**3.7 OCTA limitations**

One of the most important limitations of OCTA is the great variability in the algorithms used by different manufacturers. The immediate consequence is the difficulty of comparing images obtained with different devices [13, 46]. Projection and movement artifacts can be especially frequent in patients with macular lesions and DME, severely affecting image quality (up to 30% of images have to be discarded) [38, 46]. Simple vitreous opacities can affect image quality and interpretation [46]. Furthermore, most of the quantitative and qualitative parameters used in the literature are obtained with an external software after exporting the images, through a slow process and, on many occasions, with manual segmentation. This is absolutely unfeasible in clinical practice, where fast processing systems
