TY - JOUR
T1 - Central corneal thickness measurements with partial coherence interferometry, ultrasound, and the Orbscan system
AU - Rainer, Georg
AU - Findl, Oliver
AU - Petternel, Vanessa
AU - Kiss, Barbara
AU - Drexler, Wolfgang
AU - Skorpik, Christian
AU - Georgopoulos, Michael
AU - Schmetterer, Leopold
PY - 2004/5
Y1 - 2004/5
N2 - Objective To compare the reliability of central corneal thickness measurements (CCT) obtained with partial coherence interferometry (PCI), ultrasound pachymetry, and the Orbscan system. Design Cross-sectional study. Participants Twenty healthy subjects with CCT measurements in both eyes. Methods The CCT measurements were obtained with PCI, ultrasound pachymetry, and the Orbscan system. In each eye, 2 investigators performed 5 repeated measurements with each pachymetric device. Intraclass correlation coefficients (κ) were calculated and mean CCT measurements were compared. Main outcome measures The CCT measurements obtained with ultrasound pachymetry, the Orbscan system (Orbtek Inc., Salt Lake City, UT), and PCI. Results Mean CCT values measured with ultrasound pachymetry were significantly thicker than those measured with PCI (21.5 μm; P<0.001) or the Orbscan system (19.8 μm; P<0.001). The correlation coefficients for the intraobserver variability were 0.999 for PCI measurements, 0.983 for ultrasound pachymetry measurements, and 0.988 for Orbscan system measurements. The correlation coefficients for the interobserver variability were 0.998 for PCI measurements, 0.980 for ultrasound pachymetry measurements, and 0.988 for Orbscan system measurements. There was a slightly better consistency between ultrasound pachymetry and PCI (κ = 0.96) than between the Orbscan system and PCI (κ = 0.92) and between ultrasound pachymetry and the Orbscan system (κ = 0.89). Conclusions Partial coherence interferometry was the method with the least intraobserver or interobserver variability. Mean CCT as measured with ultrasound pachymetry was approximately 20 μm thicker than with the Orbscan system and PCI. However, corneal thickness measurements with ultrasound pachymetry and PCI were slightly more consistent than those of the Orbscan system and PCI. This slightly better consistency, however, may be important, especially in corneal refractive surgery.
AB - Objective To compare the reliability of central corneal thickness measurements (CCT) obtained with partial coherence interferometry (PCI), ultrasound pachymetry, and the Orbscan system. Design Cross-sectional study. Participants Twenty healthy subjects with CCT measurements in both eyes. Methods The CCT measurements were obtained with PCI, ultrasound pachymetry, and the Orbscan system. In each eye, 2 investigators performed 5 repeated measurements with each pachymetric device. Intraclass correlation coefficients (κ) were calculated and mean CCT measurements were compared. Main outcome measures The CCT measurements obtained with ultrasound pachymetry, the Orbscan system (Orbtek Inc., Salt Lake City, UT), and PCI. Results Mean CCT values measured with ultrasound pachymetry were significantly thicker than those measured with PCI (21.5 μm; P<0.001) or the Orbscan system (19.8 μm; P<0.001). The correlation coefficients for the intraobserver variability were 0.999 for PCI measurements, 0.983 for ultrasound pachymetry measurements, and 0.988 for Orbscan system measurements. The correlation coefficients for the interobserver variability were 0.998 for PCI measurements, 0.980 for ultrasound pachymetry measurements, and 0.988 for Orbscan system measurements. There was a slightly better consistency between ultrasound pachymetry and PCI (κ = 0.96) than between the Orbscan system and PCI (κ = 0.92) and between ultrasound pachymetry and the Orbscan system (κ = 0.89). Conclusions Partial coherence interferometry was the method with the least intraobserver or interobserver variability. Mean CCT as measured with ultrasound pachymetry was approximately 20 μm thicker than with the Orbscan system and PCI. However, corneal thickness measurements with ultrasound pachymetry and PCI were slightly more consistent than those of the Orbscan system and PCI. This slightly better consistency, however, may be important, especially in corneal refractive surgery.
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U2 - 10.1016/j.ophtha.2003.09.027
DO - 10.1016/j.ophtha.2003.09.027
M3 - Article
C2 - 15121362
AN - SCOPUS:2342457162
SN - 0161-6420
VL - 111
SP - 875
EP - 879
JO - Ophthalmology
JF - Ophthalmology
IS - 5
ER -