We read with interest the recent article by Saito et al 1 entitled ‘Macular choroidal blood flow velocity decreases with regression of acute central serous chorioretinopathy' (CSC); however, it raised a few questions. First, Saito et al measured choroidal blood flow and compared mean blur rate (MBR) changes at the macular and perimacular regions with laser speckle flowgraphy (LSFG). As described in the article, LSFG can measure only relative blood flow velocity, not an absolute value of velocity. Therefore, the velocity can be compared serially only within the same object. However, if the morphologic characteristics …