[Corneal topography and thickness in keratoconus].
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.
Liu
Zuguo
Z
Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China. zuguol@yahoo.com
Zhang
Mei
M
Chen
Jiaqi
J
Luo
Lihui
L
Chen
Longshan
L
Gong
Xiangming
X
Huang
Ting
T
Lin
Yuesheng
Y
Wang
Zhichong
Z
D000293:Adolescent; D000328:Adult; D002648:Child; D019781:Corneal Topography / Q000379:methods*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000473:pathology*; D008297:Male