1. An ophthalmic apparatus comprising: a generation unit configured to generate 3D blood vessel data indicating a blood vessel in a fundus based on a plurality of tomographic image data indicating cross sections of the fundus; a boundary obtaining unit configured to obtain layer boundary data indicating at least one layer boundary based on 3D tomographic image data including the plurality of tomographic image data indicating the cross sections of the fundus, wherein the layer boundary data indicates at least one of a boundary between a Bruch membrane and a retinal pigment epithelium layer and a boundary between the Bruch membrane and a choroid layer; and a determination unit configured to determine a blood vessel intersecting with the layer boundary by comparing the 3D blood vessel data with the layer boundary data.