title: Ocular higher-order aberrations in myopia and skiascopic wavefront repeatability.
abstract: OBJECTIVE
  To study the distribution of ocular higher-order aberrations (HOAs) in a myopic population and to assess the repeatability of HOA measurements determined by a commercially available skiascopic wavefront sensor.
  
  
  METHODS
  Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin, Israel.
  
  
  METHODS
  Ocular HOAs were examined 3 times across a 6.0 mm naturally dilated pupil in 61 eyes using the Optical Path Difference (OPD)-scan wavefront aberrometer. Root-mean-square (RMS) values of HOAs, total spherical aberration (TSA), total coma (TC), and total trefoil (TT) were analyzed. Correlation analysis was performed to assess the aberration symmetry between right and left eyes. The repeatability of the OPD-scan measurements was assessed by calculating Pearson r correlation coefficients between each pair of measurements and the interclass correlation coefficients between the 3 measurements of each score.
  
  
  RESULTS
  The mean RMS values of HOAs, TSA, TC, and TT were 0.347 microm +/- 0.252 (SD), 0.120 +/- 0.174 microm, 0.165 +/- 0.168 microm, and 0.252 +/- 0.157 microm, respectively. The HOAs, TSA, TC, and TT changed slightly and not significantly with increasing refractive error (all P>.05). The RMS level of HOAs and TTR of the 3rd measurement was significantly different from the 1st and 2nd measurements (P<.05), with overall low correlation between the 3 measurements for the HOAs, TSA, TC, and TT.
  
  
  CONCLUSIONS
  The ocular wavefront aberrations varied greatly from subject to subject. Ocular HOAs were not correlated with refractive error. The repeatability of HOAs measurements with the OPD-aberrometry was low.
authors.affiliation: Department of Ophthalmology, Assaf Harofeh Medical Center, Tel Aviv University, Zerifin 70300, Israel. dzadok@yahoo.com
authors.forename: David
authors.initials: D
authors.lastname: Zadok
authors.forename: Yair
authors.initials: Y
authors.lastname: Levy
authors.forename: Ori
authors.initials: O
authors.lastname: Segal
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Barkana
authors.forename: Yair
authors.initials: Y
authors.lastname: Morad
authors.forename: Isaac
authors.initials: I
authors.lastname: Avni
mesh_terms: D000293:Adolescent; D000328:Adult; D003315:Cornea / Q000473:pathology*; D057108:Corneal Wavefront Aberration / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D009216:Myopia / Q000175:diagnosis*; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D015203:Reproducibility of Results; D042262:Retinoscopy; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult