Comparison of Central Corneal Thickness Measurements between Angiovue Optical Coherence Tomography, Ultrasound Pachymetry and Ocular Biometry

Purpose: To compare central corneal thickness (CCT) measurements and their reproducibility when taken by Ultrasound Pachymetry, Ocular Biometry and Angiovue Optical Coherence Tomography (OCT).

Methods: Twenty-five healthy volunteers were recruited creating a sample size of 50 eyes. All subjects had pachymetric measurements by Ultrasound pachymetry (PachPen Handheld Pachymeter, Keeler Instruments Inc), Ocular biometry (IOL Master 700 Swept Source Biometry, Zeiss) and Angiovue Optical Coherence Tomography (Optovue Avanti RTVue XR Angiovue). The measurements of central corneal thickness for the three devices were taken by the same examiner twice for more accuracy.

Results: The average measurements of central corneal thickness by Ultrasound pachymetry (PachPen Handheld Pachymeter, Keeler Instruments Inc), Ocular biometry (IOL Master 700 Swept Source Biometry, Zeiss) and Angiovue Optical Coherence Tomography (Optovue Avanti RTVue XR Angiovue) were 547.26 μm, 551.36 μm, and 536.42 μm, respectively. The mean standard deviation (SD) of repeated measurements by Ocular biometry was 48.87 μm, which was greater than the mean SD of 44.24 μm and 40.35 μm (P < 0.001) by ultrasound pachymetry and Angiovue optical coherence tomography, respectively. There were statistically significant differences in the measurement results among the 3 methods (Ultrasound pachymetry vs. Ocular biometry P = 0.019; Ultrasound pachymetry vs. Angiovue Optical Coherence Tomography; P < 0.001; Ocular biometry vs. Angiovue Optical Coherence Tomography P < 0.001). There was a significant linear correlation between the Ultrasound pachymetry and Ocular biometry (r = 0.945, P<0.001), Ultrasound pachymetry and Angiovue Optical Coherence Tomography (r = 0.895, P<0.001), and Ocular biometry and Angiovue Optical Coherence Tomography (r = 0.902, P<0.001).

Conclusion: Central corneal thickness readings were comparable between PachPen Handheld Pachymeter, IOL Master 700 Biometry and Angiovue Optical Coherence Tomography; Angiovue optical coherence tomography gave significantly smaller values. The measurements of the 3 methods showed significant linear correlations with one another. All methods provided acceptable repeatability of measurements.