Corneal Thickness and Volume Measurements by Swept Source Anterior Segment Optical Coherence Tomography in Normal Subjects

Purpose: To evaluate central corneal thickness (CCT) and corneal volume (CV) in healthy eyes using swept source anterior segment optical coherence tomography (SS-AS-OCT) and other devices. Methods: Thirty-three healthy right eyes of 33 subjects were investigated. CCT was measured with SS-AS-OCT, rotating Scheimpflug camera, ultrasonic pachymetry and specular microscopy. CV was determined within a diameter of 10 mm at the center using SS-AS-OCT and Scheimpflug camera. Results: Mean CCT was 523.5 +/- 25.2 mu m by SS-AS-OCT, 523.9 +/- 26.1 mu m by Scheimpflug camera, 532.1 +/- 26.6 mu m by ultrasonic pachymetry, and 525.5 +/- 33.5 mu m by specular microscopy. The CCTs measured with SS-AS-OCT, Scheimpflug camera and specular microscopy were significantly thinner than those measured with ultrasonic pachymeter (p<0.001). The mean CV within a diameter of 10mm at the center was 57.2 +/- 3.0 mm(3) by SS-AS-OCT and 59.4 +/- 2.9 mm(3) by Scheimpflug camera. Scheimpflug measurements of CV were statistically larger than SS-AS-OCT measurements (p=0.0008). Statistically significant correlation was found between the CCT and CV measurements of each imaging devices (p<0.0001, r = 0.527, and p<0.0001, r = 0.749, respectively). Conclusion: SS-AS-OCT enables the measurements of CCTand CV, demonstrating agreement with other devices. CV in addition to CCT measurement may serve as a practical parameter of the corneal endothelial pump function.