title: Correlation between corneal and total wavefront aberrations in myopic eyes.
abstract: OBJECTIVE
  Corneal topography data expressed as corneal aberrations are frequently used to report corneal laser surgery results. However, the optical image quality depends on all optical elements of the eye, including the human lens. We investigated correlations between corneal and total wavefront aberrations and the relevance of corneal aberrations for representing the optical quality of the total eye.
  
  
  METHODS
  Thirty-three eyes of 22 myopic patients were measured using a corneal topography system and a Tscherning-type wavefront analyzer. Pupils were dilated to at least 6 mm in diameter. All measurements were centered with respect to the line of sight. Corneal and total wavefront aberrations were calculated up to the 6th Zernike order in the same reference plane.
  
  
  RESULTS
  Statistically significant correlations (P<.05) between corneal and total wavefront aberrations were found for astigmatism (C3,C5) and all 3rd Zernike order coefficients such as coma (C7,C8). No statistically significant correlations were found for 4th, 5th, or 6th order Zernike coefficients. On average, all Zernike coefficients for corneal aberrations were larger than the Zernike coefficients for total wavefront aberrations.
  
  
  CONCLUSIONS
  Due to the lack of correlation between corneal and total wavefront aberrations in most of the higher order aberrations, measurement of corneal aberrations are of limited use for representation of the optical quality of the human eye, especially after corneal laser surgery. Corneal aberrations and optical elements within the eye are optically balanced. As a consequence, ideal customized ablations must take both corneal and total wavefront aberrations into consideration.
authors.affiliation: University of Zurich, Dept. of Ophthalmology, Zurich, Switzerland. Michael.Mrochen@aug.usz.ch
authors.forename: Michael
authors.initials: M
authors.lastname: Mrochen
authors.forename: Mirko
authors.initials: M
authors.lastname: Jankov
authors.forename: Michael
authors.initials: M
authors.lastname: Bueeler
authors.forename: Theo
authors.initials: T
authors.lastname: Seiler
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000175:diagnosis*; D003315:Cornea / Q000473:pathology*; D019781:Corneal Topography; D006801:Humans; D008875:Middle Aged; D009216:Myopia / Q000473:pathology*; D011446:Prospective Studies; D012029:Refraction, Ocular; D014792:Visual Acuity