Manual analysis of anterior segment optical coherence tomography (AS-OCT) images is fairly time consuming, and inter-observer reproducibility cannot be guaranteed. Therefore, automated analysis methods of AS-OCT images are necessary in clinical applications. This paper presents a novel approach to extract the inner contour of the anterior chamber automatically from AS-OCT images using a \divide-and-conquer" strategy. We first find the anchor points in an image and these points are used to divide the image into subimages where the iris, lens and cornea are located. Then the endothelial surface of the cornea, lens surface and iris surface are obtained from these subimages with different schemes, and they are merged together to obtain the complete inner contour. In our method, the endothelial surface of the cornea is fitted by using three circular arcs under continuity constraints. Experiments show that the proposed algorithm can extract the inner contour of the anterior chamber from AS-OCT images accurately in real time.