Microstructural visual system changes in AQP4-antibody-seropositive NMOSD

Frederike C Oertel; Joseph Kuchling; Hanna Zimmermann; Claudia Chien; Felix Schmidt; Benjamin Knier; Judith Bellmann-Strobl; Thomas Korn; Michael Scheel; Alexander Klistorner; Klemens Ruprecht; Friedemann Paul; Alexander U Brandt

doi:10.1212/NXI.0000000000000334

Microstructural visual system changes in AQP4-antibody-seropositive NMOSD

Neurol Neuroimmunol Neuroinflamm. 2017 Feb 22;4(3):e334. doi: 10.1212/NXI.0000000000000334. eCollection 2017 May.

Affiliation

¹ NeuroCure Clinical Research Center (F.C.O., J.K., H.Z., C.C., F.S., J.B.-S., M.S., F.P., A.U.B.), and Department of Neurology (J.K., F.S., J.B.-S., K.R., F.P.), Charité-Universitätsmedizin Berlin; Department of Neurology (B.K., T.K.), Klinikum rechts der Isar, and Department of Experimental Neuroimmunology (T.K.), Technische Universität München; Munich Cluster for Systems Neurology (SyNergy) (T.K.), Germany; Clinical Ophthalmology and Eye Health (A.K.), Central Clinical School, Save Sight Institute, Sydney, Australia; and Experimental and Clinical Research Center (F.P.), Max Delbrueck Center for Molecular Medicine and Charité-Universitätsmedizin Berlin, Germany.

Abstract

Objective: To trace microstructural changes in patients with aquaporin-4 antibody (AQP4-ab)-seropositive neuromyelitis optica spectrum disorders (NMOSDs) by investigating the afferent visual system in patients without clinically overt visual symptoms or visual pathway lesions.

Methods: Of 51 screened patients with NMOSD from a longitudinal observational cohort study, we compared 6 AQP4-ab-seropositive NMOSD patients with longitudinally extensive transverse myelitis (LETM) but no history of optic neuritis (ON) or other bout (NMOSD-LETM) to 19 AQP4-ab-seropositive NMOSD patients with previous ON (NMOSD-ON) and 26 healthy controls (HCs). Foveal thickness (FT), peripapillary retinal nerve fiber layer (pRNFL) thickness, and ganglion cell and inner plexiform layer (GCIPL) thickness were measured with optical coherence tomography (OCT). Microstructural changes in the optic radiation (OR) were investigated using diffusion tensor imaging (DTI). Visual function was determined by high-contrast visual acuity (VA). OCT results were confirmed in a second independent cohort.

Results: FT was reduced in both patients with NMOSD-LETM (p = 3.52e^-14) and NMOSD-ON (p = 1.24e^-16) in comparison with HC. Probabilistic tractography showed fractional anisotropy reduction in the OR in patients with NMOSD-LETM (p = 0.046) and NMOSD-ON (p = 1.50e^-5) compared with HC. Only patients with NMOSD-ON but not NMOSD-LETM showed neuroaxonal damage in the form of pRNFL and GCIPL thinning. VA was normal in patients with NMOSD-LETM and was not associated with OCT or DTI parameters.

Conclusions: Patients with AQP4-ab-seropositive NMOSD without a history of ON have microstructural changes in the afferent visual system. The localization of retinal changes around the Müller-cell rich fovea supports a retinal astrocytopathy.