Superficial and Deep Macular Vessel Occlusion in West Nile Virus

Introduction

West Nile virus is a single-stranded RNA flavivirus, endemic in Africa, the Middle East, and parts of Europe, South Asia, Australia, and North America, transmitted by infected mosquitoes (Culex species). Most human infections with West Nile virus remain asymptomatic, but 20% of patients present flu-like symptoms with fever, headache, malaise, back pain, myalgia, or anorexia [1]. Severe neuroinvasive disease can occur and is characterized by fever and meningitis, encephalitis, or even paralysis, including cranial nerve palsies.

Bilateral multifocal chorioretinitis is the most common ocular manifestation of West Nile virus. Other ocular manifestations include occlusive retinal vasculitis, retinal hemorrhages, vitritis, anterior uveitis, optic neuritis, and subconjunctival hemorrhage [2].

We describe here the optical coherence tomography angiography (OCT-A) findings in a case of West Nile virus-associated chorioretinitis. It is a new noninvasive imaging technique that enables the superficial and deep capillary plexus to be revealed, and thus areas of rarefaction or disruption of the capillary plexus, which can be correlated to vascular occlusion and ischemia, as seen in our patient. OCT-A can be a valuable complementary noninvasive tool in the assessment of macular involvement.

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