title: Contrast sensitivity with silicone and poly(methyl methacrylate) intraocular lenses.
abstract: OBJECTIVE
  To compare the optical performance of silicone intraocular lenses (IOLs) with that of conventional poly(methyl methacrylate) (PMMA) IOLs.
  
  
  METHODS
  University hospital outpatient cataract clinic.
  
  
  METHODS
  Ninety-one patients were randomly assigned to receive a PMMA IOL (n = 48 eyes) or a silicone IOL (n = 43 eyes). Contrast sensitivity was evaluated 4 months after surgery using the Vistech sinusoidal-grating chart and the Pelli-Robson letter sensitivity chart.
  
  
  RESULTS
  No between-group differences were found using the Vistech test. Using the Pelli-Robson test, mean uncorrected contrast sensitivity was 1.59 log units +/- 0.13 (SD) in the PMMA group and 1.53 +/- 0.15 log units in the silicone group. Mean best corrected contrast sensitivity was 1.67 +/- 0.11 and 1.63 +/- 0.16, respectively. The differences between groups using the Pelli-Robson test were statistically significant (P < .05). No correlation was found between reduced contrast sensitivity and brownish discoloration or thickness of silicone IOLs or posterior capsule fibrosis.
  
  
  CONCLUSIONS
  Contrast sensitivity was lower in patients with silicone IOLs than in those with conventional PMMA lenses.
authors.affiliation: Department of Ophthalmology, Vejle Hospital, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Johansen
authors.forename: M
authors.initials: M
authors.lastname: Dam-Johansen
authors.forename: T
authors.initials: T
authors.lastname: Olsen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D006801:Humans; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification; D019904:Polymethyl Methacrylate; D012826:Silicone Elastomers; D014792:Visual Acuity
chemical_list: D012826:Silicone Elastomers; D019904:Polymethyl Methacrylate