20/40 or Better Visual Acuity After Optic Neuritis: Not as Good as We Once Thought?

Prognostic factors of first-onset optic neuritis based on diagnostic criteria and antibody status: a multicentre analysis of 427 eyes

BACKGROUND

Optic neuritis (ON) prognosis is influenced by various factors including attack severity, underlying aetiologies, treatments and consequences of previous episodes. This study, conducted on a large cohort of first ON episodes, aimed to identify unique prognostic factors for each ON subtype, while excluding any potential influence from pre-existing sequelae.

METHODS

Patients experiencing their first ON episodes, with complete aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) antibody testing, and clinical data for applying multiple sclerosis (MS) diagnostic criteria, were enrolled. 427 eyes from 355 patients from 10 hospitals were categorised into four subgroups: neuromyelitis optica with AQP4 IgG (NMOSD-ON), MOG antibody-associated disease (MOGAD-ON), ON in MS (MS-ON) or idiopathic ON (ION). Prognostic factors linked to complete recovery (regaining 20/20 visual acuity (VA)) or moderate recovery (regaining 20/40 VA) were assessed through multivariable Cox regression analysis.

RESULTS

VA at nadir emerged as a robust prognostic factor for both complete and moderate recovery, spanning all ON subtypes. Early intravenous methylprednisolone (IVMP) was associated with enhanced complete recovery in NMOSD-ON and MOGAD-ON, but not in MS-ON or ION. Interestingly, in NMOSD-ON, even a slight IVMP delay in IVMP by >3 days had a significant negative impact, whereas a moderate delay up to 7-9 days was permissible in MOGAD-ON. Female sex predicted poor recovery in MOGAD-ON, while older age hindered moderate recovery in NMOSD-ON and ION.

CONCLUSION

This comprehensive multicentre analysis on first-onset ON unveils subtype-specific prognostic factors. These insights will assist tailored treatment strategies and patient counselling for ON.

Myelin Oligodendrocyte Glycoprotein Antibody Disease Optic Neuritis: A Structure-Function Paradox?

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a demyelinating disorder that most commonly presents with optic neuritis (ON) and affects children more often than adults. We report 8 pediatric patients with MOG-associated ON and characterize focal optical coherence tomography (OCT) abnormalities over time that help distinguish this condition from the trajectories of other demyelinating disorders. These OCT findings are examined in the context of longitudinal visual function testing.

METHODS

This is a retrospective case series of 8 pediatric patients with MOG-associated ON who were referred for neuro-ophthalmic evaluation. Longitudinal data for demographics, clinical history, physical examination, and OCT obtained in the course of clinical evaluations were collected through retrospective medical record review.

RESULTS

Patients demonstrated acute peripapillary retinal nerve fiber layer (RNFL) thickening in one or both eyes, consistent with optic disc swelling. This was followed by steady patterns of average RNFL thinning, with 9 of 16 eyes reaching significantly low RNFL thickness using OCT platform reference databases ( P < 0.01), accompanied by paradoxical recovery of high-contrast visual acuity (HCVA) in every patient. There was no correlation between HCVA and any OCT measures, although contrast sensitivity (CS) was associated with global thickness, PMB thickness, and nasal/temporal (N/T) ratio, and color vision was associated with PMB thickness. There was a lower global and papillomacular bundle (PMB) thickness ( P < 0.01) in clinically affected eyes compared with unaffected eyes. There was also a significantly higher N:T ratio in clinically affected eyes compared with unaffected eyes in the acute MOG-ON setting ( P = 0.03), but not in the long-term setting.

CONCLUSIONS

MOG shows a pattern of prominent retinal atrophy, as demonstrated by global RNFL thinning, with remarkable preservation of HCVA but remaining deficits in CS and color vision. These tests may be better clinical markers of vision changes secondary to MOG-ON. Of the OCT parameters measured, PMB thickness demonstrated the most consistent correlation between structural and functional measures. Thus, it may be a more sensitive marker of clinically significant retinal atrophy in MOG-ON. The N:T ratio in acute clinically affected MOG-ON eyes in our study was higher than the N:T ratio of neuromyelitis optica (NMO)-ON eyes and similar to the N:T ratio in multiple sclerosis (MS)-ON eyes as presented in the prior literature. Therefore, MOG may share a more similar pathophysiology to MS compared with NMO.

Delayed oculomotor response associates with optic neuritis in youth with demyelinating disorders

INTRODUCTION

Impairment in visual and cognitive functions occur in youth with demyelinating disorders such as multiple sclerosis, neuromyelitis optica spectrum disorder, and myelin oligodendrocyte glycoprotein antibody-associated disease. Quantitative behavioral assessment using eye-tracking and pupillometry can provide functional metrics for important prognostic and clinically relevant information at the bedside.

METHODS

Children and adolescents diagnosed with demyelinating disorders and healthy, age-matched controls completed an interleaved pro- and anti-saccade task using video-based eye-tracking and underwent spectral-domain optical coherence tomography examination for evaluation of retinal nerve fiber layer and ganglion cell inner plexiform layer thickness. Low-contrast visual acuity and Symbol Digit Modalities Test were performed for visual and cognitive functional assessments. We assessed saccade and pupil parameters including saccade reaction time, direction error rate, pupil response latency, peak constriction time, and peak constriction and dilation velocities. Generalized Estimating Equations were used to examine the association of eye-tracking parameters with optic neuritis history, structural metrics, and visual and cognitive scores.

RESULTS

The study included 36 demyelinating disorders patients, aged 8-18 yrs. (75% F; median = 15.22 yrs., SD = 2.8) and 34 age-matched controls (65% F; median = 15.26 yrs., SD = 2.3). Surprisingly, pro- and anti-saccade performance was comparable between patients and controls, whereas pupil control was altered in patients. Oculomotor latency measures were strongly associated with the number of optic neuritis episodes, including saccade reaction time, pupil response latency, and peak constriction time. Peak constriction time was associated with both retinal nerve fiber layer and ganglion cell inner plexiform layer thickness. Pupil response latency and peak constriction time were associated with visual acuity. Pupil velocity for both constriction and dilation was associated with Symbol Digit Modalities Test scores.

CONCLUSION

The strong associations between oculomotor measures with history of optic neuritis, structural, visual, and cognitive assessments in these cohorts demonstrates that quantitative eye-tracking can be useful for probing demyelinating injury of the brain and optic nerve. Future studies should evaluate their utility in discriminating between demyelinating disorders and tracking disease progression.

An update on optic neuritis

Optic neuritis (ON) is the most common cause of subacute optic neuropathy in young adults. Although most cases of optic neuritis (ON) are classified as typical, meaning idiopathic or associated with multiple sclerosis, there is a growing understanding of atypical forms of optic neuritis such as antibody mediated aquaporin-4 (AQP4)-IgG neuromyelitis optica spectrum disorder (NMOSD) and the recently described entity, myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD). Differentiating typical ON from atypical ON is important because they have different prognoses and treatments. Findings of atypical ON, including severe vision loss with poor recovery with steroids or steroid dependence, prominent optic disc edema, bilateral vision loss, and childhood or late adult onset, should prompt serologic testing for AQP4-IgG and MOG-IgG. Although the traditional division of typical and atypical ON can be helpful, it should be noted that there can be severe presentations of otherwise typical ON and mild presentations of atypical ON that blur these traditional lines. Rare causes of autoimmune optic neuropathies, such as glial fibrillary acidic protein (GFAP) and collapsin response-mediator protein 5 (CRMP5) autoimmunity also should be considered in patients with bilateral painless optic neuropathy associated with optic disc edema, especially if there are other accompanying suggestive neurologic symptoms/signs. Typical ON usually recovers well without treatment, though recovery may be expedited by steroids. Atypical ON is usually treated with intravenous steroids, and some forms, such as NMOSD, often require plasma exchange for acute attacks and long-term immunosuppressive therapy to prevent relapses. Since treatment is tailored to the cause of the ON, elucidating the etiology of the ON is of the utmost importance.

Where's the Vision? The Importance of Visual Outcomes in Neurologic Disorders: The 2021 H. Houston Merritt Lecture

Neurologists have long recognized the importance of the visual system in the diagnosis and monitoring of neurologic disorders. This is particularly true because approximately 50% of the brain's pathways subserve afferent and efferent aspects of vision. During the past 30 years, researchers and clinicians have further refined this concept to include investigation of the visual system for patients with specific neurologic diagnoses, including multiple sclerosis (MS), concussion, Parkinson disease (PD), and conditions along the spectrum of Alzheimer disease (AD, mild cognitive impairment, and subjective cognitive decline). This review highlights the visual "toolbox" that has been developed over the past 3 decades and beyond to capture both structural and functional aspects of vision in neurologic disease. Although the efforts to accelerate the emphasis on structure-function relationships in neurologic disorders began with MS during the early 2000s, such investigations have broadened to recognize the need for outcomes of visual pathway structure, function, and quality of life for clinical trials of therapies across the spectrum of neurologic disorders. This review begins with a patient case study highlighting the importance using the most modern technologies for visual pathway assessment, including optical coherence tomography. We emphasize that both structural and functional tools for vision testing can be used in parallel to detect what might otherwise be subclinical events or markers of visual and, perhaps, more global neurologic decline. Such measures will be critical because clinical trials and therapies become more available across the neurologic disease spectrum.

Optic neuritis and autoimmune optic neuropathies: advances in diagnosis and treatment

Optic neuritis is an inflammatory optic neuropathy that is commonly indicative of autoimmune neurological disorders including multiple sclerosis, myelin-oligodendrocyte glycoprotein antibody-associated disease, and neuromyelitis optica spectrum disorder. Early clinical recognition of optic neuritis is important in determining the potential aetiology, which has bearing on prognosis and treatment. Regaining high-contrast visual acuity is common in people with idiopathic optic neuritis and multiple sclerosis-associated optic neuritis; however, residual deficits in contrast sensitivity, binocular vision, and motion perception might impair vision-specific quality-of-life metrics. In contrast, recovery of visual acuity can be poorer and optic nerve atrophy more severe in individuals who are seropositive for antibodies to myelin oligodendrocyte glycoprotein, AQP4, and CRMP5 than in individuals with typical optic neuritis from idiopathic or multiple-sclerosis associated optic neuritis. Key clinical, imaging, and laboratory findings differentiate these disorders, allowing clinicians to focus their diagnostic studies and optimise acute and preventive treatments. Guided by early and accurate diagnosis of optic neuritis subtypes, the timely use of high-dose corticosteroids and, in some instances, plasmapheresis could prevent loss of high-contrast vision, improve contrast sensitivity, and preserve colour vision and visual fields. Advancements in our knowledge, diagnosis, and treatment of optic neuritis will ultimately improve our understanding of autoimmune neurological disorders, improve clinical trial design, and spearhead therapeutic innovation.

The changing landscape of optic neuritis: a narrative review

Optic neuritis (ON) is an inflammatory optic neuropathy that is often a harbinger of central nervous system (CNS) demyelinating disorders. ON is frequently misdiagnosed in the clinical arena, leading to either inappropriate management or diagnostic delays. As a result, patients may fail to achieve optimal recovery. The treatment response to corticosteroids and long term risk of multiple sclerosis was established in the first clinical trials conducted roughly 30 years ago. Spontaneous resolution was observed in the vast majority of patients and intravenous high-dose corticosteroids hastened recovery; half of the patients eventually developed multiple sclerosis. Over the ensuing decades, the number of inflammatory conditions associated with ON has significantly expanded exposing substantial variability in the prognosis, treatment, and management of ON patients. ON subtypes can frequently be distinguished by distinct clinical, serological, and radiological profiles allowing expedited and specialized treatment. Guided by an increased understanding of the immunopathology underlying optic nerve and associated CNS injuries, novel disease management strategies are emerging to minimize vision loss, improve long-term surveillance strategies, and minimize CNS injury and disability. Knowledge regarding the clinical signs and symptoms of different ON subtypes is essential to guide acute therapy, prognosticate recovery, accurately identify underlying CNS inflammatory disorders, and facilitate study design for the next generation of clinical and translational trials.

Long-term outcomes in patients presenting with optic neuritis: Analyses of the MSBase registry

BACKGROUND

Short-term outcomes of optic neuritis (ON) have been well characterized. Limited data exists on longer-term visual outcomes in patients who present with ON. The large MSBase registry allows for characterization of long-term visual outcomes after ON.

METHODS

Via the MSBase Registry, data on patients from 41 centers was collected during routine clinical and research visits. Physical and visual disability were measured using the expanded disability status scale (EDSS) and the visual function score (VFS). Inclusion criteria for this analysis included age ≥ 18 years, clinically isolated syndrome (CIS), ON-onset, baseline visit within 6 months of onset, and at least one follow-up visit. Survival analysis was used to evaluate the association of disease-modifying treatment with time to conversion to clinically definite MS or sustained EDSS/VFS progression.

RESULTS

Data from 60,933 patients were obtained from the MSBase registry in July 2019. Of these, 1317 patients met inclusion criteria; 935 were treated at some point in disease course, while 382 were never treated. At baseline, mean age was 32.3 ± 8.8 years, 74% were female, median EDSS was 2 (IQR 1-2), and median VFS was 1 (IQR 0-2). Median follow-up time was 5.2 years (IQR 2.4-9.3). Treatment was associated with reduced risk and delayed conversion to clinically definite MS (HR = 0.70, p < 0.001), sustained EDSS progression (HR = 0.46, p < 0.0001) and sustained VFS (HR = 0.41, p < 0.001) progression.

CONCLUSIONS

In the MSBase cohort, treatment after ON was associated with better visual and neurological outcomes compared to no treatment. These results support early treatment for patients presenting with ON as the first manifestation of MS.

Validation of Computer-Adaptive Contrast Sensitivity as a Tool to Assess Visual Impairment in Multiple Sclerosis Patients

Background

Impairment of visual function is one of the major symptoms of people with multiple sclerosis (pwMS). A multitude of disease effects including inflammation and neurodegeneration lead to structural impairment in the visual system. However, the gold standard of disability quantification, the expanded disability status scale (EDSS), relies on visual assessment charts. A more comprehensive assessment of visual function is the full contrast sensitivity function (CSF), but most tools are time consuming and not feasible in clinical routine. The quantitative CSF (qCSF) test is a computerized test to assess the full CSF. We have already shown a better correlation with visual quality of life (QoL) than for classical high and low contrast charts in multiple sclerosis (MS).

Objective

To study the precision, test duration, and repeatability of the qCSF in pwMS. In order to evaluate the discrimination ability, we compared the data of pwMS to healthy controls.

Methods

We recruited two independent cohorts of MS patients. Within the precision cohort (n = 54), we analyzed the benefit of running 50 instead of 25 qCSF trials. The repeatability cohort (n = 44) was assessed by high contrast vision charts and qCSF assessments twice and we computed repeatability metrics. For the discrimination ability we used the data from all pwMS without any previous optic neuritis and compared the area under the log CSF (AULCSF) to an age-matched healthy control data set.

Results

We identified 25 trials of the qCSF algorithm as a sufficient amount for a precise estimate of the CSF. The median test duration for one eye was 185 s (range 129–373 s). The AULCSF had better test–retest repeatability (Mean Average Precision, MAP) than visual acuity measured by standard high contrast visual acuity charts or CSF acuity measured with the qCSF (0.18 vs. 0.11 and 0.17, respectively). Even better repeatability (MAP = 0.19) was demonstrated by a CSF-derived feature that was inspired by low-contrast acuity charts, i.e., the highest spatial frequency at 25% contrast. When compared to healthy controls, the MS patients showed reduced CSF (average AULCSF 1.21 vs. 1.42, p < 0.01).

Conclusion

High precision, usability, repeatability, and discrimination support the qCSF as a tool to assess contrast vision in pwMS.

Association of Visual Acuity Improvement With Uncorrected Refractive Error in Patients New to Low Vision Clinics

Importance

There is substantial socioeconomic and individual burden from uncorrected refractive error (URE) and chronic ocular disease. Understanding the association of visual acuity (VA) reduction with URE and the adults most likely to benefit from refraction may help support clinical decision-making in ophthalmologic care and maximize patient outcomes.

Objectives

To assess the magnitude of VA improvement associated with URE among adults under ophthalmic care who obtain low vision rehabilitation (LVR) services and identify the characteristics of the patients who are most likely to experience improvement.

Design, Setting, and Participants

This retrospective case series assessed patients 20 years or older who were new to the LVR clinics from August 1, 2013, to December 31, 2015, and who had habitual VA between 20/40 and counting fingers (not including) and underwent refraction. Data analysis was performed from April 4, 2018, to December 20, 2019.

Exposures

Patient demographics and clinical data, including habitual and refraction VA, refraction, and disease diagnosis. Habitual VA was categorized as mild (VA worse than 20/40 and at least 20/60), moderate (VA worse than 20/60 and better than 20/200), severe (VA 20/200 or worse and better than 20/500), and profound (VA 20/500 or worse) vision impairment (VI).

Main Outcomes and Measures

At least 2-line VA improvement and any VA improvement (≥1-line) by refraction.

Results

Among the 2923 patients new to LVR clinics, 1773 (mean [SD] age, 70 [18.2] years; 1069 [60.3%] female) were included in these analyses. The mean habitual VA was 20/100 (mean [SD], 0.67 [0.36] logMAR). At least 2-line improvement was observed in 493 patients (27.8%), and any VA improvement was seen in 1023 patients (57.7%). At least 2-line improvement was observed in 54 patients (34.8%) with corneal disorders and was more likely seen among patients aged 40 to <65 years compared with those aged 20 to <40 years (odds ratio [OR], 1.57; 95% CI, 1.02-2.41), African American patients compared with white patients (OR, 1.41; 95% CI, 1.08-1.85), or patients with moderate VI compared with mild VI (OR, 1.36; 95% CI, 1.07-1.72).

Conclusions and Relevance

The findings suggest that URE is prevalent among patients with ocular disease and accessing LVR and that refractive evaluation should be considered for patients with ocular disease and reduced VA, especially working-age adults aged 40 to <65 years, African American patients, and those with moderate VI.

Initial Impairment and Recovery of Vision-Related Functioning in Participants With Acute Optic Neuritis From the RENEW Trial of Opicinumab

Supplemental Digital Content is Available in the Text.

Background:

Leucine-rich repeat and immunoglobulin domain-containing Nogo receptor-interacting protein 1 (LINGO-1) is a key suppressor of oligodendrocyte differentiation and axonal remyelination and regeneration. This analysis evaluated the potential benefit of opicinumab, a human monoclonal antibody against LINGO-1, vs placebo on exploratory clinical endpoints of patient-reported vision-related functioning and high-contrast visual acuity (HCVA) in RENEW participants with acute optic neuritis (AON).

Methods:

Participants were randomized to 100 mg/kg opicinumab intravenous or placebo every 4 weeks (6 infusions). Assessments were conducted in the per-protocol (PP) population and included: 25-item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25), 10-item Neuro-Ophthalmic Supplement (NOS-10), and HCVA.

Results:

The opicinumab group (n = 33) had worse mean (SD) baseline patient-reported vision-related functioning scores vs placebo (n = 36): NEI-VFQ-25 composite, 75.5 (17.6) vs 79.0 (16.6); NOS-10 composite, 63.6 (19.8) vs 69.8 (21.2), respectively. By Week 24, the placebo and opicinumab groups experienced substantial mean improvements from baseline (NEI-VFQ-25 composite, 15.17 vs 13.51 [difference (95% CI): −1.66 (−5.11 to 1.78)]; NOS-10 composite, 17.40 vs 16.04 [difference (95% CI): −1.35 (−7.38 to 4.67)]). Between-treatment differences in mean change from baseline were not significantly different at any time point. Analysis of covariance–adjusted mean recovery from baseline in HCVA at Week 24 for the affected eyes was 11.8 and 8.7 letters for placebo and opicinumab, respectively (P = 0.202).

Conclusions:

Most participants in the RENEW PP population demonstrated substantial recovery from baseline in patient-reported vision-related functioning and HCVA, regardless of treatment and structural damage. Average scores after recovery remained lower than those of published disease-free control groups. These results provide important information on visual function recovery in patients with AON, as measured by NEI-VFQ-25 and NOS-10.

Optical coherence tomography of the retina in schizophrenia: Inter-device agreement and relations with perceptual function

BACKGROUND

Optical coherence tomography (OCT) studies have demonstrated differences between people with schizophrenia and controls. Many questions remain including the agreement between scanners. The current study seeks to determine inter-device agreement of OCT data in schizophrenia compared to controls and to explore the relations between OCT and visual function measures.

METHODS

Participants in this pilot study were 12 individuals with schizophrenia spectrum disorders and 12 age- and sex-matched controls. Spectralis and Cirrus OCT machines were used to obtain retinal nerve fiber layer (RNFL) thickness and macular volume. Cirrus was used to obtain ganglion cell layer + inner plexiform layer (GCL + IPL) thickness. Visual function was assessed with low-contrast visual acuity and the King-Devick test of rapid number naming.

RESULTS

There was excellent relative agreement in OCT measurements between the two machines, but poor absolute agreement, for both patients and controls. On both machines, people with schizophrenia showed decreased macular volume but no difference in RNFL thickness compared to controls. No between-group difference in GCL + IPL thickness was found on Cirrus. Controls showed significant associations between King-Devick performance and RNFL thickness and macular volume, and between low-contrast visual acuity and GCL + IPL thickness. Patients did not show significant associations between OCT measurements and visual function.

CONCLUSIONS

Good relative agreement suggests that the offset between machines remains constant and should not affect comparisons between groups. Decreased macular volume in individuals with schizophrenia on both machines supports findings of prior studies and provides further evidence that similar results may be found irrespective of OCT device.

Eye Conditions in Women

Changes in vision can have significant impact on health and quality of life. Differences between women and men have been identified in the incidence of several eye conditions. Some of these differences are a result of the greater longevity of women. However, the eye, like other organs, is susceptible to the impacts of inflammation and sex steroids. Conditions, such as thyroid eye disease, optic neuritis, and dry eye disease are related to autoimmune or inflammatory conditions and are, thus, more common among women. Idiopathic intracranial hypertension occurs disproportionately in women of childbearing age; the etiology of this condition appears to be related to both inflammatory and sex hormone fluctuations.

Evolution of Visual Outcomes in Clinical Trials for Multiple Sclerosis Disease-Modifying Therapies

: BACKGROUND:: The visual pathways are increasingly recognized as an ideal model to study neurodegeneration in multiple sclerosis (MS). Low-contrast letter acuity (LCLA) and optical coherence tomography (OCT) are validated measures of function and structure in MS. In fact, LCLA was the topic of a recent review by the Multiple Sclerosis Outcome Assessments Consortium (MSOAC) to qualify this visual measure as a primary or secondary clinical trial endpoint with the Food and Drug Administration (FDA) and other regulatory agencies. This review focuses on the use of LCLA and OCT measures as outcomes in clinical trials to date of MS disease-modifying therapies.

METHODS

A Pubmed search using the specific key words "optical coherence tomography," "low-contrast letter acuity," "multiple sclerosis," and "clinical trials" was performed. An additional search on the clinicaltrials.gov website with the same key words was used to find registered clinical trials of MS therapies that included these visual outcome measures.

RESULTS

As demonstrated by multiple clinical trials, LCLA and OCT measures are sensitive to treatment effects in MS. LCLA has been used in many clinical trials to date, and findings suggest that 7 letters of LCLA at the 2.5% contrast level are meaningful change. Few clinical trials using the benefits of OCT have been performed, although results of observational studies have solidified the ability of OCT to assess change in retinal structure. Continued accrual of clinical trial and observational data is needed to validate the use of OCT in clinical trials, but preliminary work suggests that an intereye difference in retinal nerve fiber layer thickness of 5-6 μm is a clinically meaningful threshold that identifies an optic nerve lesion in MS.

CONCLUSIONS

Visual impairment represents a significant component of overall disability in MS. LCLA and OCT enhance the detection of visual pathway injury and can be used as measures of axonal and neuronal integrity. Continued investigation is ongoing to further incorporate these vision-based assessments into clinical trials of MS therapies.

Optimal intereye difference thresholds by optical coherence tomography in multiple sclerosis: An international study

OBJECTIVE

To determine the optimal thresholds for intereye differences in retinal nerve fiber and ganglion cell + inner plexiform layer thicknesses for identifying unilateral optic nerve lesions in multiple sclerosis. Current international diagnostic criteria for multiple sclerosis do not include the optic nerve as a lesion site despite frequent involvement. Optical coherence tomography detects retinal thinning associated with optic nerve lesions.

METHODS

In this multicenter international study at 11 sites, optical coherence tomography was measured for patients and healthy controls as part of the International Multiple Sclerosis Visual System Consortium. High- and low-contrast acuity were also collected in a subset of participants. Presence of an optic nerve lesion for this study was defined as history of acute unilateral optic neuritis.

RESULTS

Among patients (n = 1,530), receiver operating characteristic curve analysis demonstrated an optimal peripapillary retinal nerve fiber layer intereye difference threshold of 5μm and ganglion cell + inner plexiform layer threshold of 4μm for identifying unilateral optic neuritis (n = 477). Greater intereye differences in acuities were associated with greater intereye retinal layer thickness differences (p ≤ 0.001).

INTERPRETATION

Intereye differences of 5μm for retinal nerve fiber layer and 4μm for macular ganglion cell + inner plexiform layer are robust thresholds for identifying unilateral optic nerve lesions. These thresholds may be useful in establishing the presence of asymptomatic and symptomatic optic nerve lesions in multiple sclerosis and could be useful in a new version of the diagnostic criteria. Our findings lend further validation for utilizing the visual system in a multiple sclerosis clinical trial setting. Ann Neurol 2019;85:618-629.

Time to steroid treatment in severe acute optic neuritis

OBJECTIVES

Steroid treatment can accelerate visual recovery in patients with optic neuritis (ON), but it is unknown whether the timing of the start of treatment influences the outcome. The main purpose of this observational study was to assess the effect of early onset steroid treatment of ON on visual prognosis and retinal morphology.

METHODS

Forty-nine patients with acute mild/moderate (n = 21) or severe (n = 28) ON, and an equal number of healthy controls were enrolled. Patients with severe ON either received early onset steroid treatment (initiated within 1 week of presentation with visual loss) (n = 9), late-onset treatment (initiated after 1 week) (n = 13), or no treatment (n = 6). Visual function and retinal morphology was studied after 6 and 12 months.

RESULTS

All measures of visual function had improved after 6 months (p ≤ 0.03) in the three groups with severe ON. This was not the case for Rayleigh match setting range (SR) in the nontreated group (p = 0.24), or for SR (p = 0.08) and latency to P100 of visual evoked potential (p = 0.08) in the late-onset treated group. After 12 months, further improvement occurred in the nontreated and late-treated groups, but not in the early treated group. Macular retinal nerve fiber layer (mRNFL) and ganglion cell plus inner plexiform layer had decreased significantly (p ≤ 0.001) in all three groups with severe ON after 6 months. After 12 months, only mRNFL had further significantly decreased and only in the late-onset treated group (p = 0.02).

CONCLUSION

The beneficial effects of early onset steroid treatment of ON is limited to a few months whereas the long-term prognosis is independent of the timing of treatment.

Updates and Controversies in the Management of Acute Optic Neuritis

Optic neuritis remains a common diagnosis with controversial management. Although typical optic neuritis is often associated with "good" recovery of visual acuity, patients are often left with persistent impairments of contrast sensitivity, color vision, and visual field. These permanent visual deficits correlate with structural injury to the anterior visual pathway and are closely linked to visual quality of life. High dose corticosteroids are commonly used for patients with acute optic neuritis. However, even several decades after the initial clinical trials, there remains significant controversy regarding the efficacy and utility of this treatment. There is a need for more effective treatments, and many new immunomodulatory and neuroprotective agents have been investigated recently. Atypical optic neuritis, such as that seen with neuromyelitis optica spectrum disorder, often requires more aggressive initial treatment. Thus, it is important for clinicians to have a framework for rapid diagnosis and triage of patients who present with typical or atypical optic neuritis. Lastly, optic neuritis is associated with an elevated long-term risk of developing multiple sclerosis. Some patients may benefit from initiation of medications targeting multiple sclerosis at the time of initial presentation of optic neuritis. Appropriate identification and treatment of patients at highest risk of developing multiple sclerosis may help impact their disease course, while limiting exposure to potential adverse effects in patients who are at lower risk and do not require disease-modifying treatment.

Laquinimod protects the optic nerve and retina in an experimental autoimmune encephalomyelitis model

BACKGROUND

The oral immunomodulatory agent laquinimod is currently evaluated for multiple sclerosis (MS) treatment. Phase II and III studies demonstrated a reduction of degenerative processes. In addition to anti-inflammatory effects, laquinimod might have neuroprotective properties, but its impact on the visual system, which is often affected by MS, is unknown. The aim of our study was to investigate potential protective effects of laquinimod on the optic nerve and retina in an experimental autoimmune encephalomyelitis (EAE) model.

METHODS

We induced EAE in C57/BL6 mice via MOG_35-55 immunization. Animals were divided into an untreated EAE group, three EAE groups receiving laquinimod (1, 5, or 25 mg/kg daily), starting the day post-immunization, and a non-immunized control group. Thirty days post-immunization, scotopic electroretinograms were carried out, and mice were sacrificed for histopathology (HE, LFB), immunohistochemistry (MBP, Iba1, Tmem119, F4/80, GFAP, vimentin, Brn-3a, cleaved caspase 3) of the optic nerve and retina, and retinal qRT-PCR analyses (Brn-3a, Iba1, Tmem119, AMWAP, CD68, GFAP). To evaluate the effect of a therapeutic approach, EAE animals were treated with 25 mg/kg laquinimod from day 16 when 60% of the animals had developed clinical signs of EAE.

RESULTS

Laquinimod reduced neurological EAE symptoms and improved the neuronal electrical output of the inner nuclear layer compared to untreated EAE mice. Furthermore, cellular infiltration, especially recruited phagocytes, and demyelination in the optic nerve were reduced. Microglia were diminished in optic nerve and retina. Retinal macroglial signal was reduced under treatment, whereas in the optic nerve macroglia were not affected. Additionally, laquinimod preserved retinal ganglion cells and reduced apoptosis. A later treatment with laquinimod in a therapeutic approach led to a reduction of clinical signs and to an improved b-wave amplitude. However, no changes in cellular infiltration and demyelination of the optic nerves were observed. Also, the number of retinal ganglion cells remained unaltered.

CONCLUSION

From our study, we deduce neuroprotective and anti-inflammatory effects of laquinimod on the optic nerve and retina in EAE mice, when animals were treated before any clinical signs were noted. Given the fact that the visual system is frequently affected by MS, the agent might be an interesting subject of further neuro-ophthalmic investigations.

Optic neuritis: the eye as a window to the brain

PURPOSE OF REVIEW

Acute optic neuritis is a common clinical problem, requiring a structured assessment to guide management and prevent visual loss. The optic nerve is the most accessible part of the central nervous system, so optic neuritis also represents an important paradigm to help decipher mechanisms of damage and recovery in the central nervous system. Important developments include the advent of optical coherence tomography as a biomarker of central nervous system axonal loss, the discovery of new pathological antibodies, notably against aquaporin-4 and, more recently, myelin oligodendrocyte protein, and emerging evidence for sodium channel blockade as a novel therapeutic approach to address energy failure in neuroinflammatory disease.

RECENT FINDINGS

We will present a practical approach to assessment of optic neuritis, highlighting the role of optical coherence tomography, when to test for new antibodies and the results of recent trials of sodium channel blockers.

SUMMARY

Optic neuritis remains a clinical diagnosis; increasingly optical coherence tomography is a key ancillary investigation. Patients with 'typical' optic neuritis, commonly a first presentation of multiple sclerosis, must be distinguished from 'atypical' optic neuritis, who require testing for new pathological antibodies and require more aggressive-targeted treatment. Sodium channel blockade is an emerging and novel potential therapeutic pathway in neuroinflammatory disease.

Early retinal atrophy predicts long-term visual impairment after acute optic neuritis

BACKGROUND

Visual recovery after optic neuritis (ON) used to be defined as good, although patients frequently complain of poor vision.

METHODS

We carried out a prospective study on 38 consecutive patients with acute ON followed monthly for 6 months and evaluated high- and low-contrast visual acuity (HCVA and LCVA, respectively), quality of vision (National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25)), visual fields, and retinal thickness by spectral domain optical coherence tomography (OCT).

RESULTS

We found significant impaired LCVA and color vision in ON eyes 6 months after acute ON, which impact on quality of life. LCVA and color vision were correlated with the thicknesses of the ganglion cell and inner plexiform layer (GCIPL; 2.5% LCVA r = 0.65 and p = 0.0001; color vision r = 0.75 and p < 0.0001) and that of the peripapillary retinal nerve fiber layer (pRNFL; LCVA r = 0.43 and p = 0.0098; color vision r = 0.62 and p < 0.0001). Linear regression models that included the change in the GCIPL and pRNFL thicknesses from baseline to month 1 after onset explained 47% of the change in 2.5% LCVA and 67% of the change of color vision acuity. When adjusting for the value of visual acuity at baseline, predictors of the change in vision from baseline to month 6 achieved similar performance for all three types of vision (HCVA, LCVA, and color vision).

CONCLUSION

Monitoring retinal atrophy by OCT within the first month after ON onset allows individuals at a high risk of residual visual impairment to be identified.

Capturing saccades in multiple sclerosis with a digitized test of rapid number naming

The King-Devick (K-D) test of rapid number naming is a visual performance measure that captures saccadic eye movements. Patients with multiple sclerosis (MS) have slowed K-D test times associated with neurologic disability and reduced quality of life. We assessed eye movements during the K-D test to identify characteristics associated with slowed times. Participants performed a computerized K-D test with video-oculography. The 25-Item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25) and its 10-Item Neuro-Ophthalmic Supplement measured vision-specific quality of life (VSQOL). Among 25 participants with MS (age 37 ± 10 years, range 20-59) and 42 controls (age 33 ± 9 years, range 19-54), MS was associated with significantly longer (worse) K-D times (58.2 ± 19.8 vs. 43.8 ± 8.6 s, P = 0.001, linear regression models, accounting for age). In MS, test times were slower among patients with higher (worse) Expanded Disability Status Scale scores (P = 0.01). Average inter-saccadic intervals (ISI) were significantly longer in MS participants compared to controls (362 ± 103 vs. 286 ± 50 ms, P = 0.001), and were highly associated with prolonged K-D times in MS (P = 0.006). MS participants generated greater numbers of saccades (P = 0.007). VSQOL scores were reduced in MS patients with longer (worse) K-D times (P = 0.04-0.001) and longer ISI (P = 0.002-0.001). Patients with MS have slowed K-D times that may be attributable to prolonged ISI and greater numbers of saccades. The K-D test and its requisite eye movements capture VSQOL and make rapid number naming a strong candidate efferent visual performance measure in MS.

Validity of low-contrast letter acuity as a visual performance outcome measure for multiple sclerosis

Low-contrast letter acuity (LCLA) has emerged as the leading outcome measure to assess visual disability in multiple sclerosis (MS) research. As visual dysfunction is one of the most common manifestations of MS, sensitive visual outcome measures are important in examining the effect of treatment. Low-contrast acuity captures visual loss not seen in high-contrast visual acuity (HCVA) measurements. These issues are addressed by the MS Outcome Assessments Consortium (MSOAC), including representatives from advocacy organizations, Food and Drug Administration (FDA), European Medicines Agency (EMA), National Institute of Neurological Disorders and Stroke (NINDS), academic institutions, and industry partners along with persons living with MS. MSOAC goals are acceptance and qualification by regulators of performance outcomes that are highly reliable and valid, practical, cost-effective, and meaningful to persons with MS. A critical step is elucidation of clinically relevant benchmarks, well-defined degrees of disability, and gradients of change that are clinically meaningful. This review shows that MS and disease-free controls have similar median HCVA, while MS patients have significantly lower LCLA. Deficits in LCLA and vision-specific quality of life are found many years after an episode of acute optic neuritis, even when HCVA has recovered. Studies reveal correlations between LCLA and the Expanded Disability Status Score (EDSS), Multiple Sclerosis Functional Composite (MSFC), retinal nerve fiber layer (RNFL) and ganglion cell layer plus inner plexiform layer (GCL + IPL) thickness on optical coherence tomography (OCT), brain magnetic resonance imaging (MRI), visual evoked potential (VEP), electroretinogram (ERG), pupillary function, and King-Devick testing. This review also concludes that a 7-point change in LCLA is clinically meaningful. The overall goal of this review is to describe and characterize the LCLA metric for research and clinical use among persons with MS.