title: Anatomical characterization of central, apical and minimal corneal thickness.
abstract: OBJECTIVE
  To anatomically locate the points of minimum corneal thickness and central corneal thickness (pupil center) in relation to the corneal apex.
  
  
  METHODS
  Observational, cross-sectional study, 299 healthy volunteers. Thickness at the corneal apex (AT), minimum corneal thickness (MT) and corneal thickness at the pupil center (PT) were determined using the pentacam. Distances from the corneal apex to MT (MD) and PT (PD) were calculated and their quadrant position (taking the corneal apex as the reference) determined: point of minimum thickness (MC) and point of central thickness (PC) depending on the quadrant position. Two multivariate linear regression models were constructed to examine the influence of age, gender, power of the flattest and steepest corneal axes, position of the flattest axis, corneal volume (determined using the Pentacam) and PT on MD and PD. The effects of these variables on MC and PC were also determined in two multinomial regression models.
  
  
  RESULTS
  MT was located at a mean distance of 0.909 mm from the apex (79.4% in the inferior-temporal quadrant). PT was located at a mean distance of 0.156 mm from the apex. The linear regression model for MD indicated it was significantly influenced by corneal volume (B=-0.024; 95%CI: -0.043 to -0.004). No significant relations were identified in the linear regression model for PD or the multinomial logistic regressions for MC and PC.
  
  
  CONCLUSIONS
  MT was typically located at the inferior-temporal quadrant of the cornea and its distance to the corneal apex tended to decrease with the increment of corneal volume.
authors.affiliation: Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain.
authors.forename: Federico
authors.initials: F
authors.lastname: Saenz-Frances
authors.affiliation: Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain.
authors.forename: Martha Cecilia
authors.initials: MC
authors.lastname: Bermúdez-Vallecilla
authors.affiliation: Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain.
authors.forename: Lara
authors.initials: L
authors.lastname: Borrego-Sanz
authors.affiliation: Instituto de Tecnología del Conocimiento, Universidad Complutense de Madrid, Madrid 28040, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Jañez
authors.affiliation: Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain.
authors.forename: José María
authors.initials: JM
authors.lastname: Martinez-de-la-Casa
authors.affiliation: Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Morales-Fernandez
authors.affiliation: Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Santos-Bueso
authors.affiliation: Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain.
authors.forename: Julián
authors.initials: J
authors.lastname: Garcia-Sanchez
authors.affiliation: Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain.
authors.forename: Julián
authors.initials: J
authors.lastname: Garcia-Feijoo
keywords: anatomy; corneal thickness; glaucoma