*2.2.1.3.1 SS-OCT and SS-OCTA features*

SS-OCT showed marked thinning and disorganization of the retina, irregular elevation and thickening of the RPE and altered choroidal contour. SS-OCTA showed complete loss of the choriocapillaris at the site of the scar with unveiling of the large choroidal vessels underneath (**Figure 10**).

#### **Figure 10.**

*Top left: Color fundus photo and FFA of the right eye of an 8-year-old female child with old toxoplasmosis scar. The macular area is almost entirely occupied by a large oval chorioretinal scar with sharply-circumscribed edges. The lesion shows variable grades of RPE pigmentary disturbances. The central part of the lesion shows complete chorioretinal atrophy exposing the underlying sclera. Note that the scar is sharply focused in comparison to the slightly defocused ONH and peripapillary area, which indicates the deeper plane of the scar due to excavation. On FFA, the lesion shows alternating areas of blocked fluorescence due to RPE pigment clumps formation and hyperfluorescence due to staining of scar tissue. Top right: Radial scan SS-OCT of the macular area. Note the abrupt transition from normal retinal layers at the edges of the lesion (white arrows) to marked thinning and disorganization of the neurosensory retina in the scar area. The central part of the lesion shows lumpy hyperreflective amorphous lesion representing the thickened distorted RPE layer. The underlying choroid is markedly thinned with increased optical reflectivity due to enhanced light penetration through the over-thinned layers. Bottom: En-face SS-OCTA images of the outer retina and choriocapillaris. The overthinning of the retina, and loss of choriocapillaris at the site of chorioretinal scar led to enhanced visualization of the Sattler's layer in the choriocapillaris and outer retina slabs.*
