Standard enhanced depth imaging (EDI) optical coherence tomography (OCT) is only capable of showing the structure of choroid and choriocapillaris. Disadvantages are its limited field of view, inability to demonstrate leakage, increased potential for artifacts (blinks, movement, vessel ghosting), and inability to detect blood flow below the slowest detectable flow 6, 7, 8, 9, 10, 11. Compared with FFA and Indocyanine green angiography (ICGA), which are the current retinal/choroidal angiographic gold standards, OCTA acquires volumetric scans that can be segmented to specific depths, uses motion contrast instead of intravenous dye, can be obtained within seconds, provides accurate size and localization information and delineates both the retinal and choroidal vasculature. Extensive leakage of the dye may obscure adequate visualisation of microvasculature in eyes with retinitis. Dye-based angiography has been found to be useful in assessing retinal vascular involvement and in detecting occlusive complications in retinitis 5. Optical coherence tomography angiography (OCTA) is a recent advancement which is a non-invasive alternative to fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) to assess the retinal and choroidal microvasculature 3, 4. Uveo-retinal manifestations include solitary or multifocal patches of retinitis, localised or generalised involvement of the retinal vessels in the form of beading of the vessel wall, tortuosity, and perivascular sheathing, and macular serous detachment or oedema, and optic nerve involvement 1, 2. Post fever retinitis is seen 2–4 weeks after a systemic febrile illness caused by either bacteria, viruses, or protozoa, in an immunocompetent individual 1. While OCTA is not useful if there is gross macular oedema, the altered FAZ can be indicative of macular ischemia. Although the presumed aetiology was different in all our patients, they developed similar changes on OCTA. Our series of post fever retinitis describes the salient vascular features on OCTA. The foveal avascular zone (FAZ) was altered with an irregular perifoveal network. The DCP had more capillary rarefaction when compared to the SCP. Salient features noted were changes in the superficial (SCP) and deep capillary plexus (DCP) with capillary rarefaction and irregularity of larger vessels in the SCP. 46 eyes of 33 patients were included in the study. A qualitative and quantitative analysis was done for all images. Imaging on OCTA was done for all patients with post fever retinitis at presentation with 3 × 3 mm and 8 × 8 mm scans centred on the macula and corresponding enface optical coherence tomography (OCT) scans obtained. We hereby describe the vascular changes during the acute phase of post fever retinitis on OCTA. Optical coherence angiography (OCTA) is a newer non-invasive modality that is an alternative to fundus fluorescein angiography to image the retinal microvasculature. It may occur following bacterial, viruses, or protozoal infection. Post fever retinitis is a heterogenous entity that is seen 2–4 weeks after a systemic febrile illness in an immunocompetent individual.
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