Permeability of the BRB may be measured in live laboratory animal models of retinal diseases by the extent of leakage using fluorescent dyes with predefined molecular weight such as fluorescein (Do carmo et al., 1998), Evans blue (Xu et al., 2001) and others (Ivanova et al., 2019). In the clinical setting, fundus fluorescein angiography (FFA) utilizing a fluorescent dye and fundus camera has been an established method for examining retinal vascular circulation and BRB damage (Marmor and Ravin, 2011). Recently, a newly modified OCT method was developed, the OCT-Leakage. By using a proprietary algorithm to identify sites of decreased optical reflectivity, the system quantifies and detects the correlation of retinal extracellular space with degrees of retinal edema (Cunha-Vaz et al., 2016; Cunha-Vaz, 2017). A live imaging study in 28 patients has demonstrated agreement between OCT-Leakage and FFA in identifying sites of impaired BRB in diabetes (Cunha-Vaz et al., 2017), providing a new noninvasive low-cost alternative method to detect and quantify BRB leakage.