Fig. 2

Enhanced depth imaging optical coherence tomographic (EDI-OCT) images and converted binary images in case 4. Upper row shows EDI-OCT images before treatment, and lower row shows images 6 months after the initial intravitreal methotrexate injection. EDI-OCT images through the fovea (a, d) were converted to binary images using ImageJ software. a, d The luminal area (dark area, asterisks) and the interstitial area (light area, daggers) can be seen. The examined area was determined to be 1,500 μm wide in the subfoveal choroid. It extended vertically from the retinal pigment epithelium to the chorioscleral border, and the choroidal area was set with the ROI manager of ImageJ. The rectangle surrounded by a red line was excised, and the dark areas were traced by the Niblack method. b, e Merged images of the binarized images and the margins of traced areas. In the binarized images, the light pixels were defined as the interstitial choroid or choroidal stroma, and the dark pixels were defined as the luminal area. c, f Merged images of the original EDI-OCT images and the margins of traced areas show that the traced areas coincide with the dark choroidal areas of the EDI-OCT image