**1. Introduction**

Age-related Macular Degeneration (AMD) is an acquired retina disease that can potentially cause significant central visual impairment. Advanced forms of the disease may present as areas of retinal pigment epithelium (RPE) loss, subretinal/sub-RPE hemorrhage or serous fluid, as well as subretinal fibrosis. Severely affected areas may have no visual function, since loss of RPE is associated with photoreceptor collapse.

When OCT (Optical Coherence Tomography) was not available yet, several studies proposed classifications using a wide variety of parameters for AMD grading systems [1–3]. In order to facilitate data comparison among those studies and develop a core grading system using color stereoscopic fundus photography, the International Age-Related Maculopathy Epidemiological Study Group compiled the results of a series of meetings among groups involved in the epidemiological analysis of Age-Related Maculopathy (ARM) [4].

Also The Macular Photocoagulation Study Group contributed significantly to AMD grading, to the understanding of natural history of subfoveal neovascularization as well as to the effectiveness of laser photocoagulation on juxtafoveal neovascularizations [5].

OCT applied to the study of retinal pathologies has revolutionized the understanding and management of AMD, especially with the technology of full-depth imaging (FDI) Spectral Domain (SD) OCT. With the increasing amount of data from several important studies using SD-OCT and OCT-angiography (OCT-A) we can now better classify and more accurately decode AMD.

The purpose of this chapter is to describe the most important AMD biomarkers recently discovered using SD OCT.
