1. An image processing apparatus, which analyzes retina layers of an eye to be examined, comprising: one or more processors; and at least one memory coupled to the one or more processors, the at least one memory having instructions stored thereon which, when executed by the one or more processors, cause the image processing apparatus to: extract a feature amount, which represents an anatomical feature in the eye to be examined from a fundus image of the eye to be examined; detect structures of the retina layers in a tomogram of the retina layers, wherein the tomogram corresponds to the fundus image; extract information of a shape of at least one retina layer based on the detected structures of the retina layers; determine whether the anatomical feature includes a first morbid portion or a blood vessel based on the feature amount and to determine whether or not the anatomical feature includes an age-related macular degeneration as a second morbid portion based on the information of the shape; decide at least one layer including a retinal pigment epithelium layer from the retina layers according to the determination of whether the anatomical feature includes the first morbid portion or the blood vessel; and modify the decided at least one layer and estimate, in a case where the anatomical feature includes the second morbid portion, a normal structure of the retinal pigment epithelium layer.