Optical coherence tomography differs in neuromyelitis optica compared with multiple sclerosis

The spectrum of microcystic macular edema: Pathogenetic insights, clinical entities, and functional prognosis

Microcystic macular edema (MME) is the presence of small cystoid abnormalities localized in the inner nuclear layer of the retina. First identified in the context of multiple sclerosis, successive reports highlighted the presence of microcystic changes in several optic nerve conditions, such as neuromyelitis optica, optic atrophy from several etiologies, medical retinal diseases such as age-related macular degeneration and diabetic retinopathy, and in the postoperative period after epiretinal membrane peeling. Generally, these cysts are not associated with vascular leakage, unlike the more conventional types of macular edema from vascular origin. A number of theories have been proposed to explain these findings: the suspect of neuronal loss as causative finding made the hypothesis of retrograde trans-synaptic degeneration likely, more recently flanked by theories including the presence of vitreomacular traction and Müller cells dysfunction. We gather all the insights regarding the pathogenesis, epidemiology and functional impact of MME.

Neuromyelitis optica spectrum disorder: Exploring the diverse clinical manifestations and the need for further exploration

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disorder characterized by inflammatory assaults on the central nervous system (CNS), particularly on the optic nerves and spinal cord. In recent years, a wider range of clinical manifestations of this complex disease have been observed, emphasizing the importance of gaining a more profound understanding beyond optic neuritis (ON) and transverse myelitis (TM).

CURRENT KNOWLEDGE

This study explores the many clinical symptoms of NMOSD, including common and uncommon presentations. Distinctive aspects of ON, TM, and diencephalic/brainstem syndromes are examined, highlighting their unique characteristics in contrast to conditions such as multiple sclerosis. We also discuss extra-CNS involvement, such as unusual signs, including muscle involvement, retinal injury, auditory impairment, and rhinological symptoms.

AIMS AND OBJECTIVES

Our study intends to highlight the wide range and complexity of NMOSD presentations, emphasizing the significance of identifying unusual symptoms for precise diagnosis and prompt management. The specific processes that contribute to the varied clinical presentation of NMOSD are not well understood despite existing information. This emphasizes the necessity for more study to clarify the mechanisms that cause different symptoms and discover new treatment targets for this complex autoimmune disorder.

CONCLUSION

It is essential to acknowledge the complex and varied clinical manifestations of NMOSD to enhance diagnosis, treatment, and patient results. By enhancing our comprehension of the fundamental processes and investigating innovative therapeutic approaches, we may aim to enhance the quality of life for persons impacted by this illness.

Optic Disc Cupping in Neuromyelitis Optica Spectrum Disorder, Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease, and Multiple Sclerosis and Its Relationship With Optical Coherence Tomography Parameters: A Multicenter Study

BACKGROUND

Although cupping of the optic nerve is classically a sign of glaucomatous optic neuropathy, it has been shown that cupping can sometimes occur after an episode of optic neuritis (ON). The purpose of this study was to compare cupping in patients after ON from multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), or myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and to investigate the relationship between cupping and retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thinning.

METHODS

This was a retrospective cohort involving patients (≥18 years) with ON from 3 institutions. Patients were eligible if they had optical coherence tomography (Cirrus, OCT) performed ≥6 months after a single unilateral ON. The amount of thinning and cupping was estimated from the difference in the OCT parameters between affected and unaffected eyes. Univariable and multivariable regressions were used to investigate the relationship between cupping and ON etiology. Pearson correlation was used to investigate the relationship between cupping and RNFL and GCC.

RESULTS

Eighty-six subjects (MS: 35, NMOSD: 26, and MOGAD: 25) were included. There was no significant difference in gender and race between the groups, and most patients (86.1%) were female. Patients with NMOSD were significantly older than patients with MS or MOGAD (P = 0.002). In the univariate model, cupping was significantly higher in the NMOSD group (P = 0.017); however, after adjusting for age, GCC, and RNFL of the affected eye, the difference was no longer statistically significant (P = 0.949). The correlation between cupping asymmetry and RNFL and GCC of the affected eye was inversely strong in patients with MS (R = -0.60 and R = -0.64, respectively), inversely moderate in patients with MOGAD (R = -0.34 and R = -0.40, respectively), and weak in patients with NMOSD (R = -0.03 and R = -0.17, respectively).

CONCLUSIONS

Our results demonstrated that cupping after ON is correlated with RNFL and GCC thinning; although cupping was overall greater in the NMOSD group, once adjusted for age, RNFL, and GCC, it did not differ among patients with MS, NMOSD, and MOGAD.

Comparison of macular changes according to the etiology of optic neuritis: a cross-sectional study

AIM

To compare the macular structure including foveal thickness among patients with optic neuritis (ON) according to the etiology and to investigate the possible correlation between structural and visual outcomes.

METHODS

In this retrospective cross-sectional study, the clinical data of patients with aquaporin-4 immunoglobulin G-related ON (AQP4 group, 40 eyes), myelin oligodendrocyte glycoprotein IgG-related ON (MOG group, 31 eyes), and multiple sclerosis-related ON (MS group, 24 eyes) were obtained. The retinal thickness of the foveal, parafoveal and perifoveal regions were measured. Visual acuity (VA), visual field index and mean deviation were measured as visual outcomes.

RESULTS

The AQP4 group showed a significantly thinner fovea (226.4±13.4 µm) relative to the MOG (236.8±14.0 µm, P=0.015) and MS (238.9±14.3 µm, P=0.007) groups. The thickness in the parafoveal area also was thinner in the AQP4 group, though the difference in perifoveal retinal thickness was not significant. Foveal thickness was correlated with VA in the AQP4 group (coefficient ρ=-0.418, P=0.014), but not in the MOG and MS groups (P=0.218 and P=0.138, respectively). There was no significant correlation between foveal thickness and visual field test in all three groups.

CONCLUSION

The significant thinning in the fovea and parafoveal areas in the AQP4 group compared to the MOG and MS groups are found. Additionally, macular changes in AQP4-ON show a significant correlation with VA. The results provide the possibility that retinal structural damage could reflect functional damage in AQP4-ON, distinct from MOG-ON and MS-ON.

Optical Coherence Tomography Angiography: Revolutionizing Clinical Diagnostics and Treatment in Central Nervous System Disease

Optical coherence tomography angiography (OCTA), as a new generation of non-invasive and efficient fundus imaging technology, can provide non-invasive assessment of vascular lesions in the retina and choroid. In terms of anatomy and development, the retina is referred to as an extension of the central nervous system (CNS). CNS diseases are closely related to changes in fundus structure and blood vessels, and direct visualization of fundus structure and blood vessels provides an effective "window" for CNS research. This has important practical significance for identifying the characteristic changes of various CNS diseases on OCTA in the future, and plays a key role in promoting early screening, diagnosis, and monitoring of disease progression in CNS diseases. This article reviews relevant fundus studies by comparing and summarizing the unique advantages and existing limitations of OCTA in various CNS disease patients, in order to demonstrate the clinical significance of OCTA in the diagnosis and treatment of CNS diseases.

Utility of optical coherence tomography in patients of central immune mediated demyelinating diseases - A prospective study

Optical coherence tomography (OCT) is a non-invasive tool to measure thickness of various layers of retina. Recently, retinal nerve fibre layer (RNFL) and ganglion cell and inner plexiform layer (GCIP) thinning has been observed in OCT in patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD), This study compared OCT profile, along with visual acuity (VA), color vision (CV), contrast saturation (CS) and visual evoked potentials (VEP) in two main cohorts of MS and NMOSD and with controls, during acute episode of optic neuritis (ON), at 3 and 6 months. We found that changes of ON were present in 75% of MS eyes and in 45% of NMOSD patients. Of these, subclinical involvement was present in 56.25% of MS eyes and only in 5% of NMOSD eyes suggesting frequent subclinical involvement in the former. Mean RNFL was 95.23 ± 15.53 in MS and 66.14 ± 43.73 in NMOSD after 6 months of ON episode. Thinning of NQ and IQ was observed in NMOSD eyes in the immediate period after ON attack. At 6 months relative sparing of RNFL in TQ was observed in NMOSD ON eyes and MS ON showed predilection for involvement of TQ.

Use of retinal optical coherence tomography to differentiate suspected neuromyelitis optica spectrum disorder from multiple sclerosis: A cross-sectional study

BACKGROUND

Retinal optical coherence tomography (OCT) can differentiate definite NMOSD (dNMOSD) from multiple sclerosis (MS), but has not been evaluated in patients with a high clinical suspicion of NMOSD and not fulfilling the current consensus diagnostic criteria, referred in this paper as "potential" NMOSD (pNMOSD).

AIM

To compare the retinal OCT measurements between patients with pNMOSD, dNMOSD, MS, and reference healthy controls (HC).

MATERIAL AND METHODS

In this cross-sectional study, clinical and demographic characteristics, as well as OCT measurements of peripapillary retinal nerve fiber layer (pRNFL), inner nuclear layer (INL), macular retinal nerve fiber layer (mRNFL), outer nuclear layer (ONL) ganglion cell/inner plexiform layer (GCIPL), and macular volume (MV) were compared between groups. Mixed-effects regression models adjusting for within-patient inter-eye correlations, controlling for age, gender, disease duration and history of optic neuritis per eye were explored. Subgroup analyses were performed on eyes with previous optic neuritis.

RESULTS

234 eyes (20 pNMOSD, 33 dNMOSD, 138 MS, and 43 HC) were included. Controlling for age, gender, disease duration, and history of optic neuritis per eye, pNMOSD eyes showed decreased GCIPL, pRNFL, mRNFL and MV thicknesses, similar to eyes with dNMOSD, but significantly thinner than MS and HC subjects' eyes. Similar results were obtained for the pRNFL, mRNFL, GCIPL, INL and MV thickness in the subgroup analysis exploring only eyes with history of optic neuritis (12 pNMOSD, 15 dNMOSD, and 27 MS).

CONCLUSION

Retinal OCT measurements in patients with pNMOSD were similar to dNMOSD, but significantly lower than patients with MS and healthy controls. This suggests that retinal OCT measures could be helpful markers supportive of NMOSD diagnosis and should be explored in larger studies as a valuable addition to the current consensus diagnostic criteria.

Bruch Membrane Opening Minimum Rim Width in Neuromyelitis Optica

BACKGROUND

Optical coherence tomography (OCT) analyzes the neurodegeneration in neuromyelitis optica (NMO) and multiple sclerosis (MS) and quantifies optical atrophy. The retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness are decreased, and this structural change is correlated with visual function of patients, including contrast vision and visual field deviation. The main objective of this study was to evaluate the Bruch membrane opening minimum rim width (BMO) of the patients with NMO.

METHODS

We studied the thickness of the BMO by OCT, in patients with NMO (n = 25; 34 eyes), MS (n = 50; 70 eyes), and a control group (n = 51; 100 eyes). The study evaluated the structure-function relationship with the correlation between OCT and visual function: Visual acuity, Pelli-Robson score, Sloan 2.5 and 1.25, color vision, standard automated perimetry (SAP), and frequency-doubling technology perimetry (FDT).

RESULTS

The average thickness of BMO was significantly reduced in NMO and MS with or without a history of optic neuritis (ON). Significant thinning of the average, nasal, and inferonasal BMO in the absence of ON in NMO was found compared with controls (P = 0.022, 0.006, and 0.026, respectively). BMO was strongly correlated with Pelli-Robson score (P < 0.001), Sloan 2.5 (P < 0.001), and mean deviation of SAP and FDT (P = 0.004). The sectorial study found a high correlation between the BMO and the corresponding sector of the visual field.

CONCLUSIONS

The BMO thickness is decreased after ON in NMO and MS. This study showed an improved ability of BMO over RNFL and GCL to detect infraclinical impairment in patients with NMO without a history of optic neuropathy. Like the RNFL and GCL, BMO is well correlated with visual function, including contrast vision and visual field deviation.

Optical coherence tomography angiography (OCTA) in differential diagnosis of aquaporin-4 antibody seronegative NMOSD and multiple sclerosis

BACKROUND

Optic neuritis(ON) is a common feature of both relapsing-remitting multiple sclerosis(RRMS) and neuromyelitis optica spectrum disorders(NMOSD). It is crucial to early differentiate these two diseases, as they differ in pathophysiology and treatment.

OBJECTIVE

To compare NMOSD and RRMS patients using optical coherence tomography(OCT) and OCT angiography(OCTA) to assess retinal microvascular network differences.

METHODS

Fourteen RRMS (28 eyes) and 9 NMOSD patients(18 eyes), and 11 controls were enrolled. Seropositivity for aquaporin-4 antibody (anti-AQP4 Abs) was 44.4%. Peripapillary and macular retinal nerve fiber layer(RNFL) thickness, superficial peripapillary and macular vessel density(VD), area, perimeter and circularity of foveal avascular zone(FAZ) were analyzed.

RESULTS

OCTA showed reduction in peripapillary and macular VD and FAZ size in NMOSD+ON compared to RRMS+ON and controls (p = 0.001, p<0.001 and p = 0.010, p<0.001 respectively). Peripapillary VD was similar in RRMS +ON and controls. Peripapillary VD in monophasic seronegative NMOSD+ON eyes was significantly lower than monophasic RRMS+ON eyes (p = 0.030), which was no different from controls. FAZ area was smaller in unaffected eyes in NMOSD than RRMS and controls.

CONCLUSIONS

Both OCT and OCTA revealed considerable differences between RRMS and NMOSD patients, providing promising results in favor of clinical utility of OCTA in differential diagnosis of ON, particularly in anti-AQP4 antibody negative patients. OCTA might be a useful biomarker in differentiating NMOSD from MS.

Evidence for and against subclinical disease activity and progressive disease in MOG antibody disease and neuromyelitis optica spectrum disorder

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) and aquaporin-4 IgG seropositive neuromyelitis optica spectrum disorder (AQP4-IgG+ NMOSD) are generally considered to be relapsing disorders, without clinical progression or subclinical disease activity outside of clinical relapses, in contrast to multiple sclerosis (MS). With advances in the diagnosis and treatment of these conditions, prolonged periods of remission without relapses can be achieved, and the question of whether progressive disease courses can occur has re-emerged. In this review, we focus on studies exploring evidence for and against relapse-independent clinical progression and/or subclinical disease activity in patients with MOGAD and AQP4-IgG+ NMOSD.

A comparative study of alteration in retinal layer segmentation alteration by SD-OCT in neuromyelitis optica spectrum disorders: A systematic review and meta-analysis

Background

To evaluate the feature of different retinal layer segmentation in neuromyelitis optica spectrum disorders (NMOSD) with spectral-domain optical coherence tomography (SD-OCT) and to compare it with that in multiple sclerosis (MS), healthy controls (HC), and idiopathic optic neuritis (ION).

Methods

We retrieved four electronic databases, including Pubmed, Embase, Cochrane Library, and Web of Science from inception to September 1st, 2021. A meta-analysis was performed to compare different retinal layer segmentation thicknesses between patients with or without a history of optic neuritis (ON) in NMOSD and the control group, including patients with MS, HC, and ION.

Results

Forty-two studies were included and the interval between the last ON onset and examination was greater than 3 months. Compared with that in HC eyes, the loss of retinal nerve fiber layer (RNFL) and macular ganglion cell and inner plexiform layer (GC-IPL) was serious in NMOSD eye especially after ON. Moreover, compared with that in ION eyes or MS-related-ON eyes, the injury to the peripapillary retinal nerve fiber layer (pRNFL) was severe in NMOSD-related-ON eyes. In addition, the correlation coefficient between pRNFL and prognostic visual acuity was 0.43. However, the one-arm study revealed the inner nuclear layer (INL) was thickened in NMOSD-related-ON eyes compared with HC eyes.

Conclusions

Inclusion of the RNFL and macular GC-IPL is recommended for monitoring disease progression and attention should be paid to changes in the INL.

Retinal optical coherence tomography and magnetic resonance imaging in neuromyelitis optica spectrum disorders and MOG-antibody associated disorders: an updated review

INTRODUCTION

Neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein IgG antibody-associated disorders (MOGAD) comprise two groups of rare neuroinflammatory diseases that cause attack-related damage to the central nervous system (CNS). Clinical attacks are often characterized by optic neuritis, transverse myelitis, and to a lesser extent, brainstem encephalitis/area postrema syndrome. Retinal optical coherence tomography (OCT) is a non-invasive technique that allows for in vivo thickness quantification of the retinal layers. Apart from OCT, magnetic resonance imaging (MRI) plays an increasingly important role in NMOSD and MOGAD diagnosis based on the current international diagnostic criteria. Retinal OCT and brain/spinal cord/optic nerve MRI can help to distinguish NMOSD and MOGAD from other neuroinflammatory diseases, particularly from multiple sclerosis, and to monitor disease-associated CNS-damage.

AREAS COVERED

This article summarizes the current status of imaging research in NMOSD and MOGAD, and reviews the clinical relevance of OCT, MRI and other relevant imaging techniques for differential diagnosis, screening and monitoring of the disease course.

EXPERT OPINION

Retinal OCT and MRI can visualize and quantify CNS damage in vivo, improving our understanding of NMOSD and MOGAD pathology. Further efforts on the standardization of these imaging techniques are essential for implementation into clinical practice and as outcome parameters in clinical trials.

Optical Coherence Tomography Reveals Longitudinal Changes in Retinal Damage Under Different Treatments for Neuromyelitis Optica Spectrum Disorder

Background: Progressive retinal neuroaxonal damage after acute optic neuritis may occur in neuromyelitis optica spectrum disorder (NMOSD). However, it is unclear if treatments used to prevent attacks influence neurodegeneration.

Objectives: We aimed to investigate retinal damage in patients treated with disease-modifying drugs in a longitudinal study.

Methods: We retrospectively included 50 patients with aquaporin 4-antibody-seropositive NMOSD. Peripapillary retinal nerve fiber layer (pRNFL) thickness, macular ganglion cell complex (mGCC) thickness, total macular volume (TMV), and optic disc measures were acquired by spectral domain optical coherence tomography in patients treated with tocilizumab, rituximab, and azathioprine.

Results: Longitudinally, in eyes with a history of ON (NMOSD^ON+), we observed annual thinning of mGCC [tocilizumab: −1.77 (−3.44, −0.09) μm, p = 0.041; rituximab: −2.03 (−3.58, −0.48) μm, p = 0.017; azathioprine: −1.79 (−2.22, −1.37) μm, p < 0.001], and pRNFL [tocilizumab: −2.07 (−0.75, −3.39) μm, p = 0.005; rituximab: −2.18 (−0.36, −4.00) μm, p = 0.023; azathioprine: −2.37 (−0.98, −3.75) μm, p = 0.003], reduced TMV [tocilizumab: −0.12 (−0.22, −0.01) mm³, p = 0.028; rituximab: −0.15 (−0.21, −0.08) mm³, p = 0.001; azathioprine: −0.12 (−0.20, −0.04) mm³, p = 0.006], and increased cup area [tocilizumab: 0.08 (−0.01, 0.16) mm², p = 0.010; rituximab: 0.07 (0.01, 0.12) mm², p = 0.019; azathioprine: 0.14 (0.02, 0.26) mm², p = 0.023]. However, we detected no significant differences in annual changes in mGCC, pRNFL, TMV, and cup area between patients with tocilizumab, rituximab, and azathioprine in NMOSD^ON+ eyes. NMOSD^ON− eyes did not display mGCC or pRNFL thinning in patients treated with tocilizumab and rituximab. Intriguingly, we observed significant thinning of mGCC in patients treated with azathioprine compared with tocilizumab [−0.84 (−1.50, −0.18) μm vs. −0.19 (−0.87, 0.48) μm, p = 0.012] and rituximab [−0.84 (−1.50, −0.18) μm vs. −0.07 (−1.25, −2.51) μm, p = 0.015] in NMOSD^ON− eyes.

Conclusions: This study demonstrated that retinal ganglion cell loss is independent of ON attacks in NMOSD. Tocilizumab and rituximab may delay mGCC thinning in NMOSD^ON− eyes compared with azathioprine.

Differentiation between multiple sclerosis and neuromyelitis optica spectrum disorder using optical coherence tomography angiography

Neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) are autoimmune demyelinating diseases of distinct etiology presenting with optic neuritis (ON). This study aimed to identify the macular and peripapillary neurovascular alterations that may facilitate the differentiation between NMOSD and MS eyes using spectral-domain optical coherence tomography (OCT) and OCT angiography (OCTA). A total of 13 NMOSD patients and 40 MS patients were evaluated. After ON, the radial peripapillary capillary (RPC) vessel density was significantly decreased in the superior (S) and inferior (I) sectors in NMOSD compared with MS eyes, whereas in non-ON eyes, the temporal (T) sector of RPC was reduced in MS group. In the ON eyes, the retinal nerve fiber layer in the I and T quadrants was thinner in NMOSD than in MS. Regarding ON and non-ON eyes, the macular capillary plexuses, and the ganglion cell complex thickness did not differ between NMOSD and MS. The ratios, based on the disease-specific intra-eye RPC vessel density reduction pattern, were the best discriminants between NMOSD and MS, i.e., inferior to nasal (I/N) and I/T ratios for ON eyes, and S/T and N/T ratios for non-ON eyes. Our results show that the OCTA-based simple ratios may be useful in distinguishing NMOSD and MS patients.

A novel investigation method for axonal damage in neuromyelitis optica spectrum disorder: In vivo corneal confocal microscopy

Background

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory autoimmune disorder that damages optic nerves, brainstem, and spinal cord. In vivo corneal confocal microscopy (IVCM) is a noninvasive technique that provides corneal images with dendritic cells (DCs) and corneal subbasal nerve plexus (SBP), which arises from the trigeminal nerve.

Objective

We investigated corneal SBP changes in NMOSD and proposed IVCM as a potential new disease severity biomarker for NMOSD.

Methods

Seventeen age-sex matched NMOSD patients and 19 healthy participants underwent complete neurologic and ophthalmologic examinations. The duration of disease, first symptom, presence of optic neuritis attack, antibody status, Expanded Disability Status Scale(EDSS) score and disease severity score(DSS) were recorded. Retinal nerve fibre layer (RNFL) thickness was measured with optical coherence tomography, and corneal SBP images were taken with IVCM.

Results

NMOSD patients had significantly reduced corneal nerve fibre lenght-density and corneal nerve branch lenght-density compared with controls, while DC density was increased. NMOSD patients also showed significantly reduced RNFL thickness compared with controls. EDSS,DSS levels were inversely correlated with IVCM parameters.

Conclusion

We observed significant corneal nerve fibre loss in NMOSD patients in relation to disease severity. IVCM can be a candidate noninvasive imaging method for axonal damage assessment in NMOSD that warrants further investigation.

Serum Biomarkers in Neuro-Ophthalmology: When to Test

Discovery and characterization of serologic biomarkers has revolutionized the diagnostic framework of systemic and paraneoplastic autoimmune neuro-ophthalmic diseases. Expanding recognition of the multiple ocular and visual manifestations of these conditions highlights the important role of the referring provider in identifying potential cases. Increasing ease of access to serologic testing also enables these practitioners to initiate the diagnostic work-up in suspected cases. We aimed to provide an update on the current knowledge surrounding and use of relevant autoimmune biomarkers by correlating specific clinical neuro-ophthalmic manifestations with autoantibody biomarkers. The utility of select biomarkers for myasthenia gravis, neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein-IgG-associated disorder, opsoclonus-myoclonus syndrome, anti-collapsin-response mediator protein-5 optic neuropathy, and glial fibrillary acidic protein-IgG-associated disease are discussed with particular focus on the clinical contexts in which to consider testing.

Comparison of macular structural and vascular changes in neuromyelitis optica spectrum disorder and primary open angle glaucoma: a cross-sectional study

AIMS

To compare macular structure and vasculature between neuromyelitis optica spectrum disorder (NMOSD) and primary open angle glaucoma (POAG) using optical coherence tomography angiography.

METHODS

NMOSD patients (n=124) with/without a history of optic neuritis (ON) (NMO+ON: 113 eyes; NMO-ON: 95 eyes), glaucomatous patients (n=102) with early/advanced glaucoma (G-E: 74 eyes; G-A: 50 eyes) and healthy controls (n=62; 90 eyes) were imaged. The main outcome measures were macular ganglion cell-inner plexiform layer (GC-IPL) thickness, vessel density (VD) and perfusion density (PD) in the superficial capillary plexus, and diagnostic capabilities of the parameters as calculated by area under the curve (AUC).

RESULTS

Significant losses in GC-IPL, VD and PD were detected in both patients with NMOSD and POAG. With matched losses in the peripapillary retinal nerve fibre layer, NMOSD group showed significant thinning of GC-IPL in the nasal-superior quadrant, whereas in POAG group, significant thinning was observed in the inferior and temporal-inferior quadrants. GC-IPL thinning was more prominent in the superior, nasal-superior and nasal-inferior quadrants in NMO+ON eyes. In G-A eyes, significant GC-IPL thinning was seen in the temporal-inferior quadrant. The specific structural parameters combining VD and foveal avascular zone (FAZ) indices showed the best diagnostic accuracies. The FAZ area in eyes with NMOSD was significantly smaller than the eyes of healthy controls and POAG.

CONCLUSION

NMOSD and POAG have specific patterns of macular structural and vascular changes associated with pathophysiology. Our results indicate that FAZ could be a sensitive biomarker of macular changes in NMOSD.

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.

Differential patterns of parafoveal and peripapillary vessel density in multiple sclerosis and neuromyelitis optica spectrum disorder

BACKGROUND

To compare intraocular microvascular alterations between patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) using optical coherence tomography angiography (OCT-A).

METHODS

Sixty patients were included in the study, 23 MS patients (36 eyes) and 37 NMOSD patients (47 eyes), all with a history of optic neuritis (ON). All subjects underwent comprehensive ophthalmic examinations, OCT-A, and high-definition-OCT imaging. OCT-A was used to measure the vessel density of the superficial and deep retinal capillary plexus (SRCP and DRCP) in the macular area and the radial peripapillary capillary (RPC) segment. Age, spherical equivalent, and gender were adjusted for in the analyses.

RESULTS

Patients with NMOSD showed significantly decreased vessel density of the SRCP (average, p = 0.0007; superior, p = 0.0009; inferior, p = 0.0002) and RPC segment (average, p < 0.0001; superior, p = 0.0004; inferior, p = 0.0052; temporal, p < 0.0001; nasal, p = 0.0001) compared to the MS patients. Parafoveal and peripapillary vessel density was significantly associated with the OCT parameters in both the MS and NMOSD patients. Parafoveal and peripapillary vessel density in the MS patients was significantly associated with visual function, including visual acuity and visual field defects, whereas only peripapillary vessel density was significantly associated with visual function in the NMOSD patients.

CONCLUSION

We demonstrated parafoveal and peripapillary vascular alterations between MS and NMOSD patients that varied in degree and pattern. We also found associations between vessel density and structural and functional parameters in MS and NMOSD patients. Further studies are needed to facilitate a greater understanding of the pathogenesis and its association with vascular alterations in these disorders.

Early age of onset predicts severity of visual impairment in patients with neuromyelitis optica spectrum disorder

BACKGROUND

Severe residual visual loss (SRVL) is frequent in neuromyelitis optica spectrum disorders (NMOSD). Identifying higher-risk patients at onset is important to prevent disability accumulation.

OBJECTIVE

To determine predictors of SRVL in a large NMOSD cohort.

METHODS

Patient characteristics at last visual acuity (VA) evaluation were retrospectively collected. VA was scored 0: better than 20/40, 1: 20/40-20/99, 2: 20/100-20/200, and 3: worse than 20/200. SRVL was defined as a combined score (VA worst + best eye) ⩾ 4. Descriptive statistics were used to compare groups and logistic regression to evaluate predictors of VA.

RESULTS

106 patients (mean age at disease onset (AO): 35.8 ± 16.5 years) were included. Patients with SRVL had earlier AO (mean: 26.7 vs 38.0 years) compared to non-SRVL group (p = 0.005). Patients with AO < 21 years were more likely to have SRVL, be blind, present with binocular optic neuritis, have recurrent optic neuritis, and receive oral therapy first-line than those with AO ⩾ 21. After adjusting for race, sex, and disease duration, the odds of SRVL were 4.68 times higher in patients < 21 at disease onset (95% CI: 1.53-14.34, p = 0.007).

CONCLUSION

Early AO predicts SRVL in NMOSD, independent of disease duration. High-efficacy therapies should be considered for first-line treatment in this group.

Factors Associated with Changes in Retinal Layers Following Acute Optic Neuritis: A Longitudinal Study Using Optical Coherence Tomography

This study aimed to analyze longitudinal changes in retinal microstructures following acute optic neuritis and to identify the factors that affect those changes using spectral-domain optical coherence tomography (OCT). Forty-eight eyes of 37 patients with a first episode of optic neuritis and 48 eyes of 48 healthy controls were enrolled. Patients underwent serial OCT and visual function testing for more than six months. Individual layers from macular OCT were segmented with an automated algorithm. The total retinal layer (TRL), nerve fiber layer (NFL), ganglion cell layer (GCL) and inner plexiform layer (IPL) of optic neuritis eyes showed significant thinning with time over 6–15 months (p < 0.001 for all). The outer nuclear layer (ONL) showed a later decrease in thickness (p = 0.007). The outer retinal layer (ORL) showed an increase (p = 0.007) in thickness at two to five months which was sustained over time. Low visual acuity and neuromyelitis optica (NMO) immunoglobulin (Ig) G were associated with changes in the thickness of the GCL, IPL, and ONL over time (p < 0.05 for all). Low visual acuity was also associated with changes in the thickness of the NFL over time (p = 0.033). Dynamic changes of retinal microstructures varied according to the retinal layer examined after an optic neuritis attack. Initial visual acuity and NMO-IgG were found to be significant factors affecting the changes in thickness of each retinal layer. These results will lead to a better understanding of the pathologic changes that occur in eyes with optic neuritis.

Optical Coherence Tomography in Neuromyelitis Optica spectrum disorder and Multiple Sclerosis: A population-based study

BACKGROUND

The aim of this study was to identify and compare the characteristics of retinal nerve layers using spectral domain-optical coherence tomography (SD-OCT) in neuromyelitis optica spectrum disorder (NMOSD), relapsing-remitting multiple sclerosis (RRMS) and healthy controls (HCs).

METHODS

It is a cross-sectional population-based study in Isfahan, Iran. We enrolled 98 participants including 45 NMOSD patients (90 eyes), 35 RRMS patients (70 eyes) and 18 HCs (36 eyes). Evaluation criteria were thickness of different sectors in peripapillary retinal nerve fiber layer (pRNFL) and intra-retinal layers around the macula. History of previous optic neuritis (ON) was obtained through chart review and medical record.

RESULTS

Without considering ON, total macular, ganglion cell layer (GCL) and pRNFL were significantly thinner in both groups of patients compared to HCs. On macular examination, GCL and total macular thickness were significantly thinner than HCs in all NMOSD and RRMS eyes with and without history of ON. While there was no significant difference between MS-ON and MS without a history of ON in the macular measures, the reduction in total macular and GCL thickness was significantly greater in NMOSD-ON compared to NMOSD without a history of ON. Also in NMOSD-ON eyes, the RNFL, GCL, IPL and GCIPL layers were significantly thinner than that of MS-ON. On the other hand, the pRNFL study showed significant thinning of all quadrants in the RRMS and NMOSD groups relative to HCs. While the decrease of pRNFL thickness in the eyes of NMOSD-ON and MS with and without a previous history of ON was significantly greater than that of HCs, no difference was observed between NMOSD without ON and HCs. In addition, in NMOSD patients, pRNFL was significantly thinner in eyes with history of ON compared to non ON-eyes. Furthermore, in patients with a history of ON, reduction in all sectors of pRNFl (except in T) was significantly greater in NMOSD compared to MS patients.

CONCLUSION

Our findings showed that although macular and retinal damage occurred in both NMOSD and RRMS patients without significant differences, the severity of injury in eyes with history of ON was significantly higher in NMOSD compared to MS patients, that could be considered as a marker to distinguish them. In addition, our results confirmed the absence of subclinical optic nerve involvement in NMOSD unlike MS patients.

Neuromyelitis optica spectrum disorders

The disease concept of Neuromyelitis Optica Spectrum Disorders(NMOSD) has undergone a significant change over the last two decades including the detection of Myelin Oligodendrocyte Glycoprotein(MOG) antibody in patients who are seronegative for aquaporin-4 antibody. Aquaporin-4 antibody positive NMOSD is now regarded as an immune astrocytopathy. Conversely, MOG antibody associated disease is known to target myelin rather than astrocytes, leading to an NMOSD syndrome with distinct clinical and radiological features. Incorporation of clinical features like area postrema syndrome, brainstem syndrome, diencephalic syndrome and cortical manifestations as core clinical characteristics into the revised diagnostic criteria has widened the clinical spectrum of NMOSD. With the development of these criteria, it is possible to make the diagnosis at an earlier stage so that effective immunosuppression can be instituted promptly for a better long-term prognosis. Newer therapeutic agents have been introduced for aquaporin-4 seropositive NMOSD disease; however, challenges remain in treating seronegative disease because of limited treatment options.

Differences in morphology and visual function of myelin oligodendrocyte glycoprotein antibody and multiple sclerosis associated optic neuritis

Background

Myelin oligodendrocyte glycoprotein immunoglobulin G associated optic neuritis (MOG-ON) is a recently described entity. Recent studies have shown that MOG-ON has a more severe clinical presentation than classic optic neuritis (ON).

Objective

This study aimed to define morphological characteristics of MOG-ON, correlate these with clinical characteristics and compare them with multiple sclerosis associated ON (MS-ON) and healthy controls (CTRL).

Methods

In a retrospective study, we included MOG-ON and MS-ON patients seen between 2011 and 2018 at the University Hospital Bern. Data from clinical examination, perimetry, and optical coherence tomography (OCT) were analyzed.

Results

A total of 66 eyes of 43 patients were included; 22 MS-ON and 33 CTRL eyes were sex- and age-matched to 11 MOG-ON eyes. We found significantly worse visual acuity at nadir, but better recovery and thinner global peripapillary retinal nerve fiber layer thickness in MOG-ON patients compared to MS-ON patients. Both groups exhibited irregular thinning of the macular ganglion cell layer. Furthermore, the visual acuity and visual field parameters correlated to retinal layer thickness only in MOG-ON eyes.

Conclusion

In comparison to MS-ON, MOG-ON is associated with more prominent acute vision loss and more pronounced global thinning of the pRNFL. Both entities result in similar final visual acuity and atrophy of the macular ganglion cell layer.

Peripapillary Vessel Density as Early Biomarker in Multiple Sclerosis

Background: To evaluate retinal vessel density (VD) in macular and in peripapillary regions in patients with recent onset of multiple sclerosis, at initial demyelinating event (IDE) and in matched relapsing-remitting multiple sclerosis (RRMS) patients.

Methods: We evaluated VD in superficial capillary plexus, deep capillary plexus, choriocapillaris and radial peripapillary capillary plexus in IDE, RRMS patients and in matched healthy controls (HCs) through Optical Coherence Tomography Angiography (OCT-A). Clinical history, including history of optic neuritis, Expanded Disability Status scale and disease duration of patients were collected.

Results: Thirty patients (20 with IDE and 10 with RRMS) and 15 HCs were enrolled. IDE patients showed a lower VD in radial peripapillary capillary plexus compared with controls (coeff. β = −3.578; p = 0.002). RRMS patients displayed a lower VD in both superficial capillary plexus and radial peripapillary capillary plexus compared with HCs (coeff. β = −4.955; p = 0.002, and coeff. β = −7.446; p < 0.001, respectively). Furthermore, RRMS patients showed a decreased VD in radial peripapillary capillary plexus compared with IDE patients (coeff. β = −3.868; p = 0.003).

Conclusions: Peripapillary region vessel density reduction, revealed through OCT-A, might be considered as an early event in MS, and might be relevant as a biomarker of disease pathology.

Acute Management of Optic Neuritis: An Evolving Paradigm

The current management of acute optic neuritis (ON) is focused on expediting visual recovery through the use of high-dose intravenous corticosteroids. The recent identification of specific autoantibodies associated with central nervous system inflammatory disorders has provided novel insights into immune targets and mechanisms that impact the prognosis, treatment, and recurrence of ON. Therefore, neurologists and ophthalmologists need to be aware of clinical, laboratory, and imaging findings that may provide important clues to the etiology of ON and the potential need for aggressive management. Moving forward, rapid and accurate diagnosis of inflammatory ON will likely be critical for implementing clinical care that optimizes short-term and long-term therapeutic outcomes.

Optic Neuritis

PURPOSE OF REVIEW

This article discusses the clinical presentation, evaluation, and management of the patient with optic neuritis. Initial emphasis is placed on clinical history, examination, diagnostic testing, and medical decision making, while subsequent focus is placed on examining specific inflammatory optic neuropathies. Clinical clues, examination findings, neuroimaging, and laboratory testing that differentiate autoimmune, granulomatous, demyelinating, infectious, and paraneoplastic causes of optic neuritis are assessed, and current treatments are evaluated.

RECENT FINDINGS

Advances in technology and immunology have enhanced our understanding of the pathologies driving inflammatory optic nerve injury. Clinicians are now able to interrogate optic nerve structure and function during inflammatory injury, rapidly identify disease-relevant autoimmune targets, and deliver timely therapeutics to improve visual outcomes.

SUMMARY

Optic neuritis is a common clinical manifestation of central nervous system inflammation. Depending on the etiology, visual prognosis and the risk for recurrent injury may vary. Rapid and accurate diagnosis of optic neuritis may be critical for limiting vision loss, future neurologic disability, and organ damage. This article will aid neurologists in formulating a systematic approach to patients with optic neuritis.

Association Between BDNF Val66Met Polymorphism and Optic Neuritis Damage in Neuromyelitis Optica Spectrum Disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system (CNS). The purpose of the study was to examine the association between the brain-derived neurotrophic factor (BDNF) Val66Met genotype and structural and functional optic nerve damage in the eyes of NMOSD patients. A total of 17 NMOSD subjects (34 eyes) were included in the study and were divided into subgroups based on optic neuritis (ON) history and BDNF Val66Met polymorphisms. The mean (range) age was 47.8 (23–78) years, and the mean (SD) disease duration was 7.4 (2–39) years. All participants had undergone optical coherence tomography (OCT) scans for global retinal nerve fiber layer (gRNFL) and ganglion cell-inner plexiform layer (GCIPL) thickness and multifocal visual evoked potential (mfVEP) test for amplitude and latency. BDNF Val66Met polymorphisms were genotyped in all participants. OCT and mfVEP changes were compared between two genotype groups (Met carriers vs. Val homozygotes) by using the generalised estimating equation (GEE) models. The BDNF Val66Met polymorphism was significantly associated with more severe nerve fiber layer damage and axonal loss in ON eyes of NMOSD subjects. Met carriers had more significantly reduced GCIPL (P = 0.002) and gRNFL (P < 0.001) thickness as well as more delayed mfVEP latency (P = 0.008) in ON eyes. No association was found between Val66Met variants and non-ON (NON)-eye of the participants. These findings suggest that the BDNF Val66Met polymorphism may be associated with optic nerve damage caused by acute ON attacks in NMOSD patients.

Retinal Degeneration After First-Ever Optic Neuritis Helps Differentiate Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder

Objective: Differentiation between neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) in the early phase is challenging but crucial for treatment and prognosis.

Methods: We performed a prospective cross-sectional study to discriminate NMOSD from MS by evaluating retinal degeneration in optical coherence tomography (OCT) after a first-ever optic neuritis (ON) episode. Seventy-three NMOSD patients and 38 MS patients with ON at least 3 months prior were assessed by OCT, best-corrected visual acuity (VA), and 2.5% low-contrast VA. Multivariate linear regression models were used for comparisons. Receiver operating characteristic curves and Youden index were used for determining the discriminative value of retinal nerve fiber layer thickness (RNFL) and VA in distinguishing NMOSD from MS.

Results: Among eyes with retinal degeneration after a first-ever ON episode (n = 93), NMOSD eyes (n = 60) presented thinner RNFL (p < 0.001) and worsened VA (p < 0.001) relative to MS eyes (n = 33). Furthermore, a RNFL thinner than 78.9 μm had a specificity of 93.9% for NMOSD; combined with a VA of <0.4 decimal, these characteristics provided 100% specificity for NMOSD.

Conclusions: The first-ever ON eyes showed more severe retina degeneration in patients with NMOSD than MS, which could establish a cut-off of RNFL thickness and VA to distinguish NMOSD from MS in the early phase.

Optical coherence tomography and multiple sclerosis: Update on clinical application and role in clinical trials

Optical coherence tomography (OCT) has emerged as a fast, non-invasive, inexpensive, high-resolution imaging technique in multiple sclerosis (MS). Retinal layer quantification by OCT facilitates a 'window' into not only local retinal pathology but also global neurodegenerative processes, recognised to be the principal substrates of disability accumulation in MS. While OCT measures in MS have been demonstrated to reflect visual function, inflammatory activity outside of the visual pathways, disability measures including the prediction of disability progression, whole brain atrophy, and the differential neuroprotective effects of disease-modifying therapies, debate continues regarding the clinical utility of OCT in everyday practice. This review presents an overview of the evidence supporting OCT, with particular focus on its application in the MS clinic. We will also discuss the role of OCT in MS clinical trials to develop novel neuroprotective and potential remyelinating therapies.

Aquaporin-4 IgG seropositivity is associated with worse visual outcomes after optic neuritis than MOG-IgG seropositivity and multiple sclerosis, independent of macular ganglion cell layer thinning

BACKGROUND

Comparative studies of characteristics of optic neuritis (ON) associated with myelin oligodendrocyte glycoprotein-IgG (MOG-ON) and aquaporin-4-IgG (AQP4-ON) seropositivity are limited.

OBJECTIVE

To compare visual and optical coherence tomography (OCT) measures following AQP4-ON, MOG-ON, and multiple sclerosis associated ON (MS-ON).

METHODS

In this cross-sectional study, 48 AQP4-ON, 16 MOG-ON, 40 MS-ON, and 31 healthy control participants underwent monocular letter-acuity assessment and spectral-domain OCT. Eyes with a history of ON >3 months prior to evaluation were analyzed.

RESULTS

AQP4-ON eyes exhibited worse high-contrast letter acuity (HCLA) compared to MOG-ON (-22.3 ± 3.9 letters; p < 0.001) and MS-ON eyes (-21.7 ± 4.0 letters; p < 0.001). Macular ganglion cell + inner plexiform layer (GCIPL) thickness was lower, as compared to MS-ON, in AQP4-ON (-9.1 ± 2.0 µm; p < 0.001) and MOG-ON (-7.6 ± 2.2 µm; p = 0.001) eyes. Lower GCIPL thickness was associated with worse HCLA in AQP4-ON (-16.5 ± 1.5 letters per 10 µm decrease; p < 0.001) and MS-ON eyes (-8.5 ± 2.3 letters per 10 µm decrease; p < 0.001), but not in MOG-ON eyes (-5.2 ± 3.8 letters per 10 µm decrease; p = 0.17), and these relationships differed between the AQP4-ON and other ON groups (p < 0.01 for interaction).

CONCLUSION

AQP4-IgG seropositivity is associated with worse visual outcomes after ON compared with MOG-ON and MS-ON, even with similar severity of macular GCIPL thinning.

Optical coherence tomography in central nervous system demyelinating diseases related optic neuritis

AIM

To compare the thickness of the peripapillary retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) among patients with various forms of optic neuritis (ON) and to identify whether any particular parameters or their thinning pattern can be used to distinguish the type of ON.

METHODS

This prospective study was conducted at the Department of Ophthalmology, Faculty of Medicine, Siriraj Hospital, Thailand, between January, 2015 and December, 2016. We enlisted patients over 18 years of age with history of ON and categorized patients into 4 groups: 1) aquaporin 4 antibodies (AQP4-IgG) positive; 2) multiple sclerosis (MS); 3) myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) positive; 4) idiopathic-ON patients. Healthy controls were also included during the same study period. All patients underwent complete ophthalmological examination and spectral domain optical coherence tomography (OCT) imaging to analyze RNFL and GCIPL thickness after at least 3mo since the last episode of acute ON. The generalized estimating equation (GEE) models were used to compare the data amongst ON groups.

RESULTS

Among 87 previous ON eyes from 57 patients (43 AQP4-IgG+ON, 17 MS-ON, 8 MOG-IgG+ON, and 19 idiopathic-ON), mean logMAR visual acuity of AQP4-IgG+ON, MS-ON, MOG-IgG+ON, and idiopathic-ON groups was 0.76±0.88, 0.12±0.25, 0.39±0.31, and 0.75±1.08, respectively. Average, superior, and inferior RNFL were significantly reduced in AQP4-IgG+ON, MOG-IgG+ON and idiopathic-ON eyes, relative to those of MS-ON. Differences were not statistically significant for RNFL or GCIPL between the AQP4-IgG+ON and MOG-IgG+ON groups, whereas visual acuity in MOG-IgG+ON was slightly, but not significantly, better (0.39 vs 0.76). Although RNFL thickness in MOG-IgG+ON was significantly reduced as compared to MS-ON, mean visual acuity and GCIPL were not different.

CONCLUSION

Thinning of superior and inferior quadrants of RNFL are more commonly seen in MOG-IgG+ON and AQP4-IgG+ON. Long term visual acuity in MOG-IgG+ON is often better than AQP4-IgG+ON, whereas the structural change from OCT is comparable.

Differences in clinical features between optic neuritis in neuromyelitis optica spectrum disorders and in multiple sclerosis

Background

Optic neuritis (ON) is one of the common manifestations both in neuromyelitis-optica spectrum disorders (NMOSD) and in multiple sclerosis (MS).

Objectives

The objective of this paper is to compare clinical presentations, laboratories and imaging findings in ON associated with MS and NMOSD.

Methods

A retrospective chart review was performed in patients presenting with ON in 59 NMOSD patients with 72 eyes’ involvement and 163 ON attacks, and 20 MS patients with 23 eyes’ involvement and 36 ON attacks.

Results

ON-NMOSD patients had recurrent ON more often and tended to have simultaneous bilateral ON involvement at their first ON attack. Individuals with ON-NMOSD revealed worse visual acuity at first ON attacks and also had poorer long-term visual outcome than those with ON-MS, with nearly half of ON-NMOSD patients still having LogMAR visual acuity ≥1 at their last follow-up (p = 0.035). Significant thinner average retinal nerve fiber layer thickness was found in the ON-NMOSD group. We found no significant differences in segmentation location of the optic nerve lesions and the length of involvement between the two groups.

Conclusions

It was difficult to completely differentiate ON-NMOSD from ON-MS. ON-NMOSD patients, however, tended to have simultaneous bilateral ON involvement and poorer long-term visual outcome than individuals with ON-MS.

Altered Macular Microvasculature in Neuromyelitis Optica Spectrum Disorders

PURPOSE

To evaluate macular microvascular changes in neuromyelitis optica spectrum disorders (NMOSD) by using optical coherence tomography angiography (OCT-A) and investigate their correlations with neuroaxonal structural damage evaluated with spectral-domain OCT (SD-OCT).

DESIGN

Cross-sectional study.

METHODS

Twenty eyes of 20 patients with NMOSD and 21 eyes from 21 healthy controls were enrolled. OCT-A was used to obtain microvascular network images of the whole, superficial, and deep retinal capillary plexuses (WRCP, SRCP, and DRCP) in a 3-mm-diameter area around the macula. SD-OCT was used to obtain the intraretinal thickness. Custom automated algorithms quantified the thickness of the intraretinal layers as well as microvascular density of the retinal capillary layers.

RESULTS

NMOSD patients showed significantly decreased microvascular density in both SRCP and DRCP (P < .05) compared to controls. The decreased microvascular density in SRCP and DRCP significantly correlated with the frequency of optic neuritis attack (P < .05). Both SRCP and DRCP microvascular density significantly correlated (P < .05) with retinal nerve fiber layer and ganglion cell layer with inner plexiform layer. SRCP microvascular density moderately correlated with visual acuity, while a stronger correlation was found between DRCP and visual acuity.

CONCLUSIONS

Decreased microvascular density in NMOSD patients correlated with the worsening of their visual acuity. Correlation between microvascular impairment and neuroaxonal thinning revealed that retinal microvascular alteration may contribute to neuroaxonal loss in NMOSD patients. OCT-A with measurable analysis offers a new path of study and will likely be useful as an objective biomarker for detecting microvascular impairment in NMOSD.

Differing Structural and Functional Patterns of Optic Nerve Damage in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder

PURPOSE

To assess differential patterns of axonal loss and demyelination in the optic nerve in multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD).

DESIGN

Cross-sectional study.

PARTICIPANTS

One hundred ninety-two participants, including 136 MS patients (272 eyes), 19 NMOSD patients (38 eyes), and 37 healthy control participants (74 eyes).

METHODS

All participants underwent spectral-domain OCT scans and multifocal visual evoked potential (mfVEP) recordings. High-resolution magnetic resonance imaging (MRI) with the diffusion protocol also was performed in all patients.

MAIN OUTCOME MEASURES

Ganglion cell-inner plexiform layer (GCIPL) thickness and mfVEP amplitude and latency at 5 eccentricities; global and temporal retinal nerve fiber layer thickness.

RESULTS

In optic neuritis (ON) eyes, the NMOSD patients had more severe GCIPL loss (P < 0.001) and mfVEP amplitude reduction (P < 0.001) compared with MS patients, whereas in contrast, mfVEP latency delay was more evident in MS patients (P < 0.001). The NMOSD patients showed more morphologic and functional loss at the foveal to parafoveal region, whereas the MS patients showed evenly distributed damage at the macula. Correlation analysis demonstrated a strong structure-function (OCT-mfVEP) association in the NMOSD patients, which was only moderate in the MS patients. In non-ON (NON) eyes, the MS patients showed significantly thinner GCIPL than controls (P < 0.001), whereas no GCIPL loss was observed in NON eyes in NMOSD. In addition, a significant correlation was found between all OCT and mfVEP measures in MS patients, but not in NMOSD patients. MRI demonstrated significant lesional load in the optic radiation in MS compared to NMOSD eyes (P = 0.002), which was related to the above OCT and mfVEP changes in NON eyes.

CONCLUSIONS

Our study demonstrated different patterns of ON damage in NMOSD and MS. In MS, the ON damage was less severe, with demyelination as the main pathologic component, whereas in NMOSD, axonal loss was more severe compared with myelin loss. The disproportional mfVEP amplitude and latency changes suggested predominant axonal damage within the anterior visual pathway as the main clinical feature of NMOSD, in contrast to MS, where demyelination spreads along the entire visual pathway.

Optical coherence tomography in neuromyelitis optica spectrum disorders: potential advantages for individualized monitoring of progression and therapy

Neuromyelitis optica spectrum disorders (NMOSD) are mostly relapsing inflammatory disorders of the central nervous system (CNS). Optic neuritis (ON) is the first NMOSD-related clinical event in 55% of the patients, which causes damage to the optic nerve and leads to visual impairment. Retinal optical coherence tomography (OCT) has emerged as a promising method for diagnosis of NMOSD and potential individual monitoring of disease course and severity. OCT not only detects damage to the afferent visual system caused by ON but potentially also NMOSD-specific intraretinal pathology, i.e. astrocytopathy. This article summarizes retinal involvement in NMOSD and reviews OCT methods that could be used now and in the future, for differential diagnosis, for monitoring of disease course, and in clinical trials.

Optical Coherence Tomography versus Visual Evoked Potentials for Detecting Visual Pathway Abnormalities in Patients with Neuromyelitis Optica Spectrum Disorder

Background and Purpose

Optical coherence tomography (OCT) and visual evoked potentials (VEPs) can be used to detect optic neuritis (ON). However, the comparative sensitivities of OCT and VEPs for detecting ON in neuromyelitis optica spectrum disorder (NMOSD) are unclear, and so we assessed these sensitivities.

Methods

This cross-sectional study included 73 patients with aquaporin-4 antibody-seropositive NMOSD, and 101 eyes with ON. The clinical characteristics, visual acuity (VA), Expanded Disability Status Scale (EDSS) scores, OCT peripapillary retinal nerve fiber layer (RNFL) thickness, and VEPs of the patients were evaluated.

Results

OCT and VEPs were abnormal in 68% and 73% of eyes with a history of ON, respectively, and in 2% and 9% of eyes without ON. Test sensitivities were influenced by the number of ON episodes: the OCT RNFL thickness and VEPs were abnormal in 50% and 67% of the eyes with first-ever ON episode, respectively (p=0.041), with the combination of both tests detecting abnormalities in up to 75% of the eyes. The sensitivities of the OCT RNFL thickness and VEPs increased to 95% and 83%, respectively, after the second or subsequent ON episode (p=0.06), with the combination of both tests detecting abnormalities in 95% of cases. The OCT RNFL thickness and VEP latency/amplitude were correlated with EDSS scores and VA.

Conclusions

VEPs were superior for detecting subclinical or first-ever ON, while OCT was better for detecting eyes with multiple ON episodes. The correlations of OCT and VEPs with clinical disability measures indicate that these tests are potential markers of the disease burden in NMOSD.

Morphological and Functional Inner and Outer Retinal Layer Abnormalities in Eyes with Permanent Temporal Hemianopia from Chiasmal Compression

Purpose

The aims of this study are to compare optical coherence tomography (OCT)-measured macular retinal layers in eyes with permanent temporal hemianopia from chiasmal compression and control eyes; to compare regular and slow-flash multifocal electroretinography (mfERG) in patients and controls; and to assess the correlation between OCT, mfERG, and central visual field (SAP) data.

Methods

Forty-three eyes of 30 patients with permanent temporal hemianopia due to pituitary tumors who were previously submitted to chiasm decompression and 37 healthy eyes of 19 controls were submitted to macular spectral domain OCT, mfERG, and 10-2 SAP testing. After segmentation, the thickness of the macular retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer, and photoreceptor layer (PRL) was measured. Amplitudes and oscillatory potentials (OPs) were measured on regular and slow-flash mfERG, respectively, and expressed as the mean values per quadrant and hemifield.

Results

RNFL, GCL, and IPL thickness measurements were significantly reduced in all quadrants, whereas INL, OPL, and PRL thicknesses were significantly increased in the nasal quadrants in patients compared to those in controls. Significant correlations between OCT and 10-2 SAP measurements were positive for the RNFL, GCL, and IPL and negative for the INL, OPL, and PRL. OPs and mfERG N1 amplitudes were significantly reduced in the nasal hemiretina of patients. Significant correlations were found between OP and mfERG amplitudes for inner and outer nasal hemiretina OCT measurements, respectively.

Conclusion

Patients with permanent temporal hemianopia from previously treated chiasmal compression demonstrated significant thinning of the RNFL, GCL, IPL, and thickening of the INL, OPL, and PRL associated with reduced OP and mfERG N1 amplitudes, suggesting that axonal injury to the inner retina leads to secondary damage to the outer retina in this condition.

Optical Coherence Tomography and Subclinical Optical Neuritis in Longitudinally Extensive Transverse Myelitis

Objective

The aim is to compare the retinal nerve fiber layer (RNFL) thickness of longitudinally extensive transverse myelitis (LETM) eyes without previous optic neuritis with that of healthy control subjects.

Methods

Over 20 LETM eyes and 20 normal control eyes were included in the study and subjected to optical coherence tomography to evaluate and compare the RNFL thickness.

Result

Significant RNFL thinning was observed at 8 o'clock position in LETM eyes as compared to the control eyes (P = 0.038). No significant differences were seen in other RNFL measurements.

Conclusion

Even in the absence of previous optic neuritis LETM can lead to subclinical axonal damage leading to focal RNFL thinning.

High resolution retinal scanning reveals regional structural differences between MS and NMOSD optic neuritis regardless of antibody status

BACKGROUND

There is a need for biomarkers that can classify optic neuritis (ON) attacks as belonging to either neuromyelitis optica spectrum disorder with optic neuritis (NMOSD-ON) or relapsing remitting multiple sclerosis with optic neuritis (MS-ON). This study uses spectral domain optical coherence tomography (SD-OCT) data to perform a preliminary contrast between NMOSD-ON and MS-ON by analyzing peripapillary retinal nerve fiber layer and intra-macular layer patterns of injury.

METHODS

In this cross-sectional study, we used SD-OCT to obtain peripapillary retinal nerve fiber layer and intra-macular layer data for 26 NMOSD-ON, 25 MS-ON, and 26 healthy control (HC) age-matched eyes. Additionally, sub-comparisons compared 11 NMOSD-ON eyes that were seronegative for IgG antibodies against aquaporin 4 (NMOSD-ON (-)) and 16 NMOSD-ON eyes that were seropositive (NMOSD-ON (+)) to age-matched MS-ON eyes. Layer thicknesses were assessed using an automated algorithm and were then statistically compared using generalized estimating equations to account for inter-eye correlations.

RESULTS

Selective thinning was found in the pRNFL, mRNFL, and GCL in NMOSD-ON compared to MS-ON. Thinning in the pRNFL nasal sector was found to persist in both NMOSD-ON (-) (P=0.017) and NMOSD-ON (+) (P=0.021) compared to MS-ON. Thinning in the mRNFL temporal sector was found to persist in NMOSD-ON (+) compared to MS-ON. Diffuse thinning was found in the pRNFL, mRNFL, GCL and IPL in NMOSD-ON compared to HC, and while diffuse thinning was also found in the GCL and IPL in MS-ON compared to HC, selective thinning was found in the pRNFL and mRNFL.

CONCLUSION

The nasal region of the pRNFL may be capable of distinguishing between NMOSD-ON and MS-ON regardless of antibody status. Additionally, NMOSD-ON may cause more profound nasal axonal and inferior arcuate neuronal degeneration compared to MS-ON.

Clinical characteristics of myelin oligodendrocyte glycoprotein seropositive optic neuritis: a cohort study in Shanghai, China

Qualitative and quantitative visual outcomes of Asian optic neuritis (ON) patients with seropositive myelin oligodendrocyte glycoprotein (MOG) antibodies remain unknown. We retrospectively evaluated a cohort of new-onset ON patients in Shanghai, China between January 2015 and December 2016. Serum MOG and aquaporin-4 (AQP4) antibodies were detected using cell-based assays, and patients were followed-up for at least 6 months. The clinical characteristics and optical coherence tomography (OCT) results were evaluated in the MOG-seropositive optic neuritis (MOG-ON), AQP4-seropositive (AQP4-ON), and double seronegative (Seronegative-ON) patients. Best-corrected visual acuity (BCVA) and peripapillary retinal nerve fiber layer (RNFL) thickness after 6 months of follow-up were compared. Among MOG-ON (n = 49, 64 eyes), AQP4-ON (n = 76, 102 eyes), and Seronegative-ON patients (n = 100, 116 eyes), the percentages of BCVAs better than 0.8 (20/25) at the 6-month visit were 67.19, 19.60, and 72.41%, respectively, which showed no statistical difference between MOG-ON and Seronegative-ON patients (p = 0.198), but were better than the AQP4-ON patients (P = 0.001). The average peripapillary RNFLs measured 6 months after the attack were 58.03 ± 8.73, 64.34 ± 12.88, and 78.12 ± 13.34 μm for the MOG-ON, AQP4-ON, and Seronegative-ON patients, respectively. There was no statistical difference between MOG-ON and AQP4-ON patients (P = 0.089), but both were thinner than Seronegative-ON patients (P = 0.001). The visual acuity in MOG-ON patients was as good as Seronegative-ON patients, whereas the RNFL of the optic nerve head showed a significant thinning as in the AQP4-ON patients.

Evaluation of the retinal nerve fiber layer in neuromyelitis optica spectrum disorders: A systematic review and meta-analysis

BACKGROUND

An increasing number of studies have investigated the value of optical coherence tomography in patients with neuromyelitis optica (NMO) spectrum disorders; however, no systematic review has been performed to date. We aimed to systematically review and investigate the possibility of differentiating NMO and multiple sclerosis (MS) via an optical coherence tomography measurement.

METHODS

Electronic databases, including MEDLINE, EMBASE and Web of Science, were systematically searched up to June 2017. A meta-analysis was performed to compare the retinal nerve fiber layer (RNFL) thickness between patients with NMO and MS (or healthy controls).

RESULTS

Twenty-four studies were identified. The meta-analysis demonstrated that the RNFL loss was substantially more severe in NMO than in MS; however, subclinical axon damage was also found in eyes without optic neuritis in NMO. The intereye RNFL difference between eyes with or without optic neuritis was more prominent in NMO (-30.98μm) than in MS (-9.87μm).

CONCLUSION

The RNFL loss was more severe in NMO than in MS, and the intereye RNFL difference between eyes with or without optic neuritis may be useful in differentiating NMO from MS.

The Contribution of Optical Coherence Tomography in Neuromyelitis Optica Spectrum Disorders

Neuromyelitis optica spectrum disorders (NMOSD) comprises a group of central nervous system disorders of inflammatory autoimmune origin that mainly affect the optic nerves and the spinal cord and can cause severe visual and general disability. The clinical signs are similar to those of multiple sclerosis (MS), with the result that it is often difficult to differentiate between the two, thus leading to misdiagnosis. As the treatment and prognosis of NMOSD and MS are different, it is important to make an accurate and early diagnosis of NMOSD. Optical coherence tomography (OCT) is a non-invasive technique that enables a quantitative study of the changes that the optic nerve and the macula undergo in several neurodegenerative diseases. Many studies have shown that some of these changes, such as retinal nerve fiber layer thinning or microcystic macular edema, can be related to alterations in the brain due to neurodegenerative disorders. The purpose of this mini-review is to show how OCT can be useful for the diagnosis of NMOSD and follow-up of affected patients, as well as for the differential diagnosis with MS.

Longitudinal Study of Retinal Nerve Fiber Layer Thickness and Macular Volume in Patients With Neuromyelitis Optica Spectrum Disorder

BACKGROUND

Neuromyelitis spectrum disorder (NMOSD) is a rare autoimmune disorder previously thought to be a subtype of multiple sclerosis (MS). NMOSD is characterized by episodes of inflammation and damage to astrocytes that primarily results in damage to optic nerve and spinal cord. The objective of this exploratory study was to use optical coherence tomography (OCT) to measure axonal and neuronal health in NMOSD eyes over time.

METHODS

Nine patients with definite NMOSD were assessed at baseline and follow-up visits (time between visits: 35-55 months). OCT assessment involved a macular volume protocol and a retinal nerve fiber layer (RNFL) thickness scan.

RESULTS

The temporal, inferior, nasal, or superior quadrant and the mean global RNFL thickness, macular thickness, and volume of each NMOSD patient was unchanged compared with baseline for each eye separately and both together. There also was no change between the 2 time points for the OCT measures for eyes affected and unaffected by optic neuritis and all eyes together except for a significant change in the temporal RNFL quadrant when all NMOSD eyes were pooled together (mean = 2.88 μm, SD = 3.7, P = 0.021).

CONCLUSIONS

Unlike in MS eyes, ongoing RNFL and macular thinning secondary to brain and optic nerve atrophy could not be observed in NMOSD eyes during an observation period of 4 years. This might be an additional marker to distinguish these 2 diseases. However, to confirm this finding, more long-term data are needed to compare these 2 diseases longitudinally.