Chorioretinitis: A diagnostic clue to West Nile neuroinvasive disease.

The use of ancillary ophthalmic imaging can aid in the timely and accurate diagnosis of West Nile neuroinvasive disease in the presence of chorioretinal involvement.

A 66-year-old woman was admitted to the internal medicine service at our tertiary care center with a 7-day history of malaise and a 2-day history of a maculopapular rash, confusion, fever, and ataxia. Blood cultures were negative and computed tomography (CT) and magnetic resonance imaging (MRI) of the brain were normal with no features of meningoencephalitis. Lumbar puncture showed elevated cerebrospinal fluid (CSF) protein and 1100 cells/μL white blood cell (WBC) count (neutrophils 72 %, lymphocytes 7%, and monocytes 6%), and was negative for any fungal or bacterial growth and viral polymerase chain reaction (PCR) for herpes simplex virus, varicella zoster virus and cytomegalovirus. She was started on empiric treatment with intravenous acyclovir, dexamethasone and broad-spectrum antimicrobials (ampicillin, vancomycin and ceftriaxone) with no improvement. Subsequently, human immunodeficiency virus (HIV) and syphilis serology were found to be negative, but West Nile Virus (WNV) specific antibodies were positive for IgM. The CSF volume obtained was insufficient for West Nile Virus PCR. At this time, the medicine team was convinced that WNV was the underlying etiology of this patient’s presentation. One week later, the patient developed bilateral “flashes and floaters” and was referred to the ophthalmology service.

Visual acuity was normal and the anterior segment examination was unremarkable. Fundus examination revealed mild bilateral vitritis (0.5+) and bilateral round creamy scattered chorioretinal lesions in a curvilinear distribution (Fig. 1A), which stained early with a classic “target-like” appearance on intravenous fluorescein angiography (IVFA) (Fig. 1B,C). These lesions were further identified as disruptions within the ellipsoid layer / interdigitation zones on optical coherence tomography (OCT) imaging with enhanced depth imaging (EDI), which gradually resolved (Fig. 2). A clinical diagnosis of West Nile chorioretinopathy was made and the patient was started on supportive therapy.

Fig. 1

A. Wide-angle colour photographs (right and left eyes, on the left and right, respectively) demonstrating creamy punched out target-like curvilinear chorioretinal lesions. B. Intravenous fluorescein angiography (IVFDA) wide-field photos, demonstrating early staining of the lesions with late (C.) central hypofluorescence classic of West Nile nummular staining pattern.

Fig. 2

Optical coherence photography (OCT) demonstrating disruption of the ellipsoid and interdigitation zones corresponding to a punched-out lesion close to the fovea in the right (left) and left (right) eyes of this patient at baseline (red circle) (A.), with some resolution 5 days later (B.) (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article).

WNV neuroinvasive disease develops in approximately 1% of all WNV infections, and is associated with meningoencephalitis, poliomyelitis, hepatitis, pancreatitis, and ophthalmic findings including optic neuritis, chorioretinitis (multifocal choroiditis), uveitis, retinal vasculitis, cranial nerve 6th palsy, and nystagmus [[1], [2], [3]]. Chorioretinitis is the most common finding in asymptomatic patients with WNV neuroinvasive disease and can be identified with a proper dilated fundus exam and the use of ancillary ocular imaging to aid with the correct diagnosis.

Conflicts of interest

None of the authors have any conflict of interest.

Sources of funding

None.

Consent

Informed consent has been obtained from the patient in question for publication of this illustrated case. Patient has been assured that all ophthalmic photos presented in this case are anonymized and no identifiable information will be shared or published.

Ethical approval

N/A.

Author contribution

PA: conception, data collection, writing and preparation of the manuscript, cover letter and photos.

EM: data collection, manuscript revision

Disclosure

None of the authors have any relevant financial disclosure. PA (none), EDM (advisory board: Bayer, Novartis - honoraria).