title: Changes in corneal curvature in accommodation.
abstract: OBJECTIVE
  To determine the changes in corneal curvature in accommodation.
  
  
  METHODS
  Department of Ophthalmology, St. Luke's International Hospital, Tokyo, Japan.
  
  
  METHODS
  Twenty-eight eyes of 14 healthy volunteers with a mean age of 38.9 years (range 28 to 65 years) were enrolled in this prospective study. Corneal topographies were taken before and during accommodation. Subjects achieved maximal accommodation by gazing at a target letter "A" in front of the eye. Keratometric values (K-values) obtained by topographies before and during accommodation were compared.
  
  
  RESULTS
  Steepened corneal curvatures during accommodation were observed with the difference-plot view. Maximum K-values for the central 3.0 mm, 5.0 mm, and 7.0 mm corneal diameters significantly increased by a mean of 0.62 diopters (D) +/- 0.83 (SD) (P =.0005, paired t test), 0.60 +/- 0.90 D (P =.0015), and 0.72 +/- 0.65 D (P<.0001), respectively. Respective minimum K-values significantly increased by a mean of 0.62 +/- 0.83 D (P=.0005), 0.67 +/- 0.68 D (P<.0001), and 0.64 +/- 0.62 D (P<.0001). No statistically significant relationship was found between age and change in K-values.
  
  
  CONCLUSIONS
  The results suggest that changes in corneal curvature in accommodation participate in the mechanism of accommodation.
authors.affiliation: Department of Ophthalmology, St. Luke's International Hospital, Tokyo, Japan. akiyasu@luke.or.jp
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yasuda
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Kishiko
authors.initials: K
authors.lastname: Ohkoshi
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000328:Adult; D003315:Cornea / Q000502:physiology*; D019781:Corneal Topography; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies