title: The effects of spherical aberration on static accommodative responses in emmetropes and myopes.
abstract: OBJECTIVE
  To compare the effects of spherical aberration (SA) on accommodative responses between emmetropes (EMs), stable myopes (SMs), and progressing myopes (PMs).
  
  
  METHODS
  The accommodative responses (AR) induced by negative lenses from 0 to -5 D in 1 D steps were measured with a Complete Ophthalmic Analysis System (COAS) for 10 emmetropes (EMs), 13 stable myopes (SMs), and 9 progressing myopes (PMs). Three types of AR were calculated from wavefront aberration data based on ocular foci within a paraxial area, natural pupil area, and a 3.5 mm-diameter annular pupil area. The accommodative stimulus response curves (ASRCs) were compared between the three groups and between the three AR conditions.
  
  
  RESULTS
  The difference in the slope of ASRC was significant between the three AR conditions (p < 0.0001) but it was not significant between the three refractive groups. In each group, the slope of ASRC for the accommodative response measured within the paraxial area of the pupil (paraxial AR) was significantly steeper than that measured for the natural pupil (total AR) and also for that estimated for the 3.5 mm-diameter annular pupil (p < 0.01). The difference in the y-intercept of ASRC between the three AR conditions was also significant (p = 0.02) but not between the three refractive groups. The y-intercept of ASRC for paraxial AR was more positive than that for total AR in SMs (p < 0.01) and in PMs (p < 0.05); the y-intercept of ASRC for the 3.5 mm peripheral AR was more positive than that for total AR in SMs (p < 0.05).
  
  
  CONCLUSIONS
  The spherical aberration of the eye has a significant effect on the slope of ASRC and is less in PMs than in EMs and SMs.
authors.affiliation: Eye and ENT Hospital, Fudan University, Shanghai, China             College of Optometry, Nova South Eastern University, Fort Lauderdale, Florida, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.forename: Bai-Chuan
authors.initials: BC
authors.lastname: Jiang
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D058453:Emmetropia / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009216:Myopia / Q000503:physiopathology*; D012029:Refraction, Ocular / Q000502:physiology*; D015348:Vision, Binocular / Q000502:physiology; D055815:Young Adult