Measurement of axial position of spherical objects using multiple delay element C-scan OCT

In a previous report1 we presented a novel method using en-face OCT for the evaluation of the curvature of an object, with immediate application to measurement of corneal curvature. This method relies on single shot C-scans obtained from an en-face OCT system with a multiple delay element introduced in the reference arm. In the present report we show how the same methodology can be used for the measurement of the axial position of a spherical object. The theoretical basis and the accuracy of assessing the axial position using this method are presented. The potential application of this method in the measurement and tracking of the in-vivo axial position of the eye is also discussed.