To determine an opening degree of a chamber angle with higher accuracy compared to that of a conventional technology, provided is an anterior ocular segment tomographic image analysis method including: a first determination step of determining an approximated line that approximates a shape of an anterior surface of an iris along the anterior surface of the iris in an anterior ocular segment tomographic image； a second determination step of determining an approximated line extended part obtained by extending the approximated line until the approximated line crosses a baseline in contact with an inner surface of a cornea and an inner surface of a sclera of an anterior ocular segment in the anterior ocular segment tomographic image； and a calculation step of calculating an opening degree of an anterior chamber angle of the anterior ocular segment through use of the approximated line and the approximated line extended part.
