Photocoagulation apparatus, control method of photocoagulation apparatus, and recording medium

A photocoagulation apparatus for applying subthreshold coagulation to a retina via a probe inserted in an eye, comprising:

• a laser projecting system configured to apply treatment light for subthreshold coagulation to the retina via the probe;
• a first optical coherence tomography (OCT) system configured to apply an OCT scan to the retina via the probe;
• a controller configured to perform, upon receiving an instruction from a user, control of the laser projecting system to apply the treatment light to the retina and control of the first OCT system to apply an OCT scan to the retina at least after application of the treatment light;
• a first memory that stores a first OCT image constructed from data acquired by an OCT scan applied to the retina prior to the application of the treatment light;
• an image constructing processor configured to construct a second OCT image from data acquired by the OCT scan applied to the retina after the application of the treatment light;
• a change information acquiring processor configured to acquire change information representing a tissue change in the retina caused by the treatment light by comparing the first OCT image and the second OCT image with each other;
• and
• a display controller configured to display a change image based on the change information on a display device together with a retinal image.