Figure 9 - SD OCT in normal retina.

Figure 9 - SD OCT in normal retina (up left ). In the lower images, SD OCT of the junction area between preserved retina and the geographic atrophy. Atrophic areas show retinal thinning due to atrophy of the RPE and disappearance of the external retina that includes inner and outer segment of the photoreceptors and, very frequently, the external limiting membrane(16); The outer nuclear layer may be no longer identifiable and therefore the outer plexiform layer may be in direct contact with Bruch´s membrane. The thinned retina permits the deeper penetration of light and a corresponding increased signal from the choroid within the atrophic area.