title: Changes in accommodation and ocular aberration with simultaneous vision multifocal contact lenses.
abstract: OBJECTIVE
  The aim of this study was to evaluate ocular aberration changes through different simultaneous vision multifocal contact lenses (CLs).
  
  
  METHODS
  Eighteen young-adult subjects with a mean age of 29.8±2.11 years took part. Changes in accommodative response, spherical aberration (C(4)(0)), horizontal coma (C(3)(1)), vertical coma (C(3)(-1)), and root mean square (RMS) of higher-order aberrations (HOAs, third to sixth orders) were evaluated. Measurements were obtained with a distance-single vision CL and 2 aspheric multifocal CLs of simultaneous focus center-near design (PureVision Low Add and PureVision High Add) for 2 accommodative stimuli (-2.50 and -4.00 D). All measurements were performed monocularly with a Hartmann-Shack aberrometer (IRX-3; Imagine Eyes, Orsay, France).
  
  
  RESULTS
  No statistically significant differences were found in accommodative responses to -2.50- and -4.00-D stimuli between the single vision CL and the 2 multifocal CLs. Spherical aberration was found to decrease and become more negative with accommodation for both stimuli with all three CLs. Horizontal coma decreased significantly with accommodation (-2.5- and -4.00-D stimuli) for the distance-single vision CLs (P=0.002 and P=0.003). No differences were found in vertical coma Zernike coefficients. The RMS of HOAs was found to decrease only with the single vision CLs for both stimuli (P<0.01).
  
  
  CONCLUSIONS
  Data obtained in this study suggest that in young subjects, the multifocal CLs studied do not induce large changes in accommodative response compared with the distance-single vision CLs. Spherical aberration reduced significantly with accommodation.
authors.affiliation: Optometry Research Group (GIO), Optics Department, University of Valencia, Valencia, Spain. j.ruizalcocer@hotmail.com
authors.forename: Javier
authors.initials: J
authors.lastname: Ruiz-Alcocer
authors.forename: David
authors.initials: D
authors.lastname: Madrid-Costa
authors.forename: Hema
authors.initials: H
authors.lastname: Radhakrishnan
authors.forename: Teresa
authors.initials: T
authors.lastname: Ferrer-Blasco
authors.forename: Robert
authors.initials: R
authors.lastname: Montés-Micó
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000328:Adult; D003261:Contact Lenses; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D055620:Optical Phenomena; D012029:Refraction, Ocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology*