Central Corneal Thickness Measured by Noncontact Specular Microscopy, Dual Rotating Scheimpflug Camera and Ultrasound Pachymetry

PURPOSE: To compare central corneal thickness (CCT) as measured using noncontact specular microscopy (NCSM), dual rotating Scheimpflug camera (Galilei(R)), and ultrasound pachymetry (USP). METHODS: The measurements of CCT using NCSM, dual rotating Scheimpflug camera and USP in 70 eyes of 70 healthy subjects were compared. RESULTS: The average measurements of CCT using NCSM, dual rotating Scheimpflug camera, and USP were 567.70 +/- 31.21 microm, 557.84 +/- 26.29 microm, and 553.31 +/- 29.69 microm, respectively. The CCT measurement using NCSM was statistically significantly thicker than when measured using USP (p 0.900, p < 0.001). CONCLUSIONS: The results of the 3 methods were significantly correlated but the measurement using NCSM was significantly thicker than when using USP. CCT measurements of healthy eyes using dual rotating Scheimpflug camera were more correlated with USP than NCSM. The CCT measurements using dual rotating Scheimpflug camera is a better alternative for USP than NCSM.

Corneal Thickness Measured by Dual Scheimpflug, Anterior Segment Optical Coherence Tomography, and Ultrasound Pachymetry

PURPOSE: To compare central corneal thickness (CCT) as measured by dual rotating Scheimpflug camera (Galilei), anterior segment optical coherence tomography (AS-OCT), and ultrasound pachymetry (USP). METHODS: The measurements of CCT using a dual rotating Scheimpflug camera, AS-OCT, and USP in 40 eyes of 20 healthy subjects were compared. RESULTS: The average measurements of CCT by dual rotating Scheimpflug camera, AS-OCT, and USP were 538.10 +/- 31.36 microm, 536.20 +/- 31.21 microm, and 541.93 +/- 34.93 microm, respectively. The CCT measurement by USP was statistically significantly thicker than by the dual rotating Scheimpflug camera and AS-OCT (p = 0.017, p = 0.001, respectively). There was no significant difference between the dual rotating Scheimpflug camera and AS-OCT (p = 0.054). A significant linear correlation was observed between the dual rotating Scheimpflug camera, the AS-OCT, and the USP (r > 0.900, p < 0.001). CONCLUSIONS: The results of the 3 methods have significant correlation with each other, but the measurement by USP was significantly thicker than the dual rotating Scheimpflug camera and AS-OCT. Therefore, CCT should be interpreted in the context of the instrument used.