Optical Coherence Tomography Angiography Analysis of Retinal and Choroidal Vascular Networks during Acute, Relapsing, and Quiescent Stages of Macular Toxoplasma Retinochoroiditis

Figure 1

(a–h) Active recurrent toxoplasma retinochoroiditis and evolution after treatment, in a 30-year-old 6-month pregnant woman, presenting with an initial decreased vision from 20/20 to 20/100 and regaining to 20/63 after treatment with pyrimethamine, azithromycin, and 60 mg prednisone. (a) Shows an active yellowish retinitis lesion in the foveal region due to recurrence of toxoplasmosis (A1), with reduction of size of the relapsing lesion (A2) 1 month after antiparasitic and steroid treatment (color picture (Topcon, TRC)). Fundus fluorescein angiography (FFA) early (b) and late (c) phases show progressive hyperfluorescence with centripetal peripheral staining of the recurrent lesion (yellow arrows). Enhanced-depth imaging (EDI) optical coherence tomography (OCT) shows a pachychoroid with hyperreflectivity of all retinal layers of this retrofoveolar recurrent lesion (D1), with decreased size and thickness of the lesion 1 month after treatment (D2) (yellow arrows). Optical coherence tomography angiography of the active lesion shows areas of temporofoveolar capillary loss more extended in the parafoveal superficial capillary plexus ((pSCP), 50 μm slab at +61 μm/internal limiting membrane (ILM), E1) than in the parafoveal deep capillary plexus ((pDCP), 50 μm slab at +108 μm/ILM, F1). At the choroid level, OCTA shows areas of capillary and vessel loss less extended in the choriocapillary layer ((CC), 80 μm slab at -40 μm, G1) than in the deeper choroid (80 μm slab at -118 μm, H1). One month after treatment, OCTA shows the reappearance of some retinal capillaries at the level of the pSCP (E2) and the pDCP (F2). Other capillaries and larger vessels were also seen to have reappeared at the level of the CC (G2) and deeper in the choroid (H2).

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