title: The relationship between anterior corneal aberrations and contrast sensitivity in conventional LASIK.
abstract: OBJECTIVE
  To evaluate the changes of anterior corneal aberrations before and after laser in situ keratomileusis (LASIK) and to assess the correlation between contrast sensitivity and anterior corneal aberrations.
  
  
  METHODS
  Right eyes of 51 patients including 6 males and 45 females undergoing conventional LASIK from September 2000 to July 2003 were enrolled. The calculation of anterior corneal aberrations before and after LASIK was obtained by analyzing the corneal topography from TMS-1 by using VOL-CT Version 6.23 software. Contrast sensitivity was measured after LASIK with an MCT 8000 under daytime and nighttime settings and with glare conditions. The differences of the Zernike coefficients and root mean square (RMS) of anterior corneal aberrations before and after LASIK were analyzed. The changes of contrast sensitivity at 1.5, 3, 6, 12, and 18 cpd were added separately for daytime and nighttime contrast sensitivity with and without glare after LASIK and were correlated with the changes of anterior corneal aberrations.
  
  
  RESULTS
  Vertical coma, RMS of coma-like RMS of spherical-like, RMS of trefoil-like and RMS of higher-order anterior corneal aberrations increased significantly after LASIK surgery. There were no significant correlations between the changes of anterior corneal aberrations and the changes of contrast sensitivity at daytime and nighttime, with and without glare. Contrast sensitivity at daytime and nighttime decreased at each spatial frequency after LASIK.
  
  
  CONCLUSIONS
  LASIK surgery induces changes of the anterior corneal aberrations. However, changes in anterior corneal aberrations did not correlate with the changes of contrast sensitivity at daytime and nighttime, with and without glare.
authors.affiliation: Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan. ijong@ha.mc.ntu.edu.tw
authors.forename: I-Jong
authors.initials: IJ
authors.lastname: Wang
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Sun
authors.forename: Yuan-Chieh
authors.initials: YC
authors.lastname: Lee
authors.forename: Yu-Chih
authors.initials: YC
authors.lastname: Hou
authors.forename: Fung-Rong
authors.initials: FR
authors.lastname: Hu
mesh_terms: D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology*; D003315:Cornea / Q000503:physiopathology* / Q000601:surgery; D019781:Corneal Topography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology* / Q000601:surgery; D011184:Postoperative Period; D012189:Retrospective Studies