Purpose: To present a case series of ocular findings of West Nile virus infection (WNVI) in North America.
Design: Retrospective, noncomparative, observational case series.
Participants: All patients were referred to the authors for WNVI with ocular involvement between the years 2002 and 2005.
Methods: Chart review was performed on all participants. All participants underwent complete ophthalmic evaluation during each examination, including best-corrected Snellen visual acuity measurement, tonometry, slit-lamp biomicroscopy of the anterior and posterior segments, and dilated fundus examination with indirect ophthalmoscopy. Fundus photography and fluorescein angiography were also performed on all eyes. Relevant ocular findings associated with WNVI were recorded and tabulated.
Main outcome measures: The authors studied the characteristics, frequency, and locations of ocular lesions found in participants' eyes.
Results: There were 14 eyes (7 patients) with ocular West Nile virus lesions from 2002 to 2005. Average patient age was 58.4 years (range, 32-85 years). Ocular findings in descending order of frequency included multifocal chorioretinal target lesions in 12 eyes (85.7%), retinal hemorrhages in 7 eyes (50.0%), vitritis in 6 eyes (42.9%), chorioretinal linear streaks in 4 eyes (28.6%), perivascular sheathing and vasculitis in 4 eyes (28.6%), narrowed retinal vessels in 4 eyes (28.6%), disc edema in 4 eyes (28.6%), optic atrophy in 2 eyes (14.3%), vascular occlusion in 2 eyes (14.3%), and VIth nerve palsy in 1 eye (7.1%). Peripheral fundus lesions were found in all 14 eyes (100%), whereas posterior fundus lesions were found in 8 eyes (57.1%). Five patients (71.4%) were diabetic. Diabetic retinopathy was present in 7 eyes (70%).
Conclusions: Multifocal choroiditis is the most common ocular manifestation associated with WNVI, with a typically benign clinical course. Less frequent ocular lesions, including optic neuritis and occlusive vasculitis, frequently induce persistent and likely permanent visual deficit. Diabetic patients and those older than 50 years of age are more vulnerable to the more severe features of WNVI, including more serious ocular lesions.