Image acquisition
OPTIC NERVE
Blue light FAF, fundus photographic, and fluorescein angiographic images were obtained with the modified 3-field protocol (field 1 M: 30-degree field centered on the temporal optic nerve border; field 2: 30-degree field centered on the foveal center; and field 3 M: 30-degree field centered 1 to 1.5 disc diameters temporal to the center of field 2). Heidelberg Spectralis or HRA systems (Heidelberg Engineering, Heidelberg, Germany) were used to capture FAF and near-infrared (IR) field 2 images. Heidelberg Spectralis or Cirrus (Carl Zeiss Meditec, Jena, Germany) systems were used to acquire spectral-domain optical coherence tomography (OCT) scans. Spectralis scans were obtained with 97-line volume scan (20° × 20°, high-resolution mode, Automatic Real-Time [ART] = 9) and 73-line volume scan (20° × 15°, high-resolution mode, ART = 9) protocols. Cirrus OCT scans were obtained with 512 × 128 macular cube and 5-line high-definition raster scan protocols.