title: Optical quality comparison between spherical and aspheric toric intraocular lenses.
abstract: OBJECTIVE
  To measure and compare the optical quality of spherical and aspheric toric intraocular lenses (IOLs).
  
  
  METHODS
  Wavefront aberrations of AcrySof Toric and IQ Toric IOLs (Alcon Laboratories) for different powers were measured at 3- and 5-mm pupils by Nimo TR0805 instrument. The Zernike coefficients of trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration were evaluated. The point spread functions (PSFs) of each IOL evaluated were calculated from the wavefront aberrations. The PSF images also were calculated from the IOL wavefront aberrations, adding the cornea's aberrations to simulate the optical quality after their implantation.
  
  
  RESULTS
  Spherical toric IOLs showed positive and aspheric toric IOLs negative spherical aberrations. Statistically significant differences were found in spherical aberration root mean square (RMS) values between spherical and aspheric IOLs for both pupil sizes (p<0.05). Aspheric toric IOLs showed higher spherical aberration RMS values. We found differences in PSF images between both IOL designs at 5-mm pupil. The PSFs corresponding to the aspheric toric IOLs showed more spread out than the PSFs corresponding to the spherical toric IOLs. However, when corneal aberrations were added, aspheric toric IOLs showed better optical quality than spherical toric IOLs.
  
  
  CONCLUSIONS
  At 3-mm pupil, the optical quality between the IOL designs was similar, but at 5-mm pupil the optical quality was higher for spherical IOLs than aspheric IOLs. However, when theoretical corneal aberrations were added, aspheric toric IOLs showed better optical quality than spherical toric IOLs, due to the compensation between aspheric toric IOL negative spherical aberration and corneal positive spherical aberration.
authors: GIO, Optics Department, Faculty of Physics, Universidad de Valencia, Valencia - Spain.
authors: Cari
authors: C
authors: Pérez-Vives
authors: Teresa
authors: T
authors: Ferrer-Blasco
authors: Santiago
authors: S
authors: García-Lázaro
authors: César
authors: C
authors: Albarrán-Diego
authors: Robert
authors: R
authors: Montés-Micó
mesh_terms: D057128:Aberrometry; D001251:Astigmatism / Q000601:surgery; D057108:Corneal Wavefront Aberration / Q000503:physiopathology; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008962:Models, Theoretical; D055095:Optics and Photonics