Neuromyelitis optica spectrum disorders and anti-myelin oligodendrocyte glycoprotein positive optic neuropathies
Authors:   Royal Victoria Eye and Ear Hospital, Adelaide Road, Dublin 2, D02 XK51, Republic of Ireland, Murtagh Patrick , Stephenson Kirk ,   Royal Victoria Eye and Ear Hospital, Adelaide Road, Dublin 2, D02 XK51, Republic of Ireland, Gaughan Maria ,   St Vincent&#x2019;s University Hospital, Elm Park, Dublin 4, D04 N2E0, Republic of Ireland, Ryan David ,   St Vincent&#x2019;s University Hospital, Elm Park, Dublin 4, D04 N2E0, Republic of Ireland, McNeill Graeme ,   St Vincent&#x2019;s University Hospital, Elm Park, Dublin 4, D04 N2E0, Republic of Ireland, McGuigan Christopher ,   St Vincent&#x2019;s University Hospital, Elm Park, Dublin 4, D04 N2E0, Republic of Ireland, Cassidy Lorraine ,   Royal Victoria Eye and Ear Hospital, Adelaide Road, Dublin 2, D02 XK51, Republic of Ireland
Published: July 2022

AIM: To describe the clinical characteristics and treatments associated with antibody positive optic neuropathies including anti-myelin oligodendrocyte glycoprotein (MOG) and anti-aquaporin 4 (AQP4), alongside diagnostic modalities, investigations, and outcomes.
METHODS: A cross-sectional single-centre retrospective case series consisting of 16 patients including 12 anti-MOG positive patients and 4 anti-AQP4 positive patients. Each of these patients had clinical signs and symptoms of optic neuritis and consisted of all patients who had a positive blood antibody result in our centre. Clinical findings including presence of a relative afferent pupillary defect, colour vision and disc assessment were recorded. Structured clinical exam and multimodal imaging was undertaken sequentially on each. Optical coherence tomography (OCT) scanning was preformed to examine the correlation between ganglion cell layer (GCL) thickness and visual acuity (VA) at presentation and as a determinant of final visual outcome in both groups. Initial and long-term treatment is also summarised.
RESULTS: A total of 16 patients were included in the study consisting of 12 anti-MOG and 4 anti-AQP4 positive patients. Nine of the 16 patients were female and the average age of onset was 29.2y in the MOG group and 42y in the AQP4 group. There was no statistically significant correlation (Pearson correlation) between GCL thickness and presenting and final VA [r(10)=0.081, P=0.08 and r(10)=0.089, P=0.34 respectively]. The same statistical analysis was performed for the correlation between retinal nerve fibre layer (RNFL) and VA and similar outcomes were observed [r(10)=0.04, P=0.22 and r(10)=0.09, P=0.04]. No correlation was seen for initial RNFL thickness and final visual outcome in this group either [r(2)=0.19, P=0.38]. Visual field testing and radiological findings for each group are described.
CONCLUSION: No correlation between initial VA or RNFL and final visual outcome is identified. A broad range of visual field and radiographic findings are identified, a consensus on treatment of neuromyelitis optica spectrum disorders and anti-MOG positive optic neuropathies has yet to be accepted but initial high dose immunosuppression followed by low dose maintenance therapy is favoured.