The purpose of this ancillary AREDS2 study (study acronym: A2A_SDOCT) is to identify whether measurable AMD pathology (drusen, photoreceptor layer thickness, early findings of geographic atrophy (GA) or neovascularization) imaged by spectral domain optical coherence tomography (SDOCT) can predict progression of AMD and vision loss. The A2A_SDOCT study began as an ancillary AREDS2 study; however AREDS2 had stopped gathering participant data on October 31, 2012 and will be terminated soon. This extension study is needed to complete the AREDS2 dataset by collecting images at one or two additional time points, as the study started over a year behind the AREDS2 study. The data collection period for the extension will end April 30, 2014. Data analysis will conclude by October 31, 2014. All AREDS2 study procedure guidelines for data collection will be followed, as described below, even though this visit falls outside the AREDS2 study timeline.