Figure 1: (a) Representative OCT image from a healthy subject of the right eye. (b) Layers seen on SD-OCT, These hyperreflective layers should be identified while evaluating an OCT scan: NFL, IPL, OPL, ELM, RPE, Ellipsoid zone, and Inter digitation zone. The hypo reflective layers are GCL, INL, ONL and Henle's nerve fiber layer at the macula, OSPR, and ISPR and myoid zone–Chorio capillaries and inner and outer choroidal layers. (c) Standard ETDRS. This is a representation of standard ETDRS map showing map diameters centered on the fovea and nine standard ETDRS Map ETDRS regions: Outer and inner superior quadrant, outer and inner inferior quadrant, outer temporal quadrant, inner temporal quadrant, outer nasal quadrant and INQ. The macular thickness was defined as the distance between the ILM and the inner boundary of RPE in each of the nine regions. OCT: optical coherence tomography, SD-OCT: Spectral-domain optical coherence tomography, NFL: Nerve fiber layer, IPL: Ganglion cell layer Inner plexiform layer, OPL: Outer plexiform layer, ELM: External limiting membrane, GCL: Ganglion cell layer, INL: Inner nuclear layer, ONL: Outer nuclear layer, OSPR: Outer segments of photoreceptors, ISPR: inner segment of photoreceptors, ETDRS: Early treatment diabetic retinopathy study, INQ: inner nasal quadrant, RPE: Retinal pigment epithelium, ILM: Internal limiting membrane