Print screens of real-time grading using RetmarkerAMD. (a) Calibration is achieved after manually identifying the fovea and establishing optic disc diameter (blue dot and arrow, resp.). The software then generates a reference grid (b) that follows the International Classification and Grading System for AMD [12]. (c) Both free forms and predefined circles (63 μm, 125 μm, 175 μm, 250 μm, and 500 μm) can be used for quantifying fundus features in digital color fundus photographs, including drusen, pigmentary changes, geographic atrophy, or exudative lesions.