Optic neuritis associated with chikungunya virus infection in South India.

OBJECTIVE To define optic neuritis associated with chikungunya virus (CHIKV) infection in a clinical setting. METHODS This observational case series includes 14 patients with clinical features of CHIKV infection and associated optic neuritis. Complete ophthalmic evaluations were performed, as well as other examinations, including Mantoux test, Widal test, blood profile, color vision, neuroimaging, visual fields, visual evoked potentials, VDRL test, and enzyme-linked immunosorbent assay for CHIKV-specific immunoglobulin. Relevant clinical findings of optic neuritis associated with seropositive CHIKV infection were recorded. RESULTS Nineteen eyes (in 14 patients) had optic nerve involvement. The mean +/- SD patient age was 45.8 +/- 15.6 years. Eight eyes (42%) had papillitis, 4 eyes (21%) had retrobulbar neuritis, 4 eyes (21%) had retrochiasmal (optic tract) neuritis, and 3 eyes (16%) had neuroretinitis. Parenteral corticosteroids were administered in all patients. Color vision, visual fields, and best-corrected visual acuity of 6/12 (or 20/40 Snellen visual acuity) or better improved statistically significantly by the end of 3 weeks (P < .001). Partial to complete recovery of visual function was seen in 10 patients (71%). Four patients had a poor visual outcome; 3 of them were initially seen 1 month after onset of ocular symptoms. CONCLUSIONS Acute-onset visual loss due to optic neuritis may be associated with CHIKV infection. Visual recovery is good. Corticosteroids accelerated recovery when initiated at an early stage of the disease.