**2. Retinal lesions and OCT-A**

OCT-A identifies a large number of MA that cannot be detectable on fundus exploration, but less than fluorescein angiography (FA) due to slow hematic flow in the aneurismatic dilatations [9]. Also it is possible to analyze each plexus separately. For that, it has been possible to observe that the majority of MA is located in the DCP [9, 10]. The MA could be classify following its internal reflectivity (hyper or hypo). The hyperreflective ones are associated with high flow and damage in the hemato-retinal barrier and edema. The hyporreflectives has low flow and are more difficult to detect by the OCT-A [11].

Furthermore, OCT-A is capable of detecting other vascular anomalies such as intraretinal vascular anomalies (IRMA) and define its structural characteristics and extension. It is possible to identify the changes in these vascular anomalies after the treatment with anti-VEGF drugs or laser photocoagulation.

Shimouchi et al. studied the characteristics of IRMAs before and after panretinal photocoagulation and identified five types of IRMA: (1) without changes after laser; (2) tuft type; (3) with reperfusion; (4) mix of 2 and 3; (5) worse after the laser. Types 2 and 5 were more related with proliferative diabetic retinopathy (PDR) [12].

IRMAs were identified as dilated and tortuous vessels near ischemia areas [13–15]. Compared with IRMAs, retinal neovascularization (RNV) alters the internal limiting membrane (ILM) [13] and could be identified by observing the flow signal above ILM [13, 16].

With OCT-A it is possible to identify early points of retinal neovascularization, impossible to differentiate from an MA in FA. Furthermore, OCT-A is better than FA in the accuracy identification of lesion limits as the leakage of the FA could blur the RNV border [13].
