Monocular and binocular low-contrast visual acuity and optical coherence tomography in pediatric multiple sclerosis

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.

The Impact of Neuroimmunologic Disease and Developing Nervous System

Over the last two decades, neuroimmunologic disorders of childhood have been increasingly described, phenotyped, and treated. These disorders remain rare in the general population and while sharing common therapeutic interventions due to their immune pathophysiology, are heterogeneous with regard to presentation and risk of recurrence. As such, the impact of these disorders on the developing brain has come into the forefront of emerging research in pediatric neuroimmunology. Investigations into the singular impact of monophasic disease on long-term development and the impact of early and aggressive disease-modifying therapy in relapsing conditions are quickly becoming areas of ripe investigation as the field's most optimal way to treat and monitor these conditions over time. Although critically important in evaluating the developing brain, research has been heterogeneous among these diseases and limited by small cohort size. This narrative review details the role of common neuroimmunologic disorders in long-term neurological and cognitive outcomes in children as they develop.

Inner Retinal Layer Changes Reflect Changes in Ambulation Score in Patients with Primary Progressive Multiple Sclerosis

The establishment of surrogate markers to detect disability progression in persons with multiple sclerosis (PwMS) is important to improve monitoring of clinical deterioration. Optical coherence tomography (OCT) could be such a tool. However, sufficient longitudinal data of retinal neuroaxonal degeneration as a marker of disease progression exist only for PwMS with a relapsing-remitting course (RRMS) so far. In contrast, longitudinal data of retinal layers in patients with primary-progressive MS (PPMS) are inconsistent, and the association of OCT parameters with ambulatory performance in PwMS has rarely been investigated. We aimed to investigate the relative annual rates of change in retinal layers in PwMS (RRMS and PPMS) compared with healthy controls (HC) using OCT and to evaluate their association with ambulatoryfunctionalscore (AS) worsening in PPMS. A retrospective analysis of a longitudinal OCT dataset of the retinal layers of PwMS and HC from two MS centers in Germany was performed. Walking ability was measured over a standardized distance of 500 m, and changes during the observation period were categorized using the AS and the expanded disability status scale (EDSS). 61 HC with 121 eyes and 119 PwMS (PPMS: 57 patients with 108 eyes; RRMS: 62 patients with 114 eyes) were included. The median follow-up time for PwMS was 3 years. The relative annual change of pRNFL (peripapillary retinal nerve fiber layer) and INL (inner nuclear layer) was significantly different in PwMS compared with HC. RRMS and PPMS subgroups did not differ in the annual atrophy rates. In patients with PPMS, worsening of the AS was significantly associated with increased thinning of the TMV (total macular volume), GCIP (ganglion cell and inner plexiform layer), and ONPL (outer nuclear and outer plexiform layer) (all p-value < 0.05, r > 0.30). For every -0.1% decrease in the TMV, GCIP, and ONPL, the risk of a deterioration in the AS increased by 31% (hazard ratio (HR): 1.309), 11% (HR: 1.112), and 16% (HR: 1.161), respectively. In addition, worsening EDSS in PPMS was significantly associated with the relative annual atrophy rates of pRNFL, TMV, and GCIP (all p-value < 0.05). Disability progression in PPMS can be measured using OCT, and increasing annual atrophy rates of the inner retinal layers are associated with worsening ambulation. OCT is a robust and side-effect-free imaging tool, making it suitable for routine monitoring of PwMS.

Subclinical optic neuritis in pediatric myelin oligodendrocyte glycoprotein antibody-associated disease

BACKGROUND AND OBJECTIVES

The clinical spectrum of myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is heterogenous and has evolved over time since the commercial availability of the anti-MOG antibody assay. Subclinical disease activity has been previously reported in the visual pathway, but prevalence data remains limited. We investigated subclinical optic neuritis (ON) based on changes on retinal nerve fiber layer (RNFL) thickness on optic coherence tomography (OCT) in pediatric patients who tested positive for the anti-MOG antibody.

METHODS

In this retrospective, single-center cohort study, we examined children with MOGAD with at least one complete assessment of the anterior visual pathway. Subclinical ON was defined by structural visual system disease in the absence of a subjective complaint of vision loss, pain (particularly with eye movement), or color desaturation.

RESULTS

Records were reviewed from 85 children with MOGAD, 67 of whom (78.8%) had complete records for review. Eleven children (16.4%) had subclinical ON on OCT. Ten had significant reductions in RNFL, of which one had two distinct episodes of decreased RNFL, and one had significant elevations in RNFL. Of the eleven children with subclinical ON, six (54.5%) had a relapsing disease course. We also highlighted the clinical course of three children with subclinical ON detected on longitudinal OCT, including two who had subclinical ON outside of clinical relapses.

CONCLUSION

Children with MOGAD can have subclinical ON events that can manifest as significant reductions or elevations in RNFL on OCT. OCT should be used routinely in the management and monitoring of MOGAD patients.

Optical coherence tomography as retinal imaging biomarker of neuroinflammation/neurodegeneration in systemic disorders in adults and children

The retina and the optic nerve are considered extensions of the central nervous system (CNS) and thus can serve as the window for evaluation of CNS disorders. Spectral domain optical coherence tomography (OCT) allows for detailed evaluation of the retina and the optic nerve. OCT can non-invasively document changes in single retina layer thickness and structure due to neuronal and retinal glial cells (RGC) modifications in systemic and local inflammatory and neurodegenerative diseases. These can include evaluation of retinal nerve fibre layer and ganglion cell complex, hyper-reflective retinal spots (HRS, sign of activated microglial cells in the retina), subfoveal neuroretinal detachment, disorganization of the inner retinal layers (DRIL), thickness and integrity of the outer retinal layers and choroidal thickness. This review paper will report the most recent data on the use of OCT as a non invasive imaging biomarker for evaluation of the most common systemic neuroinflammatory and neurodegenerative/neurocognitive disorders in the adults and in paediatric population. In the adult population the main focus will be on diabetes mellitus, multiple sclerosis, optic neuromyelitis, neuromyelitis optica spectrum disorders, longitudinal extensive transverse myelitis, Alzheimer and Parkinson diseases, Amyotrophic lateral sclerosis, Huntington's disease and schizophrenia. In the paediatric population, demyelinating diseases, lysosomal storage diseases, Nieman Pick type C disease, hypoxic ischaemic encephalopathy, human immunodeficiency virus, leukodystrophies spinocerebellar ataxia will be addressed.

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.

Machine learning classification of multiple sclerosis in children using optical coherence tomography

BACKGROUND

In children, multiple sclerosis (MS) is the ultimate diagnosis in only 1/5 to 1/3 of cases after a first episode of central nervous system (CNS) demyelination. As the visual pathway is frequently affected in MS and other CNS demyelinating disorders (DDs), structural retinal imaging such as optical coherence tomography (OCT) can be used to differentiate MS.

OBJECTIVE

This study aimed to investigate the utility of machine learning (ML) based on OCT features to identify distinct structural retinal features in children with DDs.

METHODS

This study included 512 eyes from 187 (n_eyes = 374) children with demyelinating diseases and 69 (n_eyes = 138) controls. Input features of the analysis comprised of 24 auto-segmented OCT features.

RESULTS

Random Forest classifier with recursive feature elimination yielded the highest predictive values and identified DDs with 75% and MS with 80% accuracy, while multiclass distinction between MS and monophasic DD was performed with 64% accuracy. A set of eight retinal features were identified as the most important features in this classification.

CONCLUSION

This study demonstrates that ML based on OCT features can be used to support a diagnosis of MS in children.

Characteristic retinal atrophy pattern allows differentiation between pediatric MOGAD and MS after a single optic neuritis episode

Background

Optic neuritis (ON) is the most prevalent manifestation of pediatric multiple sclerosis (MS^ped) and myelin-oligodendrocyte glycoprotein antibody-associated disease (MOGAD^ped) in children > 6 years. In this study, we investigated retinal atrophy patterns and diagnostic accuracy of optical coherence tomography (OCT) in differentiating between both diseases after the first ON episode.

Methods

Patients were retrospectively identified in eight tertial referral centers. OCT, VEP and high/low-contrast visual acuity (HCVA/LCVA) have been investigated > 6 months after the first ON. Prevalence of pathological OCT findings was identified based on data of 144 age-matched healthy controls.

Results

Thirteen MOGAD^ped (10.7 ± 4.2 years, F:M 8:5, 21 ON eyes) and 21 MS^ped (14.3 ± 2.4 years, F:M 19:2, 24 ON eyes) patients were recruited. We observed a significantly more profound atrophy of both peripapillary and macular retinal nerve fiber layer in MOGAD^ped compared to MS^ped (pRNFL global: 68.2 ± 16.9 vs. 89.4 ± 12.3 µm, p < 0.001; mRNFL: 0.12 ± 0.01 vs. 0.14 ± 0.01 mm³, p < 0.001). Neither other macular layers nor P100 latency differed. MOGAD^ped developed global atrophy affecting all peripapillary segments, while MS^ped displayed predominantly temporal thinning. Nasal pRNFL allowed differentiation between both diseases with the highest diagnostic accuracy (AUC = 0.902, cutoff < 62.5 µm, 90.5% sensitivity and 70.8% specificity for MOGAD^ped). OCT was also substantially more sensitive compared to VEP in identification of ON eyes in MOGAD (pathological findings in 90% vs. 14%, p = 0.016).

Conclusion

First MOGAD-ON results in a more severe global peripapillary atrophy compared to predominantly temporal thinning in MS-ON. Nasal pRNFL allows differentiation between both diseases with the highest accuracy, supporting the additional diagnostic value of OCT in children with ON.

Progressive retinal changes in pediatric multiple sclerosis

Objectives To determine to what extent acute demyelinating episodes versus chronic degenerative phenomena drive retinal neuroaxonal damage in pediatric acquired demyelinating syndromes (ADS). Methods We acquired optical coherence tomography (OCT) data (follow-up range: 2 weeks - 5 years, at variable intervals from presentation) in pediatric participants who had multiple sclerosis (MS), monophasic ADS, or were healthy. Multivariable mixed effects models were used to assess the association of the number of demyelinating episodes (either optic neuritis [ON], or non-ON relapses) with changes in retinal nerve fiber layer (RNFL) or ganglion cell layer-inner plexiform layer (GCIPL) thickness. Results 64 OCT sans from 23 MS, and 33 scans from 12 monophasic ADS participants were compared with 68 scans from 62 healthy participants. The first ON episode had the biggest impact on RNFL or GCIPL thickness in monophasic ADS (RNFL: -7.9 µm, CI=5.5, p = 0.0056; GCIPL: -8.4 µm, CI=4.4, p = 0.0002) and MS (RNFL: -16 µm, CI = 3.7, p < 10^-6; GCIPL: -15 µm, CI = 2.6, p < 10^-6). Non-ON relapses were also associated with small but significant retinal thickness reductions in MS (RNFL: -2.6 µm/relapse, CI = 1.4, p = 0.0003; GCIPL: -2.8 µm/relapse, CI = 0.89, p < 10^-6). MS participants showed progressive GCIPL thinning independent of acute demyelinating episodes (-2.7 µm/year, CI = 1.9, p = 0.0058). Conclusions We showed a prominent impact of early ON episodes on OCT measures of neuroaxonal structure in patients with ADS. We also demonstrated negative effects of non-ON relapses, and the presence of chronic retinal neurodegenerative changes, in youth with MS.

Interocular Difference in Retinal Nerve Fiber Layer Thickness Predicts Optic Neuritis in Pediatric-Onset Multiple Sclerosis

BACKGROUND

Optical coherence tomography (OCT) is capable of quantifying retinal damage. Defining the extent of anterior visual pathway injury is important in multiple sclerosis (MS) as a way to document evidence of prior disease, including subclinical injury, and setting a baseline for patients early in the course of disease. Retinal nerve fiber layer (RNFL) thickness is typically classified as low if values fall outside of a predefined range for a healthy population. In adults, an interocular difference (IOD) in RNFL thickness greater than 5 μm identified a history of unilateral optic neuritis (ON). Through our PERCEPTION (PEdiatric Research Collaboration ExPloring Tests in Ocular Neuroimmunology) study, we explored whether RNFL IOD informs on remote ON in a multicenter pediatric-onset MS (POMS) cohort.

METHODS

POMS (defined using consensus criteria and first attack <18 years) patients were recruited from 4 academic centers. A clinical history of ON (>6 months prior to an OCT scan) was confirmed by medical record review. RNFL thickness was measured on Spectralis machines (Heidelberg, Germany). Using a cohort of healthy controls from our centers tested on the same machines, RNFL thickness <86 μm (<2 SDs below the mean) was defined as abnormal. Based on previously published findings in adults, an RNFL IOD >5 μm was defined as abnormal. The proportions of POMS participants with RNFL thinning (<86 μm) and abnormal IOD (>5 μm) were calculated. Logistic regression was used to determine whether IOD was associated with remote ON.

RESULTS

A total of 157 participants with POMS (mean age 15.2 years, SD 3.2; 67 [43%] with remote ON) were enrolled. RNFL thinning occurred in 45 of 90 (50%) ON eyes and 24 of 224 (11%) non-ON eyes. An IOD >5 μm was associated with a history of remote ON (P < 0.001). An IOD >5 μm occurred in 62 participants, 40 (65%) with remote ON. Among 33 participants with remote ON but normal RNFL values (≥86 μm in both eyes), 14 (42%) were confirmed to have ON by IOD criteria (>5 μm).

CONCLUSIONS

In POMS, the diagnostic yield of OCT in confirming remote ON is enhanced by considering RNFL IOD, especially for those patients with RNFL thickness for each eye in the normal range. An IOD >5 μm in patients with previous visual symptoms suggests a history of remote ON.

Radiomic analysis of the optic nerve at the first episode of acute optic neuritis: an indicator of optic nerve pathology and a predictor of visual recovery?

OBJECTIVE

Retinal nerve fiber layer thickness (RNFL) is a biomarker of neuroaxonal loss and index of visual function in multiple sclerosis (MS). We aimed to assess the correlation between radiomic features and RNFL, visual acuity (VA) at patients' presentation, visual outcome (VO), and clinical diagnosis.

METHODS

We reviewed imaging and clinical data of 25 patients with a first episode of optic neuritis (ON) (14 females, 11 males; 5 bilateral ON; 7 left ON; 13 right ON). All patients underwent a complete ophthalmological assessment, including visual acuity and RNFL, neurological evaluation, orbits MRI. Segmentation of the optic nerves was performed through 3D slicer open software to get radiomics analysis. All patients underwent a complete neuro-ophthalmological follow-up at 6 months to assess the VO, classified as: complete recovery, partial recovery, deficit persistence/relapse, or visual worsening and were diagnosed as MS or clinically isolated syndrome.

RESULTS

We observed significant correlations between radiomic features and RNFL and between radiomic features and VA. Regression model analysis identified 1 radiomic feature with significant association with VO (Gray Level non-uniformity Normalized, p = 0.004) and 6 radiomic features with significant correlation with diagnosis (High Gray Level Zone Emphasis, p < 0.001; Entropy, p < 0.001, for T1 segmentation; Mean Absolute Deviation, p < 0.001; Coarseness < 0.001; Small Area Low Gray Level Emphasis, p < 0.001; Contrast, p = 0.008, for STIR segmentation).

CONCLUSION

Orbits MRI analysis at the first episode of ON has the potential to assess the visual function and VO in ON patients, and predict MS development.

Assessment of Pediatric Optic Neuritis Visual Acuity Outcomes at 6 Months

Importance

Optic neuritis (ON) in children is uncommon. There are limited prospective data for visual acuity (VA) outcomes, associated diseases, and neuroimaging findings. Prospective data from a large sample would be useful for counseling families on treatment decisions and prognosis.

Objective

To prospectively study children with a first episode of ON, describe VA after 6 months, and ascertain the network's (Pediatric Eye Disease Investigator Group and Neuro-Ophthalmology Research Disease Investigator Consortium) ability to enroll pediatric patients with ON prospectively.

Design, Setting, and Participants

This nonrandomized cohort study was conducted from September 20, 2016, to July 20, 2018, at 23 sites in the United States and Canada in pediatric ophthalmology or neuro-ophthalmology clinics. A total of 44 children (aged 3-15 years) presented with a first episode of ON (visual loss, pain on eye movements, or both) within 2 weeks of symptom onset and at least 1 of the following in the affected eye: a distance high-contrast VA (HCVA) deficit of at least 0.2 logMAR below age-based norms, diminished color vision, abnormal visual field, or optic disc swelling. Exclusion criteria included preexisting ocular abnormalities or a previous episode of ON.

Main Outcomes and Measures

Primary outcomes were monocular HCVA and low-contrast VA at 6 months. Secondary outcomes were neuroimaging, associated diagnoses, and antibodies for neuromyelitis optica and myelin oligodendrocyte glycoprotein.

Results

A total of 44 children (mean age [SD], 10.2 [3.5] years; 26 boys [59%]; 23 White individuals [52%]; 54 eyes) were enrolled in the study. Sixteen patients (36%) had bilateral ON. Magnetic resonance imaging revealed white matter lesions in 23 children (52%). Of these children, 8 had myelin oligodendrocyte glycoprotein-associated demyelination (18%), 7 had acute disseminated encephalomyelitis (16%), 5 had multiple sclerosis (11%), and 3 had neuromyelitis optica (7%). The baseline mean HCVA was 0.95 logMAR (20/200), which improved by a mean 0.76 logMAR (95% CI, 0.54-0.99; range, -0.70 to 1.80) to 0.12 logMAR (20/25) at 6 months. The baseline mean distance low-contrast VA was 1.49 logMAR (20/640) and improved by a mean 0.72 logMAR (95% CI, 0.54-0.89; range, -0.20 to 1.50) to 0.73 logMAR (20/100) at 6 months. Baseline HCVA was worse in younger participants (aged <10 years) with associated neurologic autoimmune diagnoses, white matter lesions, and in those of non-White race and non-Hispanic ethnicity. The data did not suggest a statistically significant association between baseline factors and improvement in HCVA.

Conclusions and Relevance

The study network did not reach its targeted enrollment of 100 pediatric patients with ON over 2 years. This indicates that future treatment trials may need to use different inclusion criteria or plan a longer enrollment period to account for the rarity of the disease. Despite poor VA at presentation, most children had marked improvement by 6 months. Associated neurologic autoimmune diagnoses were common. These findings can be used to counsel families about the disease.

Profile of macular ganglion cell-inner plexiform layer thickness in healthy 6.5 year- old Swedish children

Background

The purpose was to study the macular ganglion cell- inner plexiform layer (GC-IPL) thickness in healthy 6.5 year- old Swedish children using Optical Coherence Tomography (OCT) and to study topography symmetry within eyes and between eye pairs.

Methods

A total of 181 eyes of 92 healthy children (39 girls, 53 boys) aged 6.5 and serving as a term-born control group in the Extremely Preterm Infants in Sweden Study (EXPRESS), were examined with Cirrus HD-OCT. Main outcome measures were average and minimum values of GC-IPL thickness of the device’s predefined macular sectors. Single sectors, combined sectors defined as superior and inferior hemispheres and temporal and nasal sectors were evaluated. Intra-individual GC-IPL thickness between eye pairs was analyzed. Visual acuity, refraction and general cognition were assessed and correlated to GC-IPL outcome.

Results

Eighty-five children completed the OCT examination and 155 out of 181 scans (86%) were analyzed. The mean average GC-IPL thickness was 85.9 μm (± 5.3; 5th and 95th percentiles were 76.0 and 94.6 μm). The mean minimum GC-IPL thickness was 83.6 μm (± 4.9; 5th and 95th percentiles were 75.4 and 92.3 μm). The difference in thickness between nasal and temporal sectors and between superior and inferior hemisphere sectors were less than 2 μm. The difference between average GC-IPL thickness and minimum GC-IPL thickness was 2.3 μm (± 1.9; 5th and 95th percentiles were 0.0 and 6.0 μm). The difference between the thickest and thinnest sector within eye was 6.4 μm (± 2.2; 5th and 95th percentiles were 3.0 and 10.0 μm). There was a moderate correlation in the difference between the nasal combined and the temporal combined sectors within eye pairs (p < 0.0001, Spearman’s ρ 0.58). The average GC-IPL thickness was weakly positively correlated with SE (spherical equivalent; combined sphere and ½ cylinder) (p = 0.031, Spearman’s ρ 0.23).

Conclusions

This study provides normative GC-IPL thickness values for healthy 6.5 year- old Swedish children. The GC-IPL thickness variations within eyes and within eye pairs are generally small. It could therefore be assumed that larger variations are sensitive markers of focal GC-IPL thinning due to damage to the primary visual pathways in children.

Structural correlates of atypical visual and motor cortical oscillations in pediatric-onset multiple sclerosis

We have previously demonstrated that pediatric‐onset multiple sclerosis (POMS) negatively impacts the visual pathway as well as motor processing speed. Relationships between MS‐related diffuse structural damage of gray and white matter (WM) tissue and cortical responses to visual and motor stimuli remain poorly understood. We used magnetoencephalography in 14 POMS patients and 15 age‐ and sex‐matched healthy controls to assess visual gamma (30–80 Hz), motor gamma (60–90 Hz), and motor beta (15–30 Hz) cortical oscillatory responses to a visual‐motor task. Then, 3T MRI was used to: (a) calculate fractional anisotropy (FA) of the posterior visual and corticospinal motor WM pathways and (b) quantify volume and thickness of the cuneus and primary motor cortex. Visual gamma band power was reduced in POMS and was associated with reduced FA of the optic radiations but not with loss of cuneus volume or thickness. Activity in the primary motor cortex, as measured by postmovement beta rebound amplitude associated with peak latency, was decreased in POMS, although this reduction was not predicted by structural metrics. Our findings implicate loss of WM integrity as a contributor to reduced electrical responses in the visual cortex in POMS. Future work in larger cohorts will inform on the cognitive implications of this finding in terms of visual processing function and will determine whether the progressive loss of brain volume known to occur in POMS ultimately contributes to both progressive dysfunction in such tasks as well as progressive reduction in cortical electrical responses in the visual cortex.

High- and Low-Contrast Letter Acuity Perception Matures With Age in Normally Sighted Children

BACKGROUND

High-contrast visual acuity (HCVA) changes with age, yet little is known about pediatric-specific age- and sex-normative values for low-contrast letter acuity (LCLA). We define maturational changes in monocular and binocular HCVA and LCLA in childhood and adolescence.

METHODS

Normally sighted youth (ages 5-20 years, without neurologic or ophthalmologic disease and best-corrected HCVA of 20/25 or better in each eye) were recruited. Mean monocular and binocular scores using Early Treatment Diabetic Retinopathy Study (for HCVA) and 2.5% and 1.25% Sloan (for LCLA) charts and the magnitude of binocular summation were calculated using 2-year bins. Relationships between scores and age were explored using scatterplots with Locally Weighted Scatterplot Smoothing (LOWESS) and analysis of variance that accounts for intereye correlation, followed by test of linear trend for age effect.

RESULTS

Among 101 (202 eyes) healthy participants (mean age 13 years, 42% males), monocular and binocular scores varied by age, with highest mean scores achieved in the 13 to 14-year age group for both HCVA and LCLA. Between the ages of 5 and 14.9 years, monocular scores increased linearly with age (0.76 letter/year for HCVA, 1.11 letters/year for 2.5% LCLA, and 0.97 letter/year for 1.25% LCLA; all P < 0.0001). Binocular HCVA scores also increased with age between 5 and 14.9 years (0.71 letters/year, P < 0.0001). The magnitude of binocular summation for HCVA or LCLA did not change with age.

CONCLUSIONS

HCVA and LCLA abilities mature into adolescence, peak between 13 and 14.9 years of age, and then plateau into adulthood. Evaluation of patients with visual deficits should consider age-expected normal visual acuity.

Update on Pediatric Optic Neuritis

PURPOSE OF REVIEW

The purpose of this review is to provide an update on advances in the understanding of pediatric demyelinating optic neuritis.

RECENT FINDINGS

In the past decade, the disease phenotypes for demyelinating syndromes in children have been more clearly defined. Pediatric optic neuritis may present as a clinically isolated syndrome or in the setting of underlying neurologic disease. In addition to optic neuritis associated with multiple sclerosis or neuromyelitis optica, recent work has identified antibodies to the myelin oligodendrocyte glycoprotein (MOG IgG) as a unique demyelinating cause with distinct features regarding treatment and prognosis. The disease phenotypes for demyelinating pediatric optic neuritis have expanded. Treatment strategies vary and are not universally effective for each cause of demyelinating disease. Accurately distinguishing among these unique clinical syndromes is therefore critical for initiation of appropriate treatment to prevent disability, to maximize visual outcomes, and to provide insight into long-term prognosis.

Agreement analysis comparing iPad LCVA and Sloan testing in multiple sclerosis patients

BACKGROUND

Visual symptoms are common in multiple sclerosis (MS). Low-contrast visual acuity (LCVA) testing using Sloan charts has demonstrated increased sensitivity for visual deficits compared to high-contrast acuity testing. Computerized testing of visual acuity may facilitate use in the clinic setting.

OBJECTIVES

To evaluate the agreement between an iPad-based and Sloan testing of LCVA in a cohort of MS patients.

METHODS

A total of 38 patients with relapsing-remitting MS were enrolled after providing informed written consent at Partners MS Center, Brigham and Women's hospital. Monocular LCVA was measured using retroilluminated Sloan chart and iPad-based LogMAR chart. Number of correct letters and agreement between two measurements were assessed for each eye using Bland-Altman analysis and paired t-test.

RESULTS

For both eyes, there was no significant difference in number correct between the two measurements using a paired t-test, and there was high correlation between two measurements (oculus dextrus (OD) r = 0.89, p < 0.001; oculus sinister (OS) r = 0.78, p < 0.001). The limits of agreement were -7.9 to +8.5 letters for the right eye and -10.9 to +11.2 letters for the left eye.

CONCLUSION

An iPad-based LCVA test shows good agreement with Sloan testing in MS patients.

Optical coherence tomography and visual evoked potentials in pediatric MS

Objective:

To determine the relative ability of optical coherence tomography (OCT) and pattern-reversal visual evoked potentials (pVEPs) to detect visual pathway involvement in pediatric-onset MS.

Methods:

Pediatric-onset MS participants (onset <18 years) and healthy controls (HCs) underwent OCT (Cirrus HD-OCT) and pVEPs. Retinal nerve fiber layer (RNFL), ganglion cell layer to inner plexiform layer (GCL-IPL), and P100 pVEP latency were measured. Generalized estimating equation models were used to compare the groups, adjusting for age and intereye correlations.

Results:

Twenty-four pediatric MS participants, 14 with a history of remote (>6 months) optic neuritis (ON) in one eye (8 participants) or both the eyes (6 participants), and 24 HCs were enrolled. RNFL thinning (<83 μm, 2 SDs below HC eyes) occurred in 50% of ON eyes vs 5% of non-ON eyes. Prolonged VEP latency (>109 msec) occurred in 58% of ON eyes and 55% of non-ON eyes. A clinical history of ON predicted RNFL (p < 0.001) and GCL-IPL thinning (p = 0.011), whereas prolonged pVEP latency in children with MS occurred independent of ON history.

Conclusions:

OCT and pVEPs provide complementary but distinct insights. OCT is sensitive to retinal changes in the context of clinical ON, whereas pVEPs are useful to detect disseminated lesions of the visual pathway in children with MS.

Pediatric Optic Neuritis

Optic neuritis is rare in children in comparison to adults, but accounts for approximately 25% of pediatric acute demyelinating syndromes. Features of pediatric optic neuritis that differ from adults include a higher rate of bilaterality, poor visual acuity on presentation, and papillitis. Diagnostic work-up includes brain magnetic resonance imaging, lumbar puncture, and blood tests to exclude infectious and inflammatory disorders. Pediatric optic neuritis may occur following infection or vaccination, or in association with a systemic demyelinating process such as acute disseminated encephalomyelitis, neuromyelitis optica, or multiple sclerosis. Treatment is controversial, but most practitioners administer corticosteroids. Most children with optic neuritis experience full visual recovery. The recently launched Pediatric Optic Neuritis Prospective Data Collection Study (PON1) aims to provide estimates of visual acuity outcome and assess the potential to recruit for a future pediatric optic neuritis treatment trial.

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.

Pediatric multiple sclerosis: Clinical features and outcome

Multiple sclerosis (MS) in children manifests with a relapsing-remitting MS (RRMS) disease course. Acute relapses consist of new neurologic deficits persisting greater than 24 hours, in the absence of intercurrent illness, and occur with a higher frequency early in the disease as compared to adult-onset RRMS. Most pediatric patients with MS recover well from these early relapses, and cumulative physical disability is rare in the first 10 years of disease. Brainstem attacks, poor recovery from a single attack, and a higher frequency of attacks portend a greater likelihood of future disability. Although prospective pediatric-onset MS cohorts have been established in recent years, there remains very limited prospective data detailing the longer-term clinical outcome of pediatric-onset MS into adulthood. Whether the advent of MS therapies, and the largely off-label access to such therapies in pediatric MS, has improved prognosis is unknown. MS onset during the key formative academic years, concurrent with active cognitive maturation, is an important determinant of long-term outcome, and is discussed in detail in another article in this supplement. Finally, increasing recognition of pediatric MS worldwide, recent launch of phase III trials for new agents in the pediatric MS population, and the clear imperative to more fully appreciate health-related quality of life in pediatric MS through adulthood highlight the need for standardized, validated, and robust outcome measures.

Pediatric optic neuritis

Optic neuritis (ON) is a common presenting symptom in pediatric CNS demyelinating disorders and may be associated with dramatic visual loss. Knowledge regarding clinical presentation, associated diseases, therapy, and outcomes in ON in children has grown over the past decade. These studies have shown that younger children (<10 years of age) are more likely to present with bilateral ON and older children with unilateral ON. Furthermore, studies focusing on visual recovery have shown excellent recovery of high-contrast visual acuity in the majority of children, but functional and structural studies have shown evidence of irreversible injury and functional decline after ON in children. Although randomized controlled treatment trials have not been performed in children and adolescents with ON, standard of care suggests that the use of high-dose pulse steroids is safe and likely effective. This article reviews current knowledge about the clinical presentation and management of pediatric ON, with attention to associated syndromes and evaluative tools that may inform diagnosis and interventions.

Binocular low-contrast letter acuity and the symbol digit modalities test improve the ability of the Multiple Sclerosis Functional Composite to predict disease in pediatric multiple sclerosis

BACKGROUND

Outcome measures to capture disability, such as the Multiple Sclerosis Functional Composite (MSFC), were developed to enhance outcome measurements for clinical trials in adults with multiple sclerosis (MS). The MSFC initially included three components: a timed 25-foot walk [T25FW], 9-hole peg test [9HPT], and the Paced Auditory Serial Addition Task [PASAT]. Modifications to the original MSFC, such as adding binocular low-contrast letter acuity (LCLA) or substituting the symbol digit modalities test (SDMT) for the PASAT, improved the capacity to capture neurologic impairment in adults. Similar outcome scales for pediatric MS have not yet been established.

OBJECTIVE

To determine whether the three-component MSFC or a modified MSFC with LCLA and the SDMT better identifies neurological deficits in pediatric MS.

METHODS

We evaluated 5 measures (T25FW, 9HPT, Children's PASAT [ChiPASAT], SDMT, and binocular LCLA [Sloan charts, 1.25% contrast]) in children with MS (disease onset <18 years) and healthy controls. To be able to compare measures whose scores have different scales, Z-scores were also created for each test based on the numbers of standard deviations from a control group mean, and these individual scale scores were combined to create composite scores. Logistic regression models, accounting for age, were used to determine whether the standard 3-component MSFC or modified versions (including 4 or 5 metrics) best distinguished children with MS from controls.

RESULTS

Twenty pediatric-onset MS subjects, aged 6-21 years, and thirteen healthy controls, aged 6-19 years, were enrolled. MS subjects demonstrated worse scores on the 9HPT (p=0.004) and SDMT (p=0.001), but not the 25FTW (adjusted for height, p=0.63) or the ChiPASAT (p=0.10): all comparisons adjusted for age. Decreased (worse) binocular LCLA scores were associated with MS (vs. control status, p=0.03, logistic regression; p=0.08, accounting for age). The MSFC composite score for the traditional 3 components did not differ between the groups (p=0.28). Replacing the ChiPASAT with the SDMT (OR 0.72, p=0.05) better distinguished MS from controls. A modified MSFC-4 with the SDMT replacing the ChiPASAT and including binocular 1.25% LCLA had the greatest capacity to distinguish pediatric MS from controls (OR 0.89, p=0.04, logistic regression). Including all 5 metrics as a composite MSFC-5 did not improve the model (p=0.18).

CONCLUSIONS

A modified MSFC (25FTW, 9HPT, SMDT, and binocular 1.25% LCLA) is more sensitive than the traditional MSFC or its components to capture the subtle impairments that characterize pediatric MS and should be validated in order to be considered for future pediatric MS trials.

Retinal nerve fiber layer and ganglion cell-inner plexiform layer thickness in children with obesity

AIM

To evaluate retinal nerve fiber layer (RNFL) thickness analysis of peripapillary optic nerve head (PONH) and macula as well as ganglion cell-inner plexiform layer (GCIPL) thickness in obese children.

METHODS

Eighty-five children with obesity and 30 controls were included in the study. The thicknesses of the PONH and macula of each subject's right eye were measured by high-resolution spectral-domain optic coherence tomography (OCT).

RESULTS

The RNFL thicknesses of central macular and PONH were similar between the groups (all P>0.05). The GCIPL thickness was also similar between the groups. However, the RNFL thickness of temporal outer macula were 261.7±13.7 and 268.9±14.3 µm for the obesity and the control group, respectively (P=0.034).

CONCLUSION

Obesity may cause a reduction in temporal outer macular RNFL thickness.

Reduced retinal nerve fibre layer thickness in children with severe obesity

BACKGROUND

Some optic nerve diseases are silent and insidious. Recently, reduced thickness of retinal nerve fibre layer (RNFL) has been associated with increasing body mass index in adults.

OBJECTIVES

To investigate the association of childhood obesity with RNFL measured by optical coherence tomography imaging.

METHODS

Ninety-seven children aged 5-14 years classified according to standard deviation score of body mass index (SDS-BMI) were included. Parameters of metabolic risk, adipocytokines (leptin, adiponectin) and interleukin-6 were analyzed. All subjects underwent a comprehensive ophthalmologic examination with direct ophthalmoscopy. Evaluation of RNFL with optical coherence tomography of the head of the nerve was performed.

RESULTS

RNFL thickness on the average and inferior, superior and nasal quadrants were decreased in severely obese children (SDS-BMI > 4) with respect to the other groups. However, no statistically significant association was found between the different groups of children and RNFL thickness in the temporal quadrant. There was a significant inverse correlation of RNFL thickness with adiposity indices (P = 0.016), leptin (P = 0.029) and interleukin-6 (P = 0.030) in overweight and obese children.

CONCLUSIONS

These findings suggest that adiposity and obesity-related inflammatory factors may be associated with the loss of retinal ganglion cells in children.

Longitudinal Change of Circumpapillary Retinal Nerve Fiber Layer Thickness in Children With Optic Pathway Gliomas

PURPOSE

To evaluate longitudinal changes in circumpapillary retinal nerve fiber layer (RNFL) thickness, as measured by spectral-domain optical coherence tomography (SD OCT), in children with optic pathway gliomas.

DESIGN

Longitudinal cohort study.

METHODS

Global and quadrant-specific circumpapillary RNFL thickness measures were acquired using either a hand-held SD OCT during sedation or a table-top SD OCT in children old enough to cooperate. Vision loss was defined as either a 0.2 logMAR decline in visual acuity or progression of visual field. Percent change in circumpapillary RNFL thickness in eyes experiencing vision loss was compared to eyes with stable vision.

RESULTS

Fifty-five eyes completed 250 study visits. Ten eyes (18%) from 7 patients experienced a new episode of vision loss during the study and 45 eyes (82%) from 39 patients demonstrated stable vision across study visits. Percent decline of RNFL thickness between the baseline visit and first event of vision loss event was greatest in the superior (-14%) and inferior (-10%) quadrants as well as global average (-13%). Using a threshold of ≥10% decline in RNFL, the positive and negative predictive value for vision loss when 2 or more anatomic sectors were affected was 100% and 94%, respectively.

CONCLUSIONS

Children experiencing vision loss from their optic pathway gliomas frequently demonstrate a ≥10% decline of RNFL thickness in 1 or more anatomic sectors. Global average and the inferior quadrant demonstrated the best positive and negative predictive values. Circumpapillary RNFL is a surrogate marker of vision and could be helpful in making treatment decisions for children with optic pathway gliomas.

Applications of optical coherence tomography in pediatric clinical neuroscience

For nearly two centuries, the ophthalmoscope has permitted examination of the retina and optic nerve-the only axons directly visualized by the physician. The retinal ganglion cells project their axons, which travel along the innermost retina to form the optic nerve, marking the beginning of the anterior visual pathway. Both the structure and function of the visual pathway are essential components of the neurologic examination as it can be involved in numerous acquired, congenital and genetic central nervous system conditions. The development of optical coherence tomography now permits the pediatric neuroscientist to visualize and quantify the optic nerve and retinal layers with unprecedented resolution. As optical coherence tomography becomes more accessible and integrated into research and clinical care, the pediatric neuroscientist may have the opportunity to utilize and/or interpret results from this device. This review describes the basic technical features of optical coherence tomography and highlights its potential clinical and research applications in pediatric clinical neuroscience including optic nerve swelling, optic neuritis, tumors of the visual pathway, vigabatrin toxicity, nystagmus, and neurodegenerative conditions.

Vision and vision-related outcome measures in multiple sclerosis

Visual impairment is a key manifestation of multiple sclerosis. Acute optic neuritis is a common, often presenting manifestation, but visual deficits and structural loss of retinal axonal and neuronal integrity can occur even without a history of optic neuritis. Interest in vision in multiple sclerosis is growing, partially in response to the development of sensitive visual function tests, structural markers such as optical coherence tomography and magnetic resonance imaging, and quality of life measures that give clinical meaning to the structure-function correlations that are unique to the afferent visual pathway. Abnormal eye movements also are common in multiple sclerosis, but quantitative assessment methods that can be applied in practice and clinical trials are not readily available. We summarize here a comprehensive literature search and the discussion at a recent international meeting of investigators involved in the development and study of visual outcomes in multiple sclerosis, which had, as its overriding goals, to review the state of the field and identify areas for future research. We review data and principles to help us understand the importance of vision as a model for outcomes assessment in clinical practice and therapeutic trials in multiple sclerosis.