title: Topography-based assessment of anterior corneal curvature and asphericity as a function of age, sex, and refractive status.
abstract: OBJECTIVE
  To assess corneal asphericity (Q) and evaluate potential factors influencing the shape of the anterior corneal surface.
  
  
  METHODS
  Medical Optics Research Group, Institute of Medical Physics, University of Erlangen-Nuremberg, Erlangen, Germany.
  
  
  METHODS
  In this cross-sectional consecutive study, 3 topographic measurements were taken. Eyes were grouped by age in years (A: <or=29; B: 30 to 39; C: 40 to 49; D: 50 to 59; E: 60 to 69; F: >or=70), sex, and refraction.
  
  
  RESULTS
  The study comprised 487 eyes (205 men, 288 women; age 17 to 81 years). The mean Q of the anterior corneal surface was -0.22 +/- 0.14 (SD) overall, -0.21 +/- 0.12 in Group A, -0.25 +/- 0.11 in Group B, -0.21 +/- 0.15 in Group C, -0.23 +/- 0.14 in Group D, -0.19 +/- 0.17 in Group E, -0.20 +/- 0.15 in Group F, -0.23 +/- 0.13 in men, -0.21 +/- 0.14 in women, -0.19 +/- 0.14 in hyperopes (n = 166; >+0.50 to +6.50 diopters [D]), -0.23 +/- 0.13 in emmetropes (n = 162; -0.50 to +0.50 D), and -0.23 +/- 0.15 in myopes (n = 165; <-0.50 to -8.00 D). There was no significant correlation between Q and age; Q differed significantly between men and women (P = .005), hyperopes and emmetropes (P<.0001), and hyperopes and myopes (P = .001).
  
  
  CONCLUSIONS
  There were high interindividual variations in the Q value. Thus, proper correction of spherical aberration with intraocular lenses (IOLs) requires sophisticated selection of the asphericity of IOL surfaces based on biometric data and individual corneal Q values.
authors.affiliation: Medical Optics Research Group, Institute of Medical Physics, University of Erlangen-Nuremberg, Erlangen, Germany. katja.scholz@imp.uni-erlangen.de
authors.forename: Katja
authors.initials: K
authors.lastname: Scholz
authors.forename: Arthur
authors.initials: A
authors.lastname: Messner
authors.forename: Timo
authors.initials: T
authors.lastname: Eppig
authors.forename: Holger
authors.initials: H
authors.lastname: Bruenner
authors.forename: Achim
authors.initials: A
authors.lastname: Langenbucher
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003315:Cornea / Q000473:pathology*; D019781:Corneal Topography; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012029:Refraction, Ocular / Q000502:physiology; D012030:Refractive Errors / Q000175:diagnosis* / Q000503:physiopathology; D012737:Sex Factors; D055815:Young Adult