title: [Corneal topography and thickness in keratoconus].
abstract: OBJECTIVE
  To evaluate the corneal topography and pachymetry in keratoconus.
  
  
  METHODS
  Thirty-five patients (47 eyes) with keratoconus were evaluated by Orbscan corneal topography system. The location, anterior and posterior surface elevation, curvature and pachymetry were analyzed with special reference to the central point of cornea, the apex, the highest point of posterior surface, the point with greatest curvature and the thinnest point. The correlation between the point of greatest curvature and the apex was also analyzed.
  
  
  RESULTS
  The mean elevation of the apex was (0.102 +/- 0.044) mm, the mean distance between the apex and the central point of cornea was (0.686 +/- 0.376) mm. Most of the apexes, the points with the highest posterior surface, the points with the greatest curvature were located in the inferior temporal quadrant, followed by inferior nasal, superior temporal and superior nasal quadrant. The SimK of keratocunus was (60.9 +/- 10.4/53.4 +/- 8.7) D and the mean powers within 3 mm and 5 mm were (57.1 +/- 8.0) D and (50.7 +/- 5.4) D respectively. High correlation between apex elevation and the apex curvature was found (r = 0.697, P < 0.01), and there was also negative relationship between apex elevation and corneal thickness (r = -0.563, P < 0.01).
  
  
  CONCLUSIONS
  The Orbscan system can provide accurate and subtle information about the shape and thickness of keratoconus, which can help us to learn this disorder deeply, especially in the early diagnosis of this disease.
authors.affiliation: Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China. zuguol@yahoo.com
authors.forename: Zuguo
authors.initials: Z
authors.lastname: Liu
authors.forename: Mei
authors.initials: M
authors.lastname: Zhang
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Chen
authors.forename: Lihui
authors.initials: L
authors.lastname: Luo
authors.forename: Longshan
authors.initials: L
authors.lastname: Chen
authors.forename: Xiangming
authors.initials: X
authors.lastname: Gong
authors.forename: Ting
authors.initials: T
authors.lastname: Huang
authors.forename: Yuesheng
authors.initials: Y
authors.lastname: Lin
authors.forename: Zhichong
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D019781:Corneal Topography / Q000379:methods*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000473:pathology*; D008297:Male