title: Relationship between contrast sensitivity and spherical aberration: comparison of 7 contrast sensitivity tests with natural and artificial pupils in healthy eyes.
abstract: OBJECTIVE
  To find a contrast sensitivity test that can be used clinically to evaluate interventions aimed at minimizing spherical aberration and determine the circumstances under which these tests should be performed.
  
  
  METHODS
  Laboratory of Experimental Ophthalmology, University of Groningen, Groningen, The Netherlands.
  
  
  METHODS
  Contrast sensitivity tests were performed using 2 experimental designs. Design 1 was with a natural pupil under mesopic and photopic conditions. Design 2 was with a 5.0 mm artificial pupil after cycloplegia under photopic conditions only. Two computerized tests (vertical sine-modulated gratings [VSG] and Holladay circular sine-modulated patterns [HACSS]) and 5 chart tests (Pelli-Robson, acuity-measuring letter charts at low contrast [2.5% and 10%], VectorVision, and edge contrast sensitivity) were used. Spherical aberration was assessed with a Hartmann-Shack wavefront analyzer.
  
  
  RESULTS
  Forty-nine healthy subjects aged 20 to 35 years (n = 24) and 55 to 70 years (n = 25) participated. Design 2 showed a significant relationship between contrast sensitivity and spherical aberration with the HACSS at 3 cycles per degree (cpd) (P = .03) and 6 cpd (P = .01) and with the VSG at 6 cpd (P = .01). Design 1 yielded no significant relationships.
  
  
  CONCLUSIONS
  Using an artificial pupil, a relationship between contrast sensitivity and spherical aberration was established with the VSG and HACSS tests but not with the chart tests. No test showed a relationship using natural pupils under either lighting condition. Chart tests are unsuitable for uncovering contrast sensitivity differences related to differences in spherical aberration, as typically found in healthy phakic eyes.
authors.affiliation: Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands. k.van.gaalen@ohk.umcg.nl
authors.forename: Kim W
authors.initials: KW
authors.lastname: van Gaalen
authors.forename: Nomdo M
authors.initials: NM
authors.lastname: Jansonius
authors.forename: Steven A
authors.initials: SA
authors.lastname: Koopmans
authors.forename: Thom
authors.initials: T
authors.lastname: Terwee
authors.forename: Aart C
authors.initials: AC
authors.lastname: Kooijman
mesh_terms: D000328:Adult; D000368:Aged; D001187:Artificial Organs; D015350:Contrast Sensitivity / Q000502:physiology*; D006801:Humans; D007908:Lens, Crystalline / Q000502:physiology; D008875:Middle Aged; D011680:Pupil; D012030:Refractive Errors / Q000503:physiopathology*; D014787:Vision Tests