title: Improved functional vision with a modified prolate intraocular lens.
abstract: OBJECTIVE
  To evaluate whether the Tecnis Z9000 intraocular lens (IOL) (Pfizer) with a modified prolate anterior surface provides better quality of vision than a conventional spherical IOL.
  
  
  METHODS
  Oregon Eye Institute, Eugene, Oregon, USA.
  
  
  METHODS
  Patients presenting for cataract surgery who were randomly assigned to receive a Tecnis Z9000 IOL (Pfizer) or a Sensar OptiEdge AR40e IOL (AMO) in 1 eye were followed for 3 months postoperatively. The patient could elect to have the same type of IOL implanted in the fellow eye. The results of sine-wave grating contrast sensitivity testing under mesopic and photopic conditions were compared interindividually.
  
  
  RESULTS
  Monocular comparison was made between the 2 IOL groups, which comprised 15 patients each. The Tecnis IOL provided significantly better contrast sensitivity at 6 cycles per degree (cpd) under photopic conditions and at 1.5 and 3 cpd under mesopic conditions. Seven patients with a Tecnis IOL and 9 patients with an AR40e IOL had subsequent implantation in the fellow eye. In all eyes, including fellow eyes, having IOL implantation, the Tecnis provided significantly better contrast sensitivity at 3 and 6 cpd under photopic conditions and at 1.5, 3, and 6 cpd under mesopic conditions. The mean contrast sensitivity in fellow eyes showed that the Tecnis IOL produced significantly better results at some spatial frequencies.
  
  
  CONCLUSIONS
  Results show the Tecnis IOL with a modified prolate anterior surface may produce better contrast sensitivity than a standard spherical IOL under mesopic and photopic conditions. Because contrast sensitivity testing correlates well with functional vision, a goal of future research should be to evaluate patient performance using functional tests such as driving simulation.
authors.affiliation: Oregon Eye Institute, Eugene 97401, USA. mpacker@finemd.com
authors.forename: Mark
authors.initials: M
authors.lastname: Packer
authors.forename: I Howard
authors.initials: IH
authors.lastname: Fine
authors.forename: Richard S
authors.initials: RS
authors.lastname: Hoffman
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Piers
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002387:Cataract Extraction; D015350:Contrast Sensitivity / Q000502:physiology*; D005500:Follow-Up Studies; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008875:Middle Aged; D011474:Prosthesis Design; D011788:Quality of Life; D014785:Vision, Ocular / Q000502:physiology*