Lacrimal canaliculus imaging by dynamic OCT using extrinsic contrast agent

In this study, the human lacrimal canaliculus (LC), an important segment of the lacrimal drainage system, was imaged using dynamic optical coherence tomography (D-OCT) and the 3D structure of the LC was rendered. In D-OCT system, a turbid commercial ophthalmic solution was used as an extrinsic contrast agent. The lumen boundary of the LC appeared clearer in D-OCT images compared with simple static OCT images, making segmentation easier. D-OCT was performed by calculating the sum of the squared differences of intensities with two different normalization parameters. By color-combining these two D-OCT images and static OCT image, using image calculation software, the contrast agent and the lumen boundary can be clearly separated. 3D volumetric images of the LCs are demonstrated.