2.5% neosynephrine) wavefront data, using the Zyoptix platform. The same nomogram was used for both groups, which adjusts sphere based on the amount of preoperative higher-order aberration. All eyes had a low mesopic pupil diameter of > or =6.3 mm without pharmaceutical intervention.
  
  
  METHODS
  Postoperative 3-month visual acuity (VA), contrast sensitivity, and refractive error.
  
  
  RESULTS
  Of the non-pharmacologically dilated eyes (study) and pharmacologically dilated (control) eyes, 96.3% and 96.6%, respectively, attained postoperative uncorrected VA of 20/20 or better. Although 96.6% of the eyes were within the target SE of +/-0.50 D in the control group, 100% of the 81 study eyes were within an SE of +/-0.50 D postoperatively. The range of postoperative SE (-0.75 to +1 D) was slightly reduced among the study eyes (+/-0.50 D). Differences were not statistically significant.
  
  
  CONCLUSIONS
  When a low mesopic pupil dilates to > or =6.3 mm, pharmacological dilation with wavefront-guided ablation may provide no additional benefit with regard to spherical accuracy when compared with nonpharmacological wavefront-guided ablation. The use of the Rochester nomogram, which accounts for aberration interaction, provided excellent results with or without pharmacological dilation.
authors.affiliation: Bausch and Lomb, Rochester, New York, USA. Manoj_Subbaram@urmc.rochester.edu
authors.forename: Manoj V
authors.initials: MV
authors.lastname: Subbaram
authors.forename: Scott M
authors.initials: SM
authors.lastname: MacRae
mesh_terms: D016022:Case-Control Studies; D015350:Contrast Sensitivity / Q000502:physiology*; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D019781:Corneal Topography; D006801:Humans; D007498:Iris / Q000187:drug effects; D020731:Keratomileusis, Laser In Situ; D009184:Mydriatics / Q000494:pharmacology; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D010656:Phenylephrine / Q000494:pharmacology; D011184:Postoperative Period; D011680:Pupil / Q000502:physiology*; D012160:Retina / Q000502:physiology; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology*
chemical_list: D009184:Mydriatics; D010656:Phenylephrine