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Treatment of optic neuritis by plasma exchange (add-on) in neuromyelitis optica.

OBJECTIVE
To assess the contribution of plasma exchange (PE) in association (add-on) with pulsed intravenous corticosteroids in acute optic neuritis of neuromyelitis optica (NMO) and limited forms of NMO.


METHODS
Thirty-six patients with optic neuritis were treated from January 1, 1995, through December 31, 2010, with pulsed intravenous corticosteroids and 16 with pulsed intravenous corticosteroids plus PE. The ophthalmologic examination was performed at least 6 months after optic neuritis treatment. Visual acuity and visual field assessed with the Snellen scale and the logarithmic scale of the Early Treatment Diabetic Retinopathy Study were measured using standard automated perimetry and frequency doubling technology perimetry. Retinal peripapillary fiber thickness was measured using optical coherence tomography.


RESULTS
Final visual acuity was 20/400 in the corticosteroid group and 20/50 in the PE group (P=.04). The gain in visual acuity was 20/200 in the corticosteroid group and 20/30 in the PE group (P=.01). A poor final visual acuity outcome (≤20/200) was found in 19 of 36 patients (53%) in the corticosteroid group and 2 of 16 patients (13%) in the PE group (P=.008). Mean (SD) thickness of peripapillary retinal nervous fibers was 63.1 (20.4) μm in the corticosteroid group and 70.3 (20.3) μm in the PE group (P=.16). The mean (SD) thickness in the temporal quadrant was 38.5 (14.1) μm in the corticosteroid group and 44.5 (12.7) μm in the PE group (P=.02). In multivariate analysis, PE treatment was the only independent factor associated with a visual acuity greater than 20/200.


CONCLUSION
In optic neuritis associated with NMO, sequential treatment with pulsed intravenous corticosteroids and PE is more effective than standard monotherapy with corticosteroids on visual acuity outcome.