title: Spherical aberrations of human astigmatic corneas.
abstract: OBJECTIVE
  To evaluate whether the average spherical aberration of human astigmatic corneas is statistically equivalent to human nonastigmatic corneas.
  
  
  METHODS
  Spherical aberrations of 445 astigmatic corneas prior to laser vision correction were retrospectively investigated to determine Zernike coefficients for central corneal areas 6 mm in diameter using CTView (Sarver and Associates). Data were divided into groups according to cylinder power (0.01 to 0.25 diopters [D], 0.26 to 0.75 D, 0.76 to 1.06 D, 1.07 to 1.53 D, 1.54 to 2.00 D, and >2.00 D) and according to age by decade. Spherical aberrations were correlated with age and astigmatic power among groups and the entire population. Statistical analyses were conducted, and P<.05 was considered statistically significant.
  
  
  RESULTS
  Mean patient age was 42.6±11 years. Astigmatic corneas had an average astigmatic power of 0.78±0.58 D and mean spherical aberration was 0.25±0.13 μm for the entire population and approximately the same (0.27 μm) for individual groups, ranging from 0.23 to 0.29 μm (P>.05 for all tested groups).
  
  
  CONCLUSIONS
  Mean spherical aberration of astigmatic corneas was not correlated significantly with cylinder power or age (P>.05). Spherical aberrations are similar to those of nonastigmatic corneas, permitting the use of these additional data in the design of aspheric toric intra-ocular lenses.
authors: Abbott Medical Optics, Santa Ana, California 92705-2011, USA. huawei.zhao@amo.abbott.com
authors: Huawei
authors: H
authors: Zhao
authors: Guang-Ming
authors: GM
authors: Dai
authors: Li
authors: L
authors: Chen
authors: Henk A
authors: HA
authors: Weeber
authors: Patricia A
authors: PA
authors: Piers
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology; D001251:Astigmatism / Q000503:physiopathology* / Q000601:surgery; D003315:Cornea / Q000503:physiopathology* / Q000601:surgery; D019781:Corneal Topography; D057108:Corneal Wavefront Aberration / Q000503:physiopathology*; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult