Fig. 1.

This figure shows the chorioretinal structures En face (left images) and as a cross section (right images). The Early Treatment Diabetic Retinopathy Study map divides the macula into 9 subfields. A circular grid is centered over the fovea and consists of 3 concentric rings of diameters 1, 3, and 6 mm, respectively. A The inner and outer rings are further divided into quadrants: temporal, nasal, superior, and inferior (left). Retinal thickness was defined as the area between the internal limiting membrane (ILM) and the inner boundary of retinal pigment epithelium (RPE) (right). B Retinal nerve fiber layer thickness was defined as the area bordered in red. C Choroidal thickness was measured as the perpendicular distance between hyperreflective outer border of the retinal pigment epithelium bruch’s membrane layer and the sclera-choroidal interface