This study is being conducted to assess two imaging methods-central microperimetry and radial OCT (Optical Coherence Tomography)-in patients with Geographic Atrophy (GA) or those who are at risk of developing this condition. The study team is trying to determine whether these methods can provide more accurate measurements of GA progression toward the foveal center, the central part of the retina responsible for your sharpest, most detailed vision.

Inclusion Criteria:

• Subjects must be 55+ years of age Subjects in the "Intermediate AMD Observation Arm" must have intermediate age-related macular degeneration in one eye

Subjects in the "GA Observation Arm", "GA Continuing Treatment Arm", and "GA Treatment Arm" must have non-central GA (defined as GA has not involved the center point of the fovea) and at least 1% GA in the central 1 mm zone.

Exclusion Criteria:

• Subjects with central involvement of GA. Central involvement is defined as geographic atrophy involving the foveal center point.

Subjects with a baseline size of GA > 17.5mm2 (7.0 Macular Photocoagulation Study Disc Areas).

Subjects who are: pregnant women, adults who cannot consent for themselves, and those who use alcohol in excess. Excess alcohol use is defined by binge drinking (pattern of drinking that brings blood alcohol concentration levels to 0.08 g/dL) on 5 or more days in the past month.

Evidence of retinal atrophy due to causes other than atrophic AMD. Subjects who have had anti-VEGF injections or active choroidal neovascularization in the study eye during the last 12 months Current evidence or history of ocular disorders in the study eye that in the opinion of the investigator confounds study outcome measures, including (but not limited to):

1. Non-proliferative diabetic retinopathy involving 10 or more hemorrhages or microaneurysms, or active proliferative diabetic retinopathy
2. Branch or central retinal vein or artery occlusion
3. Macular hole
4. Pathologic myopia
5. Uveitis
6. Pseudovitelliform maculopathy
7. Intraoperative surgery within the last 90 days prior to study eye enrollment

Patients with age-related macular degeneration.