## 7 OCTA in Type 2 MNV Secondary to AMD  
Type 2 neovascular networks in AMD originate from the choroid and are located in the subretinal space [8]. The presence of subretinal hyperreflective material (SHRM) on structural OCT is a common finding in type 2 MNVs, and it was reported to be highly correlated with visual function worsening [68]. SHRM was described to be related to several components as neovascular tissue, hemorrhage, subretinal exudation (Figure 2), and fibrosis [69; 70]. Sometimes, it might be challenging to distinguish between SHRM components using conventional imaging; therefore, OCTA can be decisive in distinguishing the neovascular from the exudative component [71]. [PERSON] et al. described the visualization of a large type 2 neovascular lesion on OCT angiograms [72]. Two large central trunks and a dense branching network of smaller caliber vessels radiating in all directions from the main trunk were appreciated [72]. [PERSON] et al. observed different type 2 MNV patterns on OCTA: the \"medusa-shaped\" and the \"glomerulus-shaped\" [73]. In the medusa-shaped pattern, a compact zone of tiny blood vessels with a minimal hypodense structure inside was present, whereas the glomerulus-shaped lesions were compared with the kidney glomerulus as globular structures of entwined vessels separated by hypodense spaces [73]. The capability of OCTA in detecting the flow signal at the level of SHRM was demonstrated even when type 1 and 2 components coexist in the same neovascularization, the so-called mixed lesion [74]. [PERSON] et al. observed on OCT angiograms a qualitative and quantitative reduction of both type 1 and type 2 components of vascular networks after intravitreal VEGF-trap treatment [74]. [PERSON] et al. described the regression of type 2 lesions into a type 1 pattern after anti-VEGF treatment [75]. OCTA was also able to show the disappearance of flow signal in the subretinal space with the progressive attenuation and dislocation beneath the RPE of the same flow signal after treatment [75]. Moreover, the OCTA detection of neovascular networks in patients with subretinal fibrosis secondary to neovascular AMD was reported to be associated with poorer visual function outcomes [76]. Several authors have quantitatively analyzed OCT-A biomarkers of both type 1 and type 2 MNVs, detecting different behaviors of neovascular networks [62; 72; 74; 77; 78]. [PERSON] et al. reported that larger lesions and type 2 MNVs showed higher flow index, which is a parameter that was directly correlated with the presence of active blood flow within the vascular complex [62]. [PERSON] et al. observed that type 2 lesions showed a smaller flow area, smaller greatest vascular caliber (GVC), and smaller greatest linear dimension (GLD) when compared to type 1 lesions [77]. Moreover, type 2 networks were associated with a shorter duration of the disease, which is a parameter that was positively correlated with GVC [77]. [PERSON] et al. observed that MNV vessel and lesion size reduction after anti-VEGF treatment was mostly prominent in type 2 MNVs, rather than in more complex and long-standing vascular networks as type 1 MNVs [72]. Even other parameters such as MNV area and GLD, computed on \"en face\" OCT angiograms, were reported to decrease after anti-VEGF treatment more in type 2 than in type 1 lesions [56; 72]. Two new quantitative parameters have been recently proposed: the VT, which reflects the geometrical properties of a neovascular network, and the vessel dispersion (VDisp), which express the disorganization degree of the MNV [78]. Type 2 lesions seemed to show highest VDisp values than type 1 MNVs, whereas VT values were similar in both neovascular subtypes [56]. Figure 2: Imaging of a Type II or “classic” macular neovascularization (MNV). (**A**) Multicolor imaging showing some reddish lesion in macular area due to pigmentary changes associated with a yellowish area secondary to a focally increased reflectivity at the level of the outer retina.