title: Central corneal thickness of Iraqi population in relation to age, gender, refractive errors, and corneal curvature: a hospital-based cross-sectional study.
abstract: BACKGROUND
  Central corneal thickness (CCT) is an important indicator of corneal status. Its measurement provides valid information about corneal physiological condition and possible changes associated with diseases, traumas, and hypoxia. It is an integral part for interpretation of intraocular pressure and glaucoma patient management and in prerefractive procedure assessment.
  
  
  OBJECTIVE
  The aim of this study is to determine the mean CCT among a normal Iraqi population and to correlate between CCT and age, gender, refraction, and corneal curvature.
  
  
  METHODS
  This cross-sectional study was carried out at Ibn Al-Haitham Teaching Eye Hospital. A total of 418 eyes from 209 healthy individuals with an age range from 20 to 75 years were studied. CCT was measured by ultrasound pachymeter. Refraction was measured using an auto-refractor and confirmed by trial lenses and retinoscopy to calculate the spherical equivalent. Corneal curvature was measured using an auto-refracto-keratometer to calculate the average corneal curvature (AVK).
  
  
  RESULTS
  The mean CCT was 543.95±32.58 μm with a range from 422 to 636 μm. CCT was not affected by gender. CCT significantly negatively correlated with age and AVK. CCT significantly positively correlated with the spherical equivalence.
  
  
  CONCLUSIONS
  Among an Iraqi population, CCT significantly decreased with age. Myopics had significantly thinner corneas. There was weak but significant negative correlation between CCT and corneal curvature. We recommend further studies about the relationship between central corneal thickness and other ocular parameters in Iraqi population such as the axial length.
authors.affiliation: Ibn Al Haitham Teaching Eye Hospital, Baghdad.
authors.forename: Yasir Jawad
authors.initials: YJ
authors.lastname: Kadhim
authors.affiliation: Department of Ophthalmology, College of Medicine, University of Babylon, Babylon, Iraq.
authors.forename: Qasim K
authors.initials: QK
authors.lastname: Farhood
keywords: CCT; age; corneal curvature; gender; refractive errors; ultrasound pachymeter