Swept-Source Optical Coherence Tomography Angiography in West Nile Virus Chorioretinitis and Associated Occlusive Retinal Vasculitis.

A 65-year-old man with diabetes and a history of fever of unknown origin 2 weeks earlier complained of sudden decreased vision in the left eye. The patient was diagnosed with bilateral West Nile virus (WNV) chorioretinitis associated with occlusive retinal vasculitis in the left eye. Sweptsource optical coherence tomography angiography (SS-OCTA) of the left eye showed extensive, well-delineated, hypointense non-perfusion areas and perifoveal capillary arcade disruption in the superficial capillary plexus, as well as larger nonperfusion areas, capillary rarefaction, and diffuse capillary network attenuation and disorganization in the deep capillary plexus. OCTA may be a valuable tool for noninvasively assessing occlusive retinal vasculitis associated with WNV infection. It allows an accurate detection and precise delineation of areas of retinal capillary nonperfusion in both the superficial and deep capillary plexuses.