Retinal thickness measured with optical coherence tomography and risk of disability worsening in multiple sclerosis: a cohort study

Radiologically Isolated Syndrome and the Multiple Sclerosis Prodrome in Pediatrics: Early Features of the Spectrum of Demyelination

Radiologically isolated syndrome refers to the clinical scenario in which individuals have imaging concerning for multiple sclerosis and would otherwise satisfy radiographic dissemination in space criteria, but do not have any attributable signs or symptoms. Radiologically isolated syndrome has been increasingly recognized in the pediatric population and it is understood certain individuals will transition to a formal diagnosis of multiple sclerosis over time. This review aims to outline the available data within this unique population including the diagnostic criteria, epidemiology, risk factors associated with transitioning to multiple sclerosis, and the current therapeutic landscape. Radiologically isolated syndrome will also be positioned within a broader spectrum of demyelinating disease as recent data has pointed towards a likely prodromal phase that precedes a first clinical event and diagnosis of multiple sclerosis. Characterizing the radiographic features, clinical symptoms, and biomarkers that constitute this prodromal phase of multiple sclerosis would help identify patients who may most benefit from early intervention in the future.

Longitudinal stability of inter-eye differences in optical coherence tomography measures for identifying unilateral optic nerve lesions in multiple sclerosis

INTRODUCTION

Optical coherence tomography (OCT)-derived peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell+inner plexiform layer (GCIPL) thickness inter-eye differences (IEDs) are robust measurements for identifying clinical history acute ON in people with MS (PwMS). This study investigated the utility and durability of these measures as longitudinal markers to identify optic nerve lesions.

METHODS

Prospective, multi-center international study of PwMS (with/without clinical history of ON) and healthy controls. Data from two sites in the International MS Visual System Consortium (IMSVISUAL) were analyzed. Mixed-effects models were used to compare inter-eye differences based on MS and acute ON history.

RESULTS

Average age of those with MS (n = 210) was 39.1 ± 10.8 and 190 (91%) were relapsing-remitting. Fifty-nine (28.1%) had a history of acute unilateral ON, while 9/210 (4.3%) had >1 IB episode. Median follow-up between OCT scans was 9 months. By mixed-effects modeling, IEDs were stable between first and last visits within groups for GCIPL for controls (p = 0.18), all PwMS (p = 0.74), PwMs without ON (p = 0.22), and PwMS with ON (p = 0.48). For pRNFL, IEDs were within controls (p = 0.10), all PwMS (p = 0.53), PwMS without ON history (p = 0.98), and PwMS with history of ON (p = 0.81).

CONCLUSION

We demonstrated longitudinal stability of pRNFL and GCIPL IEDs as markers for optic nerve lesions in PwMS, thus reinforcing the role for OCT in demonstrating optic nerve lesions.

Advanced central nervous system imaging biomarkers in radiologically isolated syndrome: a mini review

Radiologically isolated syndrome is characterised by central nervous system white-matter hyperintensities highly suggestive of multiple sclerosis in individuals without a neurological history of clinical demyelinating episodes. It probably represents the pre-symptomatic phase of clinical multiple sclerosis but is poorly understood. This mini review summarises our current knowledge regarding advanced imaging techniques in radiologically isolated syndrome that provide insights into its pathobiology and prognosis. The imaging covered will include magnetic resonance imaging-derived markers of central nervous system volumetrics, connectivity, and the central vein sign, alongside optical coherence tomography-related metrics.

Retinal layer thickness predicts disability accumulation in early relapsing multiple sclerosis

BACKGROUND AND PURPOSE

This study was undertaken to investigate baseline peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell and inner plexiform layer (GCIPL) thickness for prediction of disability accumulation in early relapsing multiple sclerosis (RMS).

METHODS

From a prospective observational study, we included patients with newly diagnosed RMS and obtained spectral-domain optical coherence tomography scan within 90 days after RMS diagnosis. Impact of pRNFL and GCIPL thickness for prediction of disability accumulation (confirmed Expanded Disability Status Scale [EDSS] score ≥ 3.0) was tested by multivariate (adjusted hazard ratio [HR] with 95% confidence interval [CI]) Cox regression models.

RESULTS

We analyzed 231 MS patients (mean age = 30.3 years, SD = 8.1, 74% female) during a median observation period of 61 months (range = 12-93). Mean pRNFL thickness was 92.6 μm (SD = 12.1), and mean GCIPL thickness was 81.4 μm (SD = 11.8). EDSS ≥ 3 was reached by 28 patients (12.1%) after a median 49 months (range = 9-92). EDSS ≥ 3 was predicted with GCIPL < 77 μm (HR = 2.7, 95% CI = 1.6-4.2, p < 0.001) and pRNFL thickness ≤ 88 μm (HR = 2.0, 95% CI = 1.4-3.3, p < 0.001). Higher age (HR = 1.4 per 10 years, p < 0.001), incomplete remission of first clinical attack (HR = 2.2, p < 0.001), ≥10 magnetic resonance imaging (MRI) lesions (HR = 2.0, p < 0.001), and infratentorial MRI lesions (HR = 1.9, p < 0.001) were associated with increased risk of disability accumulation, whereas highly effective disease-modifying treatment was protective (HR = 0.6, p < 0.001). Type of first clinical attack and presence of oligoclonal bands were not significantly associated.

CONCLUSIONS

Retinal layer thickness (GCIPL more than pRNFL) is a useful predictor of future disability accumulation in RMS, independently adding to established markers.

Retinal ganglion cell loss is associated with future disability worsening in early relapsing-remitting multiple sclerosis

BACKGROUND AND PURPOSE

Thinning of the retinal combined ganglion cell and inner plexiform layer (GCIP) as measured by optical coherence tomography (OCT) is a common finding in patients with multiple sclerosis. This study aimed to investigate whether a single retinal OCT analysis allows prediction of future disease activity after a first demyelinating event.

METHODS

This observational cohort study included 201 patients with recently diagnosed clinically isolated syndrome or relapsing-remitting multiple sclerosis from two German tertiary referral centers. Individuals underwent neurological examination, magnetic resonance imaging, and OCT at baseline and at yearly follow-up visits.

RESULTS

Patients were included at a median disease duration of 2.0 months. During a median follow-up of 59 (interquartile range = 43-71) months, 82% of patients had ongoing disease activity as demonstrated by failing the no evidence of disease activity 3 (NEDA-3) criteria, and 19% presented with confirmed disability worsening. A GCIP threshold of ≤77 μm at baseline identified patients with a high risk for NEDA-3 failure (hazard ratio [HR] = 1.7, 95% confidence interval [CI] = 1.1-2.8, p = 0.04), and GCIP measures of ≤69 μm predicted disability worsening (HR = 2.2, 95% CI = 1.2-4.3, p = 0.01). Higher rates of annualized GCIP loss increased the risk for disability worsening (HR = 2.5 per 1 μm/year increase of GCIP loss, p = 0.03).

CONCLUSIONS

Ganglion cell thickness as measured by OCT after the initial manifestation of multiple sclerosis may allow early risk stratification as to future disease activity and progression.

Swept-Source Optical Coherence Tomography Thresholds in Differentiating Clinical Outcomes in a Real-World Cohort of Treatment-Naïve Multiple Sclerosis Patients

This study aimed to determine whether peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell–inner plexiform layer (GCIPL) thickness thresholds for single-time-point swept-source optical coherence tomography (SS-OCT) measures can differentiate the clinical outcomes of treatment-naïve people with multiple sclerosis (pwMS). A total of 275 patients with the clinically isolated syndrome (n = 23), benign MS (n = 8), relapsing–remitting MS (n = 185), secondary progressive MS (n = 28), primary progressive MS (n = 31), and with no history of optic neuritis were included. The mean Expanded Disability Status Scale (EDSS) score was 3.0 ± 1.6. The cut-off values of pRNFL (87 µm and 88 µm) and GCIPL (70 µm) thicknesses have been adopted from previous studies using spectral-domain OCT. PwMS with pRNFL ≤87 µm and ≤88 µm had a longer disease duration, more advanced disability, and more frequently progressive MS variants compared to those with greater pRNFL thicknesses. In distinguishing pwMS with disability greater than or equal to the mean EDSS score (EDSS ≥ 3) from those with less severe disability, GCIPL thickness <70 µm had the highest sensitivity, while pRNFL thickness ≤87 µm had the greatest specificity. The optimal cut-off values differentiating patients with EDSS ≥ 3 from those with less severe disability was 63 µm for GCIPL thickness and 93.5 µm for pRNFL thickness. In conclusion, pRNFL and GCIPL thickness thresholds for single-time-point SS-OCT measurements may be helpful in differentiating the disability status of treatment-naïve pwMS.

Changes in Retinal Thickness and Brain Volume during 6.8-Year Escalating Therapy for Multiple Sclerosis

Background. Different disease-modifying therapies (DMT) for multiple sclerosis (MS) have disparate effects on disability outcomes. Sweden has a leading position globally in initiating high-efficacy DMT instead of escalating DMT from 1st-line to high-efficacy DMT. With optical coherence tomography (OCT), retinal changes can be measured at a few micrometer level. OCT has been increasingly applied in diagnosing MS and monitoring disease course and therapeutic effect. Objective. We investigate the effects of 1st-line versus high-efficacy DMT for MS on retinal and brain atrophy and on functional outcomes during 6.8 years of escalating DMT. Materials and Methods. In this prospective longitudinal observational study, 18 MS patients were followed up for 6.8 years. Twelve of the patients were untreated at baseline. All patients underwent 1st-line DMT for median duration of 2.4 years and then switched to high-efficacy DMT for a median duration of 2.9 years. Findings from neurological examinations, MRI, and OCT measures were registered 2-4 times per year. Results. Ganglion cell-inner plexiform layer (GCIPL) thickness was significantly reduced during 1st-line DMT (73.75 μm, $p<0.01$ ) compared to baseline (76.38 μm). During high-efficacy DMT, thickness reduction was slower (73.27 μm, $p<0.05$ ), and MRI contrast-loading lesions vanished ( $p<0.01$ ). However, brain parenchymal fraction (BPF) decreased during high-efficacy DMT compared to 1st-line DMT. Estimated models showed similar results. Conclusion. GCIPL decline was most profound during 1st-line DMT and diminished during high-efficacy DMT. MRI contrast lesions vanished during high-efficacy DMT. However, brain atrophy continued regardless of high-efficacy DMT.

Recent Progress in the Identification of Early Transition Biomarkers from Relapsing-Remitting to Progressive Multiple Sclerosis

Despite extensive research into the pathophysiology of multiple sclerosis (MS) and recent developments in potent disease-modifying therapies (DMTs), two-thirds of relapsing-remitting MS patients transition to progressive MS (PMS). The main pathogenic mechanism in PMS is represented not by inflammation but by neurodegeneration, which leads to irreversible neurological disability. For this reason, this transition represents a critical factor for the long-term prognosis. Currently, the diagnosis of PMS can only be established retrospectively based on the progressive worsening of the disability over a period of at least 6 months. In some cases, the diagnosis of PMS is delayed for up to 3 years. With the approval of highly effective DMTs, some with proven effects on neurodegeneration, there is an urgent need for reliable biomarkers to identify this transition phase early and to select patients at a high risk of conversion to PMS. The purpose of this review is to discuss the progress made in the last decade in an attempt to find such a biomarker in the molecular field (serum and cerebrospinal fluid) between the magnetic resonance imaging parameters and optical coherence tomography measures.

Serum Neurofilaments and OCT Metrics Predict EDSS-Plus Score Progression in Early Relapse-Remitting Multiple Sclerosis

(1) Background: Early disability accrual in RRMS patients is frequent and is associated with worse long-term prognosis. Correctly identifying the patients that present a high risk of early disability progression is of utmost importance, and may be aided by the use of predictive biomarkers. (2) Methods: We performed a prospective cohort study that included newly diagnosed RRMS patients, with a minimum follow-up period of one year. Biomarker samples were collected at baseline, 3-, 6- and 12-month follow-ups. Disability progression was measured using the EDSS-plus score. (3) Results: A logistic regression model based on baseline and 6-month follow-up sNfL z-scores, RNFL and GCL-IPL thickness and BREMSO score was statistically significant, with χ2(4) = 19.542, p < 0.0001, R2 = 0.791. The model correctly classified 89.1% of cases, with a sensitivity of 80%, a specificity of 93.5%, a positive predictive value of 85.7% and a negative predictive value of 90.62%. (4) Conclusions: Serum biomarkers (adjusted sNfL z-scores at baseline and 6 months) combined with OCT metrics (RNFL and GCL-IPL layer thickness) and the clinical score BREMSO can accurately predict early disability progression using the EDSS-plus score for newly diagnosed RRMS patients.

Corneal axonal loss as an imaging biomarker of neurodegeneration in multiple sclerosis: a longitudinal study

Background

Resourceful endpoints of axonal loss are needed to predict the course of multiple sclerosis (MS). Corneal confocal microscopy (CCM) can detect axonal loss in patients with clinically isolated syndrome and established MS, which relates to neurological disability.

Objective

To assess corneal axonal loss over time in relation to retinal atrophy, and neurological and radiological abnormalities in MS.

Methods

Patients with relapsing-remitting (RRMS) (n = 68) or secondary progressive MS (SPMS) (n = 15) underwent CCM and optical coherence tomography. Corneal nerve fibre density (CNFD-fibres/mm²), corneal nerve branch density (CNBD-branches/mm²), corneal nerve fibre length (CNFL-mm/mm²) and retinal nerve fibre layer (RNFL-μm) thickness were quantified along with neurological and radiological assessments at baseline and after 2 years of follow-up. Age-matched, healthy controls (n = 20) were also assessed.

Results

In patients with RRMS compared with controls at baseline, CNFD (p = 0.004) and RNFL thickness (p < 0.001) were lower, and CNBD (p = 0.003) was higher. In patients with SPMS compared with controls, CNFD (p < 0.001), CNFL (p = 0.04) and RNFL thickness (p < 0.001) were lower. For identifying RRMS, CNBD had the highest area under the receiver operating characteristic (AUROC) curve (0.99); and for SPMS, CNFD had the highest AUROC (0.95). At follow-up, there was a further significant decrease in CNFD (p = 0.04), CNBD (p = 0.001), CNFL (p = 0.008) and RNFL (p = 0.002) in RRMS; in CNFD (p = 0.04) and CNBD (p = 0.002) in SPMS; and in CNBD (p = 0.01) in SPMS compared with RRMS. Follow-up corneal nerve loss was greater in patients with new enhancing lesions and optic neuritis history.

Conclusion

Progressive corneal and retinal axonal loss was identified in patients with MS, especially those with more active disease. CCM may serve as an imaging biomarker of axonal loss in MS.

Baseline retinal nerve fiber layer thickness as a predictor of multiple sclerosis progression: New insights from the FREEDOMS II study

BACKGROUND AND PURPOSE

The aim was to evaluate the potential of retinal nerve fiber layer thickness (RNFLT) measured with optical coherence tomography in predicting disease progression in relapsing-remitting multiple sclerosis (RRMS).

METHODS

Analyses were conducted post hoc of this 24-month, phase III, double-blind study, in which RRMS patients were randomized (1:1:1) to once daily oral fingolimod 0.5 mg, 1.25 mg or placebo. The key outcomes were the association between baseline RNFLT and baseline clinical characteristics and clinical/imaging outcomes up to 24 months. Change of RNFLT with fingolimod versus placebo within 24 months and time to retinal nerve fiber layer (RNFL) thinning were evaluated.

RESULTS

Altogether 885 patients were included. At baseline, lower RNFLT was correlated with higher Expanded Disability Status Scale score (r = -1.085, p = 0.018), lower brain volume (r = 0.025, p = 0.006) and deep gray matter volume (r = 0.731, p < 0.0001), worse visual acuity (r = -19.846, p < 0.0001) and longer duration since diagnosis (r = -0.258, p = 0.018). At month 12, low baseline RNFLT (<86 μm) versus high baseline RNFLT (≥99 μm) was associated with a greater brain volume loss (percentage change -0.605% vs. -0.315%, p = 0.035) in patients without optic neuritis history. At month 24, low baseline RNFLT versus high baseline RNFLT was associated with a higher number of new or newly enlarged T2 lesions (mean number 4.0 vs. 2.8, p = 0.014) and a higher risk of subsequent RNFL thinning (hazard ratio 2.55; 95% confidence interval 1.84-3.53; p < 0.001). The atrophy of the RNFL in the inferior quadrant was alleviated with fingolimod 0.5 mg versus placebo at month 24 (Δ(least squares mean) = 1.8, p = 0.047).

CONCLUSION

Retinal nerve fiber layer thickness could predict disease progression in RRMS.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT00355134, https://clinicaltrials.gov/ct2/show/NCT00355134.

Optical coherence tomography as a prognostic tool for disability progression in MS: a systematic review

Since multiple sclerosis (MS) is characterized by an unpredictable disease course, accurate prognosis and personalized treatment constitute an important challenge in clinical practice. We performed a qualitative systematic review to assess the predictive value of retinal layer measurement by spectral-domain optical coherence tomography (SD-OCT) in MS patients. Longitudinal MS cohort studies that determined the risk of clinical deterioration based on peripapillary retinal nerve fiber layer (pRNFL) and/or macular ganglion cell-inner plexiform layer (mGCIPL) atrophy were included. Our search strategy and selection process yielded eight articles in total. Of those, five studies only focused on patients with a relapsing-remitting disease pattern (RRMS). After correction for confounders such as disease duration, we found that (1) cross-sectional measurement of pRNFL thickness ≤ 88 µm; (2) cross-sectional measurement of mGCIPL thickness < 77 µm; (3) longitudinal measurement of pRNFL thinning > 1.5 µm/year; and (4) longitudinal measurement of mGCIPL thinning ≥ 1.0 µm/year is associated with an increased risk for disability progression in subsequent years. Longitudinal mGCIPL assessment consistently resulted in the highest risk estimates in our analysis. Within these studies, inclusion and exclusion criteria accounted for the retinal degeneration inherent to (acute) optic neuritis (ON). This small systematic review provides additional evidence that OCT-measured pRNFL and/or mGCIPL atrophy can predict disability progression in RRMS patients. We therefore recommend close clinical follow-up or initiation/change of treatment in RRMS patients with increased risk for clinical deterioration based on retinal layer thresholds, in particular when other poor prognostic signs co-occur.

Serum neurofilament-light and glial fibrillary acidic protein levels in hydroxychloroquine-treated primary progressive multiple sclerosis

BACKGROUND

In a recent trial, hydroxychloroquine (HCQ) treatment reduced the expected rate of disability worsening at 18 months in primary progressive multiple sclerosis (PPMS). Neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) are emerging biomarkers in multiple sclerosis.

METHODS

We measured NfL and GFAP levels in serum samples from 39 patients with inactive PPMS included in a phase II clinical trial of HCQ treatment in PPMS at multiple time points over 18 months, and investigated the association of these biomarkers with clinical disability at screening and during follow-up. Screening and 12-month retinal nerve fiber layer (RNFL) thickness was also recorded and analyzed.

RESULTS

NfL and GFAP levels increased over time, but only significantly from screening to month 6. NfL and GFAP levels did not significantly increase from month 6 up to month 18. At screening, NfL and GFAP levels did not correlate with the Expanded Disability Status Scale (EDSS), and GFAP but not NfL modestly correlated with Timed 25-Foot Walk test (T25FW). Screening NfL and GFAP levels did not predict disability worsening (≥20% worsening on the T25FW) at month 18. RNFL thickness decreased significantly from screening to month 12 and independently predicted disability worsening.

CONCLUSIONS

In this cohort of people with inactive PPMS, HCQ treatment attenuated the increase of NfL and GFAP after 6 months of treatment and up to 18 months of follow-up, suggesting a treatment effect of HCQ over these biomarkers. RNFL thickness, a marker of neuroaxonal atrophy, was associated with disability worsening, and should be explored further as a prognostic marker in this population.

Association of Vitamin D Polygenic Risk Scores and Disease Outcome in People With Multiple Sclerosis

Background and Objectives

Observational studies suggest low levels of 25-hydroxyvitamin D (25[OH]D) may be associated with increased disease activity in people with multiple sclerosis (PwMS). Large-scale genome-wide association studies (GWAS) suggest 25(OH)D levels are partly genetically determined. The resultant polygenic scores (PGSs) could serve as a proxy for 25(OH)D levels, minimizing potential confounding and reverse causation in analyses with outcomes. Herein, we assess the association of genetically determined 25(OH)D and disease outcomes in MS.

Methods

We generated 25(OH)D PGS for 1,924 PwMS with available genotyping data pooled from 3 studies: the CombiRx trial (n = 575), Johns Hopkins MS Center (n = 1,152), and Immune-Mediated Inflammatory Diseases study (n = 197). 25(OH)D-PGS were derived using summary statistics (p < 5 × 10−8) from a large GWAS including 485,762 individuals with circulating 25(OH)D levels measured. We included clinical and imaging outcomes: Expanded disability status scale (EDSS), timed 25-foot walk (T25FW), nine-hole peg test (9HPT), radiologic activity, and optical coherence tomography-derived ganglion cell inner plexiform layer (GCIPL) thickness. A subset (n = 935) had measured circulating 25(OH)D levels. We fitted multivariable models based on the outcome of interest and pooled results across studies using random effects meta-analysis. Sensitivity analyses included a modifiedpvalue threshold for inclusion in the PGS (5 × 10−5) and applying Mendelian randomization (MR) rather than using PGS.

Results

Initial analyses demonstrated a positive association between generated 25(OH)D-PGS and circulating 25(OH)D levels (per 1SD increase in 25[OH]D PGS: 3.08%, 95% CI: 1.77%, 4.42%;p= 4.33e-06; R2= 2.24%). In analyses with outcomes, we did not observe an association between 25(OH)D-PGS and relapse rate (per 1SD increase in 25[OH]D-PGS: 0.98; 95% CI: 0.87–1.10), EDSS worsening (per 1SD: 1.05; 95% CI: 0.87–1.28), change in T25FW (per 1SD: 0.07%; 95% CI: −0.34 to 0.49), or change in 9HPT (per 1SD: 0.09%; 95% CI: −0.15 to 0.33). 25(OH)D-PGS was not associated with new lesion accrual, lesion volume or other imaging-based outcomes (whole brain, gray, white matter volume loss or GCIPL thinning). The results were similarly null in analyses using otherpvalue thresholds or those applying MR.

Discussion

Genetically determined lower 25(OH)D levels were not associated with worse disease outcomes in PwMS and raises questions about the plausibility of a treatment effect of vitamin D in established MS.

Treatment of Patients with Multiple Sclerosis Transitioning Between Relapsing and Progressive Disease

Multiple sclerosis (MS) is a chronic autoimmune demyelinating and neurodegenerative disease of the central nervous system with a wide variety of clinical phenotypes. In spite of the phenotypic classification of MS patients, current data provide evidence that diffuse neuroinflammation and neurodegeneration coexist in all MS forms, the latter gaining increasing clinical relevance in progressive phases. Given that the transition phase of relapsing-remitting MS (RRMS) to secondary progressive MS (SPMS) is not well defined, and widely accepted criteria for SPMS are lacking, randomised controlled trials (RCTs) specifically designed for the transition phase have not been conducted. This review summarizes primary and secondary analyses and reports derived from phase III prospective clinical RCTs listed in PubMed of compounds authorised through the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) for the treatment of MS. The best data are available for interferon beta-1a (IFNb-1a) subcutaneous (s.c.), IFNb-1b s.c., mitoxantrone and siponimod, the latter being the most modern compound with likely the best risk-to-effect ratio. Moreover, there is a labels discrepancy for many disease-modifying treatments (DMTs) between the FDA and EMA, which have to be taken into consideration when opting for a specific DMT.

The Usefulness of Optical Coherence Tomography in Disease Progression Monitoring in Younger Patients with Relapsing-Remitting Multiple Sclerosis: A Single-Centre Study

The purpose of the study was to assess the usefulness of optical coherence tomography (OCT) in the detection of the neurodegenerative process in younger patients with multiple sclerosis (MS). The study group consisted of 61 patients with a relapsing remitting course of MS (mean age 36.4 ± 6.7 years) divided into two groups: short (≤5 years) and long (>10 years) disease duration. OCT, P300 evoked potential, Montreal Cognitive Assessment, and performance subtests (Picture Completion and Digit Symbol) of the Wechsler Adult Intelligence Scale were performed in all patients. Mean values of most parameters assessed in OCT (pRNFL Total, pRNFL Inferior, pRNFL Superior, pRNFL Temporalis, mRNFL, GCIPL, mRNFL+GCIPL) were significantly lower in MS patients in comparison to controls. And in patients with longer disease duration in comparison to those with shorter. Most OCT parameters negatively correlated with the EDSS score (p < 0.05). No significant correlation was found between OCT results and both P300 latency and the results of psychometric tests. OCT, as a simple, non-invasive, quick, and inexpensive method, could be useful for monitoring the progression of disease in MS patients.

Retinal Examinations Provides Early Warning of Alzheimer's Disease

Patients with Alzheimer's disease have difficulty maintaining independent living abilities as the disease progresses, causing an increased burden of care on family caregivers and the healthcare system and related financial strain. This patient group is expected to continue to expand as life expectancy climbs. Current diagnostics for Alzheimer's disease are complex, unaffordable, and invasive without regard to diagnosis quality at early stages, which urgently calls for more technical improvements for diagnosis specificity. Optical coherence tomography or tomographic angiography has been shown to identify retinal thickness loss and lower vascular density present earlier than symptom onset in these patients. The retina is an extension of the central nervous system and shares anatomic and functional similarities with the brain. Ophthalmological examinations can be an efficient tool to offer a window into cerebral pathology with the merit of easy operation. In this review, we summarized the latest observations on retinal pathology in Alzheimer's disease and discussed the feasibility of retinal imaging in diagnostic prediction, as well as limitations in current retinal examinations for Alzheimer's disease diagnosis.

Normative Data and Conversion Equation for Spectral-Domain Optical Coherence Tomography in an International Healthy Control Cohort

BACKGROUND

Spectral-domain (SD-) optical coherence tomography (OCT) can reliably measure axonal (peripapillary retinal nerve fiber layer [pRNFL]) and neuronal (macular ganglion cell + inner plexiform layer [GCIPL]) thinning in the retina. Measurements from 2 commonly used SD-OCT devices are often pooled together in multiple sclerosis (MS) studies and clinical trials despite software and segmentation algorithm differences; however, individual pRNFL and GCIPL thickness measurements are not interchangeable between devices. In some circumstances, such as in the absence of a consistent OCT segmentation algorithm across platforms, a conversion equation to transform measurements between devices may be useful to facilitate pooling of data. The availability of normative data for SD-OCT measurements is limited by the lack of a large representative world-wide sample across various ages and ethnicities. Larger international studies that evaluate the effects of age, sex, and race/ethnicity on SD-OCT measurements in healthy control participants are needed to provide normative values that reflect these demographic subgroups to provide comparisons to MS retinal degeneration.

METHODS

Participants were part of an 11-site collaboration within the International Multiple Sclerosis Visual System (IMSVISUAL) consortium. SD-OCT was performed by a trained technician for healthy control subjects using Spectralis or Cirrus SD-OCT devices. Peripapillary pRNFL and GCIPL thicknesses were measured on one or both devices. Automated segmentation protocols, in conjunction with manual inspection and correction of lines delineating retinal layers, were used. A conversion equation was developed using structural equation modeling, accounting for clustering, with healthy control data from one site where participants were scanned on both devices on the same day. Normative values were evaluated, with the entire cohort, for pRNFL and GCIPL thicknesses for each decade of age, by sex, and across racial groups using generalized estimating equation (GEE) models, accounting for clustering and adjusting for within-patient, intereye correlations. Change-point analyses were performed to determine at what age pRNFL and GCIPL thicknesses exhibit accelerated rates of decline.

RESULTS

The healthy control cohort (n = 546) was 54% male and had a wide distribution of ages, ranging from 18 to 87 years, with a mean (SD) age of 39.3 (14.6) years. Based on 346 control participants at a single site, the conversion equation for pRNFL was Cirrus = -5.0 + (1.0 × Spectralis global value). Based on 228 controls, the equation for GCIPL was Cirrus = -4.5 + (0.9 × Spectralis global value). Standard error was 0.02 for both equations. After the age of 40 years, there was a decline of -2.4 μm per decade in pRNFL thickness ( P < 0.001, GEE models adjusting for sex, race, and country) and -1.4 μm per decade in GCIPL thickness ( P < 0.001). There was a small difference in pRNFL thickness based on sex, with female participants having slightly higher thickness (2.6 μm, P = 0.003). There was no association between GCIPL thickness and sex. Likewise, there was no association between race/ethnicity and pRNFL or GCIPL thicknesses.

CONCLUSIONS

A conversion factor may be required when using data that are derived between different SD-OCT platforms in clinical trials and observational studies; this is particularly true for smaller cross-sectional studies or when a consistent segmentation algorithm is not available. The above conversion equations can be used when pooling data from Spectralis and Cirrus SD-OCT devices for pRNFL and GCIPL thicknesses. A faster decline in retinal thickness may occur after the age of 40 years, even in the absence of significant differences across racial groups.

Association of the retinal vasculature, intrathecal immunity, and disability in multiple sclerosis

BACKGROUND

Optical coherence tomography angiography (OCT-A) is a novel technique allowing non-invasive assessment of the retinal vasculature. During relapsing remitting multiple sclerosis (RRMS), retinal vessel loss occurs in eyes suffering from acute optic neuritis and recent data suggest that retinal vessel loss might also be evident in non-affected eyes. We investigated whether alterations of the retinal vasculature are linked to the intrathecal immunity and whether they allow prognostication of the future disease course.

MATERIAL AND METHODS

This study includes two different patient cohorts recruited at a tertiary German academic multiple sclerosis center between 2018 and 2020 and a cohort of 40 healthy controls. A total of 90 patients with RRMS undergoing lumbar puncture and OCT-A analysis were enrolled into a cross-sectional cohort study to search for associations between the retinal vasculature and the intrathecal immune compartment. We recruited another 86 RRMS patients into a prospective observational cohort study who underwent clinical examination, OCT-A and cerebral magnetic resonance imaging at baseline and during annual follow-up visits to clarify whether alterations of the retinal vessels are linked to RRMS disease activity. Eyes with a history of optic neuritis were excluded from the analysis.

RESULTS

Rarefication of the superficial vascular complex occured during RRMS and was linked to higher frequencies of activated B cells and higher levels of the pro-inflammatory cytokines interferon-γ, tumor necrosis factor α and interleukin-17 in the cerebrospinal fluid. During a median follow-up of 23 (interquartile range 14 - 25) months, vessel loss within the superficial (hazard ratio [HR] 1.6 for a 1%-point decrease in vessel density, p=0.01) and deep vascular complex (HR 1.6 for a 1%-point decrease, p=0.05) was associated with future disability worsening.

DISCUSSION

Optic neuritis independent rarefication of the retinal vasculature might be linked to neuroinflammatory processes during RRMS and might predict a worse disease course. Thus, OCT-A might be a novel biomarker to monitor disease activity and predict future disability.

Rate of Retinal Layer Thinning as a Biomarker for Conversion to Progressive Disease in Multiple Sclerosis

Background and Objectives

The diagnosis of secondary progressive multiple sclerosis (SPMS) is often delayed because of the lack of objective clinical tools, which increases the diagnostic uncertainty and hampers the therapeutic development in progressive multiple sclerosis (MS). Optical coherence tomography (OCT) has been proposed as a promising biomarker of progressive neurodegeneration. To explore longitudinal changes in the thicknesses of retinal layers on OCT in individuals with relapsing-remitting MS (RRMS) who converted to SPMS vs matched patients with RRMS who did not convert to SPMS. Our hypothesis is that the 2 cohorts exhibit different rates of retinal thinning.

Methods

From our prospective observational cohort of patients with MS at the American University of Beirut, we selected patients with RRMS who converted to SPMS during the observation period and patients with RRMS, matched by age, disease duration, and Expanded Disability Status Scale (EDSS) at the first visit. Baseline retinal measurements were obtained using spectral domain OCT, and all patients underwent clinical and OCT evaluation every 6–12 months on average throughout the study period (mean = 4 years). Mixed-effect regression models were used to assess the annualized rates of retinal changes and the differences between the 2 groups and between converters to SPMS before and after their conversion.

Results

A total of 61 participants were selected (21 SPMS and 40 RRMS). There were no differences in baseline characteristics and retinal measurements between the 2 groups. The annualized rates of thinning of all retinal layers, except for macular volume, were greater in converters before conversion compared with nonconverters by 112% for peripapillary retinal nerve fiber layer (p = 0.008), 344% for tRNFL (p < 0.0001), and 82% for cell-inner plexiform layer (GCIPL) (p = 0.002). When comparing the annualized rate of thinning for the same patients with SPMS before and after conversion, no significant differences were found except for tRNFL and GCIPL with slower thinning rates postconversion (46% and 68%, respectively).

Discussion

Patients who converted to SPMS exhibited faster retinal thinning as reflected on OCT. Longitudinal assessment of retinal thinning could confirm the transition to SPMS and help with the therapeutic decision making for patients with MS with clinical suspicion of disease progression.

Differences in Age-related Retinal and Cortical Atrophy Rates in Multiple Sclerosis

BACKGROUND AND OBJECTIVES

The timing of neurodegeneration in multiple sclerosis (MS) remains unclear. It is critical to understand the dynamics of neuroaxonal loss if we hope to prevent or forestall permanent disability in MS. We therefore used a deeply phenotyped longitudinal cohort to assess and compare rates of neurodegeneration in retina and brain throughout the MS disease course.

METHODS

We analyzed 597 patients with MS who underwent longitudinal optical coherence tomography imaging annually for 4.5 ± 2.4 years and 432 patients who underwent longitudinal MRI scans for 10 ± 3.4 years, quantifying macular ganglion cell-inner plexiform layer (GCIPL) volume and cortical gray matter (CGM) volume. The association between the slope of decline in the anatomical structure and the age of entry in the cohort (categorized by the MRI cohort's age quartiles) was assessed by hierarchical linear models.

RESULTS

The rate of CGM volume loss declined with increasing age of study entry (1.3% per year atrophy for the age of entry in the cohort younger than 35 years; 1.1% for older than 35 years and younger than 41; 0.97% for older than 41 years and younger than 49; 0.9% for older than 49 years) while the rate of GCIPL thinning was highest in patients in the youngest quartile, fell by more than 50% in the following age quartile, and then stabilized (0.7% per year thinning for the age of entry in the cohort younger than 35 years; 0.29% for age older than 35 and younger than 41 years; 0.34% for older than 41 and younger than 49 years; 0.33% for age older than 49 years).

DISCUSSION

An age-dependent reduction in retinal and cortical volume loss rates during relapsing-remitting MS suggests deceleration in neurodegeneration in the earlier period of disease and further indicates that the period of greatest adaptive immune-mediated inflammatory activity is also the period with the greatest neuroaxonal loss.

Using personalized prognosis in the treatment of relapsing multiple sclerosis: A practical guide

The clinical course of multiple sclerosis (MS) is highly variable among patients, thus creating important challenges for the neurologist to appropriately treat and monitor patient progress. Despite some patients having apparently similar symptom severity at MS disease onset, their prognoses may differ greatly. To this end, we believe that a proactive disposition on the part of the neurologist to identify prognostic “red flags” early in the disease course can lead to much better long-term outcomes for the patient in terms of reduced disability and improved quality of life. Here, we present a prognosis tool in the form of a checklist of clinical, imaging and biomarker parameters which, based on consensus in the literature and on our own clinical experiences, we have established to be associated with poorer or improved clinical outcomes. The neurologist is encouraged to use this tool to identify the presence or absence of specific variables in individual patients at disease onset and thereby implement sufficiently effective treatment strategies that appropriately address the likely prognosis for each patient.

Optical coherence tomography assessment of axonal and neuronal damage of the retina in patients with familial and sporadic multiple sclerosis

Objective

To assess axonal and neuronal damage of the retina in patients with familial (fMS) and sporadic multiple sclerosis (sMS).

Methods

87 relapsing-remitting MS patients (45 patients with sMS, 42 patients with fMS) and 30 healthy controls were included in the study. Optical coherence tomography (OCT) was performed with the spectral domain optical coherence tomography (SD-OCT, Heidelberg Engineering, Germany). The peripapillary retinal nerve fiber layer (pRNFL) thickness, ganglion cell-inner plexiform layer (GCIPL) thickness, total macular volume (TMV) and the inner nuclear layer (INL) thickness were measured.

Results

A significant reduction of the pRNFL thickness was detected in sMS and fMS compared to the control group (86.29 (+/- 16.13) μm in sMS, 84.78 (+/- 12.92) μm in fMS, 98.93 (+/- 6.71) μm in control group; p < 0.001). There was no significant difference in the pRNFL thickness between sMS and fMS (p = 0.5239). The GCIPL thickness was significantly decreased in sMS and fMS compared to the control group [66.0581 (+/- 11.2674) μm in sMS, 63.8386 (+/-10.004) μm in fMS, 76.5074 (+/- 5.0004) μm in control group; p < 0.001]. A significant reduction of the TMV was shown in sMS and fMS compared to the control group [8.4541(+/- 0.4727) mm3 in sMS, 8.3612 (+/- 0.4448) mm3 in fMS, 8.8387 (+/- 0.314) mm3 in control group; p < 0.0011]. No difference in the GCIPL thickness and TMV between sMS and fMS was found (p = 0.3689 and p = 0.3758, respectively). The INL thickness in sMS and fMS did not differ compared to the control group [34.2323 (+/- 2.7006) μm in sMS, 34.5159 (+/- 2.9780) μm in fMS, 33.6148 (+/- 2.0811) μm in control group; p = 0.5971 and p = 0.1870, respectively] and between the two forms (p = 0.4894).

Conclusion

We confirmed the presence of axonal and neuronal damage of the retina in sMS and fMS. Both forms of MS did not differ significantly from each other with respect to RFNL, GCIPL, MV and INL. ON induced significant reduction of the pRNFL, GCIPL and MV in both groups of pwMS.

Clinical onset of CNS demyelinating disease after COVID-19 vaccination: denovo disease?

BACKGROUND

Clinical onset of multiple sclerosis (MS^postvacc) and myelin-oligodendrocyte-glycoprotein-antibody-associated disease (MOGAD^postvacc) has been reported in association with SARS-CoV-2-vaccination. There is uncertainty as to whether this is causality (denovo disease) or temporal coincidence (manifestation of a preexisting, subclinical neuroinflammation).

OBJECTIVES

Comparing the clinical characteristics of MS^postvacc-patients versus patients with MS (PwMS) whose clinical onset occurred independently of vaccination (MS^reference).

METHODS

Consecutive patients with clinical onset ≤30 days after SARS-CoV-2-vaccination were included. Clinical data, cerebrospinal fluid (CSF) parameters and magnetic resonance imaging (MRI) as well as optical coherence tomography (OCT) data were compared to an age- and sex-matched MS^reference-cohort.

RESULTS

We identified 5 MS^postvacc and 1 MOGAD^postvacc patients who developed their clinical onset ≤ 30 days after SARS-CoV-2-vaccination. Clinical characteristics, CSF, MRI and OCT parameters from MS^postvacc patients were comparable to the MS^reference cohort and showed evidence of preexisting subclinical CNS disease. The single case with MOGAD^postvacc clearly differed from PwMS in higher CSF cell counts, remission of MRI lesions during follow-up, and absence of oligoclonal bands.

CONCLUSIONS

Our case series indicates that MS^postvacc patients showed a rather typical initial manifestation in temporal association with SARS-CoV-2-vaccination and harbored preexisting subclinical neuroinflammation. This argues against the denovo development of MS in this cohort.

Optical Coherence Tomography and Optical Coherence Tomography with Angiography in Multiple Sclerosis

Multiple sclerosis (MS) is an inflammatory and neurodegenerative, potentially disabling disease of the central nervous system. OCT (Optical Coherence Tomography) and OCT-A (Optical Coherence Tomography with Angiography) are imaging techniques for the retina and choroid that are used in the diagnosis and monitoring of ophthalmological conditions. Their use has recently expanded the study of several autoimmune disorders, including MS. Although their application in MS remains unclear, the results seem promising. This review aimed to provide insight into the most recent OCT and OCT-A findings in MS and may function as a reference point for future research. According to the current literature, the retinal nerve fibre layer (RNFL) and ganglion cell-inner plexiform complex (GC-IPL) are significantly reduced in people with MS and are inversely correlated with disease duration. The use of OCT might help distinguish between MS and neuromyelitis optica spectrum disorders (NMOSD), as the latter presents with more pronounced thinning in both the RNFL and GC-IPL. The OCT-A findings in MS include reduced vessel density in the macula, peripapillary area, or both, and the enlargement of the foveal avascular zone (FAZ) in the setting of optic neuritis. Additionally, OCT-A might be able to detect damage in the very early stages of the disease as well as disease progression in severe cases.

Schizophrenia in Translation: Why the Eye?

Schizophrenia is increasingly recognized as a systemic disease, characterized by dysregulation in multiple physiological systems (eg, neural, cardiovascular, endocrine). Many of these changes are observed as early as the first psychotic episode, and in people at high risk for the disorder. Expanding the search for biomarkers of schizophrenia beyond genes, blood, and brain may allow for inexpensive, noninvasive, and objective markers of diagnosis, phenotype, treatment response, and prognosis. Several anatomic and physiologic aspects of the eye have shown promise as biomarkers of brain health in a range of neurological disorders, and of heart, kidney, endocrine, and other impairments in other medical conditions. In schizophrenia, thinning and volume loss in retinal neural layers have been observed, and are associated with illness progression, brain volume loss, and cognitive impairment. Retinal microvascular changes have also been observed. Abnormal pupil responses and corneal nerve disintegration are related to aspects of brain function and structure in schizophrenia. In addition, studying the eye can inform about emerging cardiovascular, neuroinflammatory, and metabolic diseases in people with early psychosis, and about the causes of several of the visual changes observed in the disorder. Application of the methods of oculomics, or eye-based biomarkers of non-ophthalmological pathology, to the treatment and study of schizophrenia has the potential to provide tools for patient monitoring and data-driven prediction, as well as for clarifying pathophysiology and course of illness. Given their demonstrated utility in neuropsychiatry, we recommend greater adoption of these tools for schizophrenia research and patient care.

Analysis of optical coherence tomography of the optic nerve head and of the retinal macular area in multiple sclerosis patients

BACKGROUND: Multiple sclerosis is a chronic autoimmune demyelinating disease of the central nervous system. Early diagnosis of the disease is extremely important for the just-in-time start of specific therapy. Optical coherence tomography (OCT) of the optic nerve head and retina can become an early marker of the neurodegenerative process in multiple sclerosis. AIM: To determine OCT-changes in the retinal nerve fiber layer (RNFL) thickness and retinal thickness in the macular area being most specific for multiple sclerosis. MATERIALS AND METHODS: 197 patients were examined, the study group consisted of 136 patients (274 eyes) with an established diagnosis of multiple sclerosis and the disease duration of at least 6 months. The control group included 61 healthy people (122 eyes). All patients underwent a standard ophthalmological examination, OCT was performed on Spectralis OCT (Heidelberg Engineering, Germany) using 2 scanning protocols: ONH-RC-Scan (Optic Nerve Head-Radial Circle Scan) and PPAA (Posterior Pole Asymmetry Analysis) RESULTS: Only 11 patients (8.1%) had a history of retrobulbar neuritis, the best corrected visual acuity was 0.7 and higher in 83 (81%) patients with multiple sclerosis, while the optic nerve head and retinal nerve fiber layer OCT-changes typical for multiple sclerosis were found in 118 patients (87%). The most prominent thinning of the retinal nerve fiber layer in group with multiple sclerosis was revealed in the temporal part of the optic nerve head (59.9 14.8 in the study group versus 76.6 12.0 in the control group; p 0.001), the least thinning was in the nasal half (66.6 14.3 in the study group versus 69.3 12.4 in the control group; p = 0.013). The retina in the macular area in multiple sclerosis patients was thinned over the entire area, the most significant changes were in the Outer Nasal 7 zone (303.3 20.4 in the study group versus 324.3 10.0 in the control group; p 0.001). Cluster analysis found 6 new retinal zones for mapping the macular area using the scanning protocol PPAA. In order to determine the prognostic value of the obtained zones, a logistic regression model was constructed, which with a sensitivity of 87.1% and a specificity of 81.6% allows concluding on the probability of having multiple sclerosis. CONCLUSION: OCT data using the proposed mapping of the macular area with the mathematical model analysis could be used to diagnose specific optic nerve atrophy, to reveal typical thinning of the retinal nerve fiber layer associated with multiple sclerosis, and in the long run, to become an additional criterion for establishing the diagnosis of multiple sclerosis.

Retinal layer thinning as a biomarker of long-term disability progression in multiple sclerosis

BACKGROUND

Peripapillary retinal nerve fibre layer and macular ganglion cell plus inner plexiform layer thinning are markers of neuroaxonal degeneration in multiple sclerosis.

OBJECTIVE

We aimed to investigate the value of peripapillary retinal nerve fibre layer and ganglion cell plus inner plexiform layer thinning for prediction of long-term disability.

METHODS

This is a 6-year prospective longitudinal study on 93 multiple sclerosis patients. Optical coherence tomography scans were performed at baseline, after 1, 2 and 6 years. Primary endpoint was disability progression after 6 years, defined as expanded disability status scale worsening and/or cognitive deterioration. Univariate and multivariate analysis was used to investigate the value of peripapillary retinal nerve fibre layer and ganglion cell plus inner plexiform layer to predict the primary endpoint.

RESULTS

A total of 57 (61.3%) patients had disability worsening, 40 (43.0%) expanded disability status scale worsening and 34 (36.6%) cognitive deterioration. Mean peripapillary retinal nerve fibre layer and ganglion cell plus inner plexiform layer baseline thickness were 93.0 and 75.2 µm, and mean annualised peripapillary retinal nerve fibre layer and ganglion cell plus inner plexiform layer thinning rates over 6 years were 1.3 and 1.6 µm, respectively. Univariate and multivariate analysis revealed lower peripapillary retinal nerve fibre layer and ganglion cell plus inner plexiform layer baseline thickness and higher annualised thinning rates in patients with disability progression after 6 years. Effects were more pronounced for ganglion cell plus inner plexiform layer and expanded disability status scale worsening than for peripapillary retinal nerve fibre layer models and cognitive deterioration.

CONCLUSION

Ganglion cell plus inner plexiform layer and peripapillary retinal nerve fibre layer measurements depict neurodegeneration and predict disability progression in multiple sclerosis.

Choroidal Thickness in Multiple Sclerosis: An Optical Coherence Tomography Study

Background and Purpose

To identify changes in the choroidal thickness (CT) in multiple sclerosis (MS) patients with and without optic neuritis (ON) using enhanced-depth-imaging optical coherence tomography (EDI-OCT).

Methods

This cross-sectional study included 96 eyes with MS and 28 eyes of healthy controls. All participants underwent an ophthalmologic examination and EDI-OCT scanning (Spectralis, Heidelberg Engineering, Germany) to assess the CT and the retinal nerve fiber layer (RNFL) thickness. MS patients were divided into two groups: 1) with and 2) without a history of ON. The CT was evaluated in the fovea and at six horizontal and six vertical points at 500, 1,000, and 1,500 µm from the fovea. Paired t-tests were used to compare the groups, and p-value<0.05 was considered as significant.

Results

At all 13 measurements points, the CT was thicker in MS patients than in the healthy controls and was thinner in eyes with ON than in the contralateral eyes, but these differences were not statistically significant. However, the CT was always larger in all points in eyes with a history of ON than in the control eyes. The RNFL was significantly thinner (p<0.05) in both MS and ON eyes than in the control eyes.

Conclusions

The CT did not differ between MS and control eyes, but it was significantly larger in patients with a history of ON, in whom the RNFL was thinner. Further studies are necessary to establish the possible role of the choroid in MS.

Evaluation of peripapillary and subfoveal choroidal vascularity index in patients with multiple sclerosis

PURPOSE

To evaluate the changes in the peripapillary choroidal vascularity index (PCVI) and subfoveal choroidal vascularity index (SFCVI) in multiple sclerosis (MS) patients and healthy subjects METHODS: A total of 145 eyes of 73 patients were investigated in this cross-sectional study. 78 eyes of 39 MS patients (Group 1) and 67 eyes of 34 healthy subjects (Group 2) were evaluated. MS patients with a history of optic neuritis (ON) constituted Group 1a, those without a history of ON constituted Group 1b.

RESULTS

The mean PCVI was significantly lower in Group 1 than Group 2 (61,39±3,00 % vs 64,49±2,29 % respectively, p<0.001). The mean SFCVI scores of Group 1 was significantly lower than Group 2 (64,01±2,66 % vs. 66,87±2,14 % respectively, p<0.001). The mean PCVI of Group 1a (59,26±2,85 %) was significantly lower compared to Group 1b (62,87±2,08 %) and Group 2 (64,49±2,29 %, p1<0.001, p2<0.001). The mean SFCVI of Group 1a was significantly lower than Group 2 (64.26±2.75 % vs. 66.87±2.14 % respectively, p<0.001).

CONCLUSION

PCVI and SFCVI scores were significantly lower in MS patients compared to healthy controls. PCVI scores of MS patients who had a history of ON were significantly lower than those of patients without a previous ON attack, as were SFCVI scores. We consider that evaluation of PCVI and SFCVI might be useful for monitoring ocular involvement in patients with MS.

Associations of Alcohol Consumption and Smoking With Disease Risk and Neurodegeneration in Individuals With Multiple Sclerosis in the United Kingdom

IMPORTANCE

Understanding the effects of modifiable risk factors on risk for multiple sclerosis (MS) and associated neurodegeneration is important to guide clinical counseling.

OBJECTIVE

To investigate associations of alcohol use, smoking, and obesity with odds of MS diagnosis and macular ganglion cell layer and inner plexiform layer (mGCIPL) thickness.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study analyzed data from the community-based UK Biobank study on health behaviors and retinal thickness (measured by optical coherence tomography in both eyes) in individuals aged 40 to 69 years examined from December 1, 2009, to December 31, 2010. Risk factors were identified with multivariable logistic regression analyses. To adjust for intereye correlations, multivariable generalized estimating equations were used to explore associations of alcohol use and smoking with mGCIPL thickness. Finally, interaction models explored whether the correlations of alcohol and smoking with mGCIPL thickness differed for individuals with MS. Data were analyzed from February 1 to July 1, 2021.

EXPOSURES

Smoking status (never, previous, or current), alcohol intake (never or special occasions only [low], once per month to ≤4 times per week [moderate], or daily/almost daily [high]), and body mass index.

MAIN OUTCOMES AND MEASURES

Multiple sclerosis case status and mGCIPL thickness.

RESULTS

A total of 71 981 individuals (38 685 women [53.7%] and 33 296 men [46.3%]; mean [SD] age, 56.7 [8.0] years) were included in the analysis (20 065 healthy control individuals, 51 737 control individuals with comorbidities, and 179 individuals with MS). Modifiable risk factors significantly associated with MS case status were current smoking (odds ratio [OR], 3.05 [95% CI, 1.95-4.64]), moderate alcohol intake (OR, 0.62 [95% CI, 0.43-0.91]), and obesity (OR, 1.72 [95% CI, 1.15-2.56]) compared with healthy control individuals. Compared with the control individuals with comorbidities, only smoking was associated with case status (OR, 2.30 [95% CI, 1.48-3.51]). High alcohol intake was associated with a thinner mGCIPL in individuals with MS (adjusted β = -3.09 [95% CI, -5.70 to -0.48] μm; P = .02). In the alcohol interaction model, high alcohol intake was associated with thinner mGCIPL in control individuals (β = -0.93 [95% CI, -1.07 to -0.79] μm; P < .001), but there was no statistically significant association in individuals with MS (β = -2.27 [95% CI, -4.76 to 0.22] μm; P = .07). Smoking was not associated with mGCIPL thickness in MS. However, smoking was associated with greater mGCIPL thickness in control individuals (β = 0.89 [95% CI, 0.74-1.05 μm]; P < .001).

CONCLUSIONS AND RELEVANCE

These findings suggest that high alcohol intake was associated with retinal features indicative of more severe neurodegeneration, whereas smoking was associated with higher odds of being diagnosed with MS.

Structural changes in retina (Retinal nerve fiber layer) following mild traumatic brain injury and its association with development of visual field defects

BACKGROUND

Mild traumatic brain injury (mTBI)is the most common form of traumatic brain injury accounting for 70-80% of all brain injuries annually. There is increasing evidence that long lasting morphological and functional consequence can be present in visual system following mTBI. Among all the visual manifestation, awareness of Visual field defects is important because it may compromise the social, personal or professional life of any individual. Retinal structural changes such as thinning of Retinal nerve fiber layer (RFNL)captured using optical coherence tomography have emerged as a possible biomarker in many neurological diseases however very little is known in cases with mTBI OBJECTIVE: (I) To demonstrate the structural changes/morphological changes in retina if any following mTBI. (II) Whether the structural changes in retina have any association with the development of Visual field deficits leading to Visual function impairment following mTBI (III) Clinical relevance of structural changes in retina as a possible biomarker for visual function impairment due to visual field deficits.

MATERIALS AND METHODS

Our study included 60 patients with mTBI who fulfilled the inclusion criteria. All patients underwent a detailed ophthalmic evaluation with special focus on temporal recording of Retinal nerve layer thickness using SD- Optical Coherence Tomography and Visual field (Visual field Index) by Humphrey Automated Field Analyser.

RESULTS

30% of eyes had significant thinning of RFNL (> 30% of the base line thickness) at 6 months following mTBI. Visual function impairment due to visual field deficits (VFI < 80%) at 6 months was seen in 40% of the eyes. The structural changes and visual function impairment peaked at 6 months' post injury. A strong Association was noted between RFNL thinning and manifestation of Visual field deficits (VFI < 80%) leading to visual function impairment (P < 0.001). The Correlation Co-efficient between thinning of RFNL and Visual field deficits had a positive correlation(p < 0.001).

CONCLUSION

This novel study has demonstrated that visual functional impairment due to Visual field deficits is a real possibility following mTBI. Monitoring of retinal parameter such as thinning of Retinal nerve fiber layer, using Optical coherence tomography, can be a biomarker for early detection or development of visual field defects in mTBI.

Optical coherence tomography and visual evoked potential and its relationship with neurological disability in patients with relapsing-remitting multiple sclerosis

INTRODUCTION

To evaluate the relationship between retinal nerve fiber layer involvement and visual evoked potential with the neurological disability scale in relapsing remitting multiple sclerosis.

METHODS

Fifty-two patients diagnosed with relapsing-remitting multiple sclerosis were evaluated for the study. Optical coherence tomography (retinal nerve fiber layer or RNFL and macular volume or MV), pattern visual evoked potential or VEP (latency and P100 wave amplitude), and neurological disability scale (EDSS) were performed. A baseline evaluation was carried out and it was repeated after one year and two years.

RESULTS

The baseline values ​​in the retinal nerve fiber layer were 82.5 (75-93.5), the latency and amplitude of the VEP of 116 (108-125.5) and 9 (7-11), respectively, while the EDSS was 2 (1.5-3). A correlation was found between higher EDSS with prolonged latency and decreased amplitude of the P100 wave. There was an association between a higher EDSS with the prolongation of the latency of the P100 wave and a longer time of evolution of MS. No relationship was found between EDSS and macular volume. A higher EDSS was associated with a significant decrease in RNFL. When the discriminative performance of disability was evaluated, the latency of the VEP presented an area under the curve of 0.79 (CI95% 0.67- 0.92), the amplitude of the VEP an area under the curve of 0.71 (CI95% 0.56 - 0.87) and RNFL a area under the curve of 0.76 (95% CI 0.62 - 0.90. When comparing RNFL, MV and PEV in eyes without and with previous optic neuritis with RNFL values ​​of 88 (81-97) and 76 (71-81) (p 0.0007), MV of 246 (232-261) and 241 (229-251) (p 0.2541), PEV latency of 109 (105-117) and 125 (118-129) (p 0.0001), VEP amplitude of 9 (7-10) and 9 (7-11) (p 0.9391), respectively, which shows a statistically significant correlation between decrease in RNFL and prolongation of VEP latency in eyes with previous optic neuritis. In the 2-year follow-up there were no significant differences between the values ​​of RNFL, VEP and EDSS.

DISCUSSION

In our study, a relationship was evidenced between retinal nerve fiber thickness, PEV and the degree of disability measured by EDSS in patients with relapsing MS - remissions in their baseline values. A lower RNFL thickness was correlated with prolonged latency and decreased amplitude in the PEV and was associated with a higher EDSS. This relationship was more significant in eyes with previous optic neuritis in terms of decreased RNFL thickness and prolongation of PEV latency. No significant differences were found in the 2-year follow-up in the measurements made.

Optical coherence tomography in multiple sclerosis: A 3-year prospective multicenter study

Objective

To evaluate changes over 3 years in the thickness of inner retinal layers including the peripapillary retinal nerve fiber layer (pRNFL), and combined macular ganglion cell and inner plexiform layers (mGCIPL), in individuals with relapsing‐remitting multiple sclerosis (RRMS) versus healthy controls; to determine whether optical coherence tomography (OCT) is sufficiently sensitive and reproducible to detect small degrees of neuroaxonal loss over time that correlate with changes in brain volume and disability progression as measured by the Expanded Disability Status Scale (EDSS).

Methods

Individuals with RRMS from 28 centers (n = 333) were matched with 64 healthy participants. OCT scans were performed on Heidelberg Spectralis machines (at baseline; 1 month; 6 months; 6‐monthly thereafter).

Results

OCT measurements were highly reproducible between baseline and 1 month (intraclass correlation coefficient >0.98). Significant inner retinal layer thinning was observed in individuals with multiple sclerosis (MS) compared with controls regardless of previous MS‐associated optic neuritis––group differences (95% CI) over 3 years: pRNFL: −1.86 (−2.54, −1.17) µm; mGCIPL: −2.03 (−2.78, −1.28) µm (both p < 0.0001; effect sizes 0.39 and 0.34). Greater inner retinal layer atrophy was observed in individuals diagnosed with RRMS <3 years versus >5 years (pRNFL: p < 0.05; mGCIPL: p < 0.01). Brain volume decreased by 1.3% in individuals with MS over 3 years compared to 0.5% in control subjects (effect size 0.76). mGCIPL atrophy correlated with brain atrophy (p < 0.0001). There was no correlation of OCT data with disability progression.

Interpretation

OCT has potential to estimate rates of neurodegeneration in the retina and brain. The effect size for OCT, smaller than for magnetic resonance imaging based on Heidelberg Spectralis data acquired in this study, was increased in early disease.

Digital Biomarkers in Multiple Sclerosis

For incurable diseases, such as multiple sclerosis (MS), the prevention of progression and the preservation of quality of life play a crucial role over the entire therapy period. In MS, patients tend to become ill at a younger age and are so variable in terms of their disease course that there is no standard therapy. Therefore, it is necessary to enable a therapy that is as personalized as possible and to respond promptly to any changes, whether with noticeable symptoms or symptomless. Here, measurable parameters of biological processes can be used, which provide good information with regard to prognostic and diagnostic aspects, disease activity and response to therapy, so-called biomarkers Increasing digitalization and the availability of easy-to-use devices and technology also enable healthcare professionals to use a new class of digital biomarkers-digital health technologies-to explain, influence and/or predict health-related outcomes. The technology and devices from which these digital biomarkers stem are quite broad, and range from wearables that collect patients' activity during digitalized functional tests (e.g., the Multiple Sclerosis Performance Test, dual-tasking performance and speech) to digitalized diagnostic procedures (e.g., optical coherence tomography) and software-supported magnetic resonance imaging evaluation. These technologies offer a timesaving way to collect valuable data on a regular basis over a long period of time, not only once or twice a year during patients' routine visit at the clinic. Therefore, they lead to real-life data acquisition, closer patient monitoring and thus a patient dataset useful for precision medicine. Despite the great benefit of such increasing digitalization, for now, the path to implementing digital biomarkers is widely unknown or inconsistent. Challenges around validation, infrastructure, evidence generation, consistent data collection and analysis still persist. In this narrative review, we explore existing and future opportunities to capture clinical digital biomarkers in the care of people with MS, which may lead to a digital twin of the patient. To do this, we searched published papers for existing opportunities to capture clinical digital biomarkers for different functional systems in the context of MS, and also gathered perspectives on digital biomarkers under development or already existing as a research approach.

Optical Coherence Tomography in the Differential Diagnosis of Patients with Multiple Sclerosis and Patients with MRI Nonspecific White Matter Lesions

In the differential diagnosis of nonspecific white matter lesions (NSWMLs) detected on magnetic resonance imaging (MRI), multiple sclerosis (MS) should be taken into consideration. Optical coherence tomography (OCT) is a promising tool applied in the differential diagnostic process of MS. We tested whether OCT may be useful in distinguishing between MS and NSWMLs patients. In patients with MS (n = 41) and NSWMLs (n = 19), the following OCT parameters were measured: thickness of the peripapillary Retinal Nerve Fibre Layer (pRNFL) in superior, inferior, nasal, and temporal segments; thickness of the ganglion cell-inner plexiform layer (GCIPL); thickness of macular RNFL (mRNFL); and macular volume (MV). In MS patients, GCIPL was significantly lower than in NSWMLs patients (p = 0.024). Additionally, in MS patients, mRNFL was significantly lower than in NSWMLs patients (p = 0.030). The average segmental pRNFL and MV did not differ between MS and NSWMLs patients (p > 0.05). GCIPL and macular RNFL thinning significantly influenced the risk of MS (18.6% [95% CI 2.7%, 25.3%]; 27.4% [95% CI 4.5%, 62.3%]), and reduced GCIPL thickness appeared to be the best predictor of MS. We conclude that OCT may be helpful in the differential diagnosis of MS and NSWMLs patients in real-world settings.

Optical coherence tomography monitoring and diagnosing retinal changes in multiple sclerosis

This study explores the use of optical coherence tomography (OCT) to monitor and diagnose multiple sclerosis (MS). The analysis of reduced total macular volume and peripapillary retinal nerve fiber layer thinning are shown. The severity of these defects increases as MS progresses, reflecting the progressive degeneration of nerve fibers and retinal ganglion cells. The OCT parameters are noninvasive, sensitive indicators that can be used to assess the progression of neurodegeneration and inflammation in MS.

Microvascular Breakdown Due to Retinal Neurodegeneration in Ataxias

BACKGROUND

Neurodegenerative ataxias are devastating disorders of the cerebellum and spinal cord, accompanied by death of retinal ganglion cells, leading to relentlessly progressive decline of motor coordination and permanent disability. Retinal microvascular affection has not yet been determined.

OBJECTIVES

The aim of this study is to assess whether retinal microvascular alterations occur and, if so, whether they are concurrent with or follow cell death in the retina in neurodegenerative diseases.

METHODS

This study involves the cross-sectional observational study of 43 patients with ataxia and 43 controls enrolled from August 1, 2018, to September 30, 2020. The extent of ataxia was determined by the Scale for the Assessment and Rating of Ataxia. Changes in retinal vasculature were examined by optical coherence tomography angiography (OCT-A) and retinal cell and fiber density by OCT in ataxias concurrently.

RESULTS

When comparing the ataxia cohort with healthy subjects, ataxia patients exhibited reduced vessel density in the radial peripapillary capillary (RPC) network (P = 0.005), capillary density inside the optic nerve head (cdONH) (P < 0.001), nasal superficial vascular plexus (P = 0.03) as well as reduced ganglion cell layer (GCL) volume (P = 0.04), and temporal peripapillary retinal nerve fiber layer thickness (P = 0.04). Mixed effect analysis modeling laterality confirmed these findings.

CONCLUSIONS

These findings demonstrate a distinct pattern of concurrent changes in vessel density of the retinal superficial vascular complex, encompassing the superficial vascular plexus, RPC network and cdONH, and retinal GCL volume, providing new insights into the ongoing degeneration in ataxias. Our findings may have relevance for design of novel therapeutic approaches for ataxias and possibly other neurodegenerative diseases.

Detailed Evaluation of Macular Ganglion Cell Complex in Patients with Multiple Sclerosis

Introduction:

Retinal nerve fiber layer thickness has been used for monitoring of disease activity in patients with multiple sclerosis (MS). Macular ganglion cell complex (GCC) layer of retina also can be measured by OCT and has been suggested as a potential biomarker in MS. In this study we investigated the macular GCC and its role as a potential biomarker in patients with Multiple Sclerosis (MS).

Methods:

A prospective cohort-study, subjects consisted of Relapsing-Remitting MS patients (n=62) and healthy controls (n=60). Eyes of MS patients were divided into two subgroups according to the history of the optic neuritis (ON). Standard peripapillary-RNFL and macular scan protocol, and retinal auto-segmentation of spectral-domain OCT were performed. Macular RNFL (mRNFL), ganglion cell layer (GCL), and inner plexiform layer (IPL), and GCC (the sum of these former three layers) were recorded. The macula was divided into nine sectors using the ETDRS grid (4×9=36 variables).

Results:

In total, 50 eyes of 36 patients had previous ON attacks. 35/36 GCC parameters were thinner in MS patients and subgroups compared to the control group (p<0.05). When the eyes with and without a history of optic neuritis were compared, 25 of 36 parameters were thinner in those with ON. There were strong correlations between visual acuity-GCC parameters and EDSS scores in patients with a history of optic neuritis. However, no such relationship was found in those without an ON story.

Conclusion:

Ganglion cell complex gets thinner in patients with MS with a decreasing order of GCL, IPL, and mRNFL. The examination of GCC in detail could be a beneficial biomarker for MS.

Clinical and Paraclinical Biomarkers and the Hitches to Assess Conversion to Secondary Progressive Multiple Sclerosis: A Systematic Review

Conversion to secondary progressive (SP) course is the decisive factor for long-term prognosis in relapsing multiple sclerosis (MS), generally considered the clinical equivalent of progressive MS-associated neuroaxonal degeneration. Evidence is accumulating that both inflammation and neurodegeneration are present along a continuum of pathologic processes in all phases of MS. While inflammation is the prominent feature in early stages, its quality changes and relative importance to disease course decreases while neurodegenerative processes prevail with ongoing disease. Consequently, anti-inflammatory disease-modifying therapies successfully used in relapsing MS are ineffective in SPMS, whereas specific treatment for the latter is increasingly a focus of MS research. Therefore, the prevention, but also the (anticipatory) diagnosis of SPMS, is of crucial importance. The problem is that currently SPMS diagnosis is exclusively based on retrospectively assessing the increase of overt physical disability usually over the past 6–12 months. This inevitably results in a delay of diagnosis of up to 3 years resulting in periods of uncertainty and, thus, making early therapy adaptation to prevent SPMS conversion impossible. Hence, there is an urgent need for reliable and objective biomarkers to prospectively predict and define SPMS conversion. Here, we review current evidence on clinical parameters, magnetic resonance imaging and optical coherence tomography measures, and serum and cerebrospinal fluid biomarkers in the context of MS-associated neurodegeneration and SPMS conversion. Ultimately, we discuss the necessity of multimodal approaches in order to approach objective definition and prediction of conversion to SPMS.

Measuring Treatment Response in Progressive Multiple Sclerosis-Considerations for Adapting to an Era of Multiple Treatment Options

Disability in multiple sclerosis accrues predominantly in the progressive forms of the disease. While disease-modifying treatment of relapsing MS has drastically evolved over the last quarter-century, the development of efficient drugs for preventing or at least delaying disability in progressive MS has proven more challenging. In that way, many drugs (especially disease-modifying treatments) have been researched in the aspect of delaying disability progression in patients with a progressive course of the disease. While there are some disease-modifying treatments approved for progressive multiple sclerosis, their effect is moderate and limited mostly to patients with clinical and/or radiological signs of disease activity. Several phase III trials have used different primary outcomes with different time frames to define disease progression and to evaluate the efficacy of a disease-modifying treatment. The lack of sufficiently sensitive outcome measures could be a possible explanation for the negative clinical trials in progressive multiple sclerosis. On the other hand, even with a potential outcome measure that would be sensitive enough to determine disease progression and, thus, the efficacy or failure of a disease-modifying treatment, the question of clinical relevance remains unanswered. In this systematic review, we analyzed outcome measures and definitions of disease progression in phase III clinical trials in primary and secondary progressive multiple sclerosis. We discuss advantages and disadvantages of clinical and paraclinical outcome measures aiming for practical ways of combining them to detect disability progression more sensitively both in future clinical trials and current clinical routine.

Relationship Between Retinal Layer Thickness and Disability Worsening in Relapsing-Remitting and Progressive Multiple Sclerosis

BACKGROUND

Data regarding the predictive value of optical coherence tomography (OCT)-derived measures are lacking, especially in progressive multiple sclerosis (PMS). Accordingly, we aimed at investigating whether a single OCT assessment can predict a disability risk in both relapsing-remitting MS (RRMS) and PMS.

METHODS

One hundred one patients with RRMS and 79 patients with PMS underwent Spectral-Domain OCT, including intraretinal layer segmentation. All patients had at least 1 Expanded Disability Status Scale (EDSS) measurement during the subsequent follow-up (FU). Differences in terms of OCT metrics and their association with FU disability were assessed by analysis of covariance and linear regression models, respectively.

RESULTS

The median FU was 2 years (range 1-5.5 years). The baseline peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell + inner plexiform layer (GCIPL) were thinner in PMS compared with RRMS (P = 0.02 and P = 0.003, respectively). In the RRMS population, multivariable models showed that the GCIPL significantly correlated with FU disability (0.04 increase in the EDSS for each 1-μm decrease in the baseline GCIPL, 95% confidence interval: 0.006-0.08; P = 0.02). The baseline GCIPL was thinner in patients with RRMS with FU-EDSS >4 compared with those with FU-EDSS ≤4, and individuals in the highest baseline GCIPL tertile had a significantly lower FU-EDSS score than those in the middle and lowest tertile (P = 0.01 and P = 0.001, respectively). These findings were not confirmed in analyses restricted to patients with PMS.

CONCLUSIONS

Among OCT-derived metrics, GCIPL thickness had the strongest association with short-medium term disability in patients with RRMS. The predictive value of OCT metrics in the longer term will have to be further investigated, especially in PMS.

[Immunotherapy and personalized treatment of multiple sclerosis]

Personalized medicine requires a patient-oriented approach with the exact classification of the disease being determined by the underlying pathophysiological processes. In particular, the optimal treatment of multiple sclerosis (MS) requires personalized treatment that goes beyond the pure concept of precision medicine; however, due to the lack of robust biomarkers beyond cranial magnetic resonance imaging and a lacking detailed understanding of some aspects of MS pathogenesis, this approach is not yet fully implemented. Important questions for a better therapeutic stratification of MS patients are: (1) when does MS start? (2) Does the spectrum of MS really span multiple diseases? (3) When does the progressive phase of the disease begin? (4) In which phase of the disease is there a therapeutic window for immunotherapy? Recent findings indicate that MS represents a spectrum of diseases and that there is a therapeutic delay of several years, on which the optimal treatment effect of a disease-modifying treatment depends. For a personalized treatment of MS it is important to determine the exact disease stage of the patient and to react to the development or increase of focal inflammatory activity in a timely manner.

Optical Coherence Tomography and Visual Evoked Potentials as Prognostic and Monitoring Tools in Progressive Multiple Sclerosis

Understanding the mechanisms underlying progression and developing new treatments for progressive multiple sclerosis (PMS) are among the major challenges in the field of central nervous system (CNS) demyelinating diseases. Over the last 10 years, also because of some technological advances, the visual pathways have emerged as a useful platform to study the processes of demyelination/remyelination and their relationship with axonal degeneration/protection. The wider availability and technological advances in optical coherence tomography (OCT) have allowed to add information on structural neuroretinal changes, in addition to functional information provided by visual evoked potentials (VEPs). The present review will address the role of the visual pathway as a platform to assess functional and structural damage in MS, focusing in particular on the role of VEPs and OCT, alone or in combination, in the prognosis and monitoring of PMS.

Myelin-oligodendrocyte glycoprotein antibody-associated disease

Myelin-oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently identified autoimmune disorder that presents in both adults and children as CNS demyelination. Although there are clinical phenotypic overlaps between MOGAD, multiple sclerosis, and aquaporin-4 antibody-associated neuromyelitis optica spectrum disorder (NMOSD) cumulative biological, clinical, and pathological evidence discriminates between these conditions. Patients should not be diagnosed with multiple sclerosis or NMOSD if they have anti-MOG antibodies in their serum. However, many questions related to the clinical characterisation of MOGAD and pathogenetic role of MOG antibodies are still unanswered. Furthermore, therapy is mainly based on standard protocols for aquaporin-4 antibody-associated NMOSD and multiple sclerosis, and more evidence is needed regarding how and when to treat patients with MOGAD.

Automatic Diagnosis of Bipolar Disorder Using Optical Coherence Tomography Data and Artificial Intelligence

Background: The aim of this study is to explore an objective approach that aids the diagnosis of bipolar disorder (BD), based on optical coherence tomography (OCT) data which are analyzed using artificial intelligence. Methods: Structural analyses of nine layers of the retina were analyzed in 17 type I BD patients and 42 controls, according to the areas defined by the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. The most discriminating variables made up the feature vector of several automatic classifiers: Gaussian Naive Bayes, K-nearest neighbors and support vector machines. Results: BD patients presented retinal thinning affecting most layers, compared to controls. The retinal thickness of the parafoveolar area showed a high capacity to discriminate BD subjects from healthy individuals, specifically for the ganglion cell (area under the curve (AUC) = 0.82) and internal plexiform (AUC = 0.83) layers. The best classifier showed an accuracy of 0.95 for classifying BD versus controls, using as variables of the feature vector the IPL (inner nasal region) and the INL (outer nasal and inner inferior regions) thickness. Conclusions: Our patients with BD present structural alterations in the retina, and artificial intelligence seem to be a useful tool in BD diagnosis, but larger studies are needed to confirm our findings.

Retinal Dysfunction in Alzheimer's Disease and Implications for Biomarkers

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that manifests as cognitive deficits and memory decline, especially in old age. Several biomarkers have been developed to monitor AD progression. Given that the retina and brain share some similarities including features related to anatomical composition and neurological functions, the retina is closely associated with the progression of AD. Herein, we review the evidence of retinal dysfunction in AD, particularly at the early stage, together with the underlying molecular mechanisms. Furthermore, we compared the retinal pathologies of AD and other ophthalmological diseases and summarized potential retinal biomarkers measurable by existing technologies for detecting AD, providing insights for the future development of diagnostic tools.

Disorders of vision in multiple sclerosis

Multiple sclerosis (MS) is a neurological inflammatory disorder known to attack the heavily myelinated regions of the nervous system including the optic nerves, cerebellum, brainstem and spinal cord. This review will discuss the clinical manifestations and investigations for MS and other similar neurological inflammatory disorders affecting vision, as well as the effects of MS treatments on vision. Assessment of visual pathways is critical, considering MS can involve multiple components of the visual pathway, including optic nerves, uvea, retina and occipital cortex. Optical coherence tomography is increasingly being recognised as a highly sensitive tool in detecting subclinical optic nerve changes. Magnetic resonance imaging (MRI) is critical in MS diagnosis and in predicting long-term disability. Optic neuritis in MS involves unilateral vision loss, with characteristic pain on eye movement. The visual loss in neuromyelitis optica spectrum disorder tends to be more severe with preferential altitudinal field loss, chiasmal and tract lesions are also more common. Other differential diagnoses include chronic relapsing inflammatory optic neuropathy and giant cell arteritis. Leber's hereditary optic neuropathy affects young males and visual loss tends to be painless and subacute, typically involving both optic nerves. MS lesions in the vestibulocerebellum, brainstem, thalamus and basal ganglia may lead to abnormalities of gaze, saccades, pursuit and nystagmus which can be identified on eye examination. Medial longitudinal fasciculus lesions can cause another frequent presentation of MS, internuclear ophthalmoplegia, with failure of ipsilateral eye adduction and contralateral eye abduction nystagmus. Treatments for MS include high-dose corticosteroids for acute relapses and disease-modifying medications for relapse prevention. These therapies may also have adverse effects on vision, including central serous retinopathy with corticosteroid therapy and macular oedema with fingolimod.