Inflammatory Optic Neuritis: From Multiple Sclerosis to Neuromyelitis Optica

Optical coherence tomography angiography of the retina and choroid in systemic diseases

Optical coherence tomography angiography (OCTA) has transformed ocular vascular imaging, revealing microvascular changes linked to various systemic diseases. This review explores its applications in diabetes, hypertension, cardiovascular diseases, and neurodegenerative diseases. While OCTA provides a valuable window into the body's microvasculature, interpreting the findings can be complex. Additionally, challenges exist due to the relative non-specificity of its findings where changes observed in OCTA might not be unique to a specific disease, variations between OCTA machines, the lack of a standardized normative database for comparison, and potential image artifacts. Despite these limitations, OCTA holds immense potential for the future. The review highlights promising advancements like quantitative analysis of OCTA images, integration of artificial intelligence for faster and more accurate interpretation, and multi-modal imaging combining OCTA with other techniques for a more comprehensive characterization of the ocular vasculature. Furthermore, OCTA's potential future role in personalized medicine, enabling tailored treatment plans based on individual OCTA findings, community screening programs for early disease detection, and longitudinal studies tracking disease progression over time is also discussed. In conclusion, OCTA presents a significant opportunity to improve our understanding and management of systemic diseases. Addressing current limitations and pursuing these exciting future directions can solidify OCTA as an indispensable tool for diagnosis, monitoring disease progression, and potentially guiding treatment decisions across various systemic health conditions.

Optical coherence tomography angiography measurements in multiple sclerosis: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Recent literature on multiple sclerosis (MS) demonstrates the growing implementation of optical coherence tomography-angiography (OCT-A) to discover potential qualitative and quantitative changes in the retina and optic nerve. In this review, we analyze OCT-A studies in patients with MS and examine its utility as a surrogate or precursor to changes in central nervous system tissue.

METHODS

PubMed and EMBASE were systematically searched to identify articles that applied OCT-A to evaluate the retinal microvasculature measurements in patients with MS. Quantitative data synthesis was performed on all measurements which were evaluated in at least two unique studies with the same OCT-A devices, software, and study population compared to controls. A fixed-effects or random-effects model was applied for the meta-analysis based on the heterogeneity level.

RESULTS

The study selection process yielded the inclusion of 18 studies with a total of 1552 evaluated eyes in 673 MS-associated optic neuritis (MSON) eyes, 741 MS without optic neuritis (MSNON eyes), and 138 eyes without specification for the presence of optic neuritis (ON) in addition to 1107 healthy control (HC) eyes. Results indicated that MS cases had significantly decreased whole image superficial capillary plexus (SCP) vessel density when compared to healthy control subjects in the analyses conducted on Optovue and Topcon studies (both P < 0.0001). Likewise, the whole image vessel densities of deep capillary plexus (DCP) and radial peripapillary capillary (RPC) were significantly lower in MS cases compared to HC (all P < 0.05). Regarding optic disc area quadrants, MSON eyes had significantly decreased mean RPC vessel density compared to MSNON eyes in all quadrants except for the inferior (all P < 0.05). Results of the analysis of studies that used prototype Axsun machine revealed that MSON and MSNON eyes both had significantly lower ONH flow index compared to HC (both P < 0.0001).

CONCLUSIONS

This systematic review and meta-analysis of the studies reporting OCT-A measurements of people with MS confirmed the tendency of MS eyes to exhibit reduced vessel density in the macular and optic disc areas, mainly in SCP, DCP, and RPC vessel densities.

Update on Optic Neuritis: An International View

Previously, optic neuritis was thought to be typical, i.e. idiopathic or multiple sclerosis (MS) related, associated with a good visual prognosis, or atypical, i.e. not associated with MS and requiring corticosteroids or plasma exchange for vision to recover. More recently, the importance of optic neuritis in neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein (MOG) antibody disease has become more appreciated. The results of the Optic Neuritis Treatment Trial (ONTT) has influenced how optic neuritis is treated around the world. For this review we surveyed the international literature on optic neuritis in adults. Our aims were first to find the reported incidence of optic neuritis in different countries and to ascertain what percentage of cases were seropositive for anti-aquaporin 4 and anti-MOG antibodies, and second, to document the presenting features, treatment, and outcomes from a first episode of the different types of optic neuritis from these countries, and to compare the results with the outcomes of the ONTT cohort. From these data we have sought to highlight where ambiguities currently lie in how to manage optic neuritis and have made recommendations as to how future treatment trials in optic neuritis should be carried out in the current antibody testing era.

Optical Coherence Tomography Angiography of Peripapillary Vessel Density in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder: A Comparative Study

Multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) are demyelinating diseases of the central nervous system, which differ in the pathogenic mechanism. A common clinical presentation of both conditions is optic neuritis (ON). The study aimed to compare the radial peripapillary capillary (RPC) vessel density in MS and NMOSD patients using optical coherence tomography angiography (OCTA). A total of 40 MS patients, 13 NMOSD patients, and 20 controls were included. The average RPC vessel density was significantly lower in ON eyes (MS+ON, NMOSD+ON) than in non-ON eyes (MS−ON, NMOSD−ON) and in MS+ON, MS−ON, NMOSD+ON, and NMOSD−ON compared with the control group. In NMOSD+ON eyes, the vessel density in superior nasal, nasal superior, and inferior sectors was significantly more decreased than in MS+ON eyes. RPC reduction was also observed in inferior nasal and temporal superior sectors in MS−ON eyes compared with NMOSD−ON eyes. In conclusion, our findings indicate that optic neuritis is associated with a more significant RPC vessel density drop in NMOSD than in MS patients, and the predilection to superior and inferior sectors may be useful as a differential diagnostic marker.

Effects of Retinal Transcription Regulation After GB20 Needling Treatment in Retina With Optic Neuritis

Optic neuritis (ON) is one of the most frequent symptoms of multiple sclerosis (MS) that results in progressive loss of axons and neurons. In clinical trials of Traditional Chinese Medicine, needling at the GB20 acupoint has been widely used for the treatment of ocular diseases, including ON. However, the molecular mechanisms of needling at this site are still unclear. In this study, we generated an experimental autoimmune encephalomyelitis (EAE) mouse model and investigated the effects of needling treatment at the GB20 acupoint on retina with EAE-associated ON. RNA sequencing of the retinal transcriptome revealed that, of the 234 differentially expressed genes induced by ON, 100 genes were upregulated, and 134 genes were downregulated by ON, while needling at the GB20 acupoint specifically reversed the expression of 21 genes compared with control treatment at GV16 acupoint. Among the reversed genes, Nr4a3, Sncg, Uchl1, and Tppp3 were involved in axon development and regeneration and were downregulated by ON, indicating the beneficial effect of needling at GB20. Further gene ontology (GO) enrichment analysis revealed that needling at GB20 affected the molecular process of Circadian rhythm in mouse retina with ON. Our study first reported that needling treatment after ON at the GB20 acupoint regulated gene expression of the retina and reversed the expression of downregulated axon development-related genes. This study also demonstrated that GV16 was a perfect control treatment site for GB20 in animal research. Our study provided a scientific basis for needling treatments at GB20 for ocular diseases.

Clinical and radiologic manifestation B-cell mediated autoimmune diseases of central nervous system

B-cell mediated autoimmune diseases of central nervous system (CNS) put a heavy burden on different aspects of society and economy. Taken together, there are different types of autoimmune diseases in which B-cells play an important role and affect CNS in a pattern of inflammation. These diseases have some similarities in clinical presentations and radiological findings and some similarities with other diseases in different aspects such as treatments with each disease having its own characteristics. In this review article, we had a survey on some different types of B-cell mediated autoimmune diseases of CNS and explained how they can be distinguished from each other and how distinct they are according to radiological findings. The aim of this study is to distinguish B-cell mediated autoimmune diseases of CNS from other non-B-cell diseases in order to choose the best anti-B-cell treatments. At the end of this article we briefly explain different types of treatments being utilized and the role of corticosteroids in acute phases of different diseases.

Bacterial transportable toxins of the nasopharyngeal microbiota in multiple sclerosis. Nose-to-brain direct

Intranasal administration delivers molecules directly to the brain bypassing the blood-brain barrier. Three distinct routes of access have been identified; olfactory, trigeminal and via the paranasal sub-mucosa of the posterior sinuses. Consequently, environmental toxins may access the CNS directly to induce inflammatory and degenerative disease. They may also activate bacterial species of the nasal mucosal microbiome to release both immune-deviating cell wall antigens and transportable neurotoxins with local direct access to the CNS. Evidence is reviewed that toxins of the nasal bacterial microbiota may be directly implicated in the inflammatory and degenerative pathogenesis of multiple sclerosis.

Clinical Characteristics, Treatment Outcomes and Predictive Factors in Optic Neuritis

Background:

The causes, clinical presentations and treatment outcomes of optic neuritis are distinct among different populations. Early diagnosis based on clinical presentations plays an important role in treating optic neuritis patients.

Objective:

The study aimed to determine clinical characteristics, treatment outcomes and predictive factors of treatment outcomes in optic neuritis patients with and without demyelinating disease.

Methods:

A retrospective descriptive study of optic neuritis patients carried out between January 2009 and December 2016 was done. Univariate analysis and multivariate logistic regression analysis were used to evaluate the predictive factors of treatment outcomes.

Results:

Among 150 patients with optic neuritis, 58 patients were diagnosed with Neuromyelitis Optica Spectrum Disease (NMOSD), 23 patients were diagnosed with Multiple Sclerosis (MS) and 69 patients were idiopathic. The age at presentation in the NMOSD group was significantly younger than the MS group and the idiopathic group. The female:male ratio was significantly lower in the idiopathic group than in the NMOSD group. The initial Best Corrected Visual Activity (BCVA) of 20/20-20/60 (p = 0.001) and the idiopathic group (p =0.030) was associated with good visual outcomes. Initial BCVA of < 20/200 (p = 0.009) and the NMOSD group (p < 0.001) was associated with poor visual outcomes.

Conclusion:

NMOSD is a more common cause of optic neuritis than MS in Thai population. Female patients with poor initial VA, poor response to steroids treatment, and presenting recurrent attacks are highly suspicious for NMOSD. Optic neuritis without associated demyelinating disease has a better visual outcome and lower recurrence rate.

Pattern Recognition of the Multiple Sclerosis Syndrome

During recent decades, the autoimmune disease neuromyelitis optica spectrum disorder (NMOSD), once broadly classified under the umbrella of multiple sclerosis (MS), has been extended to include autoimmune inflammatory conditions of the central nervous system (CNS), which are now diagnosable with serum serological tests. These antibody-mediated inflammatory diseases of the CNS share a clinical presentation to MS. A number of practical learning points emerge in this review, which is geared toward the pattern recognition of optic neuritis, transverse myelitis, brainstem/cerebellar and hemispheric tumefactive demyelinating lesion (TDL)-associated MS, aquaporin-4-antibody and myelin oligodendrocyte glycoprotein (MOG)-antibody NMOSD, overlap syndrome, and some yet-to-be-defined/classified demyelinating disease, all unspecifically labeled under MS syndrome. The goal of this review is to increase clinicians’ awareness of the clinical nuances of the autoimmune conditions for MS and NMSOD, and to highlight highly suggestive patterns of clinical, paraclinical or imaging presentations in order to improve differentiation. With overlay in clinical manifestations between MS and NMOSD, magnetic resonance imaging (MRI) of the brain, orbits and spinal cord, serology, and most importantly, high index of suspicion based on pattern recognition, will help lead to the final diagnosis.

Risk factors for idiopathic optic neuritis recurrence

BACKGROUND

Approximately 30-50% of idiopathic optic neuritis (ION) patients experience one or multiple episodes of recurrence. The aim of this study was to search for risk factors for ION recurrence.

METHODS

Clinical data on hospitalized patients diagnosed with ION between January 2003 and January 2011 at the First Affiliated Hospital of Guangxi Medical University were retrospectively collected. Univariate and multivariate analyses were performed on factors that might cause ION recurrence. In total, 115 ION cases (32 recurrent and 83 non-recurrent cases) with complete data were analyzed. The length of the follow-up period ranged from 12 to 108 months (median: 42 months).

RESULTS

The univariate analysis showed that the recurrence rate for unilateral ION was higher than that for bilateral ION (40% vs. 12%, p=0.001). Underlying diseases had a significant impact on recurrence (p<0.001): the recurrence rates due to neuromyelitis optica (NMO), multiple sclerosis (MS), demyelinating lesions alone of the central nervous system, and unknown causes were 89%, 70%, 41%, and 8.7%, respectively. The multivariate analysis showed that the factors causing relatively high recurrence rates included NMO (odds ratio [OR], 73.5; 95% confidence interval [CI], 7.3 to 740.9), MS (OR, 33.9; 95% CI, 5.2 to 222.2), and demyelinating lesions alone (OR, 8.9; 95% CI, 2.3 to 34.4), unilateral involvement (OR, 5.7; 95% CI, 1.5 to 21.3), relatively low initial glucocorticoid dosage (equivalent to ≤ 100 mg prednisone/day) (OR, 4.3; 95% CI, 1.0 to 17.9).

CONCLUSION

Underlying diseases, laterality (unilateral or bilateral), and initial glucocorticoid dosage are important risk factors of ION recurrence. Clinical physicians are advised to treat ION patients with a sufficient dose of glucocorticoid in the initial treatment stage to reduce the recurrence risk.