title: [Normal value of the central corneal thickness measured by non-contact specular microscope].
abstract: OBJECTIVE
  To get the normal value of the central corneal thickness (CCT) measured by non-contact specular microscope and to approach relatively influenced factor from different aspects.
  
  
  METHODS
  The CCT was determined by the KONAN non-contact specular microscope. 173 normal subjects (322 eyes) were measured to get a normal value of the CCT. In the meantime, the para-central corneal thickness (12 o'clock, 2 o'clock, 10 o'clock, 6 o'clock) were measured and the corneal endothelial cell was analyzed in using the same machine. The statistical analysis was performed in using PC SPSS version 10.0 under windows system.
  
  
  RESULTS
  Measured by the non-contact specular microscope, the mean value of the CCT in normal eyes is (554.78+/-32.61), microm. There was no significant difference between right eyes and left eyes, and between male and female. There is no linear correlation between age, density and average area of the corneal endothelium cell and the CCT. The peripherial corneal thickness is thicker than the CCT. Among the peripherial corneal thickness, the thickest part is in the position of 12 o'clock,while the thinnest part is in the position of 6 o'clock.
  
  
  CONCLUSIONS
  The CCT can be accurately measured by non-contact specular microscope. The measured value is reliable.
authors.affiliation: Department of Ophthalmology, The Second Xiang ya Hospital of Central South University, Changsha 410011, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wu
authors.forename: Xuanchu
authors.initials: X
authors.lastname: Duan
authors.forename: Youqin
authors.initials: Y
authors.lastname: Jiang
authors.forename: Guoping
authors.initials: G
authors.lastname: Qing
authors.forename: Bing
authors.initials: B
authors.lastname: Jiang
authors.forename: Jingming
authors.initials: J
authors.lastname: Shi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003315:Cornea / Q000033:anatomy & histology*; D004728:Endothelium, Corneal / Q000166:cytology*; D005260:Female; D006801:Humans; D008297:Male; D008853:Microscopy / Q000592:standards*; D008875:Middle Aged; D012016:Reference Values