title: Effect of cataract surgery incision location and intraocular lens type on ocular aberrations.
abstract: OBJECTIVE
  To determine whether Hartmann-Shack wavefront sensing detects differences in optical performance in vivo between poly(methyl methacrylate) (PMMA) and foldable acrylic intraocular lenses (IOLs) and between clear corneal and scleral tunnel incisions and whether optical differences are manifested as differences in visual performance.
  
  
  METHODS
  Department of Optometry, University of Bradford, West Yorkshire, United Kingdom.
  
  
  METHODS
  This study comprised 74 subjects; 17 were phakic with no ocular pathology, 20 had implantation of a Pharmacia 722C PMMA IOL through a scleral tunnel, 21 had implantation of an Alcon AcrySof IOL through a scleral tunnel, and 16 had implantation of an AcrySof IOL through a corneal incision. Visual acuity and contrast sensitivity testing, ocular optical quality measurement using Hartmann-Shack wavefront sensing, and corneal surface measurement with a videokeratoscope were performed in all cases.
  
  
  RESULTS
  There were significant differences between groups in the total root-mean-square (RMS) wavefront aberration over a 6.0 mm pupil (F=3.91; degrees of freedom=3,70; P<.05) mediated at the 4th-order RMS, specifically spherical and tetrafoil aberrations. The PMMA-scleral group had the least aberrations and the AcrySof-corneal group the most. For a 3.5 mm diameter pupil, the total higher-order RMS wavefront aberration was not significantly different between the groups (P>.05). There were no differences between groups in corneal shape, visual acuity, or contrast sensitivity.
  
  
  CONCLUSIONS
  Implantation of the spherical PMMA IOL led to a slight reduction in total wavefront aberration compared to phakic eyes. AcrySof IOLs induced more aberrations, especially spherical aberration. Corneal-based incisions for IOL implantation compounded this increase. Studies of the optical performance of IOLs in vivo should use wavefront sensing as the main outcome measure rather than visual measures, which are readily confounded by multiple factors.
authors.affiliation: Department of Optometry, University of Bradford, West Yorkshire, United Kingdom.
authors.forename: Konrad
authors.initials: K
authors.lastname: Pesudovs
authors.forename: Holger
authors.initials: H
authors.lastname: Dietze
authors.forename: Owen G
authors.initials: OG
authors.lastname: Stewart
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Noble
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Cox
mesh_terms: D000180:Acrylic Resins; D000368:Aged; D015350:Contrast Sensitivity / Q000502:physiology; D003315:Cornea / Q000601:surgery; D019781:Corneal Topography; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D018918:Phacoemulsification / Q000379:methods*; D019904:Polymethyl Methacrylate; D012029:Refraction, Ocular / Q000502:physiology; D012030:Refractive Errors / Q000209:etiology*; D012590:Sclera / Q000601:surgery; D014792:Visual Acuity / Q000502:physiology
chemical_list: D000180:Acrylic Resins; D019904:Polymethyl Methacrylate