Fluorescein angiography (FA) and optical coherence tomography (OCT) are commonly used imaging techniques in diabetic retinopathy (DR). The first report describing FA to visualize the retinal vascular tree was in 1930 by Kikai. However, the disadvantages of FA became apparent soon. FA photographs can visualize only large superficial retinal vessels located within the nerve fiber layer and the ganglion cell layer, and perfusion of deeper retinal vasculature 
was not visible. As it is an invasive imaging technique, FA has been associated with rare but life-threatening complications such as anaphylaxis and cardiac arrest (XU et al., 2015). Optical coherence tomography (OCT), which was introduced to the scientific community in 1991 has become one of the important imaging modalities. Optical coherence tomography angiography (OCTA) was demonstrated in 2015 by Spaide et al., which could image all layers of the retinal vasculature, including the deep layers, in contrast to FA imaging (Freiberg et al., 2016).