title: Effect of residual ocular spherical aberration on objective and subjective quality of vision in pseudophakic eyes.
abstract: OBJECTIVE
  To determine the level of residual spherical aberration that gives the best objective and subjective quality of image after cataract surgery with intraocular lens (IOL) implantation.
  
  
  METHODS
  Department of Ophthalmology, CHU Bretonneau, Tours, France.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Six months after microincision (1.8 mm) cataract surgery with aspheric IOL implantation, total aberrations were computed using a Wavescan aberrometer. The modulation transfer function (MTF), Strehl ratio, and objective index of scattering were measured using the Objective Quality Analysis System. Objective depth of focus was computed as the focus range at which the Strehl ratio did not fall below 50% of maximum. Subjective depth of focus was calculated as the difference between the vergence of the punctum remotum and that of the punctum proximum.
  
  
  RESULTS
  Thirty patients (54 eyes) were evaluated. The MTF cutoff values were higher with decreasing total ocular spherical aberration (r = 0.56; P < .05). Objective and subjective depth of focus were positively correlated with total spherical aberration (r = 0.26 and r = 0.46, respectively; P < .05).
  
  
  CONCLUSIONS
  A final spherical aberration of zero obtained by compensation of IOL asphericity gave the greatest improvement in objective quality of vision and better MTF contrast. However, a final target ocular spherical aberration between 0.07 μm and 0.10 μm should be considered to be the best compromise between subjective depth of focus and objective contrast sensitivity.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors: Department of Ophthalmology, University Hospital of Tours, Tours, France. yannick.nochez@free.fr
authors: Yannick
authors: Y
authors: Nochez
authors: Samuel
authors: S
authors: Majzoub
authors: Pierre-Jean
authors: PJ
authors: Pisella