title: Effects of preoperative corneal astigmatism orientation on results with a low-cylinder-power toric intraocular lens.
abstract: OBJECTIVE
  To evaluate refractive results with a low-cylinder-power toric intraocular lens (IOL) and the effect of preoperative corneal astigmatism orientation on results.
  
  
  METHODS
  Private practice, Jackson, Michigan, USA.
  
  
  METHODS
  Comparative case series.
  
  
  METHODS
  This retrospective review of clinical records comprised patients with 0.75 to 1.38 diopters (D) of preoperative corneal astigmatism who had uneventful cataract surgery and AcrySof T3 toric or AcrySof IQ spherical monofocal IOL implantation. Surgically induced astigmatism (SIA) was calculated for eyes with postoperative keratometry results. Postoperative refractive astigmatism between groups and subgroups was compared based on the orientation of preoperative corneal astigmatism.
  
  
  RESULTS
  Of the eyes, 185 had a toric IOL and 138 had a spherical IOL. The mean preoperative corneal astigmatism was 1.06 D, with no significant difference between IOL groups or by axis of astigmatism. The mean SIA was 0.25 D, with no significant difference between IOL groups. The mean postoperative refractive astigmatism was statistically significantly lower in the toric IOL group than in the spherical IOL group (0.31 D versus 1.06 D; P<.001). The axis of preoperative corneal astigmatism was not a significant factor in the toric IOL group. In the spherical IOL group, the residual astigmatism was slightly higher for with-the-rule than for against-the-rule astigmatism (1.07 D versus 0.70 D; P<.001).
  
  
  CONCLUSIONS
  The mean refractive astigmatism after cataract surgery in patients with 0.75 D to 1.38 D of corneal astigmatism was significantly lower when a toric IOL was implanted. Postoperative refractive astigmatism with the toric IOL was independent of preoperative corneal astigmatism axis orientation.
  
  
  BACKGROUND
  Neither author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: TLC Eyecare & Laser Centers, Jackson, Michigan 49202, USA. paul.ernest@tlcmi.com
authors.forename: Paul
authors.initials: P
authors.lastname: Ernest
authors.forename: Richard
authors.initials: R
authors.lastname: Potvin
mesh_terms: D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D003315:Cornea / Q000503:physiopathology; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D018918:Phacoemulsification; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology