title: Spherical aberration reduction in nuclear cataracts.
abstract: OBJECTIVE
  To measure higher-order aberrations (HOAs) in nuclear cataracts and to investigate spherical aberration changes with nuclear cataract progression.
  
  
  METHODS
  A total of 102 eyes of older subjects (>50 years) were classified based on the nuclear opalescence (NO) grading of the Lens Opacities Classification System III: Group 1 (< NO2, 35), 2 (NO2, 23), 3 (NO3, 23), and 4 (≥ NO 4:21 eyes). Wave front measurements were performed with a Hartmann-Shack aberrometer. To investigate lenticular spherical aberration, HOAs were examined in 28 eyes before and after phacoemulsification, followed by insertion of an aberration-free intraocular lens. The relationship between lens opacity grade and ocular and lenticular spherical aberrations were investigated.
  
  
  RESULTS
  Mean spherical aberrations in groups 1, 2, 3, and 4 were 0.25 ± 0.10, 0.16 ± 0.13, 0.12 ± 0.15, and 0.10 ± 0.20 μm, respectively, and showed a significant difference with nuclear opacity grading (p = 0.001). The spherical aberration showed negative associations with nuclear opacity grading (r = -0.408, p < 0.001). The predominant change in HOAs after phacoemulsification was an increase in spherical aberration, and 86 % of lenticular spherical aberrations were presumed to have negative values. The lenticular spherical aberration was negatively correlated with nuclear opacity severity (r = -0.409, p = 0.031).
  
  
  CONCLUSIONS
  Ocular spherical aberration decreases with the progression of nuclear cataracts due to the negative correlation between lenticular spherical aberration and nuclear opacity severity.
authors.affiliation: Department of Ophthalmology, Yonsei University Wonju College of Medicine, 20, Ilsan-ro, Wonju-si, Gangwon-do, 26426, Korea.
authors.forename: Jong-Hyuck
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Yonsei University Wonju College of Medicine, 20, Ilsan-ro, Wonju-si, Gangwon-do, 26426, Korea.
authors.forename: Hun Gu
authors.initials: HG
authors.lastname: Choo
authors.affiliation: Department of Ophthalmology, Yonsei University Wonju College of Medicine, 20, Ilsan-ro, Wonju-si, Gangwon-do, 26426, Korea. eyedockim@yonsei.ac.kr.
authors.forename: Sun Woong
authors.initials: SW
authors.lastname: Kim
mesh_terms: D057128:Aberrometry; D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000145:classification / Q000151:congenital* / Q000503:physiopathology; D057108:Corneal Wavefront Aberration / Q000503:physiopathology; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D007907:Lens Nucleus, Crystalline / Q000503:physiopathology*; D008027:Light; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification; D012542:Scattering, Radiation
keywords: Cataract; Higher-order aberration; Lenticular spherical aberration; Nuclear cataract; Spherical aberration