Efficacy of Plasma Exchange for Acute Demyelinating Optic Neuritis: A Systematic Review and Meta-Analysis

Author(s): Efficacy of Plasma Exchange for Acute Demyelinating Optic Neuritis: A Systematic Review and Meta-Analysis

Background: Acute demyelinating optic neuritis (ON) is an inflammatory disorder of the optic nerve that may arise in different diseases, most commonly multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), myelin oligodendrocyte glycoprotein antibody–associated disease (MOGAD) or present as isolated idiopathic optic neuritis. High dose intravenous methylprednisolone (IVMP) is generally employed as a first line therapy; however, many patients don’t respond to steroids. The use of therapeutic plasma exchange (PLEX/TPE) is suggested as an escalation therapy; notwithstanding, the available evidence varies widely across different pathological etiologies and study designs.

Objectives: To review evidence on the effectiveness of plasma exchange in the case of acute demyelinating optic neuritis and meta-analyze comparative studies reporting extractable outcomes.

Methods: We conducted a focussed systematic review to identify eligible studies from which data were extracted for qualitative synthesis. For quantitative synthesis, we combined the comparative studies with enough data to calculate odds ratios (OR). Random effects model (DerSimonianLaird) was used. The extent of heterogeneity was estimated by I².

Results: In the qualitative synthesis, case series, retrospective cohorts, registries and randomized trials discussing acute demyelinating opyic neuritis were analyzed. Three comparative studies were used for meta-analysis. Pooled result demonstrated that PLEX was associated with lower odds of poor visual outcome (pooled OR 0.19, 95% CI 0.09- 0.41), with I²=0%. Subgroup comparison indicated that the benefit of PLEX was consistent in NMOSD, heavy cohorts and mixed etiology.

Conclusion: Evidences from different study designs support plasma exchange as an effective escalation therapy in acute demyelinating optic neuritis most likely steroid refractory severe attacks, thus, it lessens the risk of persistent poor vision. In several cohorts, it seems that earlier initiation is associated with better recovery.