title: Correlation of central and peripheral corneal thickness in healthy corneas.
abstract: OBJECTIVE
  To study the thickness profile of the normal cornea in order to establish any correlation between central and peripheral points.
  
  
  METHODS
  Sixty-seven eyes of 40 patients were subjected to central corneal thickness measurement (CCT) with an ultrasound pachymeter (UP) and corneal thickness mapping with the Oculus Pentacam. The corneal apex thickness (CAT), pupil centre thickness (recorded as CCT and corresponded to CCT of UP) and thickness at the thinnest location (CTL) were obtained and compared with each other. Corneal thickness data at 3 mm and 7 mm temporally, nasally, superiorly and inferiorly from the corneal apex were obtained. The mean corneal thickness values along the 2, 4, 6, 8 and 10 mm diameter concentric circles, with the CTL as the centre, were also obtained. The above data at different points were statistically correlated.
  
  
  RESULTS
  There was no significant difference between CCT readings measured by UP and Pentacam (P=0.721). There was high positive correlation between the CAT values and the thickness at 3 mm (R≥0.845, P<0.001) and at 7 mm points (R≥0.654, P<0.001). A gradual increase in thickness was noted from the centre to the periphery with a high positive correlation between the CTL values and the mean thickness at the circles of 2, 4, 6, 8 and 10 mm (R≥0.635, P<0.001).
  
  
  CONCLUSIONS
  The results suggest that central corneal thickness can serve as a good guide for predicting peripheral thickness. For surgical procedures specifically undertaken at mid-peripheral and peripheral zones, the actual measurements at the site of surgery may confer some advantage.
authors: Division of Ophthalmology and Visual Sciences, University of Nottingham, Eye Ear Nose Throat Centre, University Hospital, Nottingham, United Kingdom.
authors: Usama
authors: U
authors: Fares
authors: Ahmad Muneer
authors: AM
authors: Otri
authors: Mouhamed Ali
authors: MA
authors: Al-Aqaba
authors: Harminder S
authors: HS
authors: Dua
mesh_terms: D000328:Adult; D000368:Aged; D003315:Cornea / Q000033:anatomy & histology*; D019781:Corneal Topography / Q000295:instrumentation* / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D055815:Young Adult