title: Changes of higher order aberration with various pupil sizes in the myopic eye.
abstract: OBJECTIVE
  To investigate the effect of pupil diameter on higher order aberration in myopic eyes.
  
  
  METHODS
  One hundred and two eyes of 51 normal subjects were evaluated with the Nidek OPD-Scan.
  
  
  RESULTS
  All types of aberration increased significantly with increasing pupil size (P<.001). However, optical aberrations had a less pronounced increase in C3(-1) and C3(+1) , more pronounced increase in C4(0) with pupil area increased (P<.05), 2nd coma (C5(-1) and C6(+1)) and high order astigmatism (C4(-2), C4(+2) C6(-2), C6(+2) with larger pupil diameter. Compared with the aberrations of each high order aberration at 4 mm, the average increase root mean square values were 1.54, 1.59, 1.71, and 1.87 on S3, S4, S5, and S6 respectively, with a 5-mm pupil, whereas increased root mean square values were 1.46, 1.88, 1.51, and 1.60 for a 6-mm-diameter pupil.
  
  
  CONCLUSIONS
  For an equal increase of pupil size, not all Zernike polynomial coefficients induced equivalent increase of values. Coma-like aberrations increased less with pupil dilation. Spherical-like aberration showed only a small increase from 4 mm to 5 mm pupil size, but a larger increase from 5 mm to 6 mm pupil size. Other higher order aberrations (S5 and S6) increased slightly with pupil dilation. Coma-like aberration was larger than spherical aberration, and larger than other higher order aberrations for all pupil sizes.
authors.affiliation: Refractive Surgery Center Tianjin Eye Hospital & Institute, Teaching Hospital of the Tianjin Medical University, Peoples Republic of China. ophhostj@public.tpt.tj.cn
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Kanxing
authors.initials: K
authors.lastname: Zhao
authors.forename: Ying
authors.initials: Y
authors.lastname: Jin
authors.forename: Yafei
authors.initials: Y
authors.lastname: Niu
authors.forename: Tong
authors.initials: T
authors.lastname: Zuo
mesh_terms: D000293:Adolescent; D000328:Adult; D003315:Cornea / Q000503:physiopathology*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D009216:Myopia / Q000503:physiopathology*; D009799:Ocular Physiological Phenomena; D011680:Pupil / Q000502:physiology*; D011897:Random Allocation; D012029:Refraction, Ocular