Diabetic retinopathy is an important cause of preventable blindness. It is a major microvascular complication in type 2 diabetes mellitus. It leads to several structural changes in retina which correlates with severity of retinopathy. Optical coherence tomography provides information akin to live in-vivo histology of the retina. The outer highly reflective band next to retinal pigment epithelium was located at the ellipsoid in the inner segments which correlated between the retinal microstructure on the SD-OCT images and the histologic findings. Thus it is more appropriate to consider the previously termed inner segment-outer segment (IS-OS) junction to be photoreceptor inner segment ellipsoid band (ISel). Photoreceptor ISel has been found to be visible on optical coherence tomography (OCT) due to its biological activity rather than the structure in an animal model.