title: Comparison of central corneal thickness measurements using optical low-coherence reflectometry, Fourier domain optical coherence tomography, and Scheimpflug camera.
abstract: OBJECTIVE
  To compare the results of central corneal thickness (CCT) measurements obtained using optical low-coherence reflectometry (OLCR), Fourier domain optical coherence tomography (FD-OCT), and a Scheimpflug camera (SC), combined with Placido corneal topography.
  
  
  METHODS
  A total of 25 healthy subjects were enrolled in the present study, and one eye of each subject was included. A detailed ophthalmic examination was performed in all cases following CCT measurements with OLCR, FD-OCT, and SC. The results were compared using an ANOVA test. Bland-Altman analysis was used to demonstrate agreement between methods. Intra-examiner repeatability was assessed by using intraclass correlation coefficients (ICCs).
  
  
  RESULTS
  Statistically significant differences were observed between the results of the CCT measurements obtained using the three different devices (p=0.009). Significant correlations were found between OLCR and FD-OCT (r=0.97; p<0.0001), FD-OCT and SC (r=0.91; p<0.0001), and OLCR and SC (r=0.95; p<0.0001). The 95% limits of agreement (LOA) obtained from Bland-Altman plots were from -7.2 μm to 28.7 μm for OLCR versus FD-OCT, from -19.2 μm to 30.4 μm for OLCR versus SC, and from -42.6 to 32.3 μm for FD-OCT versus SC. Intra-examiner repeatability was excellent for each method, with ICCs >0.98.
  
  
  CONCLUSIONS
  Although the results of CCT measurements obtained from these three devices were highly correlated with one another and the mean differences between instruments were comparable with the reported diurnal CCT fluctuation, the measurements are not directly interchangeable in clinical practice because of the wide LOA values.
authors: Department of Ophthalmology, Selcuk University Faculty of Medicine, Konya, Turkey.
authors: Saban
authors: S
authors: Gonul
authors: Department of Ophthalmology, Selcuk University Faculty of Medicine, Konya, Turkey.
authors: Bengu Ekinci
authors: BE
authors: Koktekir
authors: Department of Ophthalmology, Selcuk University Faculty of Medicine, Konya, Turkey.
authors: Berker
authors: B
authors: Bakbak
authors: Department of Ophthalmology, Selcuk University Faculty of Medicine, Konya, Turkey.
authors: Sansal
authors: S
authors: Gedik
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D019412:Anatomy, Cross-Sectional; D001699:Biometry / Q000295:instrumentation / Q000379:methods; D002648:Child; D003315:Cornea / Q000033:anatomy & histology*; D063171:Corneal Pachymetry / Q000295:instrumentation* / Q000379:methods*; D019781:Corneal Topography / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010781:Photography / Q000295:instrumentation; D012016:Reference Values; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D041623:Tomography, Optical Coherence / Q000379:methods*; D055815:Young Adult