title: Higher order ocular aberrations in eyes with myopia in a Chinese population.
abstract: OBJECTIVE
  To describe the characteristics of higher order ocular aberrations of adult Chinese eyes with myopia.
  
  
  METHODS
  Higher order aberrations in consecutive right eyes of 166 Chinese patients with myopia who enrolled for preoperative assessment for LASIK were retrospectively reviewed. Wavefront aberrations were measured with the Bausch & Lomb Zywave over a 6-mm dilated pupil. The correlations between higher order aberrations and myopia, astigmatism, and age, respectively, were analyzed.
  
  
  RESULTS
  Mean patient age was 32.1 +/- 6.2 years, the mean refractive error was sphere -5.23 +/- 1.79 diopters (D) and cylinder -1.29 +/- 0.98 D. The mean of the total higher order root-mean-square (RMS) (third to fifth order) was 0.49 +/- 0.16 microm. Third-order RMS was largest (mean 0.37 +/- 0.16 microm), followed by fourth-order RMS (mean 0.29 +/- 0.11 microm). For individual higher order Zernike coefficients, spherical aberration (C4(0)) predominated with a mean of 0.23 +/- 0.14 microm. No correlation was found between total higher order RMS and myopia or between total higher order RMS and age. Small but statistically significant relationships were found in the following groups: age and vertical primary coma (C3(-1))(r=-0.206, P=.008); age and spherical aberration (C4(0)) (r=0.196, P=.012); and myopia and horizontal trefoil (C3(3)) (r=-0.158, P=.042).
  
  
  CONCLUSIONS
  Higher order aberrations varied among individuals with myopia. Third-order RMS was the predominant higher order aberration. Spherical aberration and vertical primary coma increased slightly with age. Our study helps establish ocular aberration standards for Chinese refractive surgery candidates.
authors.affiliation: Tianjin Medical University Eye Centre, Tianjin, China.
authors.forename: Rui Hua
authors.initials: RH
authors.lastname: Wei
authors.forename: Li
authors.initials: L
authors.lastname: Lim
authors.forename: Wing Kwong
authors.initials: WK
authors.lastname: Chan
authors.forename: Donald T H
authors.initials: DT
authors.lastname: Tan
mesh_terms: D000328:Adult; D044466:Asian People / Q000208:ethnology; D001251:Astigmatism / Q000208:ethnology / Q000601:surgery; D003315:Cornea / Q000503:physiopathology*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D008875:Middle Aged; D009184:Mydriatics / Q000008:administration & dosage; D009216:Myopia / Q000208:ethnology* / Q000601:surgery; D011680:Pupil / Q000187:drug effects; D012029:Refraction, Ocular / Q000502:physiology*; D012189:Retrospective Studies; D012846:Singapore / Q000453:epidemiology; D014331:Tropicamide / Q000008:administration & dosage
chemical_list: D009184:Mydriatics; D014331:Tropicamide