High-resolution retinal choroidal images with distinct choroidal margins were transferred to ImageJ software [40]. The high-resolution EDI-OCT images were 6000 microns wide and 2000 microns high, as indicated in the manufacturer's user's manual. EDI-OCT images to be measured were opened using ImageJ software. The Scale command was selected in the Image tab of ImageJ software menu. Using the Scale menu, width (pixels) was defined as 6000 and height (pixels) as 2000. The distance to be measured was marked on the new image of 6000x2000 pixels and measurements were done using the Measure command in Analyze tab. The choroidal margins were drawn in this software according to the specified criteria, followed by manual measurements. Measurements were taken vertically at the fovea centralis and in the nasal and temporal quadrants at distances of 1500 and 2500 microns from the fovea centralis. The same researcher repeated the measurements at different times using the double-blind method, and intraobserver and intervisit measurement repeatability was assessed.