Neuromyelitis optica spectrum disorders and anti-myelin oligodendrocyte glycoprotein positive optic neuropathies

Abstract

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.

Acute Optic Neuropathy in Older Adults

“…Each of these classical features of NAION 9 , 18 , 24 can be found in around 10%–30% of patients with MOGAD-ON. 9 , 25 However, when considered together with optic disc edema, only 1 (1.6%) patient with MOGAD-ON in our cohort had all of these 3 NAION predictors combined. If eye pain was included as a differentiator, these combined features had 100% specificity in differentiating MOGAD-ON from NAION.…”

MOG antibody-associated optic neuritis

“…In comparative studies, this proportion has been shown to be greater than in AQP4-ON (28-50%) and seronegative ON, including MS (10-46%) [48,51,58]. The majority of eye pain in MOG-ON is pain related to eye movement, with periocular pain being less common [56,57]. Pain on eye movement may arise from traction on the common tendinous ring caused by retro-orbital pathology, whereas periocular pain is presumed to be governed by the trigeminal nerve.…”

“…Eye pain may be common in MOG-ON, reported in 73-92% of cases internationally [42,43,48,51,56,57]. In comparative studies, this proportion has been shown to be greater than in AQP4-ON (28-50%) and seronegative ON, including MS (10-46%) [48,51,58].…”

“…Red desaturation and a relative afferent pupillary defect (RAPD) are common findings in ON due to any cause, and in limited studies have been identified in patients with MOG-ON [56]. However, it is important to note that in MOG-ON, where bilateral disease is common, a RAPD may be absent with bilateral, or previous contralateral, optic nerve involvement.…”

“…A wide variety of non-specific visual field defects have been reported in MOG-ON including central and paracentral scotomas, temporal field cut and complete visual field loss [56,89]. Perhaps the only distinctive pattern is that of peripheral vision loss with sparing of central vision, which can occur in MOG antibodyassociated optic perineuritis, though this pattern is more commonly seen with alternate aetiologies such as raised intracranial pressure [63,86].…”